Analysis of the Catch Records of a Purse Seine Vessel Operating in the Aegean Sea
Project no. 26296 · Status: Kapanmış · 2022
Summary
<p>Biotic and abiotic factors have a significant impact on marine life. Fisheries are not</p><p>only one of the influencing factors but also one of the affected parties. Populations that</p><p>decline due to factors reflect on catch amounts. Identifying the factors affecting catch</p><p>amounts ensures the sustainability of fisheries economically and ecological improvement,</p><p>thereby maintaining species continuity for future generations. This study aims to identify the</p><p>effects of temporal (year, month, season) and environmental variables (SST, SSS, SSC) on</p><p>catch amounts. Daily catch data were collected from a purse seiner in the Gulf of İzmir. With</p><p>these collected data, daily CPUE amounts were calculated. The relationships between CPUE</p><p>and variables were demonstrated using the regression analysis method, specifically the GLM</p><p>technique. According to the results, there is a significant effect of the years on CPUE</p><p>amounts, and a negative correlation between them was observed. The amount of SSC also has</p><p>a significant effect on CPUE, with a negative correlation noted. There is a statistically</p><p>significant decrease in CPUE amounts during the full moon phase. It was found that CPUE</p><p>amounts increased with decreasing moonlight intensity. Additionally, an increase in CPUE</p><p>amounts was observed at the end of the seasonal bans, with a decline noted until the bans</p><p>began. It is thought that factors not found statistically significant may become significant if</p><p>the time series is extended and the study is conducted with multiple purse seiners.</p><p>Nevertheless, the decline in CPUE amounts over the years is very evident, and urgent</p><p>measures need to be taken.</p><p>Keywords: Purse Seine Fishery, Gulf of İzmir, Environmental variables</p>