COASTAL CONSERVATION PROJECT€¦ · COASTAL CONSERVATION PROJECT STATUS OF BEACHES AND BAYS IN...

COASTAL CONSERVATION PROJECT STATUS OF BEACHES AND BAYS IN TOBAGO (2004 – 2008)

Prepared by:

JUNIOR DARS AN Principal Research Officer

CHRIS TOP HER ALEXIS Research Officer

JASO N BARTO N Marine Technician

OCEANOGRAPHY & COASTAL PROCESSES RES EAR CH PRO JECT , SEPT EMBER 2013

INSTITUTE OF MARINE AFFAIRS Hilltop Lane, Chaguaramas or PO Box 3160, Carenage Post Office, Carenage, Trinidad and Tobago

Tel: 868-634-4291/4 Fax: 868-634-4433 Email: [email protected]

mailto:[email protected]


INSTITUTE OF MARINE AFFAIRS OCEANOGRAPHY & COASTAL PROCESSES

ACKNOWLEDGEMENTS

This report is a collective effort of all staff of the Geology Department and other members of

the Environmental Research Programme. Special considerations are given to the researchers

who conceptualized the Coastal Conservation Project and commenced the coastal

monitoring work.

Thanks to Mrs. Charmaine O’Brien Delpesh who headed the Environmental Research

Programme for the period under review in this report. Her expertise and knowledge of the

coastal environment of Trinidad was critical in leading and guiding research in this

department.

A special thanks to the technicians in the Environmental Research Programme,

Mr. Kevin Khan, Mr. Russell Rajnauth and Mr. Aaron Mohammed, who have collected the

beach profile and littoral data that are presented in this report. Mr. Jonathan Gomez and Mr.

Rennie Peters have also contributed to the data collection.

Thank you to Mr. Adam Jehu and Mr. Hamish Asmath for preparation of maps and Ms. Lisa

Chadee for formatting the document.


INSTITUTE OF MARINE AFFAIRS OCEANOGRAPHY & COASTAL PROCESSES

ABSTRACT

The shoreline monitoring component of the Coastal Conservation Project which commenced

in 1988 provides valuable insights on the dynamics of the coastline. The scientific data are

used by government and other agencies in formulating policies and plans for the coastline.

While coastlines of Trinidad and Tobago are monitored under this project, this report

presents only the research conducted in Tobago during the period 2004 – 2008. The report

focuses on the 25 beaches and bays monitored, comprising 64 beach profiling stations. The

report reveals that most of the beaches and bays in Tobago are in a state of dynamic

equilibrium where the seasonal changes of erosion and accretion occurring on the beaches

revolve around a state of stability.

The beaches on the leeward coast are less prone to erosion due to the more resilient

metamorphic rocks that form these bays. However, changes in sand elevations due to normal

wave processes do occur. During the period 2004–2008 all beaches monitored on the

leeward coast experienced a state of dynamic equilibrium with the exception of the western

region of Pigeon Point, the eastern region of Sheerbird’s Point and the southern section of

Buccoo Bay.

All beaches on the windward coast also experienced dynamic equilibrium except Richmond

Bay, Goldsborough Bay and the western region of Barbados Bay. Erosion along this part of

the coastline threatened to breach the roadway. The erosion has prompted the employment

of coastal protection measures such as revetments and groins. This report makes

recommendations for modifying the current monitoring regime as well as highlights further

research needs.


INSTITUTE OF MARINE AFFAIRS i OCEANOGRAPHY & COASTAL PROCESSES

T A B L E O F C O N T E N T S

page #

1 INTRODUCTION ............................................................................................. 1

1.1 BACKGROUND ............................................................................................................. 1

1.2 OBJECTIVES ................................................................................................................. 4

2 SITE DESCRIPTION ......................................................................................... 5

2.1 LEEWARD COAST .......................................................................................................... 5

2.2 WINDWARD COAST ....................................................................................................... 6

3 METHODOLOGY ............................................................................................ 8

3.1 DATA COLLECTION ........................................................................................................ 8

3.2 BEACH PROFILES ........................................................................................................... 9

3.3 LITTORALS ................................................................................................................ 10

3.4 GRAIN SIZE ANALYSIS .................................................................................................. 11

4 RESULTS AND DISCUSSION .......................................................................... 14

4.1 LEEWARD COAST ........................................................................................................ 14

4.1.1 Store Bay ................................................................................................................. 19

4.1.2 Pigeon Point ............................................................................................................ 25

4.1.3 Milford Bay .............................................................................................................. 36

4.1.4 Sheebird’s Point....................................................................................................... 39

4.1.5 Buccoo Bay .............................................................................................................. 46

4.1.6 Mount Irvine ............................................................................................................ 53

4.1.7 Little Back Bay ......................................................................................................... 60

4.1.8 Stone Haven Bay ..................................................................................................... 68

4.1.9 Great Courland Bay ................................................................................................. 74

4.1.10 Arnos Vale ............................................................................................................... 84

4.1.11 Culloden Bay............................................................................................................ 89

4.1.12 Castara Bay ............................................................................................................. 93


INSTITUTE OF MARINE AFFAIRS ii OCEANOGRAPHY & COASTAL PROCESSES

4.1.13 Englishman’s Bay .................................................................................................... 97

4.1.14 Parlatuvier Bay ...................................................................................................... 101

4.1.15 Bloody Bay ............................................................................................................. 105

4.1.16 Man-o-War Bay ..................................................................................................... 109

4.2 WINDWARD COAST ................................................................................................... 113

4.2.1 Anse Bateau .......................................................................................................... 118

4.2.2 King’s Bay .............................................................................................................. 122

4.2.3 Richmond’s Bay ..................................................................................................... 126

4.2.4 Goldsborough Bay ................................................................................................. 130

4.2.5 Pinfold Bay ............................................................................................................ 136

4.2.6 Barbados Bay ........................................................................................................ 140

4.2.7 Minister Bay .......................................................................................................... 150

4.2.8 Rockly Bay ............................................................................................................. 155

4.2.9 Little Rockly Bay .................................................................................................... 161

4.2.10 Canoe Bay ............................................................................................................. 168

4.2.11 La Guira Bay .......................................................................................................... 173

5 CONCLUSION ............................................................................................ 180

6 RECOMMENDATIONS ................................................................................ 183

7 REFERENCES .............................................................................................. 186


INSTITUTE OF MARINE AFFAIRS iii OCEANOGRAPHY & COASTAL PROCESSES

L I S T O F F I G U R E S

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Figure 1: Map of the Caribbean showing the Location of Trinidad ................................................... 5

Figure 2: Coastal Classification Map of Tobago ................................................................................. 6

Figure 3: Location of IMA Beach Monitoring Stations in Tobago ...................................................... 8

Figure 4: Cross Section of a Beach ..................................................................................................... 9

Figure 5: Ternary diagram of grain size nomenclature for sediments containing gravel, sand

and mud (Source: Folk 1974) ............................................................................................ 13

Figure 6: IKONOS image of Store Bay showing IMA Station location (2007). ................................. 19

Figure 7: Sediment grain-size distributions for Store Bay Station 1 ................................................ 21

Figure 8: Showing profiles for Store Bay Station 1 the period 2004 – 2008. ................................... 21

Figure 9: Plot of Beach Width and Volume vs Number of days for Store Bay Station 1 for the

period May 1988 – October 2008. .................................................................................... 22

Figure 10: Sediment grain-size distributions for Store Bay Station 2 ................................................ 24

Figure 11: Showing profiles for Store Bay Station 2 the period 2004 – 2008. ................................... 24

Figure 12: Plot of Beach Width and Volume vs Number of days for Store Bay Station 2 for the

period March 2001 – October 2008. ................................................................................ 25

Figure 13: IKONOS image of Pigeon Point showing IMA Station locations (2007). ........................... 26

Figure 14: Sediment grain-size distributions for Pigeon Point Bay Station 1 .................................... 28

Figure 15: Showing profiles for Pigeon Point Station 1 for the period 2004 – 2008. ........................ 28

Figure 16: Plot of Beach Width and Volume vs Number of days for Pigeon Point Station 1 for

the period March 1991 – October 2008. .......................................................................... 29


Figure 18: Showing profiles for Pigeon Point Station 2 the period 2004 – 2008. .............................. 31

Figure 19: Plot of Beach Width and Volume vs Number of days for Pigeon Point Station 2

(north) for the period March 1991 – October 2008. ........................................................ 32


Figure 21: Showing profiles for Pigeon Point Station 3 the period 2004 – 2008. .............................. 34

Figure 22: Plot of Beach Width and Volume vs Number of days for Pigeon Point Station 3

(west) for the period March 1991 – October 2008. ......................................................... 35

Figure 23: IKONOS image of Milford Bay showing IMA Station location (2007). .............................. 36

Figure 24: Sediment grain-size distributions for Milford Bay ............................................................ 38

Figure 25: Showing profiles of Milford Bay for the period 2004 – 2008. .......................................... 38

Figure 26: Plot of Beach Width and Volume vs Number of days for Milford Bay for the period

May 1998 – October 2008. ............................................................................................... 39

Figure 27: IKONOS image of Store Bay showing IMA Station location (2007). ................................. 40

Figure 28: Sediment grain-size distributions for Sheebird Point station 1 ........................................ 42

Figure 29: Showing profiles for Sheebird Point Station 1 for the period 2004 – 2008 ...................... 42

Figure 30: Plot of Beach Width and Volume vs Number of days for Sheerbird’s Point, Station 1

for the period December 1998 – October 2008. .............................................................. 43

Figure 31: Sediment grain-size distributions for Sheerbird Point station 2....................................... 45


INSTITUTE OF MARINE AFFAIRS iv OCEANOGRAPHY & COASTAL PROCESSES

Figure 32: Showing profiles for Sheebird Point Station 2 for the period 2004 – 2008 ...................... 45

Figure 33: Plot of Beach Width and Volume vs Number of days for Sheerbird’s Point, Station 2

for the period March 2001 – October 2008. .................................................................... 46

Figure 34: IKONOS image of Buccoo Bay showing IMA Station location (2007). .............................. 47

Figure 35: Sediment grain-size distributions for Buccoo Bay station 1 ............................................. 49

Figure 36: Showing profiles for Buccoo Bay Station 1 for the period 2004 – 2007 ........................... 49

Figure 37: Plot of Beach Width and Volume vs Number of days for Buccoo Bay, Station 1 for

the period March 1992 – August 2007. ............................................................................ 50

Figure 38: Sediment grain-size distributions for Buccoo Bay station 2 ............................................. 52

Figure 39: Showing profiles for Buccoo Bay Station 2 for the period 2004 – 2008 ........................... 52

Figure 40: Plot of Beach Width and Volume vs Number of days for Buccoo Bay, Station 2 for

the period May 1998 – October 2008. ............................................................................. 53

Figure 41: IKONOS image of Mount Irvine Bay showing IMA Station location (2007). ..................... 54

Figure 42: Sediment grain-size distributions for Mount Irvine Bay station 1 .................................... 56

Figure 43: Showing profiles for Mount Irvine Bay station 1 for the period 2004 – 2008 .................. 56

Figure 44: Plot of Beach Width and Volume vs Number of days for Mount Irvine Bay, Station 1


Figure 45: Sediment grain-size distributions for Mount Irvine Bay station 2 .................................... 59

Figure 46: Showing profiles for Mount Irvine Bay station 2 for the period 2004 – 2008 .................. 59

Figure 47: Plot of Beach Width and Volume vs Number of days for Mount Irvine Bay, Station 2


Figure 48: IKONOS image of Little Back Bay showing IMA Station location (2007). ......................... 61

Figure 49: Sediment grain-size distributions for Little Back Bay Station 1 ........................................ 63

Figure 50: Showing profiles of Little Back Bay Station 1 for the period 2004 – 2008. ...................... 63

Figure 51: Plot of Beach Width and Volume vs Number of days for Little Back Bay, Station 1 for


Figure 52: Sediment grain-size distributions for Little Back Bay Station 2A ...................................... 66

Figure 53: Showing profiles of Little Back Bay Station 2A for the period 2004 – 2008. .................... 66

Figure 54: Plot of Beach Width and Volume vs Number of days for Little Back Bay, Station 2 for


Figure 55: IKONOS image of Stone Haven Bay showing IMA Station location (2007). ...................... 68

Figure 56: Showing profiles for Stone Haven Bay station 1 for the period 2004 – 2008 .................. 70

Figure 57: Plot of Beach Width and Volume vs Number of days for Stone Haven Bay, Station 1


Figure 58: Sediment grain-size distributions for Stone Haven Bay station 2 .................................... 73

Figure 59: Showing profiles for Stone Haven Bay station 2 for the period 2004 – 2008 .................. 73

Figure 60: Plot of Beach Width and Volume vs Number of days for Stone Haven Bay, Station 2


Figure 61: IKONOS image of Great Courland Bay showing IMA Station location (2007). ................. 75

Figure 62: Sediment grain-size distributions for Great Courland Bay station 1 ................................ 77

Figure 63: Showing profiles for Great Courland Bay Station 1 for the period 2004-2008 ................ 77


INSTITUTE OF MARINE AFFAIRS v OCEANOGRAPHY & COASTAL PROCESSES

Figure 64: Plot of Beach Width and Volume vs Number of days for Great Courland Bay, Station

1 for the period December 1999 – October 2008. ........................................................... 78




2 for the period March 1992 – October 2008................................................................... 81




3 for the period March 1992 – October 2008................................................................... 84

Figure 71: IKONOS image of Arnos Vale Bay showing IMA Station location (2007). ......................... 85

Figure 72: Sediment grain-size distributions for Arnos Vale Bay ....................................................... 86

Figure 73: Showing profiles for Arnos Vale Bay for the period 2004 – 2008 ..................................... 87

Figure 74: Plot of Beach Width and Volume vs Number of days for Arnos Vale Bay, for the

period March 1992 – October 2008. ................................................................................ 88

Figure 75: IKONOS image of Culloden Bay showing IMA Station location (2007). ............................ 89

Figure 76: Sediment grain-size distributions for Culloden Bay .......................................................... 91

Figure 77: Showing profiles for Culloden Bay for the period 2004 – 2008 ........................................ 91

Figure 78: Plot of Beach Width and Volume vs Number of days for Culloden Bay, for the period

March 2003 – October 2008. ............................................................................................ 92

Figure 79: IKONOS image of Castara Bay showing IMA Station location (2007). .............................. 93

Figure 80: Sediment grain-size distributions for Castara Bay ............................................................ 95

Figure 81: Showing profiles for Castara Bay for the period 2004 – 2008 .......................................... 95

Figure 82: Plot of Beach Width and Volume vs Number of days for Culloden Bay, for the period

January 1993 – October 2008. .......................................................................................... 96

Figure 83: IKONOS image of Englishman’s Bay showing IMA Station location (2007). ..................... 97

Figure 84: Sediment grain-size distributions for Englishman’s Bay ................................................... 99

Figure 85: Showing profiles for Englishman’s Bay for the period 2004 – 2008 ................................. 99

Figure 86: Plot of Beach Width and Volume vs Number of days for Englishman’s Bay, for the

period September 2003 – October 2008. ....................................................................... 100

Figure 87: IKONOS image of Parlatuvier Bay showing IMA Station location (2007). ...................... 101

Figure 88: Sediment grain-size distributions for Parlatuvier Bay .................................................... 103

Figure 89: Showing profiles for Parlatuvier Bay for the period 2004 – 2008 .................................. 103

Figure 90: Plot of Beach Width and Volume vs Number of days for Parlatuvier Bay, for the

period March 2003 – October 2008. .............................................................................. 104

Figure 91: IKONOS image of Bloody Bay showing IMA Station location (2007). ............................. 105

Figure 92: Sediment grain-size distributions for Bloody Bay ........................................................... 107

Figure 93: Showing profiles for Bloody Bay for the period 2004 – 2008 ......................................... 107

Figure 94: Plot of Beach Width and Volume vs Number of days for Bloody Bay, for the period

March 2003 – October 2008. .......................................................................................... 108

Figure 95: IKONOS image of Man-o-War Bay showing IMA Station location (2007). ..................... 109

Figure 96: Sediment grain-size distributions for Man-o-War Bay ................................................... 111


INSTITUTE OF MARINE AFFAIRS vi OCEANOGRAPHY & COASTAL PROCESSES

Figure 97: Showing profiles for Man-o-War Bay for the period 2004 – 2008 ................................. 111

Figure 98: Plot of Beach Width and Volume vs Number of days for Man O War Bay, for the

period September 1996 – October 2008. ....................................................................... 112

Figure 99: IKONOS image of Anse Bateau Bay showing IMA Station location (2007). .................... 118

Figure 100: Sediment grain-size distributions for AnseBateu ........................................................... 120

Figure 101: Showing profiles for AnseBateux Bay for the period 2004 – 2008. ................................ 120

Figure 102: Plot of Beach Width and Volume vs Number of days for Anse Bateau, for the period

March 2003 – October 2008. .......................................................................................... 121

Figure 103: IKONOS image of King’s Bay showing IMA Station location (2007). ............................... 122

Figure 104: Sediment grain-size distributions for King’s Bay ............................................................ 124

Figure 105: Showing profiles for King’s Bay for the period 2004 – 2008. ......................................... 124

Figure 106: Plot of Beach Width and Volume vs Number of days for Kings Bay, for the period

March 2003 – October 2008. .......................................................................................... 125

Figure 107: IKONOS image of Richmond’s Bay showing IMA Station location (2007) ...................... 126

Figure 108: Sediment grain-size distributions for Richmond’s Bay ................................................... 128

Figure 109: Showing profiles for Richmond Bay for the period 2004 – 2008. ................................... 128

Figure 110: Plot of Beach Width and Volume vs Number of days for Richmond Bay, for the

period January 1993 – October 2008. ............................................................................ 129

Figure 111: IKONOS image of Goldsborough Bay showing IMA Station location (2007) .................. 130

Figure 112: Sediment grain-size distributions for GoldsboroughBay Station 1 ................................. 132

Figure 113: Showing profiles for Goldsborough Bay Station 1 for the period 2004 – 2008. ............. 132

Figure 114: Plot of Beach Width and Volume vs Number of days for Goldsborough Bay, Station

1, for the period January 1993 – October 2008. ............................................................. 133

Figure 115: Sediment grain-size distributions for Goldsborough Bay Station 2 ................................ 135

Figure 116: Showing profiles for Goldsborough Bay Station 2 for the period 2004 – 2008. ............. 135

Figure 117: Plot of Beach Width and Volume vs Number of days for Goldsborough Bay, Station

2, for the period July 2000 – October 2008. ................................................................... 136

Figure 118: IKONOS image of Pinfold Bay showing IMA Station location (2007). ............................. 137

Figure 119: Sediment grain-size distributions for Pinfold Bay ........................................................... 138

Figure 120: Showing profiles for Pinfold Bay for the period 2004 – 2008. ........................................ 139

Figure 121: Plot of Beach Width and Volume vs Number of days for Pinfold Bay for the period

March 2003 – October 2008. .......................................................................................... 140

Figure 122: IKONOS image of Barbados Bay showing IMA Station location (2007). ......................... 141

Figure 123: Sediment grain-size distributions for Barbados Bay Station 1 ....................................... 143

Figure 124: Showing profiles for Barbados Bay Station 1 for the period 2004 – 2008. .................... 143

Figure 125: Plot of Beach Width and Volume vs Number of days for Barbados Bay, Station 1, for

the period June 2003 – October 2008. ........................................................................... 144



Figure 128: Plot of Beach Width and Volume vs Number of days for Barbados Bay, Station 2, for

the period September 2002 – October 2008. ................................................................. 147



INSTITUTE OF MARINE AFFAIRS vii OCEANOGRAPHY & COASTAL PROCESSES


Figure 131: Plot of Beach Width and Volume vs Number of days for Barbados Bay, Station32, for

the period May 1999 – January 2007. ............................................................................ 150

Figure 132: IKONOS image of Minister Bay showing IMA Station location (2007). ........................... 151

Figure 133: Sediment grain-size distributions for Minister Bay ........................................................ 153

Figure 134: Showing profiles for Minister Bay for the period 2004 – 2008. ..................................... 153

Figure 135: Plot of Beach Width and Volume vs Number of days for Minster Bay, for the period

March 1992 – October 2008. .......................................................................................... 154

Figure 136: IKONOS image of Rockly Bay showing IMA Station location (2007). .............................. 155

Figure 137: Sediment grain-size distributions for Rockly Bay station 1 ............................................ 157

