Presentation by

Livi Wilson

Ph.D Scholar

Biodiversity of Gulf of Mannar

Gulf of Mannar large shallow bay

lies between the southeastern tip of India and the west coast of Sri Lanka.

The estuaries of Thamirabarani River of south India and the Aruvi Aru River of Sri Lanka drain into the Gulf.

GEOGRAPHICAL LOCATION

Palk Strait

Palk Bay

Adam’s Bridge

Gulf of Mannar

About gulf of mannarSome features:1986- declared the Gulf of Mannar Marine National Park.

1989-The park and its 10 km buffer zone were declared a Biosphere Reserve

First marine Biosphere Reserve in South East Asia, a chain of 21 islands (10,500 km²)

Home to 3,600 rare Species of flora and fauna like fishes, coral reefs, sea horse, algae, marine plants

The islets and coastal buffer zone includes BeachesEstuaries Tropical dry broadleaf forests

The marine environments include Seaweed communities Sea grass communities Coral reefs Salt marshes Mangrove forests

Gulf of Mannar reefs lie along the 140 km stretch between Tuticorin

and Rameswaram latitude 8°47' N and 9° 15' N longitude 78° 12' E and 79° 14'E. Mannar Barrier reef which is about 140 km

long and 25 km wide between Pamban and Tuticorin

The islands have fringing coral reefs and patch reefs around them

Total area occupied by reef and its associated features is 94.3 sq km.

Reef diversity and resources

96 species of corals belonging to 36 genera

The most commonly occurring genera of corals are Acropora, Montipora and Porites.

the reefs also harbour boring sponges, molluscs, worms, echinoderms, common shrimps, and fish

ornamental fishes belonging to the family Chaetodontidae,(butterfly fish); Amphiprion spp (clown fish), Holocentrus spp (squirrel fish), Scarus spp (parrot fish), Lutjanus spp (snapper fish) and Abudefduf saxatilis (sergeant Major) are abundant. (Kumaraguru, 1997).

Extensive sea grass beds are present; green turtles, olive ridleyturtles and dugongs are dependent on the sea grasses.

A unique endemic species of Balanoglossus, a living fossil that is considered a link between vertebrates and invertebrates was recorded from this region.

Annual productivity in coral reefsbeing 2000-5000 gc/sq.m/yr.

Sea Grass Ecosystem

the sole marine

representatives of the

Angiospermae

feeding grounds of the

herbivores Green Turtle

and the sea cow

Sea grass binds

sediments and prevent

erosion.

Of the 52 species of sea

grasses recorded

worldwide, 12 species

are recorded in Gulf of

Mannar.

Sea grasses absorb

sediments thereby

Mangrove Ecosystem

salt tolerant forest ecosystems, which support

fisheries and protect the coastal zones, thus

helping the marine coastal economy and

environment.

9 species and 7 associated species were found in

Gulf of Mannar.

The two common mangrove species Rhizopora

sp and Avecinia sp.

Dolphins are a common in some parts of the Gulf.

Thousands of migratory olive ridley sea turtles pass through the Gulf to their mass nesting or arribada in Gahirmatha Orrisa.

The Krusadai Island in the Mandapam Group of islands is of biological significance in this area due to its diversity.

due to destructive fishing and pollution, coral reefs, dolphins, Dugongs (Dugong Dugon), whales and sea cucumbers are among the species which figure in the endangered list

Overall diversity

Families Species

Phytoplankton 126Zooplankton 360Forominifera 51Sponges 275Corals 128Gorgonids 14Polochaeta 75Nematoda 9Crustacea 368Molluscus 731Echinodermata 264Hemichordata 1Capture fishes 441Ornamental fishes 100Sea turtles 5Sea weed 147Sea grass 52Mangroves 16

Fishery Resources

Marine capture fisheries are the major economic

activity in Gulf of Mannar

441 species have been recorded in Gulf of

Mannar.(2,200 fish species distributed in Indian

waters)

Gulf of Mannar is one of the best regions in the

Indian subcontinent in fish biodiversity richness.

Shore seines, boat seines, trawl nets and hook

lines are the principal gear operated.

Setusamudram

Advantage

s1.Saving of upto 30 hours or 424 nautical miles

2. Considerable savings to vessels and earnings of foreign exchange.

3. Beneficial for naval defence4. Increased economic activities like

transportation, fishing and ancillary industries

5. Augmentation of external infrastructure like road/rail, water & water supply

6. A stable system with least maintenance cost

Environmental Aspect

Some of the flora and fauna of this region

Extinction of more than 700 fish

varities

More susceptible to future cyclone and

tsunamis

Disastrous effect on marine life,

fisheries, virgin beaches in case of an

accident

Whether to go for short term financial

gains or long term ecological balance

?

Biodiversity of the Gulf Of Kutch

The Gulf of Kutch is situated in Saurashtra in the western State of Gujarat in India.

separates the landmass of Saurashtra from the northern landmass of Kutch.

shallow water basin about 60 m deep at the mouth, sloping up to a depth of less than 20 m at the head, visited by 'mixed semidiurnal' tides

Gulf of Kutch Marine National Park

It is the first national marine park in India.

situated on the southern shore of the Gulf of Kutch in the Jamnagar District of Gujarat state.

