Coastal Aquaculture and Mariculture

Unit 6- Crustaceans

6.4.3. Mode of exploitation
Mostly (75%) lobster is caught as bycatch by the shrimp trawlers. Along the northwest coast 95% of the lobsters; appear in trawls, whereas on the southwest coast, indigenous gears such as traps, gill nets and trammel nets are used for shallow water lobster fishing. On the southeast coast, lobsters appear both in the trawls as well as in the indigenous gears. On the northwest coast, lobsters are caught incidentally in trawl nets operating for shrimps at Veraval. P. polyphagus constitutes 45% of total catch and the rest is by T. orientalis. In Mumbai, P. polyphagus constituted 54% and the rest was contributed by T. orientalis. P. polyphagus is available round the year. On the southwest coast, lobsters are fished in almost all the fishing villages starting from Kollam to Kanyakumari. Nearly 90% of the catch is constituted by P. homarus; Total landings gradually declined from 301 t in 1966 to 8 t in 1995-96. The fishery is seasonal and extends from August to May with peak catches from November to January. Fishing season coincides with peak breeding season (November-December) and the major portion of females caught during this period is egg bearing. Increase in fishing effort, exploitation of juvenile lobsters by trammel net and heavy exploitation of ovigerous females have led to overall decline in the landings. In Chennai, lobsters are landed both by trawls and artisanal gears. 92% of the small trawlers catch was constituted by T. orientalis. 68% of the gillnet catch was constituted by P. homarus, followed by P. ornatus (18%) and P. versicolor( 13%). 50% of the lobsters caught in trammel net are below 55 mm (Carapace Length). The spiny lobster, P. sewelli is the only deep sea species exploited for commercial purpose. During 1998-2000, an average 524 t of deep sea lobsters were landed at Cochin and Sakthikulangara. The maximum sustainable yield (MSY) was estimated to be 8000 t for the west coast and 1200 t for the east coast.