Figure 138: Showing profiles for Rockly Bay Station 1 for the period 2004 – 2008. ......................... 157

Figure 139: Plot of Beach Width and Volume vs Number of days for Rockly Bay, Station1, for the

period December 1998 – October 2008. ........................................................................ 158

Figure 140: Sediment grain-size distributions for Rockly Bay station 2 ............................................ 160

Figure 141: Showing profiles for Rockly Bay Station 2 for the period 2004 – 2008. ......................... 160

Figure 142: Plot of Beach Width and Volume vs Number of days for Rockly Bay, Station 2, for the

period January 1993 – October 2008. ............................................................................ 161

Figure 143: IKONOS image of Little Rockly Bay showing IMA Station locations (2007). ................... 162

Figure 144: Sediment grain-size distributions for Little Rockly Bay station 2 ................................... 164

Figure 145: Showing profiles for Little Rockly Bay Station 2 for the period 2004 – 2008. ................ 164

Figure 146: Plot of Beach Width and Volume vs Number of days for Little Rockly Bay, Station 2,

for the period January 2004 – October 2008. ................................................................ 165

Figure 147: Sediment grain-size distributions for Little Rockly Bay station 3 ................................... 167

Figure 148: Showing profiles for Little Rockly Bay Station 3 for the period 2004 – 2008. ................ 167

Figure 149: Plot of Beach Width and Volume vs Number of days for Little Rockly Bay, Station 3,

for the period March 1996 – October 2008. .................................................................. 168

Figure 150: IKONOS image of Canoe Bay showing IMA Station location (2007). .............................. 169

Figure 151: Sediment grain-size distributions for Canoe Bay ............................................................ 171

Figure 152: Showing profiles for Canoe Bay the period 2004 – 2008. .............................................. 171

Figure 153: Plot of Beach Width and Volume vs Number of days for Canoe Bay, for the period

March 1992 – May 2008. ................................................................................................ 172

Figure 154: IKONOS image of Canoe Bay showing IMA Station location (2007). .............................. 173

Figure 155: Sediment grain-size distributions for La Guira Bay Station 1 ......................................... 175

Figure 156: Showing profiles for La Guira Bay Station 1 the period 2004 – 2008. ............................ 175

Figure 157: Plot of Beach Width and Volume vs Number of days for La Guira Bay, Station 1, for

the period March 1992 – May 2008. .............................................................................. 176

Figure 158: Sediment grain-size distributions for La Guira Bay Station 2A ....................................... 178

Figure 159: Showing profiles for La Guira BayStation 2A the period 2004 – 2008............................ 178

Figure 160: Plot of Beach Width and Volume vs Number of days for La Guira Bay, Station 2, for

the period February 1985 – November 2008. ................................................................ 179

Figure 161: Status of Coastline Map of Tobago based on study conducted during 2004 – 2008. .... 182


INSTITUTE OF MARINE AFFAIRS viii OCEANOGRAPHY & COASTAL PROCESSES

L I S T O F T A B L E S

page #

Table 1: Description of Sorting Values used in Grain Size Analysis ................................................ 12

Table 2: Description of Kurtosis Values used in Grain Size Analysis ............................................... 12

Table 3: Description of Skewness Values used in Grain Size Analysis ............................................ 12

Table 4: Summary Littoral processes for Leeward Coast Beaches of Tobago for the period

2004 – 2008 ...................................................................................................................... 15

Table 5: Summary Grain Size for Leeward Coast Beaches of Tobago ............................................ 16

Table 6: Shoreline stability status of Leeward Coast Beaches of Tobago for the period 2004 –

2008 .................................................................................................................................. 18

Table 7: Summary Littoral processes for Windward Coast Beaches of Tobago for the period

2004 – 2008 .................................................................................................................... 114

Table 8: Summary Sediment Grain Size for Windward Coast Beaches of Tobago for the period

2004 – 2008 .................................................................................................................... 115

Table 9: Shoreline stability status of Leeward Coast Beaches of Tobago for the period 2004 –

2008 ................................................................................................................................ 117

Table 10: Beaches and Bays monitored quarterly. ......................................................................... 183

Table 11: New monitoring stations to be established (to be monitored quarterly). ..................... 185


INSTITUTE OF MARINE AFFAIRS ix OCEANOGRAPHY & COASTAL PROCESSES

L I S T O F P L A T E S

page #

Plate 1: Store Bay Station 1 (February 2013) ................................................................................. 20

Plate 2: Store Bay Station 2 (February 2013) ................................................................................. 23

Plate 3: Pigeon Point Station 1 (February 2013) ............................................................................ 27



Plate 6: Milford Bay, May 2007: Westerly view showing narrow coral lined beach. ................... 37

Plate 7: Station 1 Sheerbirds point Easterly view capturing groynes and spit (May 2007) ........... 41

Plate 8: Sheebirds Point Station 2 (February 2013) ....................................................................... 44

Plate 9: Buccoo Bay Station 1 Easterly view of Bench Mark, beach width and Jetty (May

2007) ................................................................................................................................. 48

Plate 10: Buccoo Bay Station 2 Westerly view of beach width and upper beach scarp (May

2007) ................................................................................................................................. 51

Plate 11: Mount Irvine Station 1 (February 2013) ........................................................................... 55

Plate 12: Mount Irvine Station 2 (February 2013) ........................................................................... 58

Plate 13: Station 1 Little Back Bay May 2007: Westerly view showing wide beach, berm and

cusps. ................................................................................................................................ 62

Plate 14: Station 2A Little Back Bay May 2007: Westerly view showing wide beach, berm and

cusps. ................................................................................................................................ 65

Plate 15: Stone Haven Bay Station 1 Easterly view showing wide gently sloping beach and

cusps (May 2007) .............................................................................................................. 69

Plate 16: Stone Haven Bay Station 2 Easterly view showing a wide gently sloping beach. (May

2007) ................................................................................................................................. 72

Plate 17: Great Courland Bay Station 1: Easterly view of a gentle beach slope and mid beach

berm. (May 2007) ............................................................................................................. 76

Plate 18: Great Courland bay Station 2: Easterly view showing steep beach face and berm.

(May 2007) ........................................................................................................................ 79

Plate 19: Great Courland Station 3: Easterly view showing moderately sloping beach and

berm. (May 2007) ............................................................................................................. 82

Plate 20: Arnos Vale Easterly view showing breaker uprush and wave cut platform. (January

2007) ................................................................................................................................. 85

Plate 21: Culloden Bay: Easterly view showing gentle slope and narrow beach (February

2008) ................................................................................................................................. 90

Plate 22: Castara Bay Easterly view showing a wide gently sloping beach. (January 2007) ........... 94

Plate 23: Englishman’s Bay Westerly view showing a narrow steeply sloping beach (May 2007) .. 98

Plate 24: Parlatuvier Bay (February 2013) .................................................................................... 102

Plate 25: Bloody Bay: Seaward view of profile and rocks at high water line. (May 2008) ........... 106

Plate 26: Man O War Bay: Easterly view showing a moderate beach slope. (May 2007) ............. 110

Plate 27: Anse Bateau Bay Easterly view showing a narrow, moderately sloping beach (May

2007) ............................................................................................................................... 119


INSTITUTE OF MARINE AFFAIRS x OCEANOGRAPHY & COASTAL PROCESSES

Plate 28: King’s Bay Easterly view showing a gentle beach slope and berm (May 2007) ............. 123

Plate 29: Richmond Bay Seaward view of a gently sloping beach (May 2007) ............................. 127

Plate 30: Goldsborough Bay Station 1 Easterly view of a narrow moderately sloping beach

(February 2008) .............................................................................................................. 131

Plate 31: Goldsborough Bay Station 2 Easterly view showing berm and a moderately sloping

beach (February 2008) .................................................................................................... 134

Plate 32: Pinfold Bay westerly view (February 2013) .................................................................... 137

Plate 33: Barbados Bay Station 1 Westerly view showing a narrow gently sloping beach and

rock outcrops at mid beach (May 2007) ......................................................................... 142

Plate 34: Barbados Bay Station 2 Westerly view showing a gently sloping beach (May 2007) .... 145

Plate 35: Barbados Bay Station 3 Westerly view showing a gently sloping beach and a

distinctive change in sediment at waterline (May 2007) ............................................... 148

Plate 36: Minister Bay (May 2007) ................................................................................................. 152

Plate 37: Rockly Station 1 Westerly view capturing sea wall and a narrow gently sloping beach

(2003): ............................................................................................................................. 156

Plate 38: Rockly Station 2, Easterly view showing scouring at the base of the sea wall (May

2007) ............................................................................................................................... 159

Plate 39: Little Rockly Bay Station 2 Easterly view showing a wide gently sloping beach

(January 2008) ................................................................................................................ 163

Plate 40: Little Rockly Bay Station 3, Westerly view showing a narrow gently sloping beach

(May 2007) ...................................................................................................................... 166

Plate 41: Westernly view of Canoe Bay ........................................................................................ 170

Plate 42: La Guira station 1 (February 2013) ................................................................................. 174

Plate 43: La Guira Station 2 Easterly view showing a moderately sloping beach (May 2007) ...... 177


INSTITUTE OF MARINE AFFAIRS - Oceanography & Coastal Processes 1 | P a g e

1 INTRODUCTION

1.1 BACKGROUND

The coastal environment, also called littoral zone, can be defined as the area lying at the

interface between the land and the sea. Beaches occur along the interface between land and

sea within the coastal zone. Beaches and coastal dunes constitute the most significant

accumulations of sub-aerially exposed sediment along coasts. While beaches are composed

of material ranging from fine sand to boulders, most consist of sand, shingle or sand-shingle

mixed beaches. They are dynamic coastal features which respond to storms, wind, waves,

currents and tides differently dependent on its geology. For example, where the coastal

geology is resistant to wave attack, erosion may occur at a reduced rate and where it is more

susceptible, it may be eroded at a faster rate (Van Rijn, 1998).

Beaches are natural resources which have great aesthetic appeal and recreational value. The

natural resources of beaches and bays serve a variety of uses, such as;

1. Biotic and abiotic resources e.g. marine life and sand

2. Recreation

3. Coastal protection buffers

4. Economic value (IMA, 2004).

Notwithstanding the protection by reefs, beaches are generally the primary defenses for any

coastal development. Beaches, however, are damaged by sand removal, improper building

of coastal protection structures and any activity that prevents new sediment sources from

replenishing them (Reeve et al, 2004).

Factors that affect the ability of the coastal region to resist the erosive effects of wind, waves

and surface run-off are the presence of coastal vegetation, offshore reefs, sea grass beds and

mangroves (Cambers, 1998). Areas consisting of unconsolidated sediment will be more

susceptible to erosion than those where the beach is backed by more resistant rocks

(Saunders, 1998).

As the beach is eroded, littoral drift transports the sediment either along or across the

shoreline. Sediment transported along the shoreline may change the orientation of the bay.

Sediment transported across the shoreline may either form sand bars or may be deposited

over the continental slope. Sediment which is deposited over the slope cannot return to the

beach and sediment forming the sandbars may or may not return with seasonal changes (Van

Rijn, 1998).



Generally, shorelines can be swash or drift aligned. Most shorelines naturally align

themselves parallel to the predominant wave direction although other factors are

contributory. Shorelines form and orient themselves based on the movement of sediment

within the system; either alongshore or cross-shore. On swash dominated coastlines, the

shoreline is oriented near parallel to the oncoming wave crests. On drift-aligned coasts, the

shoreline is oriented near parallel to the line of dominating longshore sediment transport

which is induced by obliquely incident waves (Reeve et al, 2004).

The general activity of waves varies seasonally. Wave activity is greater during the winter

period from November to April which results from intense mid-latitude storms in the North

Atlantic Ocean generating swell waves. These swell waves have higher energy, increased

breaker heights, shorter wave periods. These swell waves affect the north, east and west

coasts of the Caribbean islands (Cambers, 1998).

During the summer season (May–October) the beach undergoes accretion due to the lower

wave energy and longer wave periods, but in the winter season (November–April) higher

wave energy and shorter wave periods erode the beach (Cambers, 2004). However, this

seasonal beach response to external forcing mechanisms is not a fixed phenomenon on the

east coast beaches of Trinidad (Darsan, 2012). When these two cycles of erosion and

accretion occur without any long term deleterious effects on the beach, a state of dynamic

equilibrium (DE) is said to exist. Dynamic Equilibrium or a state of relative stability is also

achieved when the shorelines have adjusted (become parallel) to the prevailing pattern of

the waves (Reeve et al, 2004).

Beaches can either be classified as being in a state of erosion, accretion or dynamic

equilibrium (D.E.). Erosion can occur either horizontally where the backshore recedes

landward or vertically where the sand elevation decreases along the beach face. Cocos Bay

for example experiences high rates of coastal erosion both horizontally and vertically, being

exposed to the high energy environment of the Atlantic Ocean (Darsan, 2005a, 2005b, 2012).

Accretion however occurs where there is an increase in sediment on the beach face which

can extend the beach horizontally increasing the width of the beach

(Van Rijn, 1998). Beaches undergo both erosion and accretion cycles during the rise and fall

of the tides, changes in the moon cycles between spring and spring phases, and during the

summer and winter seasons.

Coastal land is of great value and in high demand. Stable beaches have no net loss of sediment

although their profiles change during the year (Cambers, 1998). In addition to this, other

beaches may be accreting or eroding where there is net gain or net loss of sediment

respectively. These beaches which accrete and erode are not yet stable. Beaches naturally

configure themselves to wave approach where littoral drift becomes minimal or nil (Reeve

et al, 2004).



Trinidad and Tobago together with other Small Island Developing States (SIDS) have limited

land space. Their coasts have been and are subjected to erosion whether natural or human

induced. Coastal erosion is a major problem experienced in many areas of the world. Erosion

undermines shoreline structures whether commercial, residential or even coastal defenses.

It can remove coastal agricultural land and destroy recreational areas and habitats

(Cambers, 1998). Localized tectonic events and land subsidence may result in accelerated

erosion rates especially during hurricane periods (Sharp and Hill, 1995). This can be further

exacerbated by sea level rise as the waves travel with increased energy and break further

inland. The Intergovernmental Panel on Climate Change (IPCC) reported that sea level rise

may be 0.06 m/yr in the twenty-first century (IPCC, 2007).

Beaches are the sites of natural and anthropogenic activities some of which impact the

country’s economy. A natural activity which occurs on some beaches is that of turtles nesting.

Nesting of leatherback turtles (Dermochelys coriacea) occur along the north, north-east and

east coasts of Trinidad. Turtle nesting contribute significantly to the eco-tourism product in

Trinidad.

Another natural process impacting beaches is that of heavy seas or storm conditions. Under

these conditions the beach is impacted by waves with increased energy and as a result, they

remove sediment from the shoreline. This sediment may be transported offshore to be re-

deposited when normal conditions resume (Didenkulova et al, 2006).

Anthropogenic activities on beaches include recreation, trenching and pipe laying which is

associated with the oil and gas industry (IMA, 2003), landing of telecommunication network

cables (IMA 1993) and the construction of coastal protection structures. The positioning of

these pipelines and cables is important. It has been determined that the safe depth for the

burial of these pipelines and cables is at least 2 m below the lowest elevation of the sand, so

that in the event of storms or hurricanes they have a reduced probability of being exposed

(IMA, 1993).

In some instances coastal protection structures are needed for the shoreline. Numerical

models can be used to compare the wave regime pre and post pipeline to determine if any

changes in the coastal processes would impact the shoreline morphology positively

(accretion) or negatively (erosion). In addition to beach profiling, it is recommended that

bathymetric surveys be undertaken to determine if the area has achieved equilibrium with

the coastal processes (IMA, 2003).

Hard coastal protection structures have been utilized to mitigate erosion in some areas in

Trinidad and Tobago. One such area is within Scarborough, along the Milford Road where a

seawall was constructed to protect the land from the erosive force of the waves. To date the

wall successfully protects the road (IMA, 2004). Another such area of successful coastal

protection is in Barbados Bay where residential property is protected by a low seawall (IMA,

2004).



Although coastal protection structures are designed to prevent erosion, some poorly

designed structures exacerbate the effects of erosion. An area where a coastal protection

structure is currently breached is within Mount Irvine Bay along the Shirvan Road. The

structure of the seawall has been compromised and is being flanked. If this continues, the

Shirvan Road would eventually be affected (IMA, 2004). The depth of the foundation of the

seawall should be lower than the lowest elevation of the sand, so that it would be protected

from wave reflection off the seawall and the corresponding scour effect.

At Pigeon Point coastal protection in the form of revetments exists. Flanking occurs at the

ends of the western revetment which was constructed to protect the land and infrastructure

(IMA, 2004). This is an important location as it is the most popular beach in Tobago which

also generates foreign exchange to the island.

1.2 OBJECTIVES

The IMA has been monitoring beaches and bays in Trinidad and Tobago since 1988 under

the Coastal Dynamics Component of the Coastal Conservation Project. The goals of this

project are:-

To determine coastal stability trends for Trinidad and Tobago in term of its

erosion/accretion rates.

To assess the effects of coastal development on the shorelines of Trinidad and

Tobago.

To compile a database of sediment properties in terms of its grain size for beaches

monitored.

The data generated from this monitoring project have been used to advise both public and

private interests on shoreline stability, setbacks for coastal development and on selection of

appropriate coastal protection structures. Data is also provided to students undertaking

undergraduate and graduate research.

This report assesses the status and trends of 26 beaches and bays around Tobago for the

period 2004-2008. It highlights the dynamic nature of the beaches and provides

recommendations for improving this monitoring programme.



2 SITE DESCRIPTION

2.1 LEEWARD COAST

The leeward coast of Tobago is open to the Caribbean Sea (Figure 1) and exposed to

moderate to high wave energy where breaker heights can exceed 0.80 m (IMA, 2004). This

sometimes results in beach erosion taking place at the larger sandy beaches at the western

region of Pigeon Point, the eastern region of Sheerbird’s Point and the southern sections of

Buccoo Bay. The backshores have relatively low gradient topography and consist of coralline

limestone deposits along the south-west region (Figure 2). Some bays are more indented

than others and have more pronounced headlands. These are mostly backed by steep cliffs

consisting of low-medium grade metamorphic rocks along the north-eastern region of the

island.

Figure 1: Map of the Caribbean showing the Location of Trinidad

Source: Institute of Marine Affairs (2012)



There are various geomorphological features along this coastline such as wave cut platforms,

caves, stacks and blowholes (Figure 2). The geology of the north-eastern coast makes the

bays less susceptible to coastline erosion where the bay is backed by these metamorphic

rocks. Even though no cliff recession may be observed, reduction in beach sediment volume

can be very evident at some locations.

2.2 WINDWARD COAST

The windward coast is a high energy wave environment and is exposed to the Atlantic Ocean

and the Northeast Trade Winds (Figure 1). Most beaches are in a state of dynamic

equilibrium with the exceptions of Richmond Bay, Goldsborough Bay and Barbados Bay.

Along some areas of this shoreline some coastal protection structures exist such as groynes,

revetments and seawalls which protect property and infrastructure.

Figure 2: Coastal Classification Map of Tobago

Source: Redrawn from Institute of Marine Affairs (1985)



3 METHODOLOGY

3.1 DATA COLLECTION

Primary data collected include beach profiles, littoral processes and beach sediment grain

size. The dynamic configuration of the shoreline was determined by conducting beach

profiling at regular intervals along the coast. Littoral processes data such as; wave approach,

wave height, breaker height and near shore currents were collected at each profile location

(Figure 3).

Figure 3: Location of IMA Beach Monitoring Stations in Tobago

Source: Institute of Marine Affairs (2012)



3.2 BEACH PROFILES

Beach profiles are cross sectional traces, perpendicular to the shoreline, taken along a

transect which extends from a fixed mark in a stable area (the benchmark) of the backshore

to the near shore zone (Figure 4). Each profile was obtained with the use of a Sokkia survey

level, measuring tape, survey staff and a compass. Each benchmark was marked by a

concrete encased PVC pipe capped with a 2” brass plate. The measuring tape was extended

from the benchmark along the transect to the lower beach. The survey level was mounted on

the survey tripod and set up over the tape measure in a stable area of the beach. Readings

were first taken off the staff at the benchmark and then at fixed distances along the transect,

usually every 4 m, or where there were distinct changes in the gradient.

Figure 4: Cross Section of a Beach

(Source: http://www.springerlink.com/content/u477gx630260l207/)

Readings were also taken at the vegetation line, high water mark, at the water line and

extended into the water to a depth of approximately 1.5 m. Beach profiles were conducted

at low tide conditions which allowed the maximum transect distance to be captured. For

Trinidad, beach profiles were conducted quarterly during the months of January, April, July

and October. However, for some beaches beach profiles were conducted on a monthly basis.

