Fish fauna and their occurrence characteristics observed on anchored fish aggregating devices off Goto-Retto Archipelago, Japan.

Fish occurrences at two anchored fish aggregating devices (FADs) off Goto-Retto Archipelago, Japan that occurred in close proximity, but in different environments, were observed with time-lapse cameras suspended from FADs from May 2019 to October 2020. We confirmed the occurrence of 15 species and 99,997 individuals. The most abundant species were Seriola lalandi, followed by Girella punctata, and Coryphaena hippurus. The relationship between the occurrences of these species and environmental factors was examined by generalized linear mixed model (GLMM). S. lalandi and C. hippurus were commonly observed at South FAD and G. punctata at North FAD. This may be due to the surrounding environment where the FADs are located. The occurrence of S. lalandi was related to sea surface temperature and wind direction, which were considered to indicate the season of their arrival. In addition to these effects, the daily sunshine hours and the phase of the moon had an effect on the occurrence of G. punctata. This meant that G. punctate appeared on the FAD during stormy weather. On the contrary, effects of wind speed and lunar phase on occurrence was significant for C. hippurus, suggesting that they did not appear during stormy weather. The occurrence of fish species corresponded to environmental changes on different time scales ranging from months to hours, such as season, month, and day. To effectively utilize FAD in fisheries, it is desirable to understand these characteristics for each fish species. [ABSTRACT FROM AUTHOR]