The Iberian harbour porpoise (Phocoena phocoena) is a small, genetically distinct population at the southern edge of the species' European range. Flagged as a conservation concern by the IUCN, it remains poorly resolved at fine spatial scales. This study characterized the spatiotemporal distribution and environmental drivers of porpoise occurrence off Sagres, southwest Portugal, using two decades of opportunistic whale-watching records, addressing where porpoises concentrate and how this varies seasonally, which environmental variables are associated with it, how environment compares with spatial location in explaining it, and whether occurrence has changed over time. Occurrence was concentrated in three persistent coastal cores that recurred in every season and shifted in extent rather than location. Among the environmental variables, only rock cover was independently associated with occurrence overall, while environment as a whole explained little: spatial location explained more variation than any environmental driver, and most remained unexplained, pointing to unmeasured factors such as prey or fine-scale hydrography. Encounter rate declined over the study period, most strongly in Summer; if real, this decline may signal redistribution or a true population change. The persistent cores mark priority areas for spatially targeted mitigation of bycatch, the principal threat to this population.
promotor/supervisor feedback
nothing yet