These beaches included areas with coastal development or areas of particular research

interest.

Beach profiling stations are referenced to Mean Sea Level (MSL) where The MSL elevations

for these stations were transferred from Land and Surveys tertiary benchmarks. Selected

beach profiles have been plotted to be representative of the reporting period. Both summer

and winter month profiles were selected for each of the years under consideration.

Even though this report presents data for 2004 – 2008, a more systematic methodology was

applied to beach profile data collected as far back in the 1980’s to determine whether they



are stable, eroding or accreting. Beach profiles were analyzed to determine the changes in

the horizontal beach width and beach volume, and these are presented in the form of charts.

Best fit lines were plotted to derive the underlying trend and both regression line equation

and coefficient stated.

For stations that are tied in to MSL, the horizontal beach width is the distance between the

benchmark and the position where the profile attains a value of 0.0 m elevation. This is

usually an interpolated distance value from the beach profile. The beach volume is the area

under the curve up to the profile-MSL intercept. In cases where the benchmark was set back

due to erosion, the beach volume could not be determined for previous years. It would have

been inaccurate to add the volume below the profile between the new and old benchmark

since it is not a constant value.

3.3 LITTORALS

Wind speed was collected using a digital anemometer and was measured in meters per

second (m/s) while the direction was obtained with a Brunton direct pointing compass.

Wave height was measured with a 7.6 m extendable survey staff in the zone immediately

behind the breakers and was taken as the height between the crest and trough of the waves.

The breaker heights were measured in a similar method as the wave heights but, were

measured in the breaker zone. Wave approach was measured from the shoreline with a

Brunton direct pointing compass. The compass was pointed perpendicularly toward the

oncoming waves and the direction noted.

Longshore speed was measured when a floating object was thrown into the water within the

breaker zone. The researcher then aligned himself on the shoreline with the object and

marked the sand. The movement of the object was timed for a period of one minute with a

stop watch (the researcher always kept in alignment with the object). At the end of one

minute another mark was made on the sand. The distance moved by the object was then

measured. Longshore current speed was calculated in centimeters per second (cm/s). The

direction in which the object moved was obtained with a Brunton direct pointing compass.

The compass was pointed in the direction of the object along the shoreline from the mid-

beach area. This direction was converted into a cardinal bearing and given as the longshore

drift direction.



3.4 GRAIN SIZE ANALYSIS

Sediment samples were collected from the upper beach, mid-beach and lower beach at each

profiling station. Grain size analysis was conducted using a method provided by Folk (1974).

Wet samples were oven-dried dried in 500 ml aluminum dishes at 105oC for 24 hours. The

oven-dried samples were placed in an incubator to cool at room temperature. A random

sample was obtained for analysis using a sediment sample splitter. Using an analytical

balance, approximately 120 g from the split random sample was weighed. All weights were

recorded to four decimal places. The weighed sample was transferred to the sieve pans and

placed in sieve shaker to separate into individual grain size. Sediments was sieved using U.S

Standard sieves at ½-phi () unit intervals ranging from -4.0 (16 mm) to 4.0 (0.0625 mm).

Sediment passing through the 4.0 sieve was collected in a pan and was classified as mud.

The bank of sieves was agitated in a shaker for at least 20 minutes. Each sieve fraction is then

weighed using the analytical balance.

[Phi () = -log2d, where d is diameter of the particle size in millimetres]

Grain size distribution graphs were plotted using “Grapher” software. Folk and Ward’s

(1957) statistical parameters such as mean, median, sorting, skewness and kurtosis were

calculated using data extracted from the graphs. Sorting, kurtosis and skewness descriptions

based on the calculated values are presented in Table 1, 2 and 3 respectively. Sorting of

sediments is a measure of the uniformity of the grain sizes present in the sediment.

Sediments with a smaller range of particle sizes or greater quantities of specific sizes are

better sorted than those with more ranges. The kurtosis value is a measure of the peakedness

of the sediment size distribution. The skewness value is an indication whether the sediment

distribution tails off at the finer or coarser grain size (Folk 1974). The sample is also

classified according to Folk and Ward’s system of classification (Figure 5) based upon the

percentage composition of Gravel (>2.0 mm), Sand (0.0625 mm – 2.00 mm) and Mud

(<0.0625 mm).



Table 1: Description of Sorting Values used in Grain Size Analysis

Sorting Value Description

< 0..35 Very well sorted

0.35 - 0.50 Well sorted

0.50 – 0.71 Moderately well sorted

0.71 - 1.00 Moderately sorted

1.00 - 2.00 Poorly sorted

2.00 - 4.00 Very poorly sorted

>4.00 Extremely poorly sorted

Table 2: Description of Kurtosis Values used in Grain Size Analysis

Kurtosis Value Description

< 0.67 Very Platykurtic

0.67 - 0.90 Platykurtic

0.90 - 1.11 Mesokurtic

1.11 - 1.50 Leptokurtic

1.50 - 3.00 Very Leptokurtic

>3.00 Extremely Leptokurtic

Table 3: Description of Skewness Values used in Grain Size Analysis

Skewness Value Description

-0.30 to -1.00 Strongly Coarse Skewed

-0.10 to -0.30 Coarse Skewed

+0.10 to -0.10 Near Symmetrical

+0.10 to +0.30 Fine skewed

+0.30 to +1.00 Strongly Fine Skewed



Figure 5: Ternary diagram of grain size nomenclature for sediments containing gravel, sand and mud (Source: Folk 1974)



4 RESULTS AND DISCUSSION

4.1 LEEWARD COAST

Tobago is oriented in a northeast, southwest direction. The Leeward or Caribbean coast faces

northwest, and the Windward or Atlantic coast faces southeast. The leeward coastline is

generally rocky and rugged. The northeastern part of the island is steeper and more irregular

resulting in a highly indented coastline. The southwestern region in contrast consists of a

limestone platform and is less rugged.

Tobago’s Leeward coast is rugged and fringed by coral reefs. The beaches here are generally

of biogenic origin and some of them are leatherback turtle nesting sites. The road that winds

along this coast is very scenic and many beaches are good for swimming although some of

them are accessible only by boat.

A summary of the littoral processes occurring on north coast beaches and bays is presented

in Table 4. A summary of the grain size parameters is presented in Table 5, while shoreline

erosion/accretion processes for the period 2004 – 2008 is presented in Table 6.



Table 4: Summary Littoral processes for Leeward Coast Beaches of Tobago for the period 2004 – 2008

Beach/Bay Station

Location

Wind Speed

Wind Direction

Significant Wave Height Breaker Height

Breaker Period Longshore Current Speed

Current Direction

(s) (cm/s)

Mean Range STD Mean Range STD Direction Mean Range STD Mean Range STD Mean Range STD

Store Bay 1 1.12 0.0-3.9 1.19 NE 0.33 0.05-0.6 0.14 NW 0.371429 0.05-0.7 0.17 6.69 0.00-9.00 2.16 8.03 1.17-11.73 3.39 SW

2 0.99 0.00-2.40 0.77 SE 0.33 0.1-0.8 0.18 NW 0.36 0.1-0.70 0.17 8.33 0.00-15.40 3.44 8.13 0.00-18.13 4.15 SW

Pigeon Point 1 4.02 2.0-6.5 1.3 SE 0.13 0.05-0.25 0.06 NE 0.15 0.05-0.35 0.09 5.92 4.5-7.8 0.9 14.85 8.53-29.1667 5.29 SE

2 3.9 1.30-6.00 1.47 SE 0.13 0.05-0.2 0.06 SE 0.14 0.05-0.30 0.08 6.27 0.0-8.10 1.91 15.74 0.0-43.14 10.58 W

3 1.42 0.00-3.40 0.96 SE 0.17 0.05-0.40 0.12 NW 0.2 0.05-0.50 0.14 6.79 0.00-12.60 2.76 9.73 1.17-30.33 7.07 SW

Sheebird’s Point 1 1.99 0.05-3.20 0.88 E 0.1 0.00-0.20 0.06 NE 0.12 0.00-0.20 0.06 5.79 0.00-8.90 2.51 13.07 2.90-23.33 6.15 SW

2 2.77 0.00-6.70 1.72 SE 0.08 0.00-0.15 0.04 SW 0.09 0.00-0.20 0.06 5.63 0.00-8.40 2.64 8.21 0.00-18.67 4.82 W

Buccoo Bay 1 1.91 0.70-3.50 0.83 SE 0.2 0.10-045 0.09 SW 0.24 0.10-0.50 0.11 7.16 4.50-10.20 1.71 5.19 1.17-10.67 2.94 SW

2 1.67 0.00-3.20 0.85 NE 0.34 0.10-0.60 0.13 W 0.39 0.10-0.70 0.16 7.24 4.50-9.40 1.28 10.09 3.65-17.40 4.06 SW

Mt.Irvine 1 1.51 0.00-3.00 0.78 SE 0.29 0.05-1.50 0.32 SW 0.37 0.10-2.00 0.44 7.72 6.00-9.80 1.14 9.14 1.17-29.17 6.35 SW

2 1.78 0.5-3.5 0.84 SE 0.66 0.10-3.00 0.68 NW 0.76 0.1-3.00 0.71 8.71 6.80-13.50 1.83 10.86 4.67-29.17 5.64 SW

Stone Haven 1 1.86 0.00-3.40 1.12 SW 0.63 0.30-1.00 0.21 NW 0.68 0.35-1.00 0.21 8.53 6.50-13.00 1.95 9.08 2.90-16.00 4.4 SW

2 2.38 1.00-5.50 1.26 SE 0.57 0.30-1.50 0.29 NW 0.63 0.35-1.50 0.3 8.47 6.40-11.90 1.65 12.74 0.00-42.00 10.34 SW

Great Courland 1 2.17 1.00-4.50 1.14 SE 0.39 0.20-0.60 0.14 W 0.42 0.20-0.75 0.17 7.95 0.00-13.00 2.63 10.78 4.83-16.33 3.45 SW

2 2.22 0.60-6.50 1.59 SE 0.65 0.00-2.50 0.57 NW 0.82 0.20-2.50 0.57 8.25 6.10-10.80 1.17 9.47 1.93-15.17 3.82 SW

3 1.9 0.00-7.50 1.81 SE 0.49 0.00-2.00 0.46 NW 0.56 0.20-2.00 0.46 8.47 6.80-13.00 1.46 17.91 7.47-43.17 10.34 SW

Arnos Vale 1 1.84 0.00-4.50 1.13 SW 0.41 0.10-2.00 0.48 NW 0.43 0.1-2.00 0.48 7.58 6.20-10.00 1.32 7.85 1.93-24.50 6.48 SW

Culloden Bay 1 0.88 0.00-2.10 0.7 SW 0.27 0.1-0.40 0.1 NW 0.3 0.10-0.50 0.12 8 6.40-12.00 1.52 10.73 3.20-27.73 7.06 SW

Castara Bay 1 1.35 0.00-2.80 0.95 SE 0.35 0.10-0.70 0.16 NW 0.38 0.10-0.70 0.17 7.55 5.80-9.80 1.17 8.17 1.17-13.60 4.29 SW

Englishman's Bay 1 1.08 0.00-2.10 0.68 SE 0.43 0.10-0.5 0.23 NW 0.44 0.20-0.90 0.21 7.98 6.40-9.60 1 5.55 1.17-11.33 3.84 SW

Parlatuvier 1 1.39 0.00-3.50 1.06 SE 0.24 0.05-0.5 0.12 NW 0.27 0.10-0.60 0.13 8.14 6.70-10.60 1.13 5.41 0.00-12.17 3.35 SW

Bloody Bay 1 1.01 0.00-2.80 0.89 SE 0.44 0.20-0.60 0.13 NW 0.49 0.25-0.75 0.16 8.82 6.90-11.00 1.32 9.23 3.50-18.25 4.37 SW

Man Of War Bay 1 1.16 0.00-3.50 1.13 NE 0.2 0.05-0.60 0.17 NW 0.22 0.05-0.70 0.18 7.55 6.00-9.90 1.23 7.51 0.00-14.00 3.82 SW

Milford Bay 1 1.71 0-2.70 0.78 SE 0.16 0.02-0.30 0.08 W 0.15 0.02-0.3 0.08 6.52 0-10.10 2.29 6.52 1.17-16.33 4.4 SW

Little Back Bay 1 2.3 0-5.10 1.65 SE 0.96 0.3-2.50 0.6 SE 1.01 0.30-2.00 0.59 8.61 6.60-14.60 1.92 10.86 3.50-26.67 6.76 SW

2 2.39 0.00-6.10 1.48 NE 0.92 0.40-3.0 0.66 NE 1 0.40-3.0 0.68 7.8 0.0-13.70 2.7 10.39 2.27-22.67 5.51 SW



Table 5: Summary Grain Size for Leeward Coast Beaches of Tobago

BEACH/BAY STATION DESCRIPTION SAMPLE

LOCATION

GRAPHIC MEAN MEDIAN SORTING SKEWNESS KURTOSIS PERCENTAGE COMPOSITION

CLASSIFICATION (FOLK & WARD)

mm mm mm REMARKS GRAVEL >2.0mm

SAND (0.0625 - 2.0

mm)

MUD < 0.0625mm

Man-O-War Bay 1 West

UB 1.13 0.46 1.10 0.47 1.18 0.44 Poorly sorted -0.01 1.00 3.13 96.83 0.03 Slightly Gravelly SAND

MB 0.97 0.51 0.95 0.52 0.78 0.58 Moderately sorted 0.03 1.00 1.50 98.50 0.00 Slightly Gravelly SAND

LB 1.53 0.35 1.50 0.35 0.93 0.52 Moderately sorted -0.01 0.99 0.37 99.63 0.00 Slightly Gravelly SAND

Bloody Bay 1 Central

UB 1.71 0.31 1.68 0.31 0.99 0.50 Moderately sorted -0.07 1.07 3.96 95.69 0.35 Slightly Gravelly SAND

MB 1.73 0.30 1.72 0.30 0.70 0.62 Moderately well sorted 0.02 0.99 0.13 99.83 0.03 Slightly Gravelly SAND

LB 1.30 0.41 1.34 0.40 1.26 0.42 Poorly sorted -0.09 0.82 6.62 93.38 0.00 Slightly Gravelly SAND

Parlatuvier Bay 1 West

UB 0.83 0.56 0.83 0.56 0.77 0.59 Moderately sorted 0.01 0.98 1.67 98.30 0.03 Slightly Gravelly SAND

MB 1.39 0.38 1.55 0.34 1.07 0.48 Poorly sorted -0.24 0.95 3.42 96.54 0.03 Slightly Gravelly SAND


Englishman's Bay 1 Central


MB 1.38 0.38 1.39 0.38 0.78 0.58 Moderately sorted -0.01 1.01 0.20 99.72 0.08 Slightly Gravelly SAND

LB -0.14 1.10 -0.63 1.55 1.49 0.36 Poorly sorted 0.45 0.87 37.06 62.92 0.02 Sandy GRAVEL

Castara Bay 1 Central

UB 1.67 0.31 1.65 0.32 0.62 0.65 Moderately well sorted 0.03 0.98 0.17 99.78 0.05 Slightly Gravelly SAND


LB 2.57 0.17 2.60 0.16 0.58 0.67 Moderately well sorted -0.26 1.71 0.37 99.60 0.03 Slightly Gravelly SAND

Culloden Bay 1 East



LB 1.13 0.46 1.13 0.46 0.55 0.68 Moderately well sorted 0.00 1.00 0.68 99.29 0.03 Slightly Gravelly SAND

Arnos Vale Bay 1 East

UB 0.13 0.92 0.00 1.00 0.00 1.00 Very well sorted 0.00 0.00 0.00 0.00 0.00 Gravelly SAND

MB 0.25 0.84 0.25 0.84 0.45 0.73 Well sorted 0.01 0.99 0.58 99.38 0.03 Slightly Gravelly SAND

LB -0.22 1.17 -0.22 1.16 0.50 0.71 Well sorted -0.14 1.26 9.16 90.84 0.00 Gravelly SAND

Great Courland 1 North



LB 1.55 0.34 1.55 0.34 0.77 0.58 Moderately sorted 0.00 0.98 0.88 99.05 0.07 Slightly Gravelly SAND

Great Courland 2 Central

UB 1.40 0.38 1.40 0.38 0.77 0.59 Moderately sorted -0.01 1.00 0.73 99.22 0.05 Slightly Gravelly SAND



Great Courland 3 South



LB -0.39 1.31 -0.40 1.32 0.54 0.69 Moderately well sorted 0.02 0.98 7.80 92.18 0.02 Gravelly SAND

Stone Haven Bay 1 Central

UB 2.33 0.20 2.33 0.20 0.49 0.71 Well sorted 0.00 1.00 0.00 99.98 0.02 SAND

MB 2.21 0.22 2.24 0.21 0.54 0.69 Moderately well sorted -0.10 1.08 0.00 99.99 0.01 SAND

LB 2.57 0.17 2.57 0.17 0.42 0.75 Well sorted 0.00 1.00 0.00 99.97 0.03 SAND

Stone Haven Bay 2 South UB 1.64 0.32 1.63 0.32 0.67 0.63 Moderately well sorted 0.01 0.99 0.02 99.93 0.05 Slightly Gravelly SAND

MB 1.57 0.34 1.57 0.34 0.68 0.63 Moderately well sorted 0.00 1.00 0.00 99.98 0.02 SAND



BEACH/BAY STATION DESCRIPTION SAMPLE

LOCATION




SAND (0.0625 - 2.0

mm)

MUD < 0.0625mm


Little Back Bay 1 East


MB 1.49 0.36 1.49 0.36 0.56 0.68 Moderately well sorted -0.02 1.01 1.87 98.13 0.00 Slightly Gravelly SAND

LB 1.94 0.26 1.94 0.26 0.49 0.71 Well sorted -0.01 0.98 0.10 99.87 0.03 Slightly Gravelly SAND

Little Back Bay 2 West

UB 1.91 0.27 1.90 0.27 0.49 0.71 Well sorted 0.01 1.04 0.03 99.97 0.00 Slightly Gravelly SAND



Milford Bay 1 West



LB 1.07 0.48 1.32 0.40 1.39 0.38 Poorly sorted -0.29 0.78 11.48 88.47 0.05 Gravelly SAND

Mt Irvine Bay 1 North




Mt Irvine Bay 2 South

UB 2.28 0.21 2.29 0.20 0.37 0.77 Well sorted -0.02 1.00 0.00 100.00 0.00 SAND



Pigeon Pt 1 East




Pigeon Pt 2 Central



LB 0.40 0.76 0.40 0.76 1.13 0.46 Poorly sorted 0.00 1.00 7.83 92.17 0.00 Gravelly SAND

Pigeon Pt 3 West




Sheerbird's Pt 1 West

UB 2.55 0.17 2.55 0.17 0.34 0.79 Very well sorted -0.01 1.00 0.05 99.95 0.00 Slightly Gravelly SAND



Sheerbird's Pt 2 East

UB 2.55 0.17 2.55 0.17 0.34 0.79 Very well sorted 0.00 1.00 0.02 99.98 0.00 Slightly Gravelly SAND

MB 2.29 0.20 2.29 0.20 0.47 0.72 Well sorted -0.01 1.01 0.07 99.92 0.02 Slightly Gravelly SAND


Buccoo Bay 1 East

UB 2.25 0.21 2.23 0.21 0.61 0.66 Moderately well sorted -0.03 1.09 0.08 99.83 0.08 Slightly Gravelly SAND



Buccoo Bay 2 West






Table 6: Shoreline stability status of Leeward Coast Beaches of Tobago for the period 2004 – 2008

Beach/Bay

IMA’s Beach Monitoring Station

Location

Shoreline Stability Status (+Net Annual Accretion (m);

-Net Annual Erosion (m); DE Dynamic Equilibrium)

2004 2005 2006 2007 2008

Store Bay 1 DE DE DE DE DE

2 DE DE DE DE DE

Pigeon Point 1 DE DE DE DE DE

2 DE DE DE DE DE

3 -1.50 -0.50 DE -2.00 -2.00

Sheebird’s Point

1 DE DE DE DE DE

2 -1.30 DE DE DE -0.60

Buccoo Bay 1 +0.50 DE DE +5.50 +1.50

2 -2.00 DE DE -3.50 -2.00

Mt.Irvine 1 DE DE DE DE DE

2 DE DE DE DE DE

Stone Haven 1 DE DE DE DE DE

2 DE DE DE DE DE

Great Courland 1 DE DE DE DE DE

2 DE DE DE DE DE

3 DE DE DE DE DE

Arnos Vale DE DE DE DE DE

Culloden Bay DE DE DE DE DE

Castara Bay DE DE DE DE DE

Englishman's Bay

DE DE DE DE DE

Parlatuvier DE DE DE -0.50 -0.60

Bloody Bay DE DE DE DE DE

Man Of War Bay

DE DE DE DE DE



4.1.1 Store Bay

Store Bay is 210 m long and bounded by two headlands. Figure 6 is an IKONOS (2007) image

of the bay showing the location of the IMA stations. The beach slopes moderately and is

backed by low limestone cliffs. The sand is lightly-coloured and of biogenic origin

(Plate 1).

