Resource recovery through the creation of an artificial Acanthosepion esculentum spawning ground in Namhae-gun, Gyeongsangnam-do, South Korea

This study was initiated to provide suitable substrates for Acanthosepion esculentum egg attachment, addressing the high mortality associated with eggs adhering to fishing gear. We aimed to enhance spawning success and larval recruitment in A. esculentum by establishing artificial spawning grounds off the coast of Namhae-gun, Gyeongsangnam-do. From late April to July 2024, two types of structures, netting structures and bamboo structures, were installed at two sites, Maando and Eunjeom. Each site comprised 20 netting structures and 160 bamboo structures. Weekly underwater monitoring was conducted over 12 weeks to assess spawning behavior, egg density, and spawning range. Fertilized eggs of A. esculentum and Sepioteuthis lessoniana were found in the netting structures, whereas only S. lessoniana eggs were detected in the bamboo structures. The average egg density was 2,501 eggs per m 2 in Maando and 1,258 eggs per m 2 in Eunjeom. In hatching experiments, eggs of A. esculentum and S. lessoniana showed high hatching rates (92% and 85%, respectively) along with high survival rates. An estimated 261,351 juvenile cephalopods successfully hatched from the artificial structures. These results demonstrate that artificial spawning habitats are effective in increasing cephalopod populations and reducing egg loss caused by fishing gear. This study provides practical strategies for resource restoration and the sustainable management of cephalopod species.