Annual and seasonal environmental drivers of species- and gear-specific catch rates in the Visayan Sea, Philippines

Fisheries management requires a holistic understanding of the factors that influence the stocks and their variability. While previous investigations in the Visayan Sea - a major fishing ground in the Philippines - have acknowledged the potential influence of several environmental factors, the relationships remain largely unexplored. By applying multiple analytical approaches, we explored the observed trends and effects of a set of seasonally variable environmental parameters (sea surface temperature, chlorophyll-a, net primary productivity, rainfall, wind magnitude, Southern Oscillation Index and Pacific Decadal Oscillation) on the species-specific and gear-specific catch per unit of effort (CPUE) in the Visayan Sea. Increasing sea surface temperatures had generally significant negative effects on the CPUEs of all species except one. The positive modeled effects of wind and optimal rainfall levels are attributed to these factors' favorable influence on net primary productivity and food availability, with implications on the successful early development of the different species and the condition of the parent stock. In addition to the biological responses, behavioral responses by the blue swimmer crabs were also found to influence the CPUEs. These results highlight the importance of identifying the variable influence of seasonal environmental factors to better interpret the observed temporal trends in catch rates, and serve as important first contributions to inform a more ecosystem-based and adaptive management response to the fisheries in the Visayan Sea. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Fisheries management requires understanding of the factors influencing stocks and their variability. This study explored the effects of seasonal environmental parameters on catch per unit of effort (CPUE) in the Visayan Sea. The results showed that increasing sea surface temperatures had negative effects on CPUE for most species, while wind and optimal rainfall levels had positive effects attributed to their influence on net primary productivity and food availability.