Figure 6: IKONOS image of Store Bay showing IMA Station location (2007)

Station 1

Store Bay is very dynamic beach that shows seasonal variation. There is a seasonal trend that

is clearly observed during the summer and winter periods. The beach tends to have higher

elevations of sediment with a lower swash zone gradient in the summer months and lower

elevations with a steeper profile during the winter months (Figure 7). The sediment is

transported offshore during the winter months and returned gradually during the summer

months.

1

2



Plate 1: Store Bay Station 1 (February 2013)

Littoral data indicates that wind speed averages 1.12 m/s (+/-1.19 m/s) and ranges between

0.00-3.90 m/s approaching from the northeast. Waves approach from the north west with a

mean significant wave height of 0.33 m (+/-0.14 m) and a period of 6.69 s

(+/- 2.16) while the breaker height is 0.37 m (+/- 0.17 m). Mean longshore current averages

8.03 cm/s (range 1.17-11.73 cm/s, +/- 3.39 cm/s) and flows to the southwest (Table 4).

In Table 5 it can be seen that the upper beach sediment sample is classified as SAND with a

mean and median grain size of 0.31 mm. The sample consists of 0.08% Gravel (>2.0 mm),

99.92% Sand (0.0625 - 2.0 mm) and 0% Mud (<0.0625 mm). The sample is well sorted, Near

Symmetrical and Mesokurtic.

The mid-beach sample is classified as SAND with a mean and median grain size of 0.28 mm.

The sample consists of 0.0% Gravel (>2.0 mm), 100% Sand (0.0625 - 2.0 mm) and 0.0% Mud

(<0.0625 mm). The beach sediment is well sorted, Near Symmetrical and Mesokurtic.

The lower beach sample is classified as Gravelly SAND with a mean grain size of 0.31 mm

and median grain size of 0.31 mm. The sample consists of 0.0% Gravel (>2.0 mm), 100%

Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The beach sediment is moderately

well sorted, Near Symmetrical and Mesokurtic (Figure 7).



Figure 7: Sediment grain-size distributions for Store Bay Station 1

Figure 8: Showing profiles for Store Bay Station 1 the period 2004 – 2008

Beach profiles conducted during the period 2004 – 2008 indicate that there were changes

occurring on the upper beach, with more substantial changes in sediment levels in the surf

zone region. These sediments are either transported to an offshore bar or alongshore due to

the longshore currents present. The highest beach elevation during this period was obtained

in September 2005 (Figure 8).

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Store Bay Station 1 2004 - 2008

200401 200409

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Figure 9: Plot of Beach Width and Volume vs Number of days for Store Bay Station 1 for the period May 1988 – October 2008

The beach width and beach volume graph illustrates that this part of the beach is stable. The

overall trends for beach volume and beach width parallel each other, although seasonal

changes in both parameters were observed (Figure 9).

Station 2

The beach at Station 2 (Plate 2) on the eastern section of Store Bay also exhibits dynamic

equilibrium (Table 6). The effect of the storm surge of October 2005 is reflected in the profile

(Figure 11). Recovery of the beach was observed eight months after the event.

y = -0.0001x - 1.4973R² = 0.0024

y = 0.0001x + 1.816R² = 0.0089

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STORE BAY - Station 1Changes in Beach Widths and Volumes

May 1988 - October 2008

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Number of Days (Units)



Plate 2: Store Bay Station 2 (February 2013)

Wind approaches from the southeast with an average speed of 0.99 m/s (+/-0.77 m/s).

Waves approach from the northwest. Mean significant wave height is 0.33 m (+/-0.18 m)

with a period of 8.33 (+/-3.44 s) while the breaker height is 0.36 m (+/-0.17 m). Mean

longshore current averages 8.13 cm/s (range 0.00-18.13 cm/s, +/-4.15 cm/s) and flows in a

predominantly south westerly direction (Table 4).


mean and median grain size of 0.30 mm. The sample consists of 0.0% Gravel (>2.0 mm),

99.99% Sand (0.0625 - 2.0 mm) and 0.01% Mud (<0.0625 mm). The sample is well sorted,

Near Symmetrical and Mesokurtic.


The sample consists of 0.0% Gravel (>2.0 mm), 100% Sand (0.0625 - 2.0 mm) and

0.0% Mud (<0.0625 mm). The beach sediment is well sorted, Near Symmetrical and

Mesokurtic (Figure 10).


and median grain size of 0.33 mm. The sample consists of 0.0% Gravel (>2.0 mm),

100% Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The beach sediment is

moderately well sorted, Near Symmetrical and Mesokurtic (Figure 10).



Figure 10: Sediment grain-size distributions for Store Bay Station 2

Figure 11: Showing profiles for Store Bay Station 2 the period 2004 – 2008

The beach profiles illustrate some seasonal cyclicity at this station. Although sediment loss

was observed in September 2005 and January 2006, the profile re-established equilibrium

in subsequent years and accreted up to October 2008 approximately 4 m in the 5 year study

period (Figure 11).

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Store Bay Station 2 2004 - 2008

200401 200409

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200601 200605

200701 200708

200802 200810

Accretion

Mean Sea Level



Figure 12: Plot of Beach Width and Volume vs Number of days for Store Bay Station 2 for the period March 2001 – October 2008

The long term analysis of the beach width and beach volume reinforces the positive trends

as seen in the beach profiles. A plot of the beach width and volume against number of days

elapsed since the first monitoring was conducted shows variations in both parameters

(Figure 12). These variations can be explained as a result of both seasonal and cyclic trends.

Significant negative deviations are usually the result of storm waves generated by tropical

depressions, hurricanes passing to the north as was the event in October 2005. A decline in

beach width usually reflects a negative change in volume. This is, however, not always the

case, as redistribution of sediment along the profile transect can result in a greater beach

width but a decrease in volume. At this beach however, positive changes to beach width and

volume suggest that this beach is stable, and accreting.

4.1.2 Pigeon Point

Pigeon Point beach is the western landward limit of the Buccoo Reef Marine Park and is

approximately 600 m long. This beach has a moderate slope and is characterized by its

powdery white biogenic sand. Figure 13 is an IKONOS (2007) image of Pigeon Point showing

the location of the three IMA stations along this beach.

y = 0.0003x - 0.6655R² = 0.0017

y = 0.0018x + 0.1341R² = 0.0545

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STORE BAY - Station 2Changes in Beach Widths and Volumes

March 2001 - October 2008B

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200506

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200608



Figure 13: IKONOS image of Pigeon Point showing IMA Station locations (2007)

Station 1

The beach at station 1 (Plate 3) is in dynamic equilibrium (Table 6). Little variation is seen

in the profile and the data suggests that this profile is stable (Figure 15).

1

2

3



Plate 3: Pigeon Point Station 1 (February 2013)


2.00-6.50 m/s approaching from the southeast. Waves approach from the northeast with a

mean significant wave height of 0.13 m (+/-0.06 m) and a period of 5.92 s (+/- 0.90) while

the breaker height is 0.15 m (+/- 0.09 m). Mean longshore current averages 14.85 cm/s

(range 8.53-29.17 cm/s, +/- 5.29 cm/s) and flows to the southeast (Table 4).

In Table 5 it can be seen that the upper beach sediment sample is classified as Slightly

Gravelly SAND with a mean and median grain size of 0.21 mm. The sample consists of 0.07%

Gravel (>2.0 mm), 99.91% Sand (0.0625 - 2.0 mm) and 0.02% Mud (<0.0625 mm). The

sample is well sorted, Near Symmetrical and Mesokurtic.

The mid-beach sample is classified as Slightly Gravelly SAND with a mean grain size of

0.24 mm and median grain size of 0.23 mm. The sample consists of 0.12% Gravel

(>2.0 mm), 99.88% Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The beach

sediment is well sorted, Near Symmetrical and Mesokurtic (Figure 14).

The lower beach sample is classified as Slightly Gravelly SAND with a mean grain size of 0.48

mm and median grain size of 0.48 mm. The sample consists of 0.82% Gravel


sediment is moderately sorted, Near Symmetrical and Mesokurtic (Figure 14).



Figure 14: Sediment grain-size distributions for Pigeon Point Bay Station 1

Figure 15: Showing profiles for Pigeon Point Station 1 for the period 2004 – 2008

Beach profiles show very little seasonal cyclicity along the transect over the period 2004 to

2008 (Figure 15). Data indicates that the backshore is highly dynamic, although it is to be

noted that this area is also impacted heavily by anthropogenic influences. Beach profiles

show vertical accretion of sediment of approximately 2 m over the period January 2004 to

October 2008.

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Pigeon Point Station 12004 - 2008

200401 200409

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Mean Sea Level



Figure 16: Plot of Beach Width and Volume vs Number of days for Pigeon Point Station 1 for the period March 1991 – October 2008

Analysis of beach width and beach volume however reveals a negative overall trend, despite

the accretion observed on the profiles over the 5 year period (2004 – 2008)

(Figure 16). This result highlights the importance of analysing shorter term beach profiles in

collaboration with longer quantitative datasets.

Station 2

Station 2 is located at the northernmost limit of Pigeon Point beach (Plate 4) and exhibits

dynamic equilibrium (Table 6).

y = -0.0017x + 1.0340R² = 0.5555

y = -0.0017x + 0.6739R² = 0.6892

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PIGEON POINT - Station 1Changes in Beach Widths and Volumes

March 1991 - October 2008

Bea

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(m)

Bea

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(m

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)


20000322

1998052020070514





Waves approach from the southeast. Mean significant wave height is 0.13 m (+/-0.06 m) with

a period of 6.27 (+/-1.91 s) while the breaker height is 0.14 m (+/-0.08 m). Mean longshore

current averages 15.74 cm/s (range 0.00-43.17 cm/s, +/-10.58 cm/s) and flows in a

predominantly westerly direction (Table 4).



Gravel (>2.0 mm), 99.88% Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The sample

is Moderately well sorted, Near Symmetrical and Mesokurtic (Figure 17).


0.24 mm and median grain size of 0.24 mm. The sample consists of 0.0% Gravel (>2.0 mm),

100% Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The beach sediment is

Moderately well sorted, Strongly fine skewed and Mesokurtic (Figure 17).


and median grain size of 0.76 mm. The sample consists of 7.83% Gravel (>2.0 mm), 92.17%

Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The beach sediment is poorly sorted,

Near Symmetrical and Mesokurtic.




Figure 18: Showing profiles for Pigeon Point Station 2 the period 2004 – 2008

Beach profiles at this station show more seasonal cyclicity than at station 1. The sediment on

the upper beach in January 2004 may have been redistributed to the mid beach region and

formed an elevated berm by February 2005. The beach profiles also show that reduced

sediment levels have occurred over the subsequent profiles up to the period October 2008,

with a generally consistent planform observed within the sub-aerially exposed region of the

profile. The beach profiles show seaward accretion of approximately 20 m from 2004 to

2008 (Figure 18).

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Figure 19: Plot of Beach Width and Volume vs Number of days for Pigeon Point Station 2 (north) for the period March 1991 – October 2008.

The analysis of beach width and beach volume illustrates overall negative trends for both

parameters. Observations of this area however indicate that the spit is migrating to the east,

and as such is losing sediment in this region. The perceived erosion may just be a realignment

of the spit sediment to a new equilibrium position (Figure 19).

y = -0.0083x + 3.8975R² = 0.8700

y = -0.0075x + 3.1838R² = 0.7798

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Station 3

The western section of Pigeon Point (Station 3) exhibits erosion (Table 6). Selected beach

profile data (Figure 21) shows these changes occurring at this station. Some reduction in

beach width (Figure 22) was also observed after the storm surge of October 2005 but the

data suggests that erosion has not accelerated thereafter. The berm is characterized by a

steep face and coarse sediment intermixed with coralline fragments (Plate 5).



0.00-3.40 m/s approaching from the southeast. Waves approach from the northwest with a


the breaker height is 0.20 m (+/- 0.14 m). Mean longshore current averages 9.73 cm/s (range

1.17-30.33 cm/s, +/- 7.07 cm/s) and flows to the southwest (Table 4).


Gravelly SAND with a mean grain size of 0.25 mm and median grain size of 0.26 mm. The

sample consists of 1.05% Gravel (>2.0 mm), 98.95% Sand (0.0625 - 2.0 mm) and 0.0% Mud

(<0.0625 mm). The sample is well sorted, Near Symmetrical and Mesokurtic.




sediment is well sorted, Near Symmetrical and Mesokurtic.








Figure 21: Showing profiles for Pigeon Point Station 3 the period 2004 – 2008

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Beach profile data does not illustrate much seasonal cyclical changes at this station. The

beach profiles do however, show erosion of the berm with the IMA station being setback a

distance of 80 m in the backshore. The profiles show landward retreat of the berm of

approximately 8 m over the study period from January 2004 to October 2008 (Figure 21).

Figure 22: Plot of Beach Width and Volume vs Number of days for Pigeon Point Station 3 (west) for the period March 1991 – October 2008

Beach width and volume analysis shows an overall negative trend at this station

(Figure 22). This is indicative of erosion and is also evidenced by field observation

(Plate 5) and beach profile data (Figure 21). Of the three stations around this Pigeon Point,

this station has the greatest exposure to the Caribbean Sea and its coastal processes.

y = -0.0015x + 3.5071R² = 0.6190

y = -0.0012x + 2.742R² = 0.5542

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4.1.3 Milford Bay

Milford Bay is approximately 600 m in length and is located just south of Pigeon Point. Figure

23 is an IKONOS (2007) image of the bay showing the location of the IMA station. The beach

slopes moderately and is backed by a relatively flat vegetated backshore. The sand is lightly-

coloured and of biogenic origin (Plate 6)

Figure 23: IKONOS image of Milford Bay showing IMA Station location (2007)



Plate 6: Milford Bay, May 2007: Westerly view showing narrow coral lined beach


0.00-2.70 m/s approaching from the southeast. Waves approach from the west with a mean

significant wave height of 0.16 m (+/-0.08 m) and a period of 6.52 s (+/- 2.29) while the

breaker height is 0.15 m (+/- 0.08 m). Mean longshore current averages

6.52 cm/s (range 1.17-16.33 cm/s, +/- 4.4/s) and flows to the southwest (Table 4).




sample is well sorted, Near Symmetrical and Mesokurtic.








strongly coarse skewed and platykurtic (Figure 24).



Figure 24: Sediment grain-size distributions for Milford Bay

Figure 25: Showing profiles of Milford Bay for the period 2004 – 2008

Selected beach profiles for Milford Bay over the study period 2004 to 2008 illustrate that the

beach face and backshore regions are stable. This beach shows minimal dynamism along the

sub-aerial and sub-aqueous regions of the profile.

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Milford Bay2004 - 2008

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Figure 26: Plot of Beach Width and Volume vs Number of days for Milford Bay for the period May 1998 – October 2008.

Analysis of beach width and volume indicates a long-term trend of sediment loss which

suggests that there is erosion of the beach at this point (Figure 26). As mentioned before, the

5 year period of beach profile analysis is too short a period of time to ascertain beach stability

when compared to the 20 year period for the beach width and volume trend analysis.

4.1.4 Sheebird’s Point

Sheerbird’s Point is located on the western end of a sand spit separating Buccoo Bay and Bon

Accord Lagoon, east of Pigeon Point. It is accessible only by boat or by a private road. The

spit is composed of white biogenic sand, derived from the adjacent Buccoo Reef. There is a

natural channel running parallel to the shore that is used for navigation into and out of the

lagoon. Longshore currents are weak and flow predominantly to the south. There are two

IMA stations along this spit (Figure 27).

y = -0.0010x + 1.9042R² = 0.1910

y = -0.0024x + 1.1972R² = 0.5445

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Figure 27: IKONOS image of Store Bay showing IMA Station location (2007)

Station 1

Station 1 at Sheerbird’s Point is located to the western most region of this spit (Plate 7).

During 2004 – 2008 this section of the spit exhibited dynamic equilibrium (Table 6) with

some changes to the profile transects (Figure 29).

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Plate 7: Station 1 Sheerbirds point Easterly view capturing groynes and spit (May 2007)


0.05-3.20 m/s approaching from the east. Waves approach from the northeast with a mean







is Very well sorted, Near Symmetrical and Mesokurtic.




sediment is Moderately well sorted, Coarse Skewed and Leptokurtic (Figure 28).




sediment is Moderately sorted, Skewed and Mesokurtic (Figure 28).



Figure 28: Sediment grain-size distributions for Sheebird Point station 1

Figure 29: Showing profiles for Sheebird Point Station 1 for the period 2004 – 2008

Beach profiles (Figure 29) show seasonal cyclicity with a lot of morphological changes in the

surf zone region. The highest recorded elevations were recorded in June 2005 and January

2006. The beach profiles also showed that the upper beach and berm area is stable.

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Figure 30: Plot of Beach Width and Volume vs Number of days for Sheerbird’s Point, Station 1 for the period December 1998 – October 2008

The beach width and beach volume analysis indicates that the beach at this station is stable

with an almost horizontal trend line for beach volume and an increasing trend for beach

width. This may suggest that this region of the spit is becoming morphologically flatter, with

no real increases to sediment volume. Overall, the spit appears to be stable in this region

(Figure 30).

Station 2

Station 2 at Sheerbird’s Point is located along the northern region of this spit (Plate 8).

During 2004 – 2008 this section of the spit exhibited dynamic equilibrium (Table 6) with

some noted changes to the profile transects (Figure 32).

y = 0.0008x + 1.9887R² = 0.1343

y = -0.0002x + 0.3243R² = 0.0282

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Plate 8: Sheebirds Point Station 2 (February 2013)


Waves approach from the southwest. Mean significant wave height is 0.08 m (+/-0.04 m)







is Very well sorted, Near Symmetrical and Mesokurtic.

The mid-beach sample is classified as Slightly Gravelly SAND with a mean and median grain

size of 0.20 mm. The sample consists of 0.07% Gravel (>2.0 mm), 99.91% Sand (0.0625 - 2.0

mm) and 0.02% Mud (<0.0625 mm). The beach sediment is well sorted, Near Symmetrical

and Mesokurtic (Figure 31).



Sand (0.0625 - 2.0 mm) and 0.02% Mud (<0.0625 mm). The beach sediment is Moderately

sorted, Coarse skewed and Platykurtic (Figure 31).



Figure 31: Sediment grain-size distributions for Sheerbird Point station 2

Figure 32: Showing profiles for Sheebird Point Station 2 for the period 2004 – 2008

Analysis of the beach profiles shows recession of the berm of 3 m over the 5 year period

(Figure 32). This may be attributed to mangrove die off. When this occurs there are no tree

roots to anchor the sediment from being removed by coastal processes.

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Figure 33: Plot of Beach Width and Volume vs Number of days for Sheerbird’s Point, Station 2 for the period March 2001 – October 2008

The analysis of beach width and beach volume shows a slightly negative trend at this station;

although it should be noted that this represents only 7 yrs of data. Although the station

displays some seasonal cyclicity, the overall trend is fairly stable with minimal deviation

from equilibrium (Figure 33). Due to the limited dataset, continued monitoring is necessary

to ascertain this station’s stability status.

4.1.5 Buccoo Bay

Buccoo Bay is located between Booby Point and Sheerbirds’s Point (Figure 34). The

moderately sloping beach is 1.4 km long, composed of light-brown, fine-grained sandy

sediment and is bordered by coconut palms, manchineel, and almond trees (Plate 9).

y = -0.0005x - 1.9564R² = 0.0685

y = -0.0001x - 1.9127R² = 0.0071

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Figure 34: IKONOS image of Buccoo Bay showing IMA Station location (2007)

Station 1

Station 1 is located on the eastern end of Buccoo Bay (Figure 34). This station appears to be

stable with an increase in sediment along the transect over the 5 year study period.

