St. Martin’s, a small continental island in the Bay of Bengal, is located on the southern most tip of Bangladesh separated from the mainland by a channel which is about 9 km wide. The distance between the island and Teknaf (the head of mainland) is about 34 km. It is said that in 1926, the District Collector of the British government Mr. Martin brought this island under settlement record following which the island was named “St. Martin’s Island”. Local people call this island “NARIKEL JINJIRA” because of large production of coconut in the island. The north portion of the island is called “Cheradia Dwip”, because during high tide, this portion of the island is separated from the other and also considered as the last southern landmark of Bangladesh (Fig 1)002E
Bio-geographic and scientific significance
St. Martin’s island is endowed with vast marine and land resources having a global biodiversity significance. The island is a good example of co-occurrence of corals, algae, sea weeds, grasses and mangroves. The island contains some of the most unique, but thus far not studied, benthic community association in Bangladesh, in fact not found any where else in the south Asia region.
It has been known from a study by Canadian coral biologist Dr. T. Tomasik in 1997 that notably the rocky sub-tidal habitat from the seaward margin to about 1000m offshore supports a diverse coral community represented by approximately 66 Scleractinian coral species, of which 19 are fossil corals, 36 are living corals and the rest are under families of subclass Octocorallia (11 species of soft corals).
A total of 234 species of fish have been recorded from the coastal water of St. Martin’s Island, of which 16 are fresh water species. Among the fish species, 89 are coral associated. The most abundant coral or reef associated fish are Damsel, Parrot, Surgeon, Groupers, Snappers, Emperors and Butterfly fish. The mollusk on the St. Martin’s is the largest and most beautiful in Bangladesh. 186 species of mollusk & oyster, 7 species of crab, 9 species of echinoderms, 4 species of sea urchin, 1 species of sea cucumber & some brittle stars were reported. A number of colourful nudibranch and Bryozoans were reported in adjacent area of the island.
There are confirmed records of 5 species of marine mammals in the sea surrounding the St. Martin’s Island as well as Bay of Bengal which are globally threatened according to the IUCN Red data book. The island has its fame as an important nesting ground for 3 marine turtles, including Olive ridly, all of them are considered as globally endangered by IUCN. So far, 14 species of algae have been recorded from the St. Martin’s Island. There is an estimated amount of 1500 MT red sea weed available around St. Martin’s Island. 29 reptilian species have been recorded from the island, of them 11 are locally threatened.120 species of birds have been reported from the island of which 67 species are resident and 53 migratory, many of them are in threatened list of IUCN. The economy of the local people of the island is based mainly on fishery. It is estimated that 1650 MT of fish are caught annually from the waters adjacent to this island.
At present there is a research in progress on St. Martin’s coral biodiversity and its associated fish fauna under DelPHE High Education partnership (UK-BD & PK.). Under that programme, there was an expedition held from 3-11th January, 2008 to St. Martin’s island by DelPHE research team.
During that expedition a total of 34 hard corals and 6 soft corals were collected from different places. Still work is going on for their cleaning, drying, preservation, identification, taxonomy, confirmation of identification upto species level etc. in the lab of IMSF, CU. in cooperation with overseas coral experts. Some of the under water photographs of hard and soft corals of St. Martin’s taken during diving of the present expedition can be seen in photos 2, 3, 4, and 5 respectively.
Coral associated fishes: The main attraction for any coral island is their different, varieties of multi- colour ornamental fishes. It has been reported that nearly 25%-40% of the world marine fish resources came from coral reef area. Reef area is also a major nutrients supplier for primary production in marine food chain. During our present investigation, we have collected 40 coral associated fishes. Majority are Damsel, Groupers, Parrots, Surgeon, Russ, Cardinal, Snappers, Butterfly, Angel and Swift lip fishes. Under water photographs of some coral associated fish fauna taken during the present investigation in St. Martin’s can be seen photos 6, 7, 8, 9 and 10.
It has been shown from the present investigation of DelPHE, that the abundance of coral associated fishes reduced drastically compared to Tomasik report (1997). In addition, it seems that, coral and other coastal biodiversities are also declining seriously. But to assess real status of St. Martin’s coral biodiversity and its associated flora and fauna, there need to be long-term and more in-depth studies.
Impact of uncontrolled tourism
There are nearly 7000 people on this small island of 12 sq. km. area. In tourist season (Nov.-Feb.) average 3000 people visit this island daily, which is beyond the holding capacity of this small marine island.
Besides this, there is regular big ferry services and engine boat, used for transportation of tourist, to the island (photograph 11). For this reason, a huge amount of crude oil, plastic and other non-biodegradable waste are discharged in the marine water adjacent to the island. In addition huge amounts of untreated market and domestic wastes, which include sewage matters (only 5% of the local people have sanitary latrine facilities) from the local people and tourists, are discharged into the adjacent coastal water. Thus the quality of coastal water is degrading gradually.
Coral, algae, different species of shells, star fish are collected by the tourists regularly. Local people also collect stone and rock daily for lime making and construction works, which is a threat for the existence of the island. Construction of multi-storied concrete building, hotel, motel, jetty etc. for the last few years are also posing a threat for this special type of island and its sensitive biodiversity, though that type development activities and construction have been stopped now by the government.
In addition to above factors, cyclones, storm surges, heavy fresh water run off during monsoon as well as other anthropogenic activities like over exploitation of coastal fishery resources, harmful boat anchoring practices instead of mooring buoy and uses of destructive fishing gear, mainly the use of rock weighted gill nets over the inshore boulder reefs is a prime aggravation and one of the main causes of death of the endangered rare turtle species, who came to lay their eggs considering this island as ideal nesting ground after crossing many hundred miles. Nearly everyday one/two big turtles are found dead by human activities in the coastal water of St. Martin’s island (Photo-13)
At present, there is not much data or information on the present status of corals and associated flora and fauna in St. Martin’s. No one is using currently available state of the art technology and no ‘Coastal Zone Management Unit’ exits in this island. So, proper implementation of the rules and regulations for ‘Ecologically Critical Areas (ECA’s)’, declaration and implementation of "Marine Protected Area (MPA)’ as suggested by Tomasik(1997) and other experts in ‘Eco-tourism — St. Martin’s Island’ by MoEF(GoB)(2004), control of pollution, sustainable and controlled tourism, alternative livelihood for the local people, and further research should be immediately undertaken for sustainable utilization and to save rich biodiversity of this only coral island of Bangladesh. Still there may be time to save the biodiversity and fish resources of this island, otherwise it may be too late. So, all the stakeholders including government policy makers should come forward to save the marine biodiversity of this important island and the livelihood of the local people.