Distribution and composition of seafloor macrolitter in the trawlable fishing areas along the Algerian coast (Western Mediterranean)

A total of 254 fishing hauls were sampled with a GOC73 bottom trawl during the four demersal resource assessment research cruises, respectively, in 2016, 2019, 2021 and 2022, carried out on board the BELKACEM GRINE research vessel (R/V). We performed the hauls between 22 and 660 m of depth, after which we counted and weighed each piece of marine litter separately to the nearest 0.5 g. The results show that marine litter densities varied between 1350 and 5813 item/km2. Thus, plastic is the most abundant litter, it represents a mean rate of 76 % of the whole marine litter. Among this plastic, 3.8 % was identified as fishing gears or fishing related objects. Therefore, the average loss in catch was estimated at 7 % over the study period. However, the highest density of marine litter was found in the region of Bejaia located in the Center part of the Algerian coast. Moreover, the bathymetric and geographical variability had a significant impact on both density and weight of marine litter. A marine litter monitoring program is necessary for offering a more effective solutions. •Plastic dominated the composition of marine litter with a mean rate of 76 %.•High macrolitter abundance is found in the region of Bejaia with 5813 item/km2.•Mean density of litter in fishing grounds over the study period is 373 item/km2.•Increase of mean litter density from 284 item/km2 in 2016 to 507 item/km2 in 2022.