ESTIMATION OF JUVENILES IN TRAWL FISHING ALONG MUMBAI COAST, MAHARASHTRA

Trawl fishery contributes more than 50% to the total marine fish production of India. However, trawling is a highly controversial method as it produces more discards including juveniles due to its non-selective nature. The indiscriminate exploitation of juvenile fishes in any fishery leads to both biological and economic unsustainability in the ecosystem. Mumbai contributes 50.4% and 51% to the marine capture fish production and trawlers in Maharashtra.  In this context, experimental fishing was carried out fortnightly from September 2017 to May 2018 in M.F.V NARMADA, training cum research vessel of CIFE by using shrimp trawl net (30 mm mesh size) to estimate the percentage of juveniles from trawl catch along the Mumbai coast. Fishing operations were conducted between 19°12'15.09"N to 18°57'37.50"N latitude and 72°40'23.20"E to 72°43'35.60"E longitude. During the experimental fishing, 25 hauls, each of 1 hour duration were carried out in the depth range of 6 to 21 m, at trawling speed of 1.5 to 2.5 knots. Average juvenile percentage per haul was estimated at 40%, followed by discard catch of adult fishes (35%), commercial catch of adult fishes (23%) and marine debris (2%). Of the total estimated 235.80 kg juveniles, 56.10% was contributed by commercial catch and 43.90% by discards. Juveniles of major commercially important species including Coilia dussumieri (17.30%), Otolithoides biauritus (7.70%), Johnius glaucus (6.10%), Johnius belangerii (5.80%), Parapenaeopsis stylifera (4.80%) and Uroteuthis duvaucelli (3.50%) were also recorded. Adults of non-conventional resources like Charybdis callianassa, Trypaucehen vagina, Odontamblyopus roseus, Lagocephalus inermis, Minous inermis, eels, stomatopods, etc. comprised the discarded catch. It emerged from this study that trawl fishery exploited huge quantities of juveniles of conventional and non-conventional fish resources along the Mumbai coast. Findings of the study highlights the need for regulating trawl fishery.