Modelling the distribution of fishing-related floating marine litter within the Bay of Biscay and its marine protected areas

The coastal waters of the south-east Bay of Biscay a dead-end for neustonic plastics

“…Many numerical modelling studies underline that the BoB is a trapping zone for floating plastic ( Rodríguez-Díaz et al, 2020 ; van Sebille et al, 2012 ). Others, particularly point out towards the SE BoB as one of the most important aggregation areas, especially during spring-summer seasons due to their seasonal wind and wave patterns ( Declerck et al, 2019 ; Pereiro et al, 2018 , Pereiro et al, 2019 ; Ruiz et al, 2022a ), fact that is corroborated by scientific samplings ( Ruiz et al, 2022b ). However, most studies focus on oceanic waters, and coastal areas are overlooked.…”

“…A deeper understanding of plastic distribution and concentration was necessary to target the sites exposed to this pollution. This has been addressed as part of several contributions targeting microplastics in the BoB ( Mendoza et al, 2020 ), floating marine litter abundance as part of ecosystemic surveys ( Ruiz et al, 2022b ), aggregation of floating marine litter in coastal marine litter windrows ( Ruiz et al, 2020 ), modelling of plastic sea surface distribution having rivers as sources ( Declerck et al, 2019 ), modelling of fishing activity related floating marine litter ( Ruiz et al, 2022a ), floating marine litter collection solutions ( Andrés et al, 2021 ), and beaching forecasts for efficient cleaning services ( Granado et al, 2019 ). The present contribution provides the needed information regarding Neustonic plastic abundance and distribution, and it complements the overall picture.…”

“…This is precisely what has happened is the south-east of the Bay of Biscay (SE BoB). This region has been highlighted by recent studies, based on Lagrangian computations from numerical models and observations, as a cul de sac for floating plastic ( Declerck et al, 2019 ; Lebreton et al, 2012 ; Pereiro et al, 2019 ; Ruiz et al, 2022a ; van Sebille et al, 2012 ). Some of the local authorities of this region, i.e., in Gipuzkoa (Spain) the Provincial Council of Gipuzkoa, and in the Pyrénées-Atlantiques (France) the Communauté d'Agglomération Pays Basque and the Ville de Biarritz, have shown interest in providing solutions, but they felt that they lacked the knowledge to face this problem and implement valid solutions (pers.…”

“…The BoB presents a moderate level of microplastic pollution ( Mendoza et al, 2020 ), and modelling studies have recently revealed that microplastics in the BoB tend to be freely scattered oceanward while larger items tend to stay close to shore. Particularly the longest residence times and abundances for the BoB are observed in the SE region of the BoB both for sea-based related floating macro and microplastic ( Pereiro et al, 2019 ; Rodríguez-Díaz et al, 2020 ; Ruiz et al, 2022a ). The coastal waters of the SE BoB also present particular structures at the submesoscale domain (<10 km horizontally), called marine litter windrows , that tend to aggregate floating macrolitter, seafoam, seaweeds ( Cózar et al, 2021 ; Ruiz et al, 2020 ).…”

“…This contribution, jointly with the work presented in Ruiz et al (2022a; 2020; 2022b) for micro and macro litter monitoring provide new insights on the background knowledge on marine litter in the BoB, and particularly the coastal areas of the SE BoB; information that can assist the local authorities in being more prepared to address plastic pollution in the coastlines they manage. The questions to be answered by the present contribution are how much plastic is in the coastal waters of Gipuzkoa and Pyrénées-Atlantiques (SE BoB), where do plastics accumulate, and when.…”