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The future persistence of biodiversity is likely to be affected by global climate change. We propose a qualitative framework for assessing the resilience of coastal species to climate change, incorporating current and likely future breeding success, the availability of temporal and spatial climate refugia, the effect of future sea-level rise, behavioural plasticity and the level of other specific threats.We test this framework using one of theworld's largest nesting rookeries of loggerhead sea turtles (Caretta caretta) in the island of Boa Vista (Republic of Cape Verde, West Africa). We measured air, sand and nest temperatures across more than 50 km of nesting habitat and four years to model the likely sex ratios produced and predicted what future sex ratios might be under one conservative future climate change scenario (RCP 2.6). We assessed the relative threat of sea-level rise, and other threats including beachfront construction, pollution and human harvest as well as to estimate the level of foraging behaviour plasticity observed for this population. Estimated sex ratio over the study period was 79.15% female and while an increase of 2 °C air temperature would lead to 99.86% female production, incubation temperature is unlikely to be lethal even in the hottest part of the year. Only half the total suitable length of coastline is currently used for nesting and there is a size-linked dichotomy in foraging strategies of loggerhead turtles of both sexes. Under our qualitative framework,we make the surprising observation that this population of conservation concern should have remarkable resilience to climate change due to some unique features of their habitat use and preferences. This may be compromised by high levels of human harvest and planned and on-going coastal development. The framework may be of utility in assessing the threat of climate change to other climate-sensitive, coastal and mobile species such as migratory seabirds, coastal fish and butterflies., This work was carried out with funding from the Ministry of the Environment of the Regional Government of Andalusia, the Regional Government of the Canary Islands and the Fuerteventura Inter-Island Council (Cabildo de Fuerteventura). LAH was supported by a BBSRC post-doctoral award at Bangor University during the study.

Species invasions are a widely-recognized threat to regional and global biodiversity. Lionfish (Pterois spp.), are an invasive marine fish that have been shown to reduce the recruitment and biomass of native reef fish throughout the Caribbean. Recently, it has become clear that lionfish are able to colonise a wide range of ecosystems (mesophotic reefs to brackish estuaries to mangroves) and tolerate a wider range of salinities than previously thought. Estuarine ecosystems often experience hyposaline conditions and act as critical foraging habitats for many ecologically and economically important species. Using a habitat competition experiment at two salinity treatments (10 practical salinity units (psu) and 37 psu control) we investigated the potential effects of lionfish on native Schoolmaster snapper (Lutjanus apodus; a tropical fish species found in high abundance in estuarine ecosystems). Schoolmaster snapper showed a 62% and 47% reduction in cover use when in the presence of lionfish in the 10 psu and 37 psu treatments, respectively. Further, five of the seven behaviours investigated during the interaction period, where both lionfish and snapper had access to the shelter, showed a significant reduction at low salinity, suggesting physiological or behavioural impairment of lionfish at low salinity. Because estuarine habitats are disproportionately important habitats for juvenile fishes, even physiologically or behaviourally compromised lionfish are likely to have some impact.

Climate change models predict sea level rise and increased intensity of storms and hurricanes in tropical sea turtle nesting areas. These factors could significantly increase beach inundation and erosion, thus affecting water content of sea turtle nesting beaches. Here, we conducted a field and laboratory study of how sand water content is related to embryonic development and hatching success of leatherback turtle nests. Moreover, we have experimentally incubated eggs of this species in beach sand under standardized conditions, but at different realistic levels of sand water content, varying from 1% to 12%. On the beaches, females nested from the intertidal zone to the lower part of the sand vegetation dunes, where nests were exposed to a wide range of sand water contents that ranged from 0.8% to 22%. However, both field and experimental studies revealed a strong negative correlation between sand water content and emergence success (field study: r = − 0.73, P

The basking shark (Cetorhinus maximus) is an endangered species in the north-east Atlantic, having been historically over exploited. Whilst near-shore aggregation hotspots in the UK have been identified, robust knowledge on species distribution and abundance outside these areas remains limited. Research techniques, such as habitat modelling, could however be used to gain a greater knowledge of the species distribution to inform management plans to aid population recovery. For large mobile species gathering wide-scale distribution data can be financially and logistically challenging. In lieu of conducting an expensive UK-wide strategic survey for basking sharks, we use data from two regional-scale surveys, which were conducted in southwest England and western Scotland, in an Ensemble Ecological Niche Model (EENM) to produce a spatially-explicit map of habitat suitability. When compared against a ~20-year database of public sightings of basking sharks across UK coastal seas (to 6 nautical miles offshore), patterns of habitat suitability yielded a statistically significant agreement with areas known to support basking shark sightings. EENMs could be used to advise Marine Protected Area (MPA) selection, as well as to inform environmental impact assessments for offshore developments. The application of EENM outputs could be wide-reaching and benefit not only basking sharks but other large mobile marine species in the north-east Atlantic.

