European storm-petrel occurrence 2005-2019 Atlantic Iberian arc

Marine Protected Areas (MPAs) are widely used tools for conservation and
management. Their correct delimitation is challenging, especially when the
target species are small, elusive, and inconspicuous, as little data is
generally available to adequately assess their distribution at sea.
Therefore, currently designated MPAs may not effectively cover key areas
for small seabirds, particularly during migration and wintering seasons.
We used Ensemble Species Distribution Models (ESDMs) on a 15-year
time-series dataset of at-sea census along the Atlantic Iberian arc to
predict the potential distribution of the smallest European seabird, the
European storm-petrel (Hydrobates pelagicus), and compare it with official
marine Special Protection Areas (SPAs). Occurrence of European
storm-petrel was related to shifts in sea surface temperature, and to
small distances from the coast over the continental shelf. Most relevant
area for the species in the Atlantic Iberian arc was west-central Portugal
to north-western coast of the Iberian Peninsula, with an additional key
area in the Gulf of Cádiz. Both zones host significant SPAs, but they
inadequately cover key areas for European storm-petrels. Our findings
support extending marine SPAs in the Atlantic Iberian arc to ensure their
effective protection. The distribution of the species expands over the
years, varying both in size and location. These changes might be
attributed to dynamic oceanographic variables, such as sea surface
temperature and biomass of micronekton, which seem to play a significant
role in their foraging behaviour. Synthesis and applications: Our study
highlights the importance of analysing long time series and ESDMs to
design adequate protected areas which ensure the conservation of small and
highly mobile species such as storm petrels. Our results should be
considered by decision makers to prioritise and update marine protected
areas, while incorporating the dynamic nature of the ocean within an
ecosystem-based approach.