1980-an area of 270 km2, from Okhato Jodiya was declared Marine Sanctuary.

1982-a core area of 110 km2 was declared Marine National Park under the provisions of the Wildlife (protection) Act(1972)

Contd..

Protected areas include about an archipelago made up of

42 islands.

fauna found here: coral, dugong and the finless porpoise.

Biodiversity and Conservation challenges:

extraction of corals and sands by cement industries,

increased turbidity of water, oil refineries, chemical

industries and mechanized fishing boats.

Biodiversity Excellent Coral Reefs 37 species of Hard & Soft Corals 70 species of Sponges 27 species of Prawns 30 species of Crabs 200 species of Molluscs Endangered Sea Turtles like the Green Sea, Oliver

Riddley& Leather Back. 3 Speices of Sea Mammals 94 species of Water Birds 78 species of terrestrial birds 108 species of brown, green & red Algae

Coral Reefs fringing reefs, platform reefs, patch reefs and

coral pinnacles. There are some 40 islands with patchy coral

formation of which the largest is Pirotan Island. 37 species of hard corals 12 species of soft corals the total reef area in the Gulf decreased from

217 sq km in 1975 to 123 sq km in 1986; a net loss of 43 per cent

Coral dredging by a cement company is held to be largely responsible for the heavy siltation

Locality Genera species

Gulf of Kutch* 24 37

West Coast Patches* 17 29

Lakshadweep Islands 37 103

Palk bay and Gulf of

Mannar

36 96

Tuticorin 19 21

Andaman Islands 31 82

Nicobar Islands 43 103Total for India* 37

199

Source: Bakus, G.J (1994) and * Pillai, G (1996).coral

Mangroves Jamnagar District has an area of 665.9 sq km

mangrove cover

predominantly of scrubby and sparse type

Mangrove species such as Rhizophora, Ceriops

and Aegiceros, which are reported to have once

existed in the region, are now rare, while the

species Bruguiera is extinct

Since the early 1990s, mangrove cover has been

increasing in Gujarat, from 397 sq km in1991 to

960 sq km in 2003.

- Jamnagar and Kutch - contributed to more than

90 per cent of the overall increase in mangrove

cover.

Fisheries Jamnagar contributed 10.01 per cent of the total marine

fish production in the State.

W. Pomfret

B. Pomfret

Bom. Duck

Thread fin

Jew fish

Hilsa

Clupeids

Coilia

Shark

Malabar upwelling

Upwelling occur where the wind blows parallel to a coastline.

divergence draws water from below into the surface Ekman layer in a process known as upwelling

Upwelling in coastal waters brings nutrients toward the surface.

Phytoplankton reproduce rapidly in these conditions, and grazing zooplankton also multiply and provide abundant food supplies for nekton.

Some of the world’s richest fisheries are found in regions of upwelling—for example, the temperate waters off Peru

Upwelling in these regions cools the surface

water and brings nutrient-rich subsurface water

into the sunlit layer of the ocean, resulting in a

biologically productive region.

The Malabar upwelling zone along Kerala coast

(south-west coast of India) is one of the important

upwelling systems of the world (Bakun et al.,

1998)

The Malabar coast of India is rich in primary (660

mg C m2/ day) and secondary (10–57 mgC m2

/day) production and contributes nearly 50% of

the total Indian marine fish landings

(Vivekanandan et al., 2003; Smith and

Madhupratap, 2005)

Field and satellite-derived oceanographic data

have shown that coastal upwelling occurs during

July–September with a peak in August resulting in

high nutrient concentrations and biological

productivity along the coast.

The striking feature of the Malabar upwelling

zone is the predominance of pelagic resources

such as oil sardine (Sardinella longiceps) and

Indian mackerel (Rastrelliger kanagurta)

The catch of small pelagics, especially that of the oilsardineincreased from1, 554 t in 1994 to 2,50, 469 t in 2007 in the Malabar upwelling zone off Kerala, India.

The coastal upwelling index (CUI) during south-west monsoon increased by nearly 50% during the period 1998 to 2007.

This substantial increase in coastal upwelling index elevated chlorophyll a concentration during monsoon which resulted in an increase of over 200% in annual average chlorophyll a concentration.

The increasing coastal upwelling index and chlorophyll a during monsoon sustained an increasing catch of oilsardineduring postmonsoon season.

The responses of lesser sardine and Indian mackerel, which are midlevel carnivores, were different.

The prawn fishery is supported chiefly by

Melapenaeus dobsoni (Poovalan chemmeen).

Parapenaeopsis stylifera (Karikkadi chemmeen)

and Penaeus indicus (Naaran chemmeen) also

occur in smaller quantities.

In the case of M. dobsoni, sizes ranging between

90-105 mm dominate in the fishery.

References Influence of coastal upwelling on the fishery of small pelagics off

Kerala, south-west coast of India

U. MANJUSHA, J. JAYASANKAR, R. REMYA, T. V. AMBROSE AND E. VIVEKANANDAN

The Gulf of Kutch Marine National Park and Sanctuary: A Case Study By Nilanjana Biswas

Coastal an marine wetlands of India by K.Venkataraman

Resources information system for Gulf of MannarGovernment of India

Environmental Impact Assessment for Proposed SethusamudramShip Canal Project Tuticorin Port Trust