Shark populations have suffered dramatic declines across the world as a result of overfishing. Marine protected areas (MPAs) can restore overfished populations, however, their effectiveness largely relies on understanding the ecology of the targeted species. Here, we investigated the spatial ecology of the heavily harvested but yet understudied small-spotted catshark (Scyliorhinus canicula) through acoustic telemetry in the Cíes Islands, a small MPA in the NW of the Iberian Peninsula. We found effects of diel, seasonal, biotic (sex and total length) and abiotic (bottom sea temperature) variables in the spatial ecology of S. canicula. The mean residency index was low (0.27), and movement patterns suggest a strong connection with inshore waters. While the probability of presence in the study area was mainly driven by sex (i.e. larger for females), a drastic increase in activity was observed at night (compared to day hours). Activity space decreased with larger body sizes and was larger for individuals captured with longline (compared to those captured by hand). Warmer waters were related to higher activity levels and larger activity spaces. The present findings suggest the failure of small MPAs to protect the whole range of movement of S. canicula and the possible conservation benefits that this species could gain from fishing restrictions at night.
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