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Plate 9: Buccoo Bay Station 1 Easterly view of Bench Mark, beach width and Jetty (May 2007)

Littoral data indicates that wind speed averages1.91 m/s (+/-0.83 m/s) and ranges between

0.70-3.50 m/s approaching from the southeast. Waves approach from the southwest with a







sample is moderately well sorted, Near Symmetrical and Mesokurtic.



mm) and 0.0% Mud (<0.0625 mm). The beach sediment is moderately sorted, Near

Symmetrical and Mesokurtic (Figure 35).




sediment is poorly well sorted, Coarse Skewed and Platykurtic (Figure 35).



Figure 35: Sediment grain-size distributions for Buccoo Bay station 1

Figure 36: Showing profiles for Buccoo Bay Station 1 for the period 2004 – 2007

Beach profiles over the 5 year period shows accretion of sediment along the beach face of

approximately 8 m from 2004 – 2007 (Figure 36). The subaqueous profile appears to be

dynamic from the surf zone and seaward.

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Figure 37: Plot of Beach Width and Volume vs Number of days for Buccoo Bay, Station 1 for the period March 1992 – August 2007

At this station changes to both beach width and volume suggest that this beach is stable, as

reflected by the positive trend line gradients (Figure 37). This positive trend in sediment

accumulation may be attributed to the lower wave energy which impacts the eastern end of

the bay.

Station 2

Station 2 is located on the western end of Buccoo Bay (Figure 34; Plate 10). This station

appears to be stable with an increase in sediment along the transect over the 5 year study

period.

y = 0.0013x - 3.9457R² = 0.3233

y = 0.0011x - 2.9778R² = 0.2646

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Plate 10: Buccoo Bay Station 2 Westerly view of beach width and upper beach scarp (May 2007)

Wind approaches from the northeast with an average speed of 1.67 m/s (+/-0.85 m/s).

Waves approach from the west. Mean significant wave height is 0.34 m (+/-0.13 m) with a

period of 7.24 (+/-1.28 s) while the breaker height is 0.39 m (+/-0.16m). Mean longshore






is moderately well sorted, Near Symmetrical and Mesokurtic.



mm) and 0.0% Mud (<0.0625 mm). The beach sediment is moderately well sorted, Near





sediment is moderately well sorted Near Symmetrical and leptokurtic (Figure 38).



Figure 38: Sediment grain-size distributions for Buccoo Bay station 2

Figure 39: Showing profiles for Buccoo Bay Station 2 for the period 2004 – 2008

This station is located in a more exposed area of the bay. In June 2005 exceptional accretion

was observed (possibly because of an extreme event) which persisted until August 2006.

However, by January 2007, the profile returned to its equilibrium profile (Figure 39).

Following January 2007, the profile recorded erosion.

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Figure 40: Plot of Beach Width and Volume vs Number of days for Buccoo Bay, Station 2 for the period May 1998 – October 2008

The beach width and beach volume analysis (Figure 40) suggests an overall trend of

accretion and stability as the trend lines for each parameter almost parallels each other. This

may be misleading because of the two spikes at June 2005 and October 2006 where there

were noticeable increases to both beach width and beach volume. If these spikes (anomalies)

are removed, then the overall trend of both parameters would be negative (erosion).

However, extreme events as observed in 2005 on this profile form part of the long-term

equilibrium status of beaches.

4.1.6 Mount Irvine

Mount Irvine Bay is north of Buccoo Bay. This bay is bounded by Booby Point to the

southwest and Rocky Point to the north. The bay extends east-west and north-south,

separated by an outcrop of coral-algal limestone. Figure 41 is an IKONOS (2007) image of

the bay showing the location of the IMA stations.

y = 0.0007x + 0.1553R² = 0.0178

y = 0.0011x - 4.3653R² = 0.0137

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Figure 41: IKONOS image of Mount Irvine Bay showing IMA Station location (2007)

Station 1

The north-south section of the beach (Plate 11) is 600 m long. The beach is made up of light-brown

medium-grained sand composed mainly of quartz. Longshore currents are weak, flowing to the

south.

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Plate 11: Mount Irvine Station 1 (February 2013)


0.00-3.00 m/s approaching from the southeast. Waves approach from the southwest with a






Gravel (>2.0 mm), 99.97% Sand (0.0625 - 2.0 mm) and 0% Mud (<0.0625 mm). The sample

is well sorted, Near Symmetrical and Mesokurtic.


size of 0.29 mm. The sample consists of 0.37% Gravel (>2.0 mm), 99.58% Sand

(0.0625 - 2.0 mm) and 0.05% Mud (<0.0625 mm). The beach sediment is well sorted, Near





well sorted, Coarse Skewed and leptokurtic (Figure 42).



Figure 42: Sediment grain-size distributions for Mount Irvine Bay station 1

Figure 43: Showing profiles for Mount Irvine Bay station 1 for the period 2004 – 2008

The beach profile at this station is situated in front of a lifeguard tower with a concrete base

(Plate 11). As a result, there is no landward recession of the shoreline. What can be observed

however is a variation in the elevation of the sediment with time. The profiles illustrate that

this station is in dynamic equilibrium (Figure 43).

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Figure 44: Plot of Beach Width and Volume vs Number of days for Mount Irvine Bay, Station 1 for the period March 1992 – October 2008

The analysis of beach width and volume indicates dynamic equilibrium. The almost parallel

trend lines in Figure 44 suggest that this region of Mount Irvine Bay is relatively stable with

minimal net changes in sediment.

Station 2

The east-west section of the bay is 550 m long and bordered by a seawall, built to protect the

road which runs close to the shore (Plate 12). Weak longshore currents flow to the

southwest.

y = -0.0002x - 0.0029R² = 0.0500

y = -0.0005x + 1.6708R² = 0.1693

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Plate 12: Mount Irvine Station 2 (February 2013)




longshore current averages 10.86 cm/s (range 4.67-29.17 cm/s, +/-5.64 cm/s) and flows in

a predominantly south westerly direction (Table 4).


mean grain size of 0.21 mm and median grain size of 0.20 mm. The sample consists of 0.0%

Gravel (>2.0 mm), 100% Sand (0.0625 - 2.0 mm) and 0% Mud (<0.0625 mm). The sample is

well sorted, Near Symmetrical and Mesokurtic.



mm) and 0.02% Mud (<0.0625 mm). The beach sediment is well sorted, Near Symmetrical




Sand (0.0625 - 2.0 mm) and 0.02% Mud (<0.0625 mm). The beach sediment is well sorted,

Near Symmetrical and Mesokurtic (Figure 45).



Figure 45: Sediment grain-size distributions for Mount Irvine Bay station 2

Figure 46: Showing profiles for Mount Irvine Bay station 2 for the period 2004 – 2008

The beach profiles (Figure 46) indicate seasonal cyclicity together with an accretionary

trend over the 2004 – 2008 study period. The profiles also indicate that the Shirvan road is

being protected by the seawall which shows no evidence of being breached at this location.

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Figure 47: Plot of Beach Width and Volume vs Number of days for Mount Irvine Bay, Station 2 for the period March 1992 – October 2008

An overall trend of accretion was observed with beach width and volume from 1992 to 2008

(Figure 47). This indicates stability of the beach face with sediment accumulating to increase

the buffering capacity from waves which further protects the Shirvan road.

4.1.7 Little Back Bay

Little Back Bay is located just east of Mount Irvine Bay. The bay is approximately 500 m in

length and is characterized by lightly coloured sand and well vegetated cliffs. Figure 48 is an

IKONOS (2007) image of the bay showing the location of the IMA stations at this bay.

y = 0.0007x - 3.5397R² = 0.0842

y = 0.0007x - 2.9743R² = 0.0684

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Figure 48: IKONOS image of Little Back Bay showing IMA Station location (2007)

Station 1

Little Back Bay, Station 1 is located within the central region of the bay. It is a highly dynamic

section of the bay with variable berm positions (Plate 13).

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Plate 13: Station 1 Little Back Bay May 2007: Westerly view showing wide beach, berm and cusps.


0.00-5.10 m/s approaching from the southeast. Waves approach from the southeast with a


the breaker height is 1.01 (+/- 0.59 m). Mean longshore current averages 10.86 cm/s (range

3.50-26.67 cm/s, +/- 6.76/s) and flows to the southwest (Table 4).




is moderately well sorted, Near Symmetrical and Mesokurtic.











Figure 49: Sediment grain-size distributions for Little Back Bay Station 1

Figure 50: Showing profiles of Little Back Bay Station 1 for the period 2004 – 2008

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The beach profile at station 1 (Figure 50) illustrates that this region of the bay is highly

dynamic and stable for the period under study (2004 – 2008). This may be evidenced by the

high dynamism of the beach berm. This region of the bay has a relatively uniform planform

with the exception of the profile in June 2005.

Figure 51: Plot of Beach Width and Volume vs Number of days for Little Back Bay, Station 1 for the period March 1992 – October 2008

As can be seen from Figure 51, beach width shows a slightly increasing trend over time since

the profile was first monitored. The data also illustrates a decreasing beach volume which

may suggest that the beach at this location of the bay may be getting lower and flatter.

y = 0.0004x - 6.5575R² = 0.0146

y = -0.0015x - 4.677R² = 0.0165

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Station 2

Little Back Bay, Station 2 is located toward the western region of the bay (Figure 48). This

part of the bay has more rocky outcrops when compared to the other profile transect at the

centre of the bay (Plate 14). The profile at station 2 shows a distinct envelope of dynamism

with no net loss or gain of sediment (Figure 53).

Plate 14: Station 2A Little Back Bay May 2007: Westerly view showing wide beach, berm and cusps


0.00-6.10 m/s approaching from the northeast. Waves approach from the northeast with a

mean significant wave height of 0.92 m (+/-0.66 m) and a period of 7.8 (+/- 2.7) while the

breaker height is 1.0 (+/- 0.68 m). Mean longshore current averages 10.39 cm/s (range 2.27-

22.67 cm/s, +/- 5.51/s) and flows to the southwest.















Figure 52: Sediment grain-size distributions for Little Back Bay Station 2A

Figure 53: Showing profiles of Little Back Bay Station 2A for the period 2004 – 2008

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Sediment Histogram for little Back Bay Station 2A

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The beach profile at station 2 shows that the upper beach region of the transect appears to

be fairly stable although highly dynamic. The mid to lower beach regions of the transect are

both shown to be highly dynamic with a distinct sediment envelope (the upper and lower

limits of the profile).

Figure 54: Plot of Beach Width and Volume vs Number of days for Little Back Bay, Station 2 for the period March 1992 – October 2008

Long-term trend analysis of the data indicates that Station 2 at Little Back Bay is

experiencing net loss of sediment as is illustrated by decreasing trend lines for both beach

width and beach volume (Figure 54). This data suggests that this region of the beach is being

eroded and is becoming narrower.

y = -0.0014x - 5.9517R² = 0.0667

y = -0.0058x - 4.2932R² = 0.2621

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4.1.8 Stone Haven Bay

This bay is bounded to the west by Rocky Point and to the north by Hawk’s Bill headland.

This is a turtle nesting beach. The beach slopes gently to moderately and is 900 m long,

composed of medium-grained, light-brown sand on which there are cusps. The moderate

energy waves impact the bay and approach from the northwest. Moderate longshore

currents flow towards the southwest. Figure 55 is an IKONOS (2007) image of the bay

showing the location of the IMA stations at this bay.

Figure 55: IKONOS image of Stone Haven Bay showing IMA Station location (2007)

Station 1

Station 1 is located in the central region of the bay and is adjacent to a turtle lookout.

According to the beach profile data obtained (Figure 56), has been accreting over the 5 year

study period. This station is backed by a low cliff and has no sign of landward recession (Plate

15).

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Plate 15: Stone Haven Bay Station 1 Easterly view showing wide gently sloping beach and cusps (May 2007)

Littoral data indicates that wind speed averages1.86 m/s (+/-1.12 m/s) and ranges between

0.00-3.40 m/s approaching from the southwest. Waves approach from the north west with

a mean significant wave height of 0.63 m (+/-0.21 m) and a period of 8.53 s



In Table 5 it can be seen that the upper beach sediment sample is classified as Slightly SAND

with a mean and median grain size of 0.20 mm. The sample consists of 0.00% Gravel (>2.0

mm), 99.98% Sand (0.0625 - 2.0 mm) and 0.02% Mud (<0.0625 mm). The sample is well

sorted, Near Symmetrical and Mesokurtic.

The mid-beach sample is classified as SAND with a mean grain size of 0.22 mm and median

grain size of 0.21 mm. The sample consists of 0.00% Gravel (>2.0 mm), 99.99% Sand (0.0625

- 2.0 mm) and 0.01% Mud (<0.0625 mm). The beach sediment is well sorted, Coarse Skewed


The lower beach sample is classified as SAND with a mean grain size of 0.17 mm and median

grain size of 0.17 mm. The sample consists of 0.00% Gravel (>2.0 mm), 99.97% Sand (0.0625

- 2.0 mm) and 0.03% Mud (<0.0625 mm). The beach sediment is well sorted, Near




Figure 56: Showing profiles for Stone Haven Bay station 1 for the period 2004 – 2008

The profile at station 1 (Figure 56) shows some seasonal cyclicity with pronounced accretion

over the study period. The beach prograded approximately 15 m from 2004 to 2008, with

the beach face becoming less steep in the upper beach region. This morphological change

may assist turtles in reaching a suitable nesting site on the upper beach during the nesting

period.

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Figure 57: Plot of Beach Width and Volume vs Number of days for Stone Haven Bay, Station 1 for the period March 1992 – October 2008

The beach width and beach volume analysis illustrates increasing beach width and

decreasing beach volume for station 1 (Figure 57). This suggests that the sediment at this

station is being redistributed along the profile. The beach at this location has become wider

and flatter over time.

Station 2

y = 0.0018x + 14.7263R² = 0.1196

y = -0.0025x + 20.545R² = 0.0714

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Station 2 is located toward the western end of the bay and is backed by low sparsely

vegetated cliffs (Plate 16). The base of these cliffs may be impacted by wave action on a

spring high tide.

Plate 16: Stone Haven Bay Station 2 Easterly view showing a wide gently sloping beach. (May 2007)




longshore current averages 12.74 cm/s (range 0.00-42.00 cm/s, +/-10.34 cm/s) and flows

in a predominantly south westerly direction (Table 4).




(<0.0625 mm). The sample is moderately well sorted, Near Symmetrical and Mesokurtic.


The sample consists of 0.0% Gravel (>2.0 mm), 99.98% Sand (0.0625 - 2.0 mm) and 0.02%

Mud (<0.0625 mm). The beach sediment is moderately well sorted, Near Symmetrical and

Mesokurtic (Figure 58).




sediment is poorly sorted, Near Symmetrical and Platykurtic (Figure 58).



Figure 58: Sediment grain-size distributions for Stone Haven Bay station 2

Figure 59: Showing profiles for Stone Haven Bay station 2 for the period 2004 – 2008

The beach profile at station 2 (Figure 59) shows seasonal cyclicity, and erosion of 10 m over

the 5 year period (2004 – 2008). The beach face has become less steep in the upper beach

region (October 2008), but has become steeper overall when compared to the profile of

January 2004.

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Figure 60: Plot of Beach Width and Volume vs Number of days for Stone Haven Bay, Station 2 for the period March 1992 – October 2008

The long-term increasing trends of beach width and beach volume parameters indicate that

the beach at station 2 is experiencing accretion. This may appear to contradict what was

found using the beach profiles, but while beach profiles are representative of a 5 year period,

beach width and beach volume (Figure 60) are representative of a 16 year period. This data

therefore suggests that the erosion observed in the beach profiles represents a short-term

erosion sequence in a longer-term accretionary trend at this station.

4.1.9 Great Courland Bay

Great Courland Bay is 1.8 km long and bounded to the north by Courland Point and to the

southwest by Hawk’s Bill headland (Figure 61). Two rivers enter the bay; the larger

Courland River enters at its northern end while the other river enters in its southern section.

y = 0.0007x + 1.5493R² = 0.0183

y = 0.0032x - 5.5242R² = 0.1882

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The beach comprises light-brown, medium-grained sandy sediments and cusps are a

common feature. The northern end is moderately sloping, and the central area slopes more

steeply.

This bay is a turtle nesting site, and Figure 61 is an IKONOS (2007) image of the bay showing

the location of the IMA stations at this bay.

Figure 61: IKONOS image of Great Courland Bay showing IMA Station location (2007)

Station 1

Station 1 is located in the northern region of Great Courland Bay. It comprises light-brown,

medium-grained sandy sediments and cusps. There is a distinct berm which buffers the

impact of wave energy on the flat vegetated backshore (Plate 17).

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Plate 17: Great Courland Bay Station 1: Easterly view of a gentle beach slope and mid beach berm. (May 2007)





(range 4.98-16.33 cm/s, +/- 3.45 cm/s) and flows to the southwest (Table 4).







(0.0625 - 2.0 mm) and 0.07% Mud (<0.0625 mm). The beach sediment is moderately well

sorted, Near Symmetrical and Mesokurtic (Figure 62).







Figure 62: Sediment grain-size distributions for Great Courland Bay station 1

Figure 63: Showing profiles for Great Courland Bay Station 1 for the period 2004-2008

Beach profiles show a stable upper beach with dynamic mid and lower beach regions (Figure

63). The profile also shows some accretion at the mid beach to the lower beach regions over

the 2004 to 2008 study period. The wave event of August 2006 led to substantial accretion

on the profile, however by January 2007, the profile returned to its former state. This data

suggests that this profile is stable with no landward retreat observed.

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Figure 64: Plot of Beach Width and Volume vs Number of days for Great Courland Bay, Station 1 for the period December 1999 – October 2008

The long-term analysis indicates that the beach at this station location is very stable, and

accreting. This can be seen with the positive trends for both beach width and beach volume

over the 17 year period (Figure 64). This may be attributed by the location of Station 1 being

situated at the most sheltered region of the bay.

y = 0.0019x - 0.5657R² = 0.2331

y = 0.0039x + 2.6726R² = 0.5573

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Station 2

This station is situated toward the central region of the bay south of the Courland River.

There is a very high distinct berm which protects the backshore from wave attack

(Plate 18).

Plate 18: Great Courland bay Station 2: Easterly view showing steep beach face and berm. (May 2007)








sample consists of 0.73 Gravel (>2.0 mm), 99.22% Sand (0.0625 - 2.0 mm) and 0.05% Mud














The profile shows that that beach width is generally constant at 45 m from the IMA

benchmark (Figure 66). Profiles also show that there were deviations from the normal

profile planform in September 2004 and February and June of 2005. Although sediment was

removed, there was subsequent recovery to the equilibrium profile observed in October

2008.

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Figure 67: Plot of Beach Width and Volume vs Number of days for Great Courland Bay, Station 2 for the period March 1992 – October 2008

In Figure 67 the beach width and beach volume analysis illustrates a generally stable trend

for beach width and an increasing trend for beach volume. This suggests that the beach

sediment is accreting vertically, with no lateral extension to the sub-aerially exposed beach.

Station 3

Station 3 is located toward the southern end of Great Courland Bay in close proximity to the

smaller of the two rivers which flow into this bay. There is a pronounced berm and a well

vegetated backshore (Plate 19).

y = 0.0017x - 7.3652R² = 0.4318

y = 0.0127x - 29.452R² = 0.6892

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Plate 19: Great Courland Station 3: Easterly view showing moderately sloping beach and berm. (May 2007)










The mid-beach sample is classified as Slightly Gravelly SAND with a mean grain size of 0.53



well sorted, Coarse Skewed and Leptokurtic (Figure 68).




well sorted, Near Symmetrical and Mesokurtic (Figure 68).





Figure 69 illustrates a stable upper beach and backshore region. The profile also illustrates

some seasonal cyclicity over the 5 year study period. It also illustrates erosion of the mid

beach area of the beach face from January 2004 to February 2005. The profile however

recovers by June 2005 with extensive accretion, and remains in dynamic equilibrium

thereafter.

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Figure 70: Plot of Beach Width and Volume vs Number of days for Great Courland Bay, Station 3 for the period March 1992 – October 2008

Beach width and beach volume trends illustrate a very stable beach with sustained elevated

beach volume levels over the study period (2004-2008). The elevated sediment levels may

have been caused by riverine inputs from the smaller of the Courland Bay Rivers. The

exposed nature of this station allows for greater impact by incoming waves and by extension

greater morphological change to the beach face. The overall long-term trend is that of

accretion (Figure 70).

