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- A novel expert-driven methodology to develop thermal response curves and project habitat thermal suitability for cetaceans under a changing climatePublication . Sousa, Andreia G.; Fernandez, Marc; Alves, Filipe M. A.; Arranz, Patricia; Dinis, Ana; González García, Laura; Morales, Misael; Lettrich, Matthew D.; Coelho, R. Encarnação; Costa, Hugo; Lourenço, T. Capela; Azevedo, José M. N.; Santos, Catarina FrazãoOver the last decades, global warming has contributed to changes in marine species composition, abundance and distribution, in response to changes in oceanographic conditions such as temperature, acidification, and deoxygenation. Experimentally derived thermal limits, which are known to be related to observed latitudinal ranges, have been used to assess variations in species distribution patterns. However, such experiments cannot be undertaken on free-swimming large marine predators with wide-range distribution, like cetaceans. An alternative approach is to elicit expert's knowledge to derive species' thermal suitability and assess their thermal responses, something that has never been tested in these taxa. We developed and applied a methodology based on expert-derived thermal suitability curves and projected future responses for several species under different climate scenarios. We tested this approach with ten cetacean species currently present in the biogeographic area of Macaronesia (North Atlantic) under Representative Concentration Pathways 2.6, 4.5 and 8.5, until 2050. Overall, increases in annual thermal suitability were found for Balaenoptera edeni, Globicephala macrorhynchus, Mesoplodon densirostris, Physeter macrocephalus, Stenella frontalis, Tursiops truncatus and Ziphius cavirostris. Conversely, our results indicated a decline in thermal suitability for B. physalus, Delphinus delphis, and Grampus griseus. Our study reveals potential responses in cetaceans' thermal suitability, and potentially in other highly mobile and large predators, and it tests this method's applicability, which is a novel application for this purpose and group of species. It aims to be a cost-efficient tool to support conservation managers and practitioners.
- Alongside but separate : Sympatric baleen whales choose different habitat conditions in São Miguel, AzoresPublication . González García, Laura; Pierce, Graham J.; Autret, Emmanuelle; Torres-Palenzuela, Jesús M.Fin whales and sei whales are two migratory baleen whale species sighted every year across the waters of the Azores. Improved understanding of the ecological niche and habitat requirements of these baleen whales is needed to identify persistent or predictable oceanographic events that may set the time of their migration, as well as local or ephemeral oceanographic features that may aggregate their prey in a particular area. In dynamic environments such as the open ocean, mesoscale and submesoscale features can become decisive to determine the distributions of highly mobile species such as baleen whales. In this study, we analyse the habitat preferences of fin whales and sei whales around São Miguel Island (Azores) using environmental variables at different temporal and spatial scales. For both species, model results showed a clear influence of variables linked with primary production and therefore, prey availability; as well as a noticeable preference for oceanographically dynamic areas which directly affect distribution and aggregation of prey. Those environmental choices may indicate different levels of foraging habitat use for both species. Differences were found between the species, highlighting preferences for colder waters in fin whales and areas with stronger sea surface temperature gradients in sei whales. Model results obtained for fin whales were similar with those previously published for blue whales, suggesting that both species make similar use of the waters around São Miguel, often foraging during the migration across these waters. Results for sei whale, however, emphasize dynamic variables, indicating that travelling may prevail over feeding behaviour during their migration by the Azores.
- MONICET: The Azores whale watching contribution to cetacean monitoringPublication . González García, Laura; Fernandez, Marc; Manuel N. Azevedo, JoséABSTRACT: The Azores islands have been historically linked to cetaceans, becoming an example of a successful transition from whaling to whale watching. Twenty-eight cetacean species have been sighted in these waters, making the archipelago one of the most recognised whale and dolphin watching destinations worldwide. The business is well-established in the region, operates in four of the nine islands year-round or seasonally and provides an excellent opportunity to collect long term information on cetacean distribution and abundance in an affordable way. Continuous monitoring is indeed essential to establish baseline knowledge and to evaluate cetacean response to potential natural or anthropogenic impacts. Opportunistic data greatly complement traditional dedicated surveys, providing additional support for appropriate management plans.
- Long-Range Longitudinal Movements of Sperm Whales (Physeter macrocephalus) in the North Atlantic Ocean Revealed by Photo-IdentificationPublication . Mullin, Keith D.; Steiner, Lisa; Dunn, Charlotte; Claridge, Diane; González García, Laura; Gordon, Jonathan; Lewis, TimThis article summarises a sperm whale photo-id match from the Gulf of Mexico to the Azores, another match from the Bahamas to the Azores and a match from the Gulf of Mexico to the Bahamas.