Alarming signs detected in the small pelagic fishery on the west coast of Sri Lanka

Abstract

Abstract Small pelagic fishery particularly on the west coast plays a vital role both in terms of livelihood and food security in Sri Lanka. The present study was carried out using the time series data on the west coast representing four fisheries districts; Kalutara, Colombo, Negombo, and Chialw of 2001–2020 extracted from the Small Pelagic Database of the National Aquatic Resources Research and Development Agency, Sri Lanka with an aim of exploring the present status of the fishery. The target fish groups in the fishery include sardines, herrings, anchovies, and mackerels which are mainly caught by outboard engine fiber-reinforced plastic boats with a wide mesh size range of gillnets. The recent five-year landings data indicated that the highest average Catch per Unit Effort (CPUE) occurred during the onset of the southwest monsoon and extended until the end of the northeast monsoon. During the recent decade, the CPUE of fishery exhibited greater inter-annual fluctuation, with an average of 66.7 ± 17.3 kg per trip. Moreover, the Mean Trophic Level (MTL) of the coastal fish landings ranged from 3.13 to 3.62 over the past two decades with the lowest record in 2014. The average MTL value forecast for 2022–2026 will be 3.38. Among the key stocks, Amblygaster sirm showed a diminishing trend in relative contribution and catch rate. Declining catch trends of key target species allied with the same trend in MTL could be considered as alarming signals which are indicating concerning implications for management strategies.