title: Predicting occurrence of juvenile shark habitat to improve conservation planning.
abstract: Fishing and habitat degradation have increased the extinction risk of sharks, and conservation strategies recognize that survival of juveniles is critical for the effective management of shark populations. Despite the rapid expansion of marine protected areas (MPAs) globally, the paucity of shark-monitoring data on large scales (100s-1000s km) means that the effectiveness of MPAs in halting shark declines remains unclear. Using data collected by baited remote underwater video systems (BRUVS) in northwestern Australia, we developed generalized linear models to elucidate the ecological drivers of habitat suitability for juvenile sharks. We assessed occurrence patterns at the order and species levels. We included all juvenile sharks sampled and the 3 most abundant species sampled separately (grey reef [Carcharhinus amblyrhynchos], sandbar [Carcharhinus plumbeus], and whitetip reef sharks [Triaenodon obesus]). We predicted the occurrence of juvenile sharks across 490,515 km2of coastal waters and quantified the representation of highly suitable habitats within MPAs. Our species-level models had higher accuracy (ĸ ≥ 0.69) and deviance explained (≥48%) than our order-level model (ĸ = 0.36 and deviance explained of 10%). Maps of predicted occurrence revealed different species-specific patterns of highly suitable habitat. These differences likely reflect different physiological or resource requirements between individual species and validate concerns over the utility of conservation targets based on aggregate species groups as opposed to a species-focused approach. Highly suitable habitats were poorly represented in MPAs with the most restrictions on extractive activities. This spatial mismatch possibly indicates a lack of explicit conservation targets and information on species distribution during the planning process. Non-extractive BRUVS provided a useful platform for building the suitability models across large scales to assist conservation planning across multiple maritime jurisdictions, and our approach provides a simple for method for testing the effectiveness of MPAs.
authors.affiliation: IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, The University of Western Australia, M470, 35 Stirling Highway, Crawley, WA, 6009, Australia.|Australian Institute of Marine Science, The UWA Oceans Institute, MO96, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Beverly Z L
authors.initials: BZL
authors.lastname: Oh
authors.affiliation: IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, The University of Western Australia, M470, 35 Stirling Highway, Crawley, WA, 6009, Australia.|Australian Institute of Marine Science, The UWA Oceans Institute, MO96, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Ana M M
authors.initials: AMM
authors.lastname: Sequeira
authors.affiliation: Australian Institute of Marine Science, The UWA Oceans Institute, MO96, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Mark G
authors.initials: MG
authors.lastname: Meekan
authors.affiliation: Department of Renewable Resources, University of Alberta, 116 Street and 85 Avenue, 442 Earth Sciences Building, Edmonton, Alberta AB, T6G 2E3, Canada.
authors.forename: Jonathan L W
authors.initials: JLW
authors.lastname: Ruppert
authors.affiliation: IOMRC and The UWA Oceans Institute, School of Animal Biology and Centre for Marine Futures, The University of Western Australia, M470, 35 Stirling Highway, Crawley, WA, 6009, Australia.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Meeuwig
mesh_terms: D000818:Animals; D001315:Australia; D003247:Conservation of Natural Resources; D004463:Ecology; D017753:Ecosystem; D012754:Sharks
keywords: Carcharhinus amblyrhnchos; Carcharhinus plumbeus; Triaenodon obesus; baited remote underwater video; modelos de distribución de especies; species distribution models; video remoto subacuático con carnada