4.1.10 Arnos Vale

Arnos Vale Bay is located east of Plymouth. This bay is bounded by headlands to the east and

west. It is a secluded pocket beach that is 225 m long. The beach has light-brown, coarse-

grained sand and is steeply sloping (Plate 20). Waves are of moderate energy and approach

from the northwest. Figure 71 is an IKONOS (2007) image of the bay showing the location of

the IMA station at this bay.

y = 0.0036x + 0.1385R² = 0.3423

y = 0.0103x + 1.7068R² = 0.4129

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Figure 71: IKONOS image of Arnos Vale Bay showing IMA Station location (2007)

Plate 20: Arnos Vale Easterly view showing breaker uprush and wave cut platform. (January 2007)



Wind approaches from the southwest with an average speed of 1.84 m/s (+/-1.13 m/s).



longshore current averages 7.85/s (range 1.93-24.50 cm/s, +/-6.48 cm/s) and flows in a


In Table 5 it can be seen that the upper beach sediment sample is classified as Gravelly SAND

with a mean grain size of 0.92 mm and median grain size of 0.93 mm. The sample consists of

6.11% Gravel (>2.0 mm), 93.89% Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The

sample is very well sorted, Near Symmetrical and very Platykurtic.



(0.0625 - 2.0 mm) and 0.03% Mud (<0.0625 mm). The beach sediment is well sorted, Near





Coarse Skewed and Leptokurtic (Figure 72).

Figure 72: Sediment grain-size distributions for Arnos Vale Bay

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Figure 73: Showing profiles for Arnos Vale Bay for the period 2004 – 2008

The beach profile (Figure 73) shows some cyclicity but the profile shape seems to be also

influenced by river outflow from the southwest (which creates a channel which flows across

the profile line at times throughout the year). The backshore cliff is stable with no evidence

of landward retreat.

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Figure 74: Plot of Beach Width and Volume vs Number of days for Arnos Vale Bay, for the period March 1992 – October 2008.

Analysis of beach width and beach volumes indicates this profile is stable with minimal

increases to both parameters. The decreases in beach and beach volume may be accounted

for by the river flowing across the profile at variable times. The overall trend however is that

of accretion (Figure 74).

y = 0.0005x + 0.9993R² = 0.0319

y = 0.0015x + 2.3321R² = 0.074

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4.1.11 Culloden Bay

Culloden Bay is located north of Arnos Vale Bay. It is a small bay backed inland by cliffs 20 to

30 m high, except around the main access road. The cliffs backing the beach can be seen to

be eroding and this has resulted in the development of small caves at the base of the cliffs, as

well as the accumulation of boulders within the nearshore area of the bay

(Plate 21).

The beach which slopes moderately to steeply is dissected by cliffs into two small pocket

beaches, one 63 m long, located near the road, and the other 112 m long where a resort is

sited. The beach is composed of dark brown to black, medium-grained sand with some algae

present. Culloden Reef, a fringing coral reef, lies 100 m offshore. Figure 75 is an IKONOS

(2007) image of the bay showing the location of the IMA station at this bay.

Figure 75: IKONOS image of Culloden Bay showing IMA Station location (2007)



Plate 21: Culloden Bay: Easterly view showing gentle slope and narrow beach (February 2008)


0.00-2.10 m/s approaching from the southwest. Waves approach from the north west with

a mean significant wave height of 0.27 m (+/-0.10 m) and a period of 8.00 s









(0.0625 - 2.0 mm) and 0.03% Mud (<0.0625 mm). The beach sediment is moderately well

sorted, Near Symmetrical and Mesokurtic (Figure 76).




sediment is moderately well sorted, Near Symmetrical and Mesokurtic (Figure 76).



Figure 76: Sediment grain-size distributions for Culloden Bay

Figure 77: Showing profiles for Culloden Bay for the period 2004 – 2008

The beach profile shows that the beach is stable with minimal seasonal cyclicity along the

beach face with the exception of August 2006, which may have been caused by a wave event

(Figure 77). This wave event as observed at other locations led to an extreme accretion along

the entire length of the profile, which was removed in subsequent months. Outside of

extreme events, there is minimal deviation from the equilibrium profile.

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Figure 78: Plot of Beach Width and Volume vs Number of days for Culloden Bay, for the period March 2003 – October 2008

The beach width and beach volume graph illustrates that this beach is stable with the wave

event of October 2006 being the only notable outlier. This has skewed the graph toward a

positive trend rather than a more horizontal trend line (Figure 78). Continued monitoring

will reveal the true stability status of this beach.

y = 0.0019x + 1.5334R² = 0.0221

y = 0.0022x + 1.0926R² = 0.0284

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4.1.12 Castara Bay

Castara Bay is a pocket bay bounded by vegetated headlands. The beach is 308 m long, and

the Castara River enters the bay at its centre. The beach is made up of light-brown, fine-

grained sandy sediments (Plate 22). Figure 79 is an IKONOS (2007) image of the bay

showing the location of the IMA station at this bay.

Figure 79: IKONOS image of Castara Bay showing IMA Station location (2007)



Plate 22: Castara Bay Easterly view showing a wide gently sloping beach. (January 2007)



with a period of 7.55 (+/-1.17s) while the breaker height is 0.38 m (+/-0.17 m). Mean


predominantly south westerly direction (table 4).












sediment is moderately well sorted, Coarse Skewed and Very Leptokurtic (Figure 80).



Figure 80: Sediment grain-size distributions for Castara Bay

Figure 81: Showing profiles for Castara Bay for the period 2004 – 2008

The beach profile at Castara Bay illustrates a general trend of seasonal cyclicity at this station

location. The most notable change in beach face occurred in August 2006, where sediment

accreted along the profile to a distance of 45 m more than the sub-aerial equilibrium profile

of 35 m. The profile returned to its equilibrium position in subsequent months (Figure 81).

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200401 200409200502 200506200608 200701200708 200802200810

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Figure 82: Plot of Beach Width and Volume vs Number of days for Culloden Bay, for the period January 1993 – October 2008

Beach width and beach volume analysis illustrates that Castara Beach is stable with the

notable outlier of the August 2006 wave event. This event has resulted in sediment

accumulation which skewed the trend line in a positive direction (Figure 82). As a result it

may be misleading to think that Castara beach is accreting at this location.

y = 0.0027x - 0.4851R² = 0.1195

y = 0.0016x - 2.4596R² = 0.0203

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4.1.13 Englishman’s Bay

This is a deeply indented bay located on the leeward coast between Castara and Parlatuvier

Bays and bounded by headlands to the east and west. There is dense vegetation in the central

section of the bay. It is 360 m long and steeply sloping. It is composed of light-brown,

medium-grained sand (Plate 23). Moderate energy waves approach from the northwest.

Moderate longshore currents flow to the southwest and there is a strong backwash. A river

flows parallel to the beach through the thick vegetation on the landward side and flows into

the sea at the western end of the bay. Figure 83 is an IKONOS (2007) image of the bay

showing the location of the IMA station at this bay.

Figure 83: IKONOS image of Englishman’s Bay showing IMA Station location (2007)



Plate 23: Englishman’s Bay Westerly view showing a narrow steeply sloping beach (May 2007)


0.00-2.10 m/s approaching from the southeast. Waves approach from the north west with a

mean significant wave height of 0.43 m (+/-0.23 m) and a period of 7.98 s

(+/- 1.00) while the breaker height is 0.44m (+/- 0.21 m). Mean longshore current averages





(<0.0625 mm). The sample is moderately sorted, Near Symmetrical and Mesokurtic.



(0.0625 - 2.0 mm) and 0.08% Mud (<0.0625 mm). The beach sediment is moderately sorted,


The lower-beach sample is classified as Sandy Gravel with a mean grain size of 1.10 mm and

median grain size of 1.55 mm. The sample consists of 37.06% Gravel (>2.0 mm), 62.92%


strongly fine skewed and Platykutric (Figure 84).



Figure 84: Sediment grain-size distributions for Englishman’s Bay

Figure 85: Showing profiles for Englishman’s Bay for the period 2004 – 2008

The beach profile at Englishman’s Bay shows almost no seasonal cyclicity but illustrates

sediment accumulation along the entire length of the profile during a wave event in August

2006 (Figure 85). The profile regained its equilibrium profile position in subsequent months.

This may be an indication of the stability of this bay.

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200401 200409

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Figure 86: Plot of Beach Width and Volume vs Number of days for Englishman’s Bay, for the period September 2003 – October 2008

Figure 86 illustrates positive trends for beach width and beach volume. This trend line was

skewed by the August 2006 wave event. Excluding this anomaly, the overall trend for

Englishman’s Bay is one of stability.

y = 0.0010x + 0.2775R² = 0.0303

y = 0.0034x + 0.8262R² = 0.0303

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4.1.14 Parlatuvier Bay

Parlatuvier Bay is located between Englishman’s Bay and Bloody Bay. Two rivers,

Parlatuvier East and Parlatuvier West, empty into the bay, which is bounded by two well-

vegetated headlands. The beach is 450 m long, slopes steeply and is comprised of light-

brown, fine-grained sand (Plate 24). Waves of moderate energy approach from the

northwest. Figure 87 is an IKONOS (2007) image of the bay showing the location of the IMA

station at this bay.

Figure 87: IKONOS image of Parlatuvier Bay showing IMA Station location (2007)



Plate 24: Parlatuvier Bay (February 2013)










The mid-beach sample is classified as Slightly Gravelly SAND with a mean grain size



sediment is poorly sorted, Coarse Skewed and Mesokurtic (Figure 88).







Figure 88: Sediment grain-size distributions for Parlatuvier Bay

Figure 89: Showing profiles for Parlatuvier Bay for the period 2004 – 2008

The beach profile at Parlatuvier Bay shows little seasonal cyclicity. Data indicates that over

the period 2004 – 2008 the beach has lost sediment along the entire profile length with

October 2008 being the lowest recorded elevation. The loss of sediment occurred as vertical

erosion (Figure 89).

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200802 200810

Erosion

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Figure 90: Plot of Beach Width and Volume vs Number of days for Parlatuvier Bay, for the period March 2003 – October 2008

The beach width and beach volume trend analysis indicates that the beach at the western

end of Parlatuvier Bay is stable at this point in time, despite showing erosion over the period

2004 – 2008. However, if erosion continues, the long-term analysis will start recording

negative trends at this station.

y = -0.0002x + 2.7256R² = 0.0064

y = 0.0004x + 2.8627R² = 0.0056

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4.1.15 Bloody Bay

Bloody Bay is a small bay located east of Parlatuvier. It is backed by densely vegetated

headlands except in the area where the Bloody Bay River exits at the eastern end of the bay.

The beach is 371 m long and moderate in slope.

The beach comprises light-brown, medium-grained sand, with pebbles and gravel

intermixed with the sand, especially in the upper beach (Plate 25). Moderate energy waves

approach from the northwest. Figure 91 is an IKONOS (2007) image of the bay showing the

location of the IMA station at this bay.

Figure 91: IKONOS image of Bloody Bay showing IMA Station location (2007)



Plate 25: Bloody Bay: Seaward view of profile and rocks at high water line. (May 2008)




longshore current averages 9.23 cm/s (range 3.50 – 18.25 cm/s, +/-4.37 cm/s) and flows in

a predominantly south westerly direction (Table 4).















Figure 92: Sediment grain-size distributions for Bloody Bay

Figure 93: Showing profiles for Bloody Bay for the period 2004 – 2008

Beach profiles at this station illustrate season cyclicity. Apart from the exceptional accretion

observed in September 2005, the beach profile at this bay appears to be stable, and not

varying much from its equilibrium profile. There is also a distinct berm which helps protect

the backshore region of the bay (Figure 93).

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Sediment Histogram for Bloody Bay

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Figure 94: Plot of Beach Width and Volume vs Number of days for Bloody Bay, for the period March 2003 – October 2008

Beach width and beach volume analysis shows a relationship captured by the beach profile

with the sharp increase in September 2005 followed by the decrease in October 2007. The

overall trends are stable beach width and decreasing beach volume. This may suggest that

the beach is experiencing lower sediment input levels from the adjacent river.

y = 0.0007x - 0.0369R² = 0.0034

y = -0.0023x + 0.6627R² = 0.0236

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4.1.16 Man-o-War Bay

Man O War Bay is located on the northern tip of Tobago. This is a large bay, bounded by

North Point to the north by Corvo Point to the west. The steeply sloping pocket beach is 750

m long with brown, medium-grained sand (Plate 26). Low energy waves approach from the

northwest. Figure 95 is an IKONOS (2007) image of the bay showing the location of the IMA

station at this bay.

Figure 95: IKONOS image of Man-o-War Bay showing IMA Station location (2007)



Plate 26: Man O War Bay: Easterly view showing a moderate beach slope. (May 2007)


0.00-3.50 m/s approaching from the northeast. Waves approach from the northwest with a



0.00- 14.00 cm/s, +/- 3.82 cm/s) and flows to the southwest (Table 4).




(<0.0625 mm). The sample is poorly sorted, Near Symmetrical and Mesokurtic.











Figure 96: Sediment grain-size distributions for Man-o-War Bay

Figure 97: Showing profiles for Man-o-War Bay for the period 2004 – 2008

The beach profile shows that Man-o-War Bay exhibits some seasonal cyclicity around a

generally uniform profile. It also shows the profile as a result of a possible wave event in

September 2005 (Figure 97). The beach profile shows substantial accumulation of sediment

at the lower beach and surf zone regions of the beach profile in September 2005. Following

this event, the profile returns to its equilibrium profile.

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200401 200409

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Figure 98: Plot of Beach Width and Volume vs Number of days for Man O War Bay, for the period September 1996 – October 2008

The long-term analysis of beach width and beach volume indicates that the sediment at this

location of Man-o-War Bay is stable and the beach is increasing in width and volume over

the study period (Figure 98). This is important as a buffer of wave energy since the beach

width along Man O War bay is narrow.

y = 0.0011x - 2.4703R² = 0.1569

y = 0.0014x - 0.5404R² = 0.315

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4.2 WINDWARD COAST

The Windward coast is the more populated side of Tobago with its Windward Road running

from the capital, Scarborough, up to Charlotteville. All of the beaches and bays along this

coast tend to be more exposed and are reached via the Windward Road. This drive is very

scenic and is punctuated by many small villages and towns.

A summary of the littoral processes occurring on north coast beaches and bays is presented

in Table 7. A summary of the grain size parameters is presented in Table 8, while shoreline

erosion/accretion processes for the period 2004 – 2008 is presented in Table 9.



Table 7: Summary Littoral processes for Windward Coast Beaches of Tobago for the period 2004 – 2008

Beach/Bay Station

Location

Wind Speed

Wind Direction

Significant Wave Height Breaker Height

Breaker Period Longshore Current Speed

Current Direction

(s) (cm/s)

Mean Range STD Mean Range STD Direction Mean Range STD Mean Range STD Mean Range STD

Anse Bateau 1 1.36 0.00-3.00 0.97 SE 0.27 0.1-0.50 0.11 SE 0.29 0.15-0.50 0.12 6.85 4.90-10.00 1.46 5.76 1.07-10.67 2.62 SW

King's Bay 1 2.35 0.00-3.50 1.1 SE 1.19 0.00-0.05 0.14 SW 1.22 0.00-0.60 0.18 7.32 4.20-11.30 1.81 11.27 4.67-26.77 6.13 SW

Richmond Bay 1 1.1 0.00-2.50 0.86 SE 0.3 0.1-0.5 0.09 SW 0.32 0.15-0.50 0.1 7.05 4.90-10.40 1.61 7.38 2.33-19.33 3.95 SW

Goldsborough

1 1.41 0.00-3.30 1.03 SE 0.43 0.25-0.75 0.13 SE 0.45 0.30-0.70 0.11 6.88 4.80-9.60 1.26 11.37 2.33-27.07 6.51 SW

2 2.81 0.00-5.00 1.32 SE 0.45 0.20-0.70 0.14 SE 0.48 0.20-0.70 0.13 6.96 4.80-10.10 1.19 12.79 4.67-42.00 9.67 SW

Pinfold 1 3.75 1.00-5.90 1.49 SE 0.69 0.40-1.20 0.2 SE 0.76 0.40-1.30 0.2 6.93 4.80-9.80 1.19 13.97 1.17-34.07 10.68 SW

Barbados Bay

1 0.73 0.00-2.20 0.73 SE 0.35 0.15-0.60 0.12 SW 0.4 0.15-0.60 0.12 8.15 6.50-10360 1.04 7.63 0.00-18.13 4.81 SW

2 1.68 0.30-3.50 0.81 SE 0.38 0.20-0.60 0.09 SW 0.42 0.2-0.60 0.09 6.84 4.50-7.90 0.95 9.46 3.50-17.03 3.24 SW

3 2.57 0.00-3.50 1.28 SE 1.3 0.10-1.00 0.27 SE 1.31 0.1-1.00 0.27 6.75 0.00-8.10 2.35 11.51 4.67-19.47 5.12 SW

Minister Bay 1 3.04 1.50-5.70 1.1 SE 0.66 0.30-1.20 0.27 SE 0.75 0.40-1.20 0.27 7.38 5.80-11.00 1.23 19.22 4.53-52.50 15.26 SW

Rockly

1 2.98 0.20-7.70 1.72 SE 0.5 0.30-0.90 0.17 SE 0.54 0.35-0.80 0.14 7.21 5.00-11.00 1.5 11.92 7.93-26.67 4.65 SW

2 3.02 2.00-6.20 1.44 SE 0.47 0.30-0.80 0.13 SE 0.5 0.30-0.80 0.12 6.8 5.00-9.70 1.42 13.78 3.50-27.07 6.58 SW

Little Rockly

2 3.55 1.00-7.40 1.7 SE 0.55 0.20-1.20 0.27 SE 0.59 0.25-1.20 0.25 7.11 5.70-10.30 1.18 17.56 7.47-33.38 7.83 SW

3 3.21 1.20-6.80 1.42 SE 0.6 0.25-1.50 0.34 SE 0.64 0.30-1.50 0.33 7.19 5.80-10.70 1.5 19.9 10.67-40.83 8.16 SW

Canoe Bay 1 1.67 0.00-3.20 0.9 SE 0.18 0.10-0.30 0.07 SW 0.21 0.10-0.30 0.08 7.25 5.50-8.70 0.76 8.93 1.17-19.33 4.42 W

La Guira

1 3.19 1.00-5.80 1.45 SE 0.49 0.15-1.00 0.22 S 0.54 0.20-1.00 0.21 6.79 4.30-10.00 1.42 11.29 3.50-29.00 7.41 W

2 1.41 0.00-3.50 0.92 SE 0.11 0.00-0.30 0.08 SW 0.15 0.00-0.40 0.11 5.01 0.00-8.20 3.02 11.91 1.93-43.52 11.12 W



Table 8: Summary Sediment Grain Size for Windward Coast Beaches of Tobago for the period 2004 – 2008

BEACH/ BAY STATION DESCRIPTION SAMPLE

LOCATION




SAND (0.0625 - 2.0

mm)

MUD < 0.0625mm

Anse Bateau 1 Central



LB 0.30 0.81 0.67 0.63 1.59 0.33 Poorly sorted -0.37 1.05 21.95 78.05 0.00 Gravelly SAND

King's Bay 1 East

UB 2.15 0.23 2.16 0.22 0.71 0.61 Moderately well

sorted 0.00 0.98 0.95 98.78 0.27 Slightly Gravelly SAND


LB 1.37 0.39 1.33 0.40 1.23 0.43 Poorly sorted 0.00 1.00 3.92 95.98 0.10 Slightly Gravelly SAND

Richmond Bay 1 East




Goldsborough Bay 1 East

UB 1.07 0.48 1.07 0.48 0.83 0.56 Moderately sorted 0.00 1.00 0.77 99.20 0.03 Gravelly SAND



Goldsborough Bay 2 Central



MB 1.32 0.40 1.25 0.42 0.68 0.62 Moderately well


LB 0.94 0.52 0.90 0.54 0.61 0.66 Moderately well


Pinfold Bay 1 Central




Barbados Bay 1 East




Barbados Bay 2 Central



sorted -0.15 1.19 1.80 98.00 0.20 Slightly Gravelly SAND

LB 2.67 0.16 2.67 0.16 0.47 0.72 Well sorted 0.00 1.00 0.75 99.23 0.02 Slightly Gravelly SAND

Barbados Bay 3 West UB 1.55 0.34 1.55 0.34 0.85 0.56 Moderately sorted 0.00 1.00 0.25 99.72 0.03 Slightly Gravelly SAND




BEACH/ BAY STATION DESCRIPTION SAMPLE

LOCATION




SAND (0.0625 - 2.0

mm)

MUD < 0.0625mm


Minister Bay 1 West





Rockly Bay 1 East




Rockly Bay 2 West





Little Rockly Bay 2 Central


MB 2.80 0.14 2.79 0.14 0.32 0.80 Very well sorted 0.00 1.00 0.82 99.15 0.03 Slightly Gravelly SAND


Little Rockly Bay 3 South





Canoe Bay 1 Central

UB 2.71 0.15 2.72 0.15 0.40 0.76 Well sorted 0.00 1.00 0.00 100.00 0.00 SAND




La Guira Bay 1 East






La Guira Bay 2 West




LB 0.37 0.77 0.43 0.74 0.78 0.58 Moderately sorted -0.16 1.00 7.03 92.97 0.00 Gravelly SAND



Table 9: Shoreline stability status of Leeward Coast Beaches of Tobago for the period 2004 – 2008

Beach/Bay

IMA’s Beach Monitoring Station

Location

Shoreline Stability Status (+Net Annual Accretion (m);

-Net Annual Erosion (m); DE Dynamic Equilibrium)

2004 2005 2006 2007 2008

Anse Bateux 1 DE DE DE DE DE

King's Bay 1 DE DE DE DE DE

Richmond Bay 1 -2.50 -3.50 DE -0.10 -0.10

Goldsborough 1 DE DE DE DE DE

2 DE -0.50 -0.20 -0.20 DE

Pinfold 1 DE DE DE DE DE

Barbados Bay 1 DE DE DE DE DE

2 DE DE DE DE DE

3 DE -1.00 DE DE -2.00

Minister Bay 1 DE DE DE DE DE

Rockly 1

2 DE DE DE DE DE

Little Rockly 2 DE DE DE DE DE

3

Canoe Bay 1 DE DE DE DE DE

La Guira 1 DE DE DE DE DE

2 DE DE DE DE DE



4.2.1 Anse Bateau

This is a pocket beach bounded on each end by rocky headlands. Erosion at the base of these

headlands, especially the northern end, is causing the formation of caves. Beach erosion at

the southern end is causing the accumulation of gravel.

