327 Bycatch from Trawlers with special reference to Its Impact on Commercial Fishery, off Mangalore A.P. Dineshbabu 1 *, Sujitha Thomas 1 and E.V. Radhakrishnan 2 Mangalore Research Centre of CMFRI Post Box No. 244, Bolar, Mangalore - 575 001 Dakshina Kanara, Karnataka, India 2 Central Marine Fisheries Research Institute, P.O. Box 1603, Cochin - 682 018, Kerala, India *E-mail: dineshbabuap@yahoo.co.in Introduction Trawling, though one of the most efficient methods of fish capture, is also found to be the most important human caused physical disturbance on the world’s continental shelves and hence the physical destruction of ecosystems (Jennings and Kaiser, 1998). Trawl fishery is generally a mixed fishery, targeting a number of species and sizes, simultaneously. Discarding is the practice of returning an unwanted section of the catch back to the sea during fishing operations (Alverson, 1994; Van Beek, 1998; Hall, 2000). Discards not only include non-commercial species, but also commercial species that are below minimum landing size (MLS) or less profitable species owing to market conditions and quota restrictions (Catchpole et al., 2005). The resource damage due to discarding of the bycatch has been taken seriously by international bodies like FAO and during the past decade, a decline in global discards has been observed in the major world fisheries due to decline of catches with high discards rates, greater utilisation for human consumption and the progressive attitude by fisheries managers, user groups, and society towards the need to resolve the bycatch problem (FAO, 2004). Boopendranath (2007) has reviewed the studies on bycatch and discards from the Indian waters. Sivasubramanyam (1990) observed that shrimp bycatch in Visakhaptnam is constituted by 85 species and Gordon (1991) estimated that 25-30% of discards comprised of juvenile shrimps along the Visakhapatnam coast. BOBP study indicated that the quantity of bycatch discarded by the east coast trawlers have been 0.1-0.13 million t,