Direct evidence of a spawning aggregation of cubera snapper (Lutjanus cyanopterus) in southeastern Brazil and its management implications

Abstract

Identifying fish spawning aggregations is crucial to determine effective fisheries management measures and protect key reproduction sites. We found direct evidence (the presence of post-ovulatory follicles) of a spawning aggregation of cubera snapper (Lutjanus cyanopterus) within the largest multiple-use marine protected area in southeastern Brazil, representing the first in-situ validation of a cubera snapper spawning aggregation in subtropical waters off the southwestern Atlantic. Out of 127 specimens (weighing ~ 2253 kg total) illegally caught by a fishing vessel on January 17th, 2021, fourteen individuals, ranging from 82 to 115.4 cm, were randomly selected and analyzed. The histological examination of six ovaries showed spawning-capable individuals and multiple spawning patterns. This cubera snapper spawning aggregation event probably relates to increased temperatures in the summer months, and the complexity of habitats and geomorphological formations in the region. Even though the species has high economic value in the region, targeted by both commercial and recreational fishing, Brazilian legislation imposes capture restrictions that ignore scientific evidence and are limited to the winter months, a season lacking aggregation reports. Our findings highlight the need for a comprehensive management strategy that includes seasonal fishing closures and monitoring and research collaborative programs.