In recent years, information about the movements and timing of migration by male sea turtles has begun to be unraveled. Here, we present the first satellite tracking of male loggerhead sea turtles ( Caretta caretta ) in the eastern Atlantic. Satellite linked transmitters were attached to five adult males, captured in the near shore waters off Boavista, Republic of Cape Verde. This archipelago hosts the single most important breeding site of loggerhead turtles in the eastern Atlantic. Animals were tracked for periods ranging between 48 and 537 days, including a probable annual remigration to the vicinity of the nesting ground for one turtle. Males showed a variety of movement patterns both during and after the breeding season. Of three males that transmitted for 85, 329 and 537 days, two (the smallest) migrated east and remained in oceanic waters for the tracking period and another (larger turtle) migrated 810 km northeast, to neritic waters off the coast of Mauritania, Western Africa. Results suggest males may show the same size-linked dichotomy in migratory strategies, as has been shown for females from this population.

Conserving and managing populations of marine vertebrates can be complex when they occupy the waters of multiple nations, crossing heterogeneous legal and management landscapes. Hawksbill turtles ( Eretmochelys imbricata ) are subject to varying levels of use in Caribbean countries and their conservation and management is complicated by the extent to which they are a ‘shared’ resource. In 1997 and 2000, Cuba attempted to ‘downlist’ hawksbills from Cuban waters to CITES Appendix II to allow limited international trade. The research on movement and dispersal of hawksbills reported here was undertaken to better inform discussion about the impacts of their harvest. Flipper tagging and satellite tracking demonstrate that the majority of study turtles remained in Cuban territorial waters. Of 1170 hawksbills tagged (525 adults and 606 juveniles), 12% ( n = 143) were recaptured. All recaptured adults ( n = 16 males, 38 nesting females and 30 adult females in-water) were in Cuban waters. Of the 59 juveniles recaptured, only four recaptures were outside Cuban waters (Nicaragua = 2, Colombia = 1, USA = 1). Fourteen hawksbills tagged in the waters of other nations were recaptured in Cuban waters. We also satellite tracked 21 turtles (one adult male, ten nesting females and ten non-nesting adult females), of which five tags failed, 11 stayed in Cuban waters for the duration of transmissions (1–809 days) and five foraged in the waters of other nations (Mexico n = 1 an adult female; Honduras n = 2, both post-nesting turtles; Colombia n = 1 an adult female; and the eastern Lesser Antilles n = 1, an adult male), with differences for nesting and non-nesting turtles. Our results, demonstrating extended site fidelity within Cuban waters, suggest that strengthening national management within national jurisdictions that host hawksbill turtles is fundamental to improving regional conservation as a whole.

Summary Marine turtles undergo dramatic ontogenic changes in body size and behavior, with the loggerhead sea turtle, Caretta caretta , typically switching from an initial oceanic juvenile stage to one in the neritic, where maturation is reached and breeding migrations are subsequently undertaken every 2–3 years [1–3]. Using satellite tracking, we investigated the migratory movements of adult females from one of the world's largest nesting aggregations at Cape Verde, West Africa. In direct contrast with the accepted life-history model for this species [4], results reveal two distinct adult foraging strategies that appear to be linked to body size. The larger turtles (n = 3) foraged in coastal waters, whereas smaller individuals (n = 7) foraged oceanically. The conservation implications of these findings are profound, with the population compartmentalized into habitats that may be differentially impacted by fishery threats in what is a global fishing hotspot [5]. Although the protection of discrete areas containing coastal individuals may be attainable, the more numerous pelagic individuals are widely dispersed with individuals roaming over more than half a million square kilometers. Therefore, mitigation of fisheries by-catch for sea turtles in the east Atlantic will likely require complex and regionally tailored actions to account for this dichotomous behavior.