Population dynamic and spawning potential ratio of long-barbel sheatsfish (Kryptopterus limpok) itasik giam siak kecil waters, bengkalis, riau province, indonesia

Intensive exploitation due to high market demand of long-barbel sheatsfish (Kryptopterus limpok), locally known as “selais fish”, has continuously occurred throughout the year, so that it could threaten resources sustainability. Scientific assessment on population dynamic and spawning potential ratio are required as an input to support an apropriate fisheries management. The purpose of this study was to identify population dynamic and spawning potential ratio of the K. limpok with survey method. The study was conducted in Tasik Giam Siak Kecil, Bengkalis and surrounding waters based on data collected during period of survey, from April 2017 to November 2017. Result showed that the length at first capture (Lc) of K. limpok was 18.9 cm (total length) and the size of length at first maturity (Lm) was 19.9 cm. Sex ratio was slightly unbalance (1.0:1.1). The growth rate parameter (K) was 0.59/year with maximum length (L_∞) of 43.05 cm. The estimate total mortality rate (Z) was 2.61 per year. While yearly ratio of fishing mortality (F) and natural mortality (M) were 1.41 and 1.2 respectively. Recruitment pattern occured throughout the year with one peak in June. The exploitation rate (E) was 0.54 per year and the spawning potential ratio (SPR) was 2.1%. Therefore the stock status was categorized as overfished. In order to ensure the sustainability of K. limpok, there is needed to apply the precautionary approach such as reducing existing catch by 8% of the current situation.