Modelling common dolphin (Delphinus delphis) coastal distribution and habitat use: Insights for conservation

The world's ecosystems are altered to different extents by anthropogenic activities. Marine habitats, especially coastal areas, are subjected to an increasing pressure derived from human activities on both land and ocean. Information about species distribution is fundamental to develop effective conservation and management measures and counteract negative anthropogenic impacts. The present work explores the use of species distribution models by using the Environmental Niche Factor Analysis (ENFA) to assess the habitat suitability of common dolphins (Delphinus delphis) in Northwest Spain, and its application to the development of effective conservation and management measures. The relationship between presence-only data and ecogeographical variables (EGV) was used to assess the potential distribution of the species. Data was collected during 273 days at sea, covering a total distance of 9 417 km between March 2014 and October 2017 with a total of 91 common dolphin encounters. This study shows that tide level and sea surface salinity are the main EGVs driving the distribution of the species in coastal areas especially in waters above the continental shelf. Additionally, this study reveals the most suitable habitats for common dolphin and outlines the need to develop conservation measures and management plans to promote the protection of this species. Findings of the study contribute to a more accurate and comprehensive understanding of the common dolphin distribution and emphasize the importance of species distribution models in the development of effective conservation and management strategies.