Determination of the Utilization and Effort Level of Mackerel Scad ( Decapterus spp ) in the Bitung Waters North Sulawesi

Determination of utilization level and effort level of scad mackerel (Decapterus spp) are very important to know the status of fisheries management. This fish needs to be managed well because even as a renewable natural resources, but can undergo depletion or extinction. One of the approach in the management of fish resources is by mathematics modeling. In this research using Surplus Production Model (SPM) with 5 estimator methods, that are: Schaefer, Fox, Schnute, Walter-Hilborn, and Clarke Yoshimoto Pooley. The analysis was performed aiming to get the best estimate for the surplus production model to determine the maximum sustainable yields (MSY), utilization level, and effort level of scad mackerel. The criteria of the best model (estimator) are: sign suitability of regression equation, value of coefficient determination, validation values (residual), and significance of regression coefficients. From the best model by using the formula can be determined the maximum sustainable yields (MSY) of catching, utilization level, and effort level. The data of catch and fishing effort of scad mackerel collected from the Marine and Fisheries the Bitung City and North Sulawesi Province from 1998 - 2016. The best SPM, which is used to assess the potential of scad mackerel is Schaefer Model. Optimal effort (EMSY) of 4,449 trips per year, with catch of optimal CMSY19,793.601 tons per year. The effort level for 2014 is 86.58%, which shows the quite efficient effort, the utilization level of 73.10% showing the production still can be increased.