The Mediterranean Sea has registered great abundances of benthic marine litter (ML). The seafloor is often where it accumulates, an area shared with the activity of bottom trawlers, which can accidentally catch the litter from the seafloor, in strategies named Fishing for Litter (FFL). Thus, this study describes, quantifies and maps the ML caught by bottom trawlers along the Catalan coast (NW Mediterranean Sea). The litter was obtained from 305 hauls performed during three years (2019-2021) from 9 different ports at 3 depth strata covering from 20 to 700 m. In the laboratory, the ML was weighted and classified in six different categories (metal, plastic, rubber, textile, wood, and other waste). ML was present in 97 % of the hauls, which composition varied according to zone, port and depth, with the highest densities found in highly urbanized areas (13.75 ± 3.25 kg km^-2), which mainly contained plastics (74,3 %). The port of Barcelona had the highest presence of plastics (23.62 ± 6.49 kg km^-2), mainly wet wipes. Regarding depth, the continental shelf had the highest density of ML, with 12.24 ± 2.40 kg km^-2. The effect of different ML sources was tested in order to evaluate spatial distribution of ML in the Catalan seafloor. To conclude, the bottom trawl fleet of the Catalan coast has the potential to remove 237 ± 36 t of marine litter yearly. Therefore, FFL initiatives should be part of a multidisciplinary approach to tackle marine litter, which must include prevention, monitoring, and cleaning actions.

Primary Presenter: Eve Galimany, Institut de Ciències del Mar (ICM-CSIC) / Institut Català de Recerca per a la Governança del Mar (ICATMAR) (galimany@icm.csic.es)

Authors:

Marc Balcells,   ()

Marta Blanco,   ()

Ana I. Colmenero,   ()

Claudio Barría,   ()

Ricardo Santos-Bethencourt,   ()

David Nos,   ()

Cristina López-Pérez,   ()

Jordi Ribera-Altimir,   ()

Joan Sala-Coromina,   ()

Mariona Garriga-Panisello,   ()

Alba Rojas,   ()

Víctor Martín-Vélez,   ()

Joan B. Company,   ()