Status of the squid jigging fishery using biodegradable fish aggregating devices (FADs) in Palk Bay and the Gulf of Mannar, south-east coast of India

Abstract

This study reports the use of six different plant species as fish aggregating devices (FADs) along with FRP-coated PUF (polyurethane foam) floats, for squid jigging operations in Palk Bay and the Gulf of Mannar, south-east coast of India. The annual average cephalopod landings obtained by squid jigging during 2010-2021 was 1948 and 414 t in the Gulf of Mannar and Palk Bay, respectively. Fishing is carried out at a distance of 6-10 nm (nautical miles) from the shore, at 13-25 m depth in the Gulf of Mannar, whereas in Palk Bay fishing is done at 4 and 6 nm and depths of 5-8 m. The jigs are deployed directly from the vallam/FRP (fibre-reinforced plastic) boats or using small thermocol (polystyrene) floats and FRP  coated PUF  floats. Whole plants or branches of locally available plant materials are used as FADs. The peak fishing seasons fall during April-June and August-September. The annual average Landings per Unit Effort (LPUE) and Landings per Hour (LPH) for cephalopods during 2010–2021 were 13.37 kg unit^-1 and 2.86 kg  h^-1 in Palk Bay, whereas in the Gulf of Mannar,  the estimates were 9.5 kg unit^-1 and 1.7 k /h^-1. The major species contributing to the squid jigging fishery in Palk Bay were Sepioteuthis lessoniana, Acanthosepion pharaonis, Sepioteuthis prabahari and Amphioctopus aegina., whereas A. pharaonis, S. lessoniana and Octopus cyanea dominated the fishery in the Gulf of Mannar. A. pharaonis was the dominant species in both regions.

Keywords: Cephalopods, Fishing season, Landings per hour, Landings per unit effort, Polyurethane foam float