This moderate to steep sloping beach is 315 m long, comprised of light-brown, medium-

grained sand (Plate 27). Low energy waves approach from the southeast. Figure 99 is an

IKONOS (2007) image of the bay showing the location of the IMA station at this bay.

Figure 99: IKONOS image of Anse Bateau Bay showing IMA Station location (2007)



Plate 27: Anse Bateau Bay Easterly view showing a narrow, moderately sloping beach (May 2007)



a period of 6.85 s (+/-1.46 s) while the breaker height is 0.29 m (+/-0.12 m). Mean longshore














Strongly Coarse Skewed and Mesokurtic (Figure 100).



Figure 100: Sediment grain-size distributions for AnseBateu

Figure 101: Showing profiles for AnseBateux Bay for the period 2004 – 2008

The beach profile illustrates minimal seasonal cyclicity (Figure 101). The beach profile also

shows a similar accretion event along the profile line during September 2005 as observed at

other bays. Outside of this extreme event, the beach profiles illustrate a stable equilibrium

beach profile.

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Figure 102: Plot of Beach Width and Volume vs Number of days for Anse Bateau, for the period March 2003 – October 2008

Analysis of beach width and beach volume reveals that Anse Bateau is stable with increasing

beach width and increasing beach volume trends (Figure 102). This accumulation of

sediment would act as an important buffer for the hotel against wave attack from mild

storms and swell events.

y = 0.0010x + 0.7218R² = 0.0529

y = 0.0003x - 0.1449R² = 0.0045

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4.2.2 King’s Bay

This bay is bounded by Pedro Point to the east, and the King’s Bay River exits in the mid

section. The backshore is flat and well vegetated. There are patches of reef between the

river and the eastern headland. The gently to moderately sloping beach is 600 m long, and

comprises dark brown, fine-grained sandy sediments (Plate 28). Figure 103 is an IKONOS

(2007) image of the bay showing the location of the IMA station at this bay.

Figure 103: IKONOS image of King’s Bay showing IMA Station location (2007)



Plate 28: King’s Bay Easterly view showing a gentle beach slope and berm (May 2007)


0.0- 3.50 m/s approaching from the southeast. Waves approach from the southwest with a

mean significant wave height of 1.19 m (+/-0.14 m) and a period of 7.32 s (+/- 1.81 s) while









mm) and 0.13% Mud (<0.0625 mm). The beach sediment is moderately sorted, Near




(>2.0 mm), 95.98% Sand (0.0625 - 2.0 mm) and 0.1% Mud (<0.0625mm). The beach

sediment is poorly sorted, Symmetrical and Mesokurtic (Figure 104).



Figure 104: Sediment grain-size distributions for King’s Bay

Figure 105: Showing profiles for King’s Bay for the period 2004 – 2008

The beach profile suggests that this bay is stable as illustrated by minimal movement from

the equilibrium profile. There was also a small progradation of the beach face over the 5 year

study period (Figure 105).

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Figure 106: Plot of Beach Width and Volume vs Number of days for Kings Bay, for the period March 2003 – October 2008

The beach width and volume analysis indicates positive trends at King’s Bay for both

morphological parameters over the duration of the study period 2004-2008 (Figure 106).

The overall trend is one of accretion which may have been influenced by the input of the

river just west of the profile.

y = 0.0027x + 1.7429R² = 0.7335

y = 0.0034x - 1.5841R² = 0.7351

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4.2.3 Richmond’s Bay

Richmond Bay is approximately 600 m long and is located west of King’s Bay. It is backed by

a well vegetated headland to the east and a vegetated backshore. A river enters the bay at its

central region west of the profile location (Figure 107; Plate 29). Waves of moderate energy

approach from the south. This bay is experiencing erosion at its eastern end where the IMA

profile is located. Figure 107 is an IKONOS (2007) image of the bay showing the location of

the IMA station at this bay.

Figure 107: IKONOS image of Richmond’s Bay showing IMA Station location (2007)



Plate 29: Richmond Bay Seaward view of a gently sloping beach (May 2007)

Wind approaches from the southeast with an average speed of 1.1 m/s (+/-0.86 m/s). Waves

approach from the southwest. Mean significant wave height is 0.3 m (+/-0.09 m) with a

period of 7.05 (+/-1.61 s) while the breaker height is 0.32 m (+/-0.10 m). Mean longshore










sediment is moderately sorted, Strongly Coarse Skewed and Mesokurtic (Figure 108).







Figure 108: Sediment grain-size distributions for Richmond’s Bay

Figure 109: Showing profiles for Richmond Bay for the period 2004 – 2008

Beach profile data for Richmond Bay indicates seasonal cyclicity of the transects

(Figure 109). Data also reveals erosion of the backshore cliff of 6 m over the 5 year period

(2004 -2008).

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Figure 110: Plot of Beach Width and Volume vs Number of days for Richmond Bay, for the period January 1993 – October 2008

Beach width and volume analysis indicates a stable beach at Richmond Bay with an

increasing trend in beach volume over the 15 year observation period. This increase may be

as a result of the continuous sediment supply by the river which is in relatively close

proximity to the profile, in combination with the existence of a closed system at this bay

(Figure 110).

y = 0.0002x - 1.8139R² = 0.0052

y = 0.0018x + 3.6705R² = 0.1626

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4.2.4 Goldsborough Bay

Goldsborough Bay is located west of Richmond Bay and is approximately 1100 m in length.

The Goldsborough River exits toward the western end of the bay. The backshore is well

vegetated. The sand is dark in colour and of medium grain size (Plate 30). Waves of moderate

energy approach the bay from the south east and longshore currents flow to the south west.

Figure 111 is an IKONOS (2007) image of the bay showing the location of the IMA stations at

this bay.

Figure 111: IKONOS image of Goldsborough Bay showing IMA Station location (2007)

1

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Station 1

This station at Goldsborough Bay is located in front of a small wetland (Plate 30). The

sediment level here has increased in 2008 from its previous level in 2004.

Plate 30: Goldsborough Bay Station 1 Easterly view of a narrow moderately sloping beach (February 2008)


0.0- 3.30 m/s approaching from the southeast. Waves approach from the southeast with a

mean significant wave height of 0.43 m (+/-0.13 m) and a period of 6.88 s (+/- 1.26s) while


(range 2.33-27.07cm/s, +/- 6.51 cm/s) and flows to the southwest (Table 7).

In Table 8 it can be seen that the upper beach sediment sample is classified as Gravelly SAND

with a mean grain size of 0.48 mm and median grain size of 0.48 mm. The sample consists of

0.77% Gravel (>2.0 mm), 99.20% Sand (0.0625 - 2.0 mm) and 0.03% Mud (<0.0625 mm).

The sample is Moderately sorted, Near Symmetrical and Mesokurtic.

The mid-beach sample is classified as Slightly Gravelly SAND with a mean grain size 0.26 and

median grain size of 0.27 mm. The sample consists of 1.25% Gravel (>2.0 mm), 98.75% Sand

(0.0625 - 2.0 mm) and 0.0% Mud (<0.0625 mm). The beach sediment is moderately sorted,








Figure 112: Sediment grain-size distributions for GoldsboroughBay Station 1

Figure 113: Showing profiles for Goldsborough Bay Station 1 for the period 2004 – 2008

Beach profile data at Goldsborough Bay Station 1 illustrates seasonal cyclicity of the transect

at this location. An increase in sediment levels are observed on the profiles. The beach width

experienced approximately 5 m increase over the 5 year study period.

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Figure 114: Plot of Beach Width and Volume vs Number of days for Goldsborough Bay, Station 1, for the period January 1993 – October 2008

Long-term trend analysis of beach width and beach volume also illustrates this overall

accretionary trend (Figure 114) as seen with the beach profiles. This is indication of beach

stability at this location.

y = 0.0014x - 0.8235R² = 0.1830

y = 0.0008x - 0.7663R² = 0.0952

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Station 2

Goldsborough Station 2 is located toward the central region of the bay. The profile here is

characterized by a distinct berm and cuspate formations (Plate 31). Evidence of sand mining

may still be observed to date.

Plate 31: Goldsborough Bay Station 2 Easterly view showing berm and a moderately sloping beach (February 2008)




















Figure 115: Sediment grain-size distributions for Goldsborough Bay Station 2

Figure 116: Showing profiles for Goldsborough Bay Station 2 for the period 2004 – 2008

In Figure 116 the beach profiles indicates some seasonal cyclicity with a general beach

planform. The data illustrates a lowering of the entire beach face with pronounced changes

to the upper beach of approximately 1.5 m of vertical sediment loss. The landward lateral

loss of sediment was approximately 2 m over the 5 year period of the study.

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Figure 117: Plot of Beach Width and Volume vs Number of days for Goldsborough Bay, Station 2, for the period July 2000 – October 2008

The beach width and beach volume analysis illustrates sediment loss as depicted by the

beach profiles in Figure 116. The beach width is illustrated as stable but the beach volume

illustrates a negative trend (Figure 117). This reinforces the evidence of sand mining activity

at this bay which is showing to have negative repercussions to beach volumes.

4.2.5 Pinfold Bay

This beach is about 600 m long, with a moderate to steep slope and is comprised of dark

brown to black, fine-grained sand (Plate 32). The moderate energy waves approach from

the southeast. Rip currents are sometimes present. Longshore currents are weak and flow

to the southwest. Figure 118 is an IKONOS (2007) image of the bay showing the location of

the IMA stations at this bay.

y = -0.0005x + 1.5255R² = 0.0106

y = -0.0056x + 5.358R² = 0.4216

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Figure 118: IKONOS image of Pinfold Bay showing IMA Station location (2007)

Plate 32: Pinfold Bay westerly view (February 2013)





mean significant wave height of 0.69 m (+/-0.20 m) and a period of 6.93 s (+/- 1.19s) while


(range 1.17- 34.07 cm/s, +/- 10.68 cm/s) and flows to the southwest (Table 7).













Figure 119: Sediment grain-size distributions for Pinfold Bay

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Figure 120: Showing profiles for Pinfold Bay for the period 2004 – 2008

The beach profile at Pinfold Bay (Figure 120) illustrates some seasonal cyclicity of the profile

transect. The beach profile indicates a generally consistent moderate gradient which may

assist the formation of rip currents.

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Figure 121: Plot of Beach Width and Volume vs Number of days for Pinfold Bay for the period March 2003 – October 2008

The beach width and beach volume analysis illustrates a stable beach width and an overall

slightly decreasing trend for beach volume (Figure 121).

4.2.6 Barbados Bay

Barbados Bay is located just west of Pinfold Bay. It is approximately 1500 m in length and is

backed by low cliffs and a vegetated backshore. The beach is characterized by medium

grained to coarse sand. The moderate energy waves approach from the southeast. Longshore

currents are weak and flow to the southwest. Figure 122 is an IKONOS (2007) image of the

bay showing the location of the IMA stations at this bay.

y = -0.0002x + 2.7355R² = 0.0014

y = -0.0009x + 4.4499R² = 0.0149

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Figure 122: IKONOS image of Barbados Bay showing IMA Station location (2007)

Station 1

Barbados Bay, Station 1 is located at its eastern most section at the mouth of a river. The

beach has a gentle gradient at low tide (Plate 33).

1

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Plate 33: Barbados Bay Station 1 Westerly view showing a narrow gently sloping beach and rock outcrops at mid beach (May 2007)









(<0.0625 mm). The sample is very well sorted, Near Symmetrical and Very Platykurtic.




sediment is poorly sorted, Strongly Coarse Skewed and Leptokurtic (Figure 123).




sediment is poorly sorted, Strongly Coarse Skewed and Platykurtic (Figure 123).



Figure 123: Sediment grain-size distributions for Barbados Bay Station 1

The beach profile shows that the low backshore scarp at station 1 was under constant wave

attack from high tide. As a result coastal protection in the form of gabion baskets were used

at this station to prevent further landward recession (Figure 124).

Figure 124: Showing profiles for Barbados Bay Station 1 for the period 2004 – 2008

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Beach width and Beach volume trend lines shows an overall decrease of both parameters.

This indicates an erosion trend occurring at this station (Figure 125).

Figure 125: Plot of Beach Width and Volume vs Number of days for Barbados Bay, Station 1, for the period June 2003 – October 2008

Station 2

This station is located at the central region of the bay. At low tide there is a wide beach with

a gentle slope. This station is also located updrift of a large groyne (Plate 34).

y = -0.0016x - 1.2952R² = 0.1356

y = -0.0012x + 0.0135R² = 0.1059

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Plate 34: Barbados Bay Station 2 Westerly view showing a gently sloping beach (May 2007)


0.30-03.50 m/s approaching from the southeast. Waves approach from the southwest with

a mean significant wave height of 0.38 m (+/-0.09 m) and a period of 6.84 s (+/- 0.95) while


3.50- 17.03 cm/s, +/- 3.24 cm/s) and flows to the southwest (Table 7).








sediment is moderately well sorted, Coarse Skewed and Leptokurtic (Figure 126).








Beach profile shows some seasonal cyclicity of the transect with all profiles deviating slightly

from the equilibrium profile. The transect shows that the berm reduced in height by 0.50 m

in October 2008 from its position in January 2004. Beach profiles also shows that the mid

beach and lower beach regions have both accreted from January 2004 to October 2008

(Figure 127).


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The beach width and beach volume analysis reveals a stable beach with both parameters

positively increasing (Figure 128). This accumulation maybe as a result of the influence of

the groyne to the west.

Figure 128: Plot of Beach Width and Volume vs Number of days for Barbados Bay, Station 2, for the period September 2002 – October 2008

y = 0.0021x + 0.6813R² = 0.0814

y = 0.0004x + 0.6103R² = 0.0129

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Station 3

Barbados Bay Station 3 is located on the western most region of the bay down-drift of a large

groyne. The low cliff is impacted by the incoming waves and slumps from undercutting. The

sediment here is coarse and loosely compacted (Plate 35).

Plate 35: Barbados Bay Station 3 Westerly view showing a gently sloping beach and a distinctive change in sediment at waterline (May 2007)









(<0.0625 mm). The sample is Moderately sorted, Near Symmetrical and Mesokurtic.










sediment is moderately sorted, Fine Skewed and Mesokurtic (Figure 129).


The beach profiles shows some cyclicity of the transect over the study period (Figure 130). Beach profiles also illustrate where erosion of the backshore cliff and the profile occurred


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in May 2007. This may have been a result of the station being located downdrift of the

groyne. The profile also shows accretion of sediment in August 2006.

Figure 131: Plot of Beach Width and Volume vs Number of days for Barbados Bay, Station32, for the period May 1999 – January 2007

4.2.7 Minister Bay

Minister Bay is located to the east of Scarborough, the main port of entry into Tobago. It is

approximately 1500 m long and is backed by a well vegetated backshore. There is a river

which exits into the bay toward its eastern end. High energy waves approach the bay from

the south east and longshore currents flow to the southwest. Figure 132, is an IKONOS

(2007) image of the bay showing the location of the IMA station at this bay. Plate 36 is a

picture of the Bay.

y = 0.0008x - 1.2490R² = 0.0107

y = -0.0006x - 1.9084R² = 0.0052

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Figure 132: IKONOS image of Minister Bay showing IMA Station location (2007)



Plate 36: Minister Bay (May 2007)




















Figure 133: Sediment grain-size distributions for Minister Bay

Figure 134: Showing profiles for Minister Bay for the period 2004 – 2008

Beach profile illustrates some seasonal cyclicity over the 5 year period. Data indicates a

generally uniform planform with minimal deviation from the equilibrium profile. Although

the profiles show that a small amount of accretion may have occurred up to October 2008,

this is only a short-term study period and may not truly be representative of the sediment

cycle of this beach (Figure 134).

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The beach width and beach volume analysis (Figure 135) indicates decreasing beach volume

but increasing beach width. This may suggest a flattening of the profile or a redistribution of

the sediment along the profile.

Figure 135: Plot of Beach Width and Volume vs Number of days for Minster Bay, for the period March 1992 – October 2008

y = 0.0009x + 8.6693R² = 0.0342

y = -0.0009x + 4.3664R² = 0.0936

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4.2.8 Rockly Bay

West of the Scarborough port is a 2 km long sandy beach. Moderate energy waves approach

from the southeast. The beach comprises medium-grained sandy sediment and slopes gently

to the sea. The western end of Rockly Bay is affected by coastal erosion. The beach is backed

by a seawall, behind which there is a promenade. There is no natural vegetation. Figure 136

is an IKONOS (2007) image of the bay showing the location of the IMA stations at this bay.

Figure 136: IKONOS image of Rockly Bay showing IMA Station location (2007)

Station 1

1

2



Station 1 at Rockly Bay is located west of the Scarborough port. It is backed by a seawall

(Plate 37) and has a narrow beach which fronts the seawall.

Plate 37: Rockly Station 1 Westerly view capturing sea wall and a narrow gently sloping beach (2003)



a period of 7.21 (+/-1.50s) while the breaker height is 0.54 m (+/-0.14 m). Mean longshore


predominantly south westerly direction.








sediment is poorly sorted, Coarse Skewed and Mesokurtic (Figure 137).







Figure 137: Sediment grain-size distributions for Rockly Bay station 1

The beach profile shows negligible seasonal cyclicity with a consistent equilibrium profile

over the 5 year study period. The beach profile transect indicated that August 2006 had

greater sediment accumulation on the upper beach as compared to other times

(Figure 138).

Figure 138: Showing profiles for Rockly Bay Station 1 for the period 2004 – 2008

Beach width and beach volume graph indicates an overall positive trend to both parameters

(Figure 139). This indicates that this beach is stable.

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Figure 139: Plot of Beach Width and Volume vs Number of days for Rockly Bay, Station1, for the period December 1998 – October 2008

Station 2

y = 0.0017x - 2.1874R² = 0.2079

y = 0.0013x - 2.4718R² = 0.1976

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Station 2 at Rockly Bay is located west of Rockly Bay Station 1. It is backed by a seawall (Plate

38) and has a narrow beach which fronts the seawall.

Plate 38: Rockly Station 2, Easterly view showing scouring at the base of the sea wall (May 2007)













sediment is poorly sorted, Strongly Coarse Skewed and Leptokurtic (Figure 140).




sediment is moderately sorted, Strongly Coarse Skewed and Leptokurtic (Figure 140).



Figure 140: Sediment grain-size distributions for Rockly Bay station 2

Beach profiles illustrate what appears to be an uncompromised seawall and a stable

equilibrium transect over the study period 2004-2008 (Figure 141). The data indicates that

divergence from the equilibrium profile is minimal.

