Research Article: Skipjack tuna (Katsuwonus pelamis) sustainable resource management through fishing vulnerability and some population dynamic analysis in Malang south coast waters, East Java

Skipjack tuna (Katsuwonus pelamis) represents an essential fishery resource in the waters off Malang's South Coast in East Java, possessing significant economic and ecological importance. However, escalating fishing pressures and climate variability, particularly fluctuations in sea surface temperature (SST), have raised concerns about the sustainability of its stock. This research aimed to evaluate the fishing vulnerability and population dynamics of skipjack tuna in the area. Data was gathered from January ۲۰۲۱ to October ۲۰۲۱ at the Pondokdadap Coastal Fishing Port (CFP) Malang South Coast Waters, involving the analysis of ۱,۰۶۲ skipjack tuna. The Productivity and Susceptibility Analysis (PSA) was utilized to assess vulnerability, while growth, mortality, and recruitment patterns were examined through length-frequency distribution and the von Bertalanffy growth model. The findings revealed that skipjack tuna had a productivity score of ۲.۴۴ and a susceptibility score of ۲.۳۳, resulting in a low vulnerability classification (۱.۴۴). Nonetheless, the species faces overfishing, as indicated by an exploitation rate (E=۰.۵۸) surpassing the sustainable threshold of ۰.۵۰. The relationship between SST and catch per unit effort (CPUE) and recruitment patterns showed a low to moderate inverse correlation, indicating that environmental factors affect stock variations. To promote sustainability, it is crucial to implement effective management strategies, including regulations on fishing efforts, size restrictions, and seasonal closures. Adopting ecosystem-based fisheries management (EBFM) approaches incorporating climate adaptation strategies is also advisable. These results offer important insights into the interplay between SST dynamics and skipjack tuna fisheries, aiding future stock management and conservation initiatives.

کلیدواژه ها:

Skipjack tuna ، East Java ، Productivity ، Susceptibility ، Sea surface temperature ، Vulnerability