Residency and swimming behavior of Acanthopagrus schlegelii, Trachinotus blochii, and Acanthopagrus latus in relation to artificial reef models in a captivity experiment

Abstract

Global capture fisheries production has declined rapidly over the past decades because of the growing demand for fisheries resources. To restore fisheries resources, artificial reefs (ARs) are deployed on the seafloor to provide new habitats for marine life. However, the effects of ARs on fish behavior in natural environments are poorly understood. Accordingly, the present study employed Ethovision XT 13 video tracking software to examine the behavior of the three most common fish species in marine stock enhancements in Taiwan (Acanthopagrus schlegelii, Trachinotus blochii, and Acanthopagrus latus) by conducting a captivity experiment that involved three treatment models: no AR (control), circular AR, and rectangular AR models. We observed that A. schlegelii and A. latus preferred AR models with higher shelter availability, but T. blochii avoided being close to the models. Regarding swimming speed, A. schlegelii was slower in the first 10 min, but T. blochii was faster in the first 10 min in all three treatments. The swimming speed of A. latus demonstrated no change in the various time phases and treatments. Moreover, we noted that the fish swimming speed was associated with the distance between the fish; a faster swimming speed was associated with a greater distance between the fish. These findings can serve as a reference for marine stock enhancement programs and ecosystem management for the implementation of sus-tainable fisheries.