Spatiotemporal distribution and sexual segregation in the Critically Endangered angelshark Squatina squatina in Spain’s largest marine reserve

Mead, LR and Jiménez Alvarado, D and Meyers, E and Barker, J and Sealey, M and Caro, MB and Toledo, H and Pike, C and Gollock, M and Piper, A and Schofield, G and Herraiz, E and Jacoby, DMP (2023) Spatiotemporal distribution and sexual segregation in the Critically Endangered angelshark Squatina squatina in Spain’s largest marine reserve. Endangered Species Research, 51. pp. 233-248. ISSN 1863-5407

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Abstract

Establishing how threatened wildlife are distributed spatially and temporally is essential for effective conservation and management planning. While many shark species are threatened globally, knowledge on sex-specific differences in behaviour and fine-scale habitat use remains limited, hindering the implementation of appropriate conservation actions. Here, acoustic telemetry was used to investigate sex-specific space use in the Critically Endangered angelshark Squatina squatina in the Canary Islands (Atlantic Ocean), a key stronghold for the species. We collected data on space use, residency and movement of adult males (n = 32) and females (n = 72) in Spain’s largest marine reserve (La Graciosa Marine Reserve) over 4 yr (2018-2022). Presence in offshore sites (>80 m depth) indicated long-term utilisation of deep-water habitat, not previously observed in this species. Males were more likely to be detected in deep water and displayed significantly greater levels of activity and roaming behaviour than females. Patterns of behaviour in shallow waters indicated both social and habitat sexual segregation. Diel variability was also recorded, with greater activity occurring nocturnally. This study demonstrates the importance of considering the spatiotemporal distribution of both sexes, horizontally and vertically, when designing effective conservation measures.