Dr. Md. Abdul Quader
Professor
Institute of Marine Science
University of Chittagong
Bangladesh has a coast line 480 km long. The territorial limit of the country is 19.31 km (12 miles) measured seaward from the base line at 18.29 m (10 fathom) depth contour. The exclusive economic zone is 321.87 km (200 miles) seaward from the base line. According to the survey conducted by FAO research vessel “Dr. Fridtj of Nansen” in 1979–80, the whole continental shelf area of Bangladesh from 10 m to 200 m depth contour is about 40,000 (4 × 104) Sq. Km., while the area of shallow region up to 10 m depth is about 24,000 (24 × 103) Sq. Km. (Shahidullah 1983).
The Bay though offers a potential source of fisheries for Bangladesh. The surveys conducted by different national and international research vessels from 1958–1986 charted 4 major fishing grounds in the Bay of Bengal (Shahidullah 1983; personal communication). The surveys detected rich plankton, shrimp larvae and shrimps and plentiful commercial fishes in the Bay of Bengal. The fishes found sufficient for commercial exploitation were: shad (Hilsa), mackerels, pomfrets, Indian salmon, catfish, eel, croakers and snappers. A total of 490 species of fish belonging to 133 families were recorded and out of these 65 species are of commercial importance (Hossain, 1971). Out of 19 species of shrimps/prawns commonly available in the area (Chowdhury & Sanaullah 1991) 6 species viz. Penaeus monodon (tiger shrimp). P. indicus (white shrimp), P. merguiensis (banana shrimp). P. semisulcatus (green tiger shrimp), Metapenaeus monoceros and M. brevicornis (brown shrimp) are found in abundance. 6 species of lobsters were also identified and out of these only Panulirus polyphagous and Scyllarus nearctus are found commonly. Large number of zooplanktons were also identified of which about 15–20 species of copepoda are dominant species. Besides these, shrimp larvae, crab larvae, fish eggs and larvae, euphosids, uropods and Chaetognaths are found in abundance.
Other than shrimps and oysters about 50 species of crabs have been identified. Of these, Scylla serrata, Portunus pelagicus and P. sanguinolentus are commercially important. Their standing stocks have not been assessed and very little is known about their status of exploitation.
7 species of squids and 2 species of cuttle fish or sepia have been recorded from the Bay of Bengal (Quddus and Shafi 1983). But is known of their stock sizes, spawning seasons or fecundity. 3 species of turtles viz. Caretta caretta, Chelonia sp. and Dermochelys sp. of commercial importance (FAO 1990) have been recorded from the area but their stock size, spawning seasons and fecundity have not yet been studied.
165 species of algae have been recorded from around St. Martin's Island, Sunderban area and the coastal areas of Chittagong (Islam 1976). Most of these are red algae while 10 species of dinophyceae, 2 species of cyanophyceae and about 64 species of diatoms have been recorded as floating flora. Many of these algae are commercially important and may be used as human food, fodder, paste, jelly and medicine.
17 species of algae may be used for extraction of antibiotics. The biomass of these algae and diatoms constituting the primary productivity of the area has not yet been estimated.
The standing stock sizes of the Bay of Bengal as assessed by Penn in 1982–83 are as follows:
| Variety | Standing stock (in tons) | Maximum annual harvestable stock (in tons) | |
| a. | Demersal fish | 2 × 105–2.5 × 105 | 105–1.25 × 105 |
| b. | Pelagic fish | 1.6× 105–2 × 105 | 3×104–6 × 104 |
| c. | Shrimp | 4 × 103–6 × 103 | 2×103–3 × 103 |
He also estimated 10,360 Sq.Km. as the effective fishing area for marine fish and 5,180 Sq.Km. for shrimp.
The standing stock size of the areas from 10 m down to 200 m depth has been estimated but the standing stock size of the area up to 10 m depth were not possible to assess due to the operation of the set beg nets, gill nets etc. However the R.V. Machranga of the Directorate of Fisheries is engaged for assessing stock.
Suggestions for Proper Management:
For proper management and utilization of marine resources the following steps are suggested:
The stock of each individual species should be assessed;
The yearly/seasonal growth, recruitment, fecundity, spawning pattern, and mortality should be estimated;
Indiscriminate killing of seed fish and shrimp should be banned;
Fishing during spawning period should be stopped;
Wild shrimp collection should be regulated so that it does not affect the stock in the sea;
Fishing at MSY levels should be allowed through imposition of regulatory measures on the number of boats, gears and mesh size;
Mariculture should be encouraged through adequate feed and seed supply;
Feed should be formulated with indigenous raw materials;
Seaweed culture should be encouraged;
The sea and its estuaries should be protected from pollution;
References:
Chowdhury, Z.A. and M. Sanaullah (1991). A check list of the shrimps/ prawns of the Maheshkhali Channel, Cox's Bazar. Bangladesh J. Zool. 19 (1) : 147–150.
FAO (1990). FAO Fisheries synopsis 11 (125), sea turtles of the world. FAO species catalogue FAO, Rome.
Hossain, M.M. (1971). The commercial fishes of the Bay of Bengal (survey for the development of fisheries, East Pakistan, chittagong) UNDP Project publ. No. 1 PAK 22:1–6.
Islam A.K.M.N. (1976). Contribution to the study of the marine algae of Bangladesh, Biliotheca phycologica, J. cramer (Ed.) Band 19. pp 1–253.
Quddus, M.M.A. and M. Shafi (1983). Bangupshagerer Matsya Shampad. Bangla Academy.
Shahidullah, M. (1983). Review of the exploratory surveys undertaken to assess the marine fisheries resources of Bangladesh and the present status of exploitation, Directorate of Fisheries, Marine Fisheries Dept:, Chittagong pp 1–33.
