Adapting to a pollution hotspot? Catsharks shift to plastic substrates for oviposition

9 pages, 5 figures, 2 tables.-- Data availability: Data will be made available on request

Plastic pollution is widely recognized as one of the major threats to marine ecosystems. However, our knowledge on the ecological interactions between plastic and marine fauna is still limited. Here, we analyzed the substrate preferences for oviposition in the small-spotted catshark (Scyliorhinus canicula) and explored the influence of pollution, environmental conditions, and fishing pressure as potential drivers. For the first time, we report this catshark species using marine debris for oviposition, unraveling a behavioral shift in the oviposition substrate preferences towards plastics, particularly ghost fishing gear, when biological substrates are unavailable. Our results indicate that this behavioral change may be driven by the combined effects of plastic pollution and habitat degradation. Preferences also change with depth, with a larger preference for the hydrozoan Lytocarpia myriophyllum on the continental shelf, followed by sponges, as in this region mesophotic and deep benthic communities are still more abundant although impacted by human pressures. In contrast, on the continental slope, the preference shifts to tube-dwelling polychaetes and plastics, primarily ghost fishing gear, due to the limited availability of biological substrates in this region. We highlight that plastic-fish interactions may become increasingly recurrent as plastic substrates increase and habitat forming invertebrates decline due to trawl fishing and other anthropogenic activities, especially in the Mediterranean Sea. The implications of this behavior for catshark fitness are still largely unknown, which prompts further research concerning the potential impact on its survival and/or dispersal in the plastic age and highlights the urgency of preserving biogenic habitats

B.F. was supported by a Ramon y Cajal grant (RYC2022-036268-I) funded by MICIU/AEI/10.13039/501100011033 and FSE+, a Beatriu de Pinós grant (2019 BP 00183), from the Catalan Government and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 801370, and the MedCalRes project Grant PID2021-125323OA-I00 funded by MCIN/AEI/10.13039/501100011033 and ‘ERDF A way of making Europe’. With the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S). B.F. is part of the Marine Conservation research group funded by Generalitat de Catalunya (2021 SGR 01073). This research was supported by the Biodiversity Foundation of the Ministry for the Ecological Transition and Demographic Challenge under the project ECEME (CA_BM_2019). DR-G was supported by a FPU grant of the Spanish Ministry of Universities (MIU). A.S-V. acknowledge the financial support by a Catalan Government Grups de Recerca Consolidats grant (2021 SGR 01195) and the ICREA Academia program

Peer reviewed