Environmental Hazards and Conservation Approach to the Biodiversity and Ecosystem of the St. Martin’s Island in Bangladesh - Management of Natural Resources in a Changing Environment - page 252

Status of Floral Diversity in St. Martin's Island Status of Faunal Diversity in St. Martin's Island

Mammals

Marine Algae

Birds

Amphibians

Trees

Reptiles

Shurbs Fishes

Carbs

Climbers

Mollusks

Echinoderms

Herbs

Corals

0 50 100 150 200 0 50 100 150 200 250

Number of recorded species Number of recorded species

Fig. 2 Number of recorded species of fl oras and faunas in St. Martin's Island ( Source : Tomascik
1997 ; Quader 2010 ; UNDP 2010 )

The following mangrove species are found in the leftover scrap of mangrove
forest: Acanthus ilicifolius , Hibiscus tiliceous , Sonneratia apetala, Excoecaria
agallocha , Avicennia marina and Clerodendrum inerme (Tomascik 1997 ). Aegialitis
rotundifolia , an early coloniser, has disappeared from the island (UNDP 2010 ).
So far 154 species of marine algae have been identifi ed, largely from the island's
inter-tidal and littoral zone (Tomascik 1997 ). Marine algae form an important source
of nutrients for the myriads of animal life in the sea (Fig. 2 ).

Faunal Diversity

A total of only nine species belonging to eight genera in four classes of the phylum
Echinodermata have been identifi ed to species level from the island, these comprise
four species of sea urchin, one species of sea star, three species of nudibranchs, and
one species of sea cucumber (Tomascik 1997 ).
Due to its suitable environment, St. Martin is the only spot in Bangladesh where
coral colonies are found. Coral communities extend to about 200 m offshore of the
island (Islam and Islam 2008 ). A total of 66 coral species were recorded, of which
19 are fossil corals, 36 living corals and the rest are under six families of subclass
Octocorallia (soft corals) (Tomascik 1997 ). The genera Porites, Favites, Goniopora,
Cyphastrea and Goniastrea are the most abundant. The soft coral community off the
east coast of St. Martin's Island is a unique feature of the subtidal zone (Islam and
Islam 2008 ).
A total of 187 species of mollusks have been recorded from the island, among
which 44 species are gastropods and the rest are bivalves. Tomascik ( 1997 ) reported
the presence of some economically important gastropods which at that time were
abundant, e.g. Conus striatus , Conus textile and Conus geogrphes , and also two
economically important gastropods, Trochus niloticus and Turbo marmoratus that
are heavily depleted worldwide.
About 12 species of crab have been recorded from the island, including
commercially important crab species such as the mangrove crab Scylla olivacea ,