Effect of artificial lights on catch efficiency and capture patterns in Asian paddle crab (Charybdis japonica) gillnet fishery

The gillnet fishery targeting Asian paddle crab (Charybdis japonica) is an important commercial fishery in the Yellow Sea of China. However, low catch rates represent a challenge, and solutions for improving the catch efficiency are crucial for economical sustainability in this fishery. Therefore, we tested whether the use of artificial fishing lights could improve gillnet catch performance. Specifically, we investigated the effect of using different colored light-emitting diodes (LED) on gillnet catch efficiency and capture patterns. The results showed that attaching white and blue LED lights to gillnets did not significantly affect the catch efficiency of C. japonica, compared to the conventional gillnets without LED lights attached. However, green LED lights significantly improved catch efficiency of legal-sized C. japonica by an average of 57%. Furthermore, a significant reduction (
35%) in the catch efficiency of undersized crabs was observed for gillnets equipped with red LEDs; however, without any significant effect on catches of legal-sized C. japonica. Moreover, significant differences were observed for the catch composition of species between gillnets with and without LED lights. The findings of this study can provide insight into potential improvements of the fishing strategies in the C. japonica gillnet fishery.