India Palk Bay blue swimming crab - gillnet

The FIP is targetting blue swimming crab (Portunus pelagicus) from the Palk Bay region of the Tamil Nadu coast in India.

The fishing gear is gill net (nandu valai). Each “nandu valai” is about 1000 m long with 40-50 joints and 80-100cm in height and weighs about 55 Kg. The netting is made of high-density nylon mono-filament with a stretched mesh of 90-110 mm. The head rope is nylon with a 1.5 cm in thickness and small floats are attached at intervals of about one and a half feet or marked by a flag and the footrope is with small sinkers. Each weighs about 20g and in one complete stretch of the net, a total of 350 numbers of sinkers are there weighing about 7kg in total weight (BSC FMP). The crew on each fishing boat deploying gillnets at sea, tie several nets (also called gillnet joints) end to end forming a long chain so that they cover a considerable area at sea (e.g. Devipattinam - 12 nets x 70 meters used in OBBSGN). 

The crafts involved in the fishery are classified as Outboard bottom set gillnets (OBBSGN), Nonmechanised bottom set gillnets (NMBSGN), Inboard bottom set gillnets (IBBSGN) and Outboard gillnets (OBGN) (Srinath et al., 2005). The crafts employed for gillnet operation include catamarans, plank-built boats, dugout canoes, and fiberglass coated plywood boats. Motorization of the gillnet crafts, by fitting inboard or outboard engines is also reported, and in recent years’ fiberglass boats with an overall length range of 6-10 m are more commonly used for deploying fishing gears. 

The Blue Swimming Crab (BSC) gillnet fishers in Palk Bay operate under an open-access regime that is based on a top-down management approach with several applicable laws at Federal, State & District levels. Gillnets locally called “Nandu valai” primarily target Portunus pelagicus which comprises more than 98% of the crab landings (CMFRI 2018) with the remaining 2% comprised of Portunus sanguinolentus and Charybdis natator species. BSC fishery in Palk Bay is managed by Tamil Nadu State Fisheries Department (DoF) which issues licenses for fishing boats and applies several management measures (3 days: 4 days Rule for mechanized boats, a token system for trawlers, etc.) to mitigate conflicts between various actors (fishing boats and trawlers). A good account of the management history, fishing practices, historical fishing levels, and other resource attributes in Palk Bay is provided in Stephen et al, (2013); Salagrama (2014); and CMFRI (2018) reports.