Cetacean distribution and habitat modelling in the NE Atlantic Ocean

• Main Author: Purcari, Ana-Maria
• Other Authors: Castilho, Rita
• Format: Master Thesis
• Language: English
• Published: 2023
• Subjects: Cetáceos; Modelação de nicho ecológico; Maxent; Adequação do habitat; Portugal; Atlântico nordeste; Domínio/Área Científica::Ciências Naturais::Outras Ciências Naturais; Balaenoptera acutorostrata; Balaenoptera physalus; Fin whale; minke whale
• Online Access: http://hdl.handle.net/10400.1/20554

The world's ocean, central to life on our planet, is rapidly deteriorating due to human activities. Cetaceans, many of which hold the position of apex predators, play a pivotal role in upholding the integrity of marine ecosystems, serving as indicators of ecosystem health and productivity. However, the conservation of these species is hindered by the scarcity of available data concerning their occurrence and distribution patterns. Ecological niche models are useful in studying habitat suitability concerning the environmental preferences of the species. Combining data from platforms of opportunity and citizen science can overcome difficulties in collecting marine data. This study aimed to model habitat suitability for the most sighted cetacean species: the short-beaked common dolphin (Delphinus delphis), common bottlenose dolphin (Tursiops truncatus), fin whale (Balaenoptera physalus), and minke whale (Balaenoptera acutorostrata) in the Algarve region, South Portugal. Seasonal habitat preference for the target species was investigated using the Maximum Entropy Model for the period 2019-2022. The results show that cetaceans are highly dependent on the coastal habitats of the Algarve, likely due to upwelling events and notable topographic features such as capes, that lead to resource-rich waters. For the short-beaked common dolphin, chlorophyll-a concentration was a key predictor, reflecting prey availability. Models revealed distribution differences between inshore and offshore populations of the common bottlenose dolphin. Fin whales use this area as a migratory corridor, moving between high latitude feeding grounds and low latitude breeding grounds. Minke whales are considered residents in Portuguese waters, present year-round but more reported in spring and summer. Given the great importance of cetaceans for the planet’s well-being and the rapid increase in economic activities in the Algarve, these findings should influence future marine protected area plans to preserve the biodiversity and associated cultural ...