Live Grouper Fisheries and Population Assessment Using Fishery-Dependent and Non-Fishery-Dependent Indicators: Northwest Sulu Sea, Philippines

Abstract

The LRF in the Philippines started in the 1970s. The influx of traders and fishers to the Calamianes Islands contributed to the overharvest of groupers in the area. While LRF in the southwest of the Sulu Sea started in Talakanen Island, Taytay Bay, in 1997, the “Boom and Bust” trend in fisheries threatens the populations of target valuable species due to overharvesting. Survey studies are essential for fisheries management, but only a few studies were conducted in the West Sulu Sea. This study aimed to document the LRF of the Northwest Sulu Sea and use fisheries dependent and non-fisheries dependent methods to assess the population of P. leopardus in the area. Fisheries dependent and non-fisheries dependent methods were used to determine CPUE, population size structure, abundance, and composition of grouper LRF species. The fishing grounds of LRF were in the inner portion of the bay during Northeast Monsoon, while extended to outer portions during Southwest Monsoon. Three kinds of handlines were used to catch groupers: Sibid, Undak, and Latak. The duration of fishing was categorize as Sibid (half-day), Balikan (within the day), and Dayo (multiple days). There was a low number of mature P. leopardus in the area. Twelve species of serranids compose the LRF. The average size of P. leopardus significantly decreased from 33.5cm in 2010 to 16.0cm in 2015. The CPUE of P. leopardus remarkably decreased from 89.0g in 2010 to 25.0g per hour/fishers in 2015. The population of P. leopardus in the Northwest Sulu Sea showed signs of depletion. Keywords : species management, length and weight conversion, live food fish.