Habitat value of artificial oyster reefs in the Chesapeake Bay

Shelley E. Sullivan, Mark W. Prinz, Lara D. Orensky, Daniel M. Dauer

Old Dominion University, Norfolk, VA

Outline

• Oyster reefs– History– Decline – Restoration efforts

• Objective• Collection

– Location– Methods

• Results – Taxonomic Composition– Reef Characteristics

• Discussion

Outline

• Oyster reefs– History– Decline – Restoration efforts

• Objective• Collection

– Location– Methods

• Results – Taxonomic Composition– Reef Characteristics

• Discussion

History of reefs

• History of reefs– Keystone species.– Dietary component Native Americans – Supported a major fishery in the Chesapeake since

colonial times. – Filtering capacity (the water of the bay every 3.3

days).– Present Oyster at 4% of the 1884 levels.

Causes for decline

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

1950

1952

1954

1956

1958

1960

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

1998

2000

2002

2004

2007

Year

Met

ric T

ons

of O

yste

rOyster harvest in Virginia

Reef Restoration in Virginia

Outline

• Oyster reefs– History– Decline – Restoration efforts

• Objective• Collection

– Location– Methods

• Results – Taxonomic Composition– Reef Characteristics

• Discussion

Objectives

• Value of oyster reefs as habitat • Measured using motile epibenthos

Outline

• Oyster reefs– History– Decline – Restoration efforts

• Objective• Collection

– Location– Methods

• Results – Taxonomic Composition– Reef Characteristics

• Discussion

Location

Southern Branch

Lafayette River

Western Branch

Eastern Branch

Location

Southern Branch

Lafayette River

Western Branch

Eastern Branch

Location

Southern Branch

Lafayette River

Western Branch

Eastern Branch

Location

Southern Branch

Lafayette River

Western Branch

Eastern Branch

• Creation of collection units– Provide habitat for crabs, shrimp, fish, and other

transient species– Collected at 2 week and 4 week intervals

COLLECTION METHOD

Sample Retrieval

Back at the lab

Reef characteristics Reef elevation

subtidal intertidal

Reef types mounds beds

Reef positions topmiddlebottom

Reef characteristics Reef elevation

subtidal intertidal

Reef types mounds beds

Reef positions topmiddlebottom

Outline

• Oyster reefs– History– Decline – Restoration efforts

• Objective• Collection

– Location– Methods

• Results – Taxonomic

Composition– Reef Characteristics

• Discussion

• 632 Individuals225 - Mud crabs 84 - Box crabs

10 - Other crabs105 - Fish 92 - Molluscs 77 - Shrimp

9 - Polycheates 6 - Amphipods

Taxonomic Composition

37%

14%17%

13%

2% 1% 1%15%

Intertidal Bed

Iinter/Subtidal Mounds

Subtidal Mound

Non Reef

Stress: 0.15

Species Composition

Subtidal Comparison:Diversity

0

1

2

3

4

5

6

7

Intertidal/Subtidal Mound Subtidal Mound Non Reef

Top Middle Bottom average

Subtidal Comparison:Number of Individuals

0

10

20

30

40

50

60

sub/intertidal mound subtidal mound Non Reef

top mid bottom avg

Subtidal Comparison:Biomass

0

5

10

15

20

25

30

35

40

45

50

sub/intertidal mound subtidal mound Non Reef

Bio

mas

s in

gra

ms

top mid bottom avg

Intertidal Comparison:Diversity

0

1

2

3

4

5

6

7

Intertidal 1 Intertidal 2 Intertidal 3 Non reef

Intertidal Comparison:Number of Individuals

0

5

10

15

20

25

Intertidal 1 Intertidal 2 Intertidal 3 Non Reef

Intertidal Comparison:Biomass

0

2

4

6

8

10

12

14

16

18

20

Intertidal 1 Intertidal 2 Intertidal 3 Non-reef

Bio

mas

s in

gra

ms

Reef Comparison:Diversity

0

1

2

3

4

5

6

7

Intertidal Bed Sub/Intertidal Mound Subtidal Mound Non Reef

Model I ANOVA P<0.0001Intertidal Bed Sub/Intertidal Mound Subtidal Mound Non Reef______________________________________ ______________

___________

Reef Comparison: Number of Individuals

0

5

10

15

20

25

30

35

Intertidal Bed Sub/Intertidal Mound Subtidal Mound Non Reef

Model I ANOVA P<0.0001Intertidal Bed Sub/Intertidal Mound Subtidal Mound Non Reef______________________________________ ______________

___________

Reef Comparison:Biomass

0

5

10

15

20

25

30

35

40

45

Intertidal Bed Sub/Intertidal Mound Subtidal Mound Non Reef

Model I ANOVA P=0.0002Intertidal Bed Sub/Intertidal Mound Subtidal Mound Non Reef___________ ____________________ ___________ ____________

SummarySubtidal Reefs have the greatest diversity, number of individuals, and Biomass

Intertidal Reefs have the least

Used by very different species

Older Reefs have greater numbers

Outline

• Oyster reefs– History– Decline – Restoration efforts

• Objective• Collection

– Location– Methods

• Results – Taxonomic Composition– Reef Characteristics

• Discussion

Discussion• Is there a benefit to establishing artificial

reefs for motile epibenthos?

Acknowledgements• Yolima Carr,

Hermitage Foundation

• Michael Lane - Statistical analysis

• Streett Coale, Virginia Zoo

• Anthony Rodi – Field work and Identification