Movement patterns of bonefish (Albula vulpes) in tidal creeks and coastal waters of Eleuthera, The Bahamas

Abstract

Bonefish (Albula spp.) are a group of fishes that inhabit tropical and subtropical marine waters worldwide. Large gaps in our understanding of the ecology of these fishes exist despite their economic importance as a sport fish and their potential role in the ecological functioning of coastal systems. Using a passive acoustic telemetry array, we monitored the movement patterns of A. vulpes along the north coast of Cape Eleuthera, The Bahamas. During the course of the study, we successfully detected 15 individuals for periods exceeding six months that permitted us to observe several previously unknown movement patterns for bonefish. Data indicate that bonefish exhibit periods of site fidelity where they repeatedly visit the same tidal creeks, interspersed with transient periods (up to 339 days) in which they utilize large areas of shallow coastal habitats or disappear from the study area entirely. Relative activity space, as measured by minimum linear dispersal, median distance traveled, and mean number of receivers visited daily, did not vary with fish size. Individuals associated in schools tended to display nearly synchronous movements. School-fidelity in bonefish may be influenced by school size, the duration in which an individual has been in the school, and the frequency with which schools mix. Bonefish responded to tidal influences and tended to move out of tidal creeks on outgoing tides and into creeks or shallow habitats during incoming tides. There was also evidence of increased use of tidal creeks during daytime when controlling for tidal phase. Seasonal movements toward the seaward portion of the array likely correspond with spawning. In general, the movement patterns of bonefish we observed demonstrate the importance of this species in the connectivity between nearshore (e.g., mangrove tidal creeks) and offshore habitats. Moreover, because residency patterns in a given area vary greatly among individuals and over time, this work points to the need to examine population mixing and spatial ecology over larger temporal and spatial scales.