Effects of spatial-temporal conditions and fishing-vessel capacity on the capture of swimming crabs by using different fishing gear around the waters of Taiwan

Abstract

Context Swimming crab is a vital fishery resource and a valuable source of income in the southern East China Sea, but it lacks management strategies, especially when using different fishing gear.Aims This study aimed to determine the effects of spatial-temporal conditions and vessel capacity on swimming crabs by using different fishing-gear types in the Taiwan Strait (TS).Methods We used generalised linear mixed models (GLMMs) to investigate data from Taiwanese vessels (2011-2019) on how spatial-temporal conditions and vessel capacity affected the catch of swimming crabs when using trawls, gill-nets and traps.Key results The results showed that the traps (>80.0%) caught more swimming crabs in the TS than did the gill-nets (6.6%) and trawls (8.0%). Additionally, the GLMM analysis showed that Charybdis feriatus, Portunus pelagicus and Portunus sanguinolentus catches by traps and trawls were significantly affected by different fishing locations, climate events, work hours and vessel sizes. However, for gill-nets, spatial-temporal conditions and vessel capacity did not affect the catch of C. feriatus.Conclusions Monitoring fishing efforts and environmental factors is vital to understanding their impacts on marine ecosystems.Implications These findings enable future sustainable crab fishing through harvesting strategy planning, ecosystem management and spatial-temporal governance.