Length-Based Assessment of an Artisanal Albulid Fishery in the South Pacific: a Data-Limited Approach for Management and Conservation

Data-limited fisheries assessment methods have great potential to help inform small island communi

Convergence of marine megafauna movement patterns in coastal and open oceans

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Proceedings of the National Academy of Sciences of the United States of America 115 (2018): 3072-3077, doi:10.1073/pnas.1716137115.The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyse a global dataset of 2.8 million locations from > 2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared to more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal micro-habitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise and declining oxygen content.Workshops funding granted by the UWA Oceans Institute, AIMS, and KAUST. AMMS was supported by an ARC Grant DE170100841 and an IOMRC (UWA, AIMS, CSIRO) fellowship; JPR by MEDC (FPU program, Spain); DWS by UK NERC and Save Our Seas Foundation; NQ by FCT (Portugal); MMCM by a CAPES fellowship (Ministry of Education)

Global Spatial Risk Assessment of Sharks Under the Footprint of Fisheries

Effective ocean management and conservation of highly migratory species depends on resolving overlap between animal movements and distributions and fishing effort. Yet, this information is lacking at a global scale. Here we show, using a big-data approach combining satellite-tracked movements of pelagic sharks and global fishing fleets, that 24% of the mean monthly space used by sharks falls under the footprint of pelagic longline fisheries. Space use hotspots of commercially valuable sharks and of internationally protected species had the highest overlap with longlines (up to 76% and 64%, respectively) and were also associated with significant increases in fishing effort. We conclude that pelagic sharks have limited spatial refuge from current levels of high-seas fishing effort. Results demonstrate an urgent need for conservation and management measures at high-seas shark hotspots and highlight the potential of simultaneous satellite surveillance of megafauna and fishers as a tool for near-real time, dynamic management

Selective removal of problem individuals as an environmentally responsible approach for managing shark bites on humans

Selective removal of problem individuals following shark bite incidents would be consistent with current management practices for terrestrial predators, and would be more effective and more environmentally responsible than current mass-culling programs. In parallel, and in addition to traditional forensics analysis, we recommend the routine collection of shark DNA from wounds or devices following shark bite incidents in order to genetically identify the individual responsible. This approach would require creating an extensive database of shark identities in high-risk areas against which to compare DNA forensically recovered from shark bite incidents. At a local and regional scale, we propose utilizing existing shark tagging programs and artificial shark aggregation sites to collect DNA, behavioural and morphological data for the database, and to facilitate removal of problem individuals. In several places around the world, selective removal of problem individuals would not be significantly more expensive and definitely less environmentally-destructive than traditional approaches and would also help reconcile people and sharks by underlining individuality in shark behaviour.acceptedVersio

Individual shark profiling: An innovative and environmentally

Most shark-induced human fatalities are followed by widespread and unselective culling campaigns that have limited effectiveness and may have high ecological costs for threatened species. The blanket culling strategy implicitly assumes that incident risk is directly correlated with shark density, an assumption that has yet to be demonstrated. We present the alternative hypothesis that incidents are more likely to be caused by behavioral variability among individual sharks than due to shark density. Throughout their ontogenetic development, large species of sharks opportunistically establish a diet that is rarely, if ever, inclusive of humans as a food source. We propose that, some animals with specific behaviors (including boldness) may potentially pose a higher risk than conspecifics. Under this scenario, the risk of a shark attack in a given area would relate to the presence of a limited number of high-risk individuals rather than shark density. In terms of management of human fatalities, such a hypothesis would favor abandoning general culling campaigns and replacing them with approaches that profile and selectively remove the potential problem individuals, as is done in the terrestrial realm when managing predators that attack humans or livestock.publishedVersio

Improved Baited Remote Underwater Video (BRUV) for 24 h Real-Time Monitoring of Pelagic and Demersal Marine Species from the Epipelagic Zone

Bait-based remote underwater video (BRUV) systems are effective devices for remotely observing fish and other marine organisms in challenging environments. The development of a long duration (24 h) surface BRUV observation surveys allowed the monitoring of scarce and elusive pelagic sharks and the direct impact on non-targeted species of longline fishing in the Western Mediterranean. Technological limitations, such as the limited storage capacity and a single surface camera, were improved by (i) adding a deep camera equipped with light (below 80 m depth) and (ii) replacing Gopros with a multi-camera video surveillance system (surface and depth) with a storage capacity of several days and access to real-time observation. Based on a deployment effort of 1884 h video data, we identified 11 blue sharks (Prionace glauca) and one bluntnose sixgill shark (Hexanchus griseus), a deep-sea species that scarcely swims at the surface. The real-time observation capability was a powerful tool for reducing logistical costs and for raising environmental awareness in educational and outreach programmes

Videos to BEH 3810

   Video 1. Slow straight-line swimming (Table 1, Section 3.1.2). Video 2. Self-body cleaning (Table 1, Section 3.1.10). Video 3. Courtship and Copulation (Table 2, Sections 3.2.8–3.2.12, 3.2.15, 3.2.18). Video 4a. Basking shark ram feeding on plankton (Table 3, Section 3.3.1). Video 4b. Reef manta rays ram feeding on plankton (Table 3, Section 3.3.6). Video 5. Saw Bite (Table 4, Section 3.4.5). Video 6. Vertical breach with prey seizure (Table 5, Section 3.5.4). Video 7. Horizontal bite and lateral head shake (Table 5, Sections 3.5.6, 3.5.8–3.5.9). Video 8. Scavenging on sea lion (Table 5, Section 3.5.14). Video 9. Schooling (Table 6, Section 3.6.7). Video 10. Swim by (Table 6, Section 3.6.10). Video 11. Aggressive behaviours (Table 7, Sections 3.7.2, 3.7.4–3.7.5, 3.7.7–3.7.8) Video 12. Tail slap (Table 7, Section 3.7.10). Video 13. Exaggerated tail beats and looping (Table 7, Section 3.7.12). Video 14. Reflex biting (Table 7, Section 3.7.24). Video 15. Anti-predatory biting (Table 8, Section 3.8.5).</p