Bay of Bengal 03

South patches located at 91.30ºE to 92.10ºE and 20.55ºS to 21.52ºS, having a total area of 3,662 sq km. Depth ranging from 10m to 100m, but 90% of the total area is less than 40m deep. Bottom sediment is sandy or slightly muddy sand. Nearest distance of the ground from Chittagong and Cox's Bazar is 40 km and 10 km respectively. Salinity in surface water ranges from 26% to 32% and 30% to 35% in bottom water. Water temperature varies between 20 and 28ºC.

South of south patches located at 91.30ºE to 92.20ºE and 20.15ºS 20.50ºS, having an area of 2,538 sq km. The nearest boundary of this area is 5 km from Teknaf. Depth ranges from 10m to 100m. Within this ground 75% of the area is more than 40m deep. Bottom is sandy or muddy sand. Surface salinity ranges from 18% to 34% and bottom water salinity from 28% to 38%. Water temperature ranges between 22ºC and 30ºC.

Middle ground located at 90.20ºE to 91.30ºE and 20.25ºS to 21.20ºS, having a total area of about 4,600 sq km. The nearest distance from Cox's Bazar is about 65 km. The depth of 70% of the total area is more than 40m. Bottom sediment is soft mud or muddy sand. Surface salinity ranges from 22% to 34% and bottom salinity 28% to 35%. Water temperature is between 26ºC and 28ºC.

Swatch of no Ground located at 89.35ºE to 90.10ºE and 20.55ºS to 21.55ºS, about 30 km away from Dublarchar and 40 km from Sunarchar. Total area is about 3,800 sq km, of which 70% is more than 40m deep. Overall depth of the area ranges from 10m to 100m. Bottom sediment consists of muddy sand. Surface salinity is 28% to 34%, while the bottom salinity is 30% to 35%. Water temperature falls within 24ºC to 30ºC.

All these fishing grounds are potential reserves for fish and shrimp. Most of the known commercial species of shrimps and fishes are harvested from these areas by trawlers or mechanized fishing boats. Commercially important shrimp and fish species include tiger shrimp, karuma shrimp, cat fish, Bombay duck, snapper, flounder, Indian salmon, crocker, seabream, jawfish, mullet, pomfret, ribbon fish, anchovy, hilsa, oil sardine, tuna, mackerel and skipjack. [Hossain Zamal]

Pollution marine environment of Bangladesh is directly or indirectly becoming polluted due to addition of so many polluting agents. To protect water pollution and control of mine drainage, large scale drilling and production of natural gas from the Sangu offshore gasfield, discovery of Kutubdia offshore gasfield and exploration of beach sand placer deposits from the offshore islands of Chittagong and Cox's Bazar districts must follow standard regulations both from mine safety and environmental protection point of view. Sangu gasfield is located about 50 km southwest of Chittagong City and stands at a depth of 10m water in the Bay of Bengal. Kutubdia gasfield is about 92 km southwest of chittagong port.

The coastal environment of Bangladesh is contaminated by oil tanker traffic, harbour operations and effluents discharged from petroleum processing. sewage disposal by the karnafuli and pasur rivers into the Bay of Bengal contains higher concentration of Biochemical Oxygen Demand (BOD) and foecal coliform. Moreover, the coastal environment of Bangladesh has also been affected by industrial effluents, agricultural residues, some other human activities like deforestation and irrational expansion of coastal shrimp farming, etc resulting in ecological degradation. Overfishing and dumping of discarded fishes in these areas are becoming a threat to the resourcefulness of the fishing grounds. Only proper management of the existing grounds and finding of new fishing grounds can ensure the continuous harvest of fisheries resources. [Sifatul Quader Chowdhury]
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