Browsing by Author "Croxall, John"
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- Important At-Sea areas of colonial breeding marine predators on the Southern Patagonian ShelfPublication . Baylis, Matthew; Tierney, Megan; Orben, Rachael; Evans, Victoria Warwick; Wakefield, Ewan; Grecian, William James; Trathan, Phil; Reisinger, Ryan R.; Ratcliffe, Norman Arthur; Croxall, John; Campioni, Letizia; Catry, Paulo; Crofts, Sarah; Boersma, P. Dee; Galimberti, Filippo; Granadeiro, José Pédro; Handley, Jonathan; Hayes, Sean; Hedd, April; Masello, Juan; Montevecchi, William A.; Pütz, Klemens; Quillfeldt, Petra; Rebstock, Ginger A.; Sanvito, Simona; Staniland, Iain; Brickle, PaulThe Patagonian Shelf Large Marine Ecosystem supports high levels of biodiversity and endemism and is one of the most productive marine ecosystems in the world. Despite the important role marine predators play in structuring the ecosystems, areas of high diversity where multiple predators congregate remains poorly known on the Patagonian Shelf. Here, we used biotelemetry and biologging tags to track the movements of six seabird species and three pinniped species breeding at the Falkland Islands. Using Generalized Additive Models, we then modelled these animals' use of space as functions of dynamic and static environmental indices that described their habitat. Based on these models, we mapped the predicted distribution of animals from both sampled and unsampled colonies and thereby identified areas where multiple species were likely to overlap at sea. Maximum foraging trip distance ranged from 79 to 1,325 km. However, most of the 1,891 foraging trips by 686 animals were restricted to the Patagonian Shelf and shelf slope, which highlighted a preference for these habitats. Of the seven candidate explanatory covariates used to predict distribution, distance from the colony was retained in models for all species and negatively affected the probability of occurrence. Predicted overlap among species was highest on the Patagonian Shelf around the Falkland Islands and the Burdwood Bank. The predicted area of overlap is consistent with areas that are also important habitat for marine predators migrating from distant breeding locations. Our findings provide comprehensive multi-species predictions for some of the largest marine predator populations on the Patagonian Shelf, which will contribute to future marine spatial planning initiatives. Crucially, our findings highlight that spatially explicit conservation measures are likely to benefit multiple species, while threats are likely to impact multiple species.
- Spatial scales of marine conservation management for breeding seabirdsPublication . Oppel, Steffen; Bolton, Mark; Carneiro, Ana Paula B.; Dias, Maria P.; Green, Jonathan A.; Masello, Juan F.; Phillips, Richard A.; Owen, Ellie; Quillfeldt, Petra; Beard, Annalea; Bertrand, Sophie; Blackburn, Jez; Boersma, P. Dee; Borges, Alder; Broderick, Jess; Catry, Paulo; Cleasby, Ian; Clingham, Elizabeth; Creuwels, Jeroen; Crofts, Sarah; Cuthbert, Richard J.; Dallmeijer, Hanneke; Davies, Delia; Davies, Rachel; Dilley, Ben J.; Dinis, Herculano; Dossa, Justine; Dunn, Michael J; Efe, Marcio A.; Fayet, Annette; Figueiredo, Leila; Frederico, Adelcides Pereira; Gjerdrum, Carina; Godley, Brendan J.; Granadeiro, José Pedro; Guilford, Tim; Hamer, Keith C.; Hazin, Carolina; Hedd, April; Henry, Leeann; Hernández-Montero, Marcos; Hinke, Jefferson; Kokubun, Nobuo; Leat, Eliza; Tranquilla, Laura McFarlane; Metzger, Benjamin; Militão, Teresa; Montrond, Gilson; Mullié, Wim; Padget, Oliver; Pearmain, Elizabeth J.; Pollet, Ingrid L.; Pütz, Klemens; Quintana, Flavio; Ratcliffe, Norman; Ronconi, Robert A.; Ryan, Peter G.; Saldanha, Sarah; Shoji, Akiko; Sim, Jolene; Small, Cleo; Soanes, Louise; Takahashi, Akinori; Trathan, Phil; Trivelpiece, Wayne; Veen, Jan; Wakefield, Ewan; Weber, Nicola; Weber, Sam; Zango, Laura; Daunt, Francis; Ito, Motohiro; Harris, Michael P.; Newell, Mark A.; Wanless, Sarah; González-Solís, Jacob; Croxall, JohnKnowing the spatial scales at which effective management can be implemented is fundamental for conservation planning. This is especially important for mobile species, which can be exposed to threats across large areas, but the space use requirements of different species can vary to an extent that might render some management approaches inefficient. Here the space use patterns of seabirds were examined to provide guidance on whether conservation management approaches should be tailored for taxonomic groups with different movement characteristics. Seabird tracking data were synthesised from 5419 adult breeding individuals of 52 species in ten families that were collected in the Atlantic Ocean basin between 1998 and 2017. Two key aspects of spatial distribution were quantified, namely how far seabirds ranged from their colony, and to what extent individuals from the same colony used the same areas at sea. There was evidence for substantial differences in patterns of space-use among the ten studied seabird families, indicating that several alternative conservation management approaches are needed. Several species exhibited large foraging ranges and little aggregation at sea, indicating that area-based conservation solutions would have to be extremely large to adequately protect such species. The results highlight that short-ranging and aggregating species such as cormorants, auks, some penguins, and gulls would benefit from conservation approaches at relatively small spatial scales during their breeding season. However, improved regulation of fisheries, bycatch, pollution and other threats over large spatial scales will be needed for wide-ranging and dispersed species such as albatrosses, petrels, storm petrels and frigatebirds.