Stock assessment of Spondylus varius (Sowerby, 1827) in lianga bay, surigao del sur, Eastern Mindanao, Philippines
Paper Details
Stock assessment of Spondylus varius (Sowerby, 1827) in lianga bay, surigao del sur, Eastern Mindanao, Philippines
Abstract
The study was conducted to determine the status of the current stocks of the S. varius in Lianga Bay, Surigao del Sur from July 2016 to August 2019. Some variables in population dynamics, such as asymptotic length (L∞), growth coefficient (K), mortality rate (Z, F and M) and the exploitation rate of S. varius were estimated from length frequencies analyses by means of FAO-ICLARM Stock Assessment Tools (FISAT). Results showed that the growth performance index (φ) was 3.79, asymptotic length (L∞) was 202.65mm and growth coefficient (K) was predicted to be 0.15yr-1. Total mortality (Z) for S. varius was 1.04yr-1 with fishing mortality (F) and natural mortality (M) of 0.74yr-1 and 1.90yr-1, respectively. The increased of fishing mortality over natural mortality, decreased of size of the catch, inflated current exploitation rates (E) of 0.7 which was higher than the optimum level of exploitation (E= 0.50). The Emax, and E10 were 1.29, and 1.55 respectively which interpreted as overexploited. It is therefore to recommend for immediate action in ecological, economical and legal aspects in the fishery of S. varius in Lianga Bay Surigao del Sur, Philippines.
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