Figure 141: Showing profiles for Rockly Bay Station 2 for the period 2004 – 2008

The beach width and beach volume graph is indicative of a stable profile with consistent

values for beach volumes. The beach width displays seasonal cyclicity, however, this is

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merely a redistribution of sediment along the sub-aerially exposed profile as the beach

volume remains fairly constant (Figure 142).

Figure 142: Plot of Beach Width and Volume vs Number of days for Rockly Bay, Station 2, for the period January 1993 – October 2008

4.2.9 Little Rockly Bay

The beach is 1.3 km long, bounded to the south by a lagoon just north of Petit Trou Lagoon

and to the north by Red Point and Lambeau Village. It is comprised of medium-grained

y = -0.0003x + 3.0526R² = 0.0072

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biogenic material (coral, seashell and other white fragments), and is light-brown in colour.

The waves are of moderate energy approaching from the southeast. The central section of

the beach is protected by an offshore reef, and has a gentle slope. Figure 142 is an IKONOS

(2007) image of the bay showing the location of the IMA stations at this bay.

Figure 143: IKONOS image of Little Rockly Bay showing IMA Station locations (2007)

Station 2

This station is located at the central region of the bay. It has a gentle beach slope and appears

to be stable. Marine debris line the high water mark along the beach (Plate 39).

3

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Plate 39: Little Rockly Bay Station 2 Easterly view showing a wide gently sloping beach (January 2008)









(<0.0625 mm). The sample is very well sorted, Near Symmetrical and Mesokurtic.




sediment is very well sorted, Near Symmetrical and Mesokurtic (Figure 144).







Figure 144: Sediment grain-size distributions for Little Rockly Bay station 2

The beach profiles show generally consistent equilibrium profiles and a small increase of

sediment in the upper beach region (Figure 145). The beach profiles though exhibiting small

seasonal changes, do not seem to deviate much from the general planform.

Figure 145: Showing profiles for Little Rockly Bay Station 2 for the period 2004 – 2008

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The beach width and beach volume analysis illustrates an overall stable beach with the trend

lines of both parameters almost parallel (Figure 146).

Figure 146: Plot of Beach Width and Volume vs Number of days for Little Rockly Bay, Station 2, for the period January 2004 – October 2008

y = -0.0005x + 5.3792R² = 0.0011

y = 0.0012x - 1.0505R² = 0.0284

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Station 3

This station is located just east of the Petit Trou lagoon. It has a gentle beach slope and is

impacted by wave attack at high tide (Plate 40).

Plate 40: Little Rockly Bay Station 3, Westerly view showing a narrow gently sloping beach (May 2007)













sediment is moderately well sorted, Near Symmetrical and Leptokurtic (Figure 147).







Figure 147: Sediment grain-size distributions for Little Rockly Bay station 3

Figure 148: Showing profiles for Little Rockly Bay Station 3 for the period 2004 – 2008.

The beach profile illustrates little seasonal cyclicity. Beach profile data shows accretion with

an elevated profile in September 2005 (Figure 148).

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Analysis of beach width and beach volume indicates an overall trend of accretion at this

station, with increasing trends for both beach width and beach volume (Figure 149).

Figure 149: Plot of Beach Width and Volume vs Number of days for Little Rockly Bay, Station 3, for the period March 1996 – October 2008

4.2.10 Canoe Bay

This beach is 100 m long moderately sloping and is comprised of fine-grained, light-brown

to whitish sand. Low energy waves approach from the southwest and longshore currents

y = 0.0022x + 2.8551R² = 0.1434

y = 0.0024x + 1.2201R² = 0.2328

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flowing to the northwest. This beach is man-made and was created in 1985 (Plate 41). The

riprap structures built to protect the beach remain on both sides. Figure 150 is an IKONOS

(2007) image of the bay showing the location of the IMA stations at this bay.

Figure 150: IKONOS image of Canoe Bay showing IMA Station location (2007)



Plate 41: Westerly view of Canoe Bay


Waves approach from the southwest. Mean significant wave height is 0.18 m (+/-0.07 m)





mean grain size of 0.15 mm and median grain size of 0.15 mm. The sample consists of 0.0%





(>2.0 mm), 99.98% Sand (0.0625 - 2.0 mm) and 0.0% Mud (<0.0625mm). The beach








Figure 151: Sediment grain-size distributions for Canoe Bay

The beach profiles indicate stable backshore, upper beach, mid beach and lower beach

regions of the profile. The equilibrium profile can be clearly seen with the exception of

September 2005, when excessive accretion occurred on the beach face (Figure 152).

Figure 152: Showing profiles for Canoe Bay the period 2004 – 2008

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The beach width and beach volume trendlines indicate a very stable beach at Canoe Bay with

the trends of both morphological parameters almost superimposing on each other. This

notable accretion event is also visible on the graph on September 2005 (Figure 153).

Figure 153: Plot of Beach Width and Volume vs Number of days for Canoe Bay, for the period March 1992 – May 2008

y = 0.0002x + 1.4009R² = 0.0005

y = 0.0008x + 1.0942R² = 0.0128

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4.2.11 La Guira Bay

This bay is located at the south-western end of Tobago and is approximately 2500 m in

length. It is backed by low cliffs, a vegetated backshore and mangrove trees (Plate 42). Waves

approach from the south east and longshore currents flow to the south west.

Figure 154 is an IKONOS (2007) image of the bay showing the location of the IMA stations at

this bay.

Figure 154: IKONOS image of Canoe Bay showing IMA Station location (2007)

2A

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Station 1

This station has a narrow beach and a small berm. The profile does not show much variation

in planform and the beach slope is moderate (Plate 42).

Plate 42: La Guira station 1 (February 2013)


1.00-5.80 m/s approaching from the southeast. Waves approach from the south with a mean



11.29 cm/s (range 3.50-29.00 cm/s, +/- 7.41 cm/s) and flows to the west (Table 7).








sediment is moderately well sorted, Strongly Coarse Skewed and Mesokurtic (Figure 155).







Figure 155: Sediment grain-size distributions for La Guira Bay Station 1

The beach profiles show seasonal cyclicity of the transect over the 5 year period. Beach

profile shows a stable backshore and upper beach region and dynamic mid beach and lower

beach regions (Figure 156).

Figure 156: Showing profiles for La Guira Bay Station 1 the period 2004 – 2008

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Analysis of beach width and beach volume illustrates a stable beach at this location with

overall positive trend lines for both parameters (Figure 157).

Figure 157: Plot of Beach Width and Volume vs Number of days for La Guira Bay, Station 1, for the period March 1992 – May 2008

y = 0.0009x + 1.7265R² = 0.1465

y = 0.0003x + 2.597R² = 0.0201

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Station 2A

La Guira Station 2A also has a narrow beach with a small berm (Plate 43).

Plate 43: La Guira Station 2 Easterly view showing a moderately sloping beach (May 2007)



















sorted, Coarse Skewed and Mesokurtic (Figure 158).

Figure 158: Sediment grain-size distributions for La Guira Bay Station 2A

The beach profile shows some seasonal cyclicity and a berm (January 2004) which was

eroded by October 2008. Beach profile indicates lateral erosion of approximately 4 m over

the 5 year study period (Figure 159).

Figure 159: Showing profiles for La Guira Bay Station 2A the period 2004 – 2008

0

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Sediment Histogram for La Guira Bay Station 2

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200810

Erosion

Mean Sea Level



The beach width and beach volume parameters show an overall increasing trend for both

parameters at this location on the beach (Figure 160).

Figure 160: Plot of Beach Width and Volume vs Number of days for La Guira Bay, Station 2, for the period February 1985 – November 2008

y = 0.0008x - 1.3115R² = 0.1131

y = 0.0011x - 2.006R² = 0.1461

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La Guira BAY - Station 2 - EastChanges in Beach Widths and Volumes

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5 CONCLUSION

Most of the beaches and bays monitored by the IMA for the period 2004-2008 were in a state

of dynamic equilibrium (Figure 161). The majority of Tobago’s leeward coast beaches are

predominantly stable and in dynamic equilibrium. Four bays showed erosion and one

showed accretion. Although this coastline is backed by the more resistant metamorphic

rocks (in the north-eastern region), erosion was observed on the sandy beaches where there

was a lowering of sand elevations and not as a result of cliff recession. At Parlatuvier Bay

there was a lowering of the sand levels progressively from 2004 to 2008. Sheerbird’s north

profile has shown some erosion. This may be as a result of some mangrove die off where the

sediment would be loose and more susceptible to removal from the waves and currents.

Erosion was seen at the western end of Buccoo Bay, which may be because of its greater

exposure to wave impact than on the eastern side. Accretion was observed at Buccoo Bay

east, where this station is located in the lee of a large headland. The headland would have

absorbed some of the incoming wave energy which would impact the eastern side of the bay.

The windward coast beaches of Tobago are mostly in dynamic equilibrium with the

exception of Richmond, Goldsborough and Barbados Bays. These bays are experiencing

erosion. Richmond Bay is showing landward recession of the coastline as a result of weakly

consolidated material being removed by wave attack at high tide. The beach volume analysis

however shows that sediment at this section of the bay is increasing. This increase may be

as a result of the sediment input of the adjacent river into a possible closed system.

Goldsborough Bay is showing a lowering of sand levels toward the central region of the bay.

This sediment loss may be attributed to sand mining where deep pits were observed during

site visits. The western end of Barbados Bay is also experiencing erosion which may be as a

result of the down-drift impact of the large groyne in close proximity to that IMA station. The

low cliff is being undercut and slumping results. Attention may be needed here as this is

occurring within 7 m of the Windward Road.

The main factors driving erosion are the aspect or configuration of the bay, geology of the

backshore, hydrography, oceanography and sediment supply. For most bays in Tobago,

erosion is a naturally occurring phenomenon caused by the rise and fall of tides and wave

action. Other natural forces that exacerbate erosion would include storm surges, weathering,

wind and surface run off. Coastal development, construction and offshore activities such as

offshore dredging or construction in the near shore zone also have severe environmental

impacts on the coastline interfering with the natural coastal processes. Any disturbance to

this natural equilibrium can affect wave energy and longshore drift which results in erosion.

Hard engineering structures can arrest the erosion problems but, studies on the near shore

wave dynamics and coastal processes have to be conducted before any decision can be made

to select the most effective method of coastal defence. The coastal environment varies both



spatially and temporally and therefore designs are site specific. Usually long term offshore

and nearshore wave data are needed to make accurate predictions for optimum structure

design. Factors such as cost, availability of raw material, availability of scientific data for

competent design, aesthetics, maintenance and other variables play an integral part of the

decision making process. Other factors such as physical, biological, cultural, and safety for

the general public also need to be taken into consideration when deciding on hard

engineering coastal defence solutions. Options to remediate and arrest the erosion using

hard engineering structures can range from seawalls, rip rap revetments, groynes and

breakwaters. Soft engineering methods such as artificial beach nourishment, re-vegetation

or even re-location can also be used. Regardless of the method chosen, sound scientific

studies must be conducted for the decision making process.



Figure 161: Status of Coastline Map of Tobago based on study conducted during 2004 – 2008



6 RECOMMENDATIONS

The Coastal Conservation Project at the IMA provides valuable insight into the status of the

coastlines of Trinidad and Tobago. Monitoring of the beaches and bays around the country’s

coastlines are generally well covered. Beaches currently not monitored are primarily due to

limitations of access and the general nature of the coastline, such as the cliffs on the north

east coast. The findings of the research during 2004 – 2008 presented in this report indicate

that most beaches are in dynamic equilibrium. There are however some beaches that are

being eroded. Monitoring of beaches is conducted quarterly. There is a cost factor to the

collection of data under this project and hence decisions have to be made on the frequency

in which these beaches and bays are monitored. Eroding beaches that are monitored

quarterly may need additional stations to fully ascertain the extent of the erosion.

Within recent times an additional station has been added at Pigeon Point. There are however,

other areas along the coastline that are not monitored but accessible such as; Queen’s Beach,

Hope Bay along the windward coast and Hermitage Bay on the Leeward coast. For the larger

bays such as, La Guira, Minister, King’s, Richmond and Goldsborough bays, additional

stations may be necessary to capture any erosion taking place since it is not always reflected

in the current IMA monitoring stations. Tables 10 -11 presents a revised monitoring

programme based upon the findings of this research.

Table 10: Beaches and Bays monitored quarterly.

BEACH STATION NUMBER / LOCATION

REMARKS

Store Bay 1 2

A site of national interest. One of the more popular spots of Tobago.

Pigeon Point 1 2 3

Dynamic spit. One of the more popular spots of Tobago.

Sheerbird’s Point 1 2

Spit. Private development currently taking place in close proximity at this bay.

Buccoo Bay 1 2

New goat racing facility constructed and should be monitored to inform management.

Mount Irvine Bay 1 2

Popular spot located in front of a hotel constructed on the beach.

Stone Haven Bay 1 2

A turtle nesting site. High water line close to base of cliff on which road is located. Hotel is located behind road.



BEACH STATION NUMBER / LOCATION

REMARKS

Great Courland Bay

1 2 3

Popular turtle nesting beach.

Culloden Bay

Pristine reef nearshore

Castara Bay

Fishing village. Coastal development in close proximity to beach.

Englishman’s Bay

Voted in the top ten beaches of the world.

Parlatuvier Bay

Fishing village. Coastal development in close proximity to beach. Preservation and maintenance of the benchmarks in the event of coastal development or to advise Government or in the event of coastal development or to provide advice to the Government or Government agencies

Bloody Bay

Tourist destination

Man O War Bay

Important fishing community. Coastal development adjacent to shoreline. Preservation and maintenance of the benchmarks in the event of coastal development or to advise Government or in the event of coastal development or to provide advice to the Government or Government agencies

Anse Bateau

Hotel constructed on beach. Will be impacted by storm surge.

King’s Bay

Tourist destination

Richmond Bay

House under threat from erosion

Goldsborough Bay 1 2

Evidence of possible sand mining occurring at this beach.

Barbados Bay 1 2 3

Western station under threat, which is adjacent to Windward Road.

Minister Bay

Possible development

Rockly Bay 1 2

Scarborough port and Milford Road in close proximity to stations

Little Rockly Bay 2 3

Magdelana Grande hotel land under threat from wave attack

Canoe Bay

Private resort

La Guira Bay 1 2

Beach is in close proximity to airport runway



Table 11: New monitoring stations to be established (to be monitored quarterly).

BEACH STATION NUMBER /LOCATION

REMARKS

Queen’s Bay Popular tourist destination

Hope Bay Popular tourist destination

Additional monitoring stations to be established (to be monitored quarterly).

Great Courland Bay, Englishman’s Bay, Parlatuvier Bay, Man O War Bay, King’s Bay,

Goldsborough Bay, Minister Bay, Little Rockly Bay and La Guira Bay.

Also, the IMA has the technology and the capability to broaden its research capacity in

shoreline monitoring. The changing coastline can be mapped through remote sensing using

satellite imagery (IKONOS) and images obtained from Google maps. This data can be ground

truthed by conducting shoreline monitoring studies at areas that show signs of erosion.

Coupled with the current research at the IMA, a policy framework for building line setbacks

for the management of coastal development can be drafted. This can be used to advise

government on enacting laws for any coastal development based on location and other

influencing factors. This data will form an integral part of the integrated coastal zone

management (ICZM) process.

The IMA has a wealth of data from research conducted over the years that is not yet fully

analyzed, and this analysis can go a long way in terms of developing trends and models for

our changing coastline. The analysis and production of data products is necessary and are

usually made available to the public in the form of technical reports and published works in

journals. There also exists a need for greater collaboration among other government

agencies and academic institutions in coastal monitoring and protection to avoid duplication

of research, resources, and to build capacity.



7 REFERENCES

Bachew, S and Hudson, D. 1986. Evaluation of Coastal Erosion Processes for Recreational

Facility at Granville Bay, South Trinidad. Institute of Marine Affairs. Document prepared

for the Town and Country Planning Division, Ministry of finance and Planning.

Bachew, S, Hudson, D and Gerrard, A. 1983. An analysis of the Coastal Erosion Problem at

Los Iros Trinidad, West Indies. Institute of Marine Affairs. Document prepared for the

Town and Country Planning Division, Ministry of Finance and Planning.

Bachew, S, Joseph, P and Hudson, D. (nd). Hydrographic and Marine Geological Surveys of

Los Iros Bay, southern Trinidad. Institute of Marine Affairs..

Bertrand, Diane and Lewis, Neil. 1989. Beaches handbook of Trinidad. Institute of Marine

Affairs.

Cambers, J. 1998. Coping with beach erosion. UNESCO Coastal Management Sourcebooks 1,

UNESCO, 117 pp.

Chadwick. A, D. Reeve, C. Reeve. 2004. Coastal Engineering: Processes, Theory and Design

Practice. SPON.

Chrzastowski, Michael J. . 2005. Beach Features. In Encyclopedia of Coastal Science. Springer

Netherlands. Pp 145-147.

Darsan, J. 2005a. A comparative study of the coastal geomorphology of Cocos Bay and Las

Cuevas Bay, Trinidad. Caribbean Geography 14(2): 116-132.

Darsan, J. 2005b. A comparative study of the coastal geomorphology of Manzanilla and Las

Cuevas Bays, along the eastern and north-western coasts of Trinidad. Unpublished BA

Thesis., Department of Geography and Geology, University of the West Indies, Mona

Campus, Kingston, Jamaica.

Darsan, J. 2012. An analysis of the coastal geomorphology and evolution of Cocos Bay

(Manzanilla), Trinidad. Unpublished PhD Thesis., Department of Geography and Geology,

University of the West Indies, Mona Campus, Kingston, Jamaica.

Deane, C. 1971. Coastal Erosion Point Fortin to Los Gallos. Second Interim Report. 1971.

Government of Trinidad and Tobago, Ministry of Planning and Development and Ministry

of Works.

Didenkulova, I., A. V. Slunyaev, E. N. Pelinovsky, and C. Kharif. 2006. Freak Waves in 2005.

Nat. Hazards Earth Syst. 6, 1007–1015, 2006.

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Georges, C. (nd). The Physical Characteristics of Salybia, Vessigny and Los Iros Beaches.

Institute of Marine Affairs. Technical Report.

Georges, C., Hudson, D. and Bachew, S. 1986. The dynamics of the Erin Spit south Trinidad.

In Transaction of 11th Caribbean Geological Conference, Barbados.

Institute of Marine Affairs 1993a. Final Report: Coastal Erosion Protection Project, Station

Beach, La Brea, Trinidad.

Institute of Marine Affairs 1993b. Draft Final Report: Environmental Impact

Assessment/Feasibility Study for the Laying and Landing of Project Oxygen Submarine

cables in Saline Bay. Document prepared for the Telecommunication Services of Trinidad

and Tobago.

Institute of Marine Affairs 1999. Final Report: Environmental Impact Statement for the

Americas 1 Submarine Cable Project, Macqueripe Bay, Trinidad.

Institute of Marine Affairs 2002. Risks Posed to Leatherback Turtle Egg Clutches at Grand

Riviere Beach, Trinidad

Institute of Marine Affairs 2003. Final Report: Monitoring of Beach Stability and Sediment

Quality at Guapo Bay, Trinidad.

Institute of Marine Affairs Research Projects, 1995.

Institute of Marine Affairs, 2004. A Guide to Beaches and Bays of Trinidad and Tobago. Yara

Trinidad Ltd.

Institute of Marine Affairs, 2012. Status of Beaches and Bays in Trinidad (2004 – 2008).

Kenny, J. S. 1995. The Changing Coastline of the Cedros Peninsula, Trinidad. In Living World,

J Trinidad and Tobago Field Naturalist Club, 2002. 6pp.

Kenny, J. S. 1998. Trinidad and Tobago – Sinking or Swimming. Alternative explanation of

some natural coastal phenomena. Open Lecture Series University of the West Indies, St.

Augustine. 7pp.

Oostdam. B, 1984. Coastal egression and Transgression at the Junction of Serpent’s Mouth

and the Gulf of Paria Trinidad. Proc. 10th Carib. Geol. Confer., Cartagena, Colombia, p.

318-329

Saunders, J.B., 1998. Trinidad and Tobago Geological Map.

Sharp, J.M. Jr. and D.W. Hill. 1995. Land subsidence along the northeastern Texas Gulf coast:

Effects of deep hydrocarbon production. Environmental Geology. Springer Berlin /

Heidelberg. Volume 25, Number 3 April, 1995. pp 181 – 191.

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