Spatial and temporal patterns in Serranus cabrilla habitat use in the NW Mediterranean revealed by acoustic telemetry

We used acoustic telemetry to describe the spatial and temporal patterns of habitat use of one of the species most targeted by recreational anglers in the NW Mediterranean, Serranus cabrilla (Linnaeus, 1758). Temporal patterns and fish position were determined using a fixed-receiver array located in a marine protected area (MPA) in Palma Bay (Balearic Islands). Fish position as centre of activity (COA, the centre of the area the fish uses during a specific time) and space utilisation preferences could be described due to a receiver array design with a high range detection overlap (more densely distributed near the COA). There were significantly more detections per time unit during the day, which was interpreted as increased activity possibly related to feeding habits and social behaviour. S. cabrilla spent 95% of its time in an average area of 0.77 +/- 0.17 km(2), with a core area (50% of the time) of 0.10 +/- 0.29 km(2). The home range size was not related to fish size or diel pattern (i.e. the size of the daytime home range was not significantly different from the night range). The linearity index and the index of reuse (proxies of site fidelity) also demonstrated that this species has high site fidelity, which suggests that it is sedentary with a limited adult dispersal capacity. Two main habitats were observed in the study area, and S. cabrilla spent on average much less time in seagrass meadows (Posidonia oceanica beds) compared to soft, gravel and detritus bottoms. A relatively small MPA would be a useful management tool for establishing sustainable exploitation levels of this species.