Browsing by Author "Godley, Brendan J."
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- Assessing climate change associated sea level rise impacts on sea turtle nesting beaches using drones, photogrammetry and a novel GPS systemPublication . Varela, Miguel R.; Patrício, Ana Rita; Anderson, Karen; Broderick, Annette C.; DeBell, Leon; Hawkes, Lucy A.; Tilley, Dominic; Snape, Robin T. E.; Westoby, Matthew J.; Godley, Brendan J.Climate change associated sea level rise (SLR) is expected to have profound impacts on coastal areas, affecting many species including sea turtles which depend on these habitats for egg incubation. Being able to accurately model beach topography using digital terrain models (DTMs) is therefore crucial to project SLR impacts and develop effective conservation strategies. Traditional survey methods are typically low-cost with low accuracy or high-cost with high accuracy. We present a novel combination of drone-based photogrammetry and a low-cost and portable real-time kinematic (RTK) GPS to create DTMs which are highly accurate (<10 cm error) and visually realistic. This methodology is ideal for surveying coastal sites, can be broadly applied to other species and habitats, and is a relevant tool in supporting the development of Specially Protected Areas. Here we applied this method as a case-study to project three SLR scenarios (0.48, 0.63 and 1.20 m) and assess the future vulnerability and viability of a key nesting habitat for sympatric loggerhead (Caretta caretta) and green turtle (Chelonia mydas) at a key rookery in the Mediterranean. We combined the DTM with 5 years of nest survey data describing location and clutch depth, to identify (1) regions with highest nest densities, (2) nest elevation by species and beach, and (3) estimated proportion of nests inundated under each SLR scenario. On average, green turtles nested at higher elevations than loggerheads (1.8 m vs. 1.32 m, respectively). However, because green turtles dig deeper nests than loggerheads (0.76 m vs. 0.50 m, respectively), these were at similar risk of inundation. For a SLR of 1.2 m, we estimated a loss of 67.3% for loggerhead turtle nests and 59.1% for green turtle nests. Existing natural and artificial barriers may affect the ability of these nesting habitats to remain suitable for nesting through beach migration. This article is protected by copyright. All rights reserved.
- First census of the green turtle at Poilão, Bijagós Archipelago, Guinea-Bissau: the most important nesting colony on the Atlantic coast of AfricaPublication . Catry, Paulo; Barbosa, Castro; Indjai, Bucar; Almeida, Amadeu; Godley, Brendan J.; Vié, Jean-ChristopheThe island of Poilão in the Bijagós Archipelago, Guinea-Bissau, is known to be an important nesting site for the green turtle Chelonia mydas, but until recently there were no quantitative estimates of the number of clutches deposited annually. In 2000 a survey was carried out to assess the magnitude of nesting, and an estimated 7,400 green turtle clutches were deposited. Four nesting hawksbill turtles Eretmochelys imbricata were also encountered. This study confirmed that Poilão is one of the most important nesting sites for green turtles in the Atlantic, and the largest known nesting colony on the west coast of Africa. Traditionally Poilão has been regarded as a sacred site by the Bijagós people, and this has contributed to the conservation of these turtles. However, the development of fisheries in this region is an emerging threat. To conserve this site a National Marine Park was designated in August 2000.
- 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.