A Surplus Production Model for Sustainable Management of Anchovies (Stolephorus sp.) in the Fisheries of Larangan Waters, Tegal

The surplus production model is a mathematical framework used to evaluate fish stocks and to determine the maximum sustainable catch. This model is an important tool for supporting sustainable fishing practices. Anchovy fishing in Tegal, Central Java, faces serious challenges due to indications of overfishing. The level of anchovy resource utilization has exceeded the maximum sustainable yield (MSY), and the optimal fishing effort level (fopt) has also been exceeded. In addition, fisheries management is considered ineffective due to a lack of adequate data and policies that are unable to limit fishing effort. This study aimed to identify the most appropriate surplus production model and to determine the maximum sustainable yield (MSY), utilization rate, and fishing effort level for anchovy in Larangan Waters, Tegal. The method used is descriptive analysis utilizing secondary data, including catch, fishing effort, and catch per unit effort (CPUE) from 2019 to 2023. The data were analyzed using regression tests from several surplus production models, Schaefer, Fox, Schnute, and Walter-Hilborn models. The best model was determined based on the R-squared value and the significance of the regression coefficients. The results indicate that the Walter-Hilborn model is the most appropriate, with an R² value of 0.964 and a significance level of f < 0.05. Based on this model, the optimal fishing effort (E_MSY) is estimated at 6.786 trips/year, and the maximum sustainable catch (C_MSY) is estimated at 948.228 kg/year. Data analysis show that fishing effort in Tegal has exceeded sustainable limits since 2021, reaching 117,38% and scalating to 144,31% in 2023. This trend confirms the presence of overfishing, requiring a strategic management approach to regulate fishing activies and number of fishing gear.