Disentangling the impact of artificial substrata on the trophic ecology of the highly endangered marine invertebrate Patella ferruginea Gmelin, 1791

ABSTRACT Limpets are keystone species worldwide, promoting marine biodiversity in coastal areas. Of special concern are the so-called giant limpets such as Patella ferruginea, either due to their role in marine ecosystems and/or threatened status. The proliferation of artificial substrata caused by human population growth has allowed their use as a surrogate habitat for many species of limpets. However, little is known about the impact on the trophic ecology of these species caused by artificial substrata. The stable isotope approach has been widely used to explore the trophic ecology of marine species and so was used in the present study of P. ferruginea. The results of this study indicated that diet consumption differs between artificial and natural substrata for P. ferruginea. Enrichment in δ15N values of specimens collected within the harbour of Ceuta indicates that this endangered species would be a useful indicator for detecting anthropogenically derived organic matter in coastal areas. Further research is required to evaluate the impact of artificial substrata from a conservational perspective.