Growth, Mortality and Exploitation Rate of Spiny Lobster ( Panulirus Homarus) from Kebumen and Cilacap Coastal

Abstract

The southern coast of Java, including Kebumen and Cilacap coastal, has important commodities that have high economic value which is lobster. However, this economic value become a trigger for uncontrolled exploitation, whether the number of catches and their size. Monitoring the status of lobster resources is difficult to do due to inadequate quality of catch data. Another method needs to be done using better validity data by making capture and direct recording data. The aims of this study is to determine the growth, mortality and exploitation rate of spiny lobsters (Panulirus homarus) on the beaches of Kebumen and Cilacap. Periodic sampling by measuring carapace length was carried out at these two beaches from November 2017 to March 2018. Longer studies were not possible because outside these months spiny lobsters were caught in very small quantities. The growth of spiny lobster (Panulirus homarus) is done with the Von Bertalanfy growth model in the form of Lt = L∞ (1-exp (-K (t- t0)), calculating growth parameters K, L∞ used Elefan 1 in the FISAT II software. t0, Mortality and exploitation rates are calculated using Pauly’s (1984) empirical formula. The results showed that successive growth parameters were as follows: K = 0.1300; L∞ = 116.55; t0 = -0,1806; Z = 0.2823; M = 0.2655; F = 0.0167 and E = 0.0595. The low level of exploitation indicates that the resources of spiny lobsters on both beaches have not experienced overfishing. However, based on the results of sampling of spiny lobsters, as many as 910, only 8.5% had carapace length more than 80 mm