Environmental Influences on Patterns of Vertical Movement and Site Fidelity of Grey Reef Sharks (Carcharhinus amblyrhynchos) at Aggregation Sites

摘要: We used acoustic telemetry to describe the patterns of vertical movement, site fidelity and residency grey reef sharks (Carcharhinus amblyrhynchos) on outer slope coral reefs in Palau, Micronesia, over a period two years nine months. tagged 39 (mostly adult females) which 31 were detected regularly throughout study. Sharks displayed strong inter-annual with greater attendance at monitored sites during summer than winter More individuals day night. Mean depths increased from 35 m 60 spring following an increase water temperature m, maximum mean attained when temperatures stabilised around 29°C. descended wider range time full moon. There also crepuscular cycles depth, moving into shallower waters dawn dusk each day. suggest that daily, lunar seasonal movement are strategies for optimising both energetic budgets foraging behaviour. Cyclical response environmental variables might affect susceptibility fishing, consideration should be taken account implementation conservation strategies.