MEPS prepress abstract   -  DOI: https://doi.org/10.3354/meps14429

ABSTRACT: Functional connectivity patterns of threatened species provide critical information for an effective management and conservation spatial planning. In this study, we use a non-lethal novel combination of acoustic telemetry and stable isotope analysis (SIA) on the “Near threatened” elasmobranch, Raja undulata, to evaluate shifts in resource/space use in response to differences in residency patterns within a marine protected area (MPA) in NW Spain. By using acoustic telemetry, we classified individuals of a local population of Raja undulata as high or low residence fish based on estimates of residence index (% of days present within the studied MPA). Individuals with a high residence index (≥50%) showed narrower isotopic niche width than low residence fish, as they were exposed to a limited variety of habitats and food resources. Conversely, low residence fish (mainly females) showed wider isotopic niche widths, indicative of greater diversity of resources from different environments. Therefore, we hypothesize that low residence individuals play an important role connecting different habitats and, even, populations, particularly through dispersion patterns of females along the coast. This study provides valuable insights into the movement and resource ecology of Raja undulata and their role in the functional connectivity of the coastal ecosystem, with direct applicability to inform management of the studied marine protected area.