Need to regulate the thalluvalai fishery along Palk Bay, southeast coast of India

Abstract

Along the coast of Palk Bay the juveniles of the green tiger prawn Penaeus semisulcatus are indiscriminately exploited from the nursery ground by the artisanal gear thalluvalai round-the-year except during the 45-day ban period. Studies on the thalluvalai fishery from one of the fishing villages namely, Thirupalaikudi was carried out during the years 2006-08. The fishing ground where the net is operated comprise mostly of seagrass and seaweed beds, dominated by the seagrass Cymodocea serrulata, serving as a potential nursery ground for the juveniles of P. semisulcatus. The estimated monthly landings of P. semisulcatus by thalluvalai at Thirupalaikudi landing centre fluctuated with an average of 3.4 t, the maximum of 10.0 t observed in March 2007. It was found that a large number of females constituting a significant proportion were exploited before the first spawning. The total number of immature females was estimated at 3.9 million constituting on an average 85.4% of the total number of females landed by thalluvalai. Juvenile females measuring less than 100 mm in total length contributed 39.1% of the total landings of females. The size composition of P. semisulcatus landed by thalluvalai was compared with that landed by trawlers and gillnets operated in the Palk Bay.