FISHERIES RESEARCH INSTITUTE,MOA,TAIWAN

The sergestid shrimp (Sergia lucens) is an important fishery species in the southwestern waters off Taiwan. It has a short life cycle and its abundance is easily affected by environmental changes. This study aggregated and analyzed the logbook data, including the year, month, fishing area, operating hour, and catch data, of 13 sergestid shrimp fishery sampling vessels that operated in the southwestern waters off Taiwan from 2005 to 2019. The catch per unit effort (CPUE) was used as the resource index. A generalized linear model (GLM) was used to establish a CPUE variation model of the sergestid shrimp in order to explore the relationship between the changes in resources and environmental factors, and to identify the environmental factors that caused fluctuations in the resources. In order to cope with the different time series of data, this study only used data from November 2013 through May 2018 for the model establishment. The results showed that the sympathetic effects of sea surface temperatures in fishing areas and wind speed and direction in the Kaohsiung area have a significant impact on the CPUE of sergestid shrimp. The model interpretation rate was 12.5%. Comparing the CPUE and model estimates of CPUE trends, a year-by-year trend chart showed that the trends of the model CPUE and CPUE from 2013 to 2019 were the same, with both showing a downward trend. The CPUE trend estimated by this research model can serve as a reference for the management of sergestid shrimp fisheries.