Marine litter from sea-based activities arises from multiple sources (GESAMP 2015; GESAMP 2020b), for example, all affordable, lightweight and durable maritime equipment is made of plastics. Major sea-based sources of plastics and microplastics include fisheries and aquaculture (FAO 2020); shipping and offshore operations and ship-based tourism. In Europe, based on numerous surveys, aquaculture is estimated to contribute 14 per cent of this debris (Veiga et al. 2016; European Commission 2018a).
On beaches along the coastline of the Adriatic and Ionian Seas mussel nets were the seventh most frequent items found
(Vlachogianni et al. 2017; Fleet et al. 2021), while in sea floor
surveys litter from aquaculture accounted for 15 per cent of the items recorded (Spedicato et al. 2019). Statistics from the
PRODCOM database indicate that the contribution of fishing
gear and aquaculture to waste and marine litter (netting and
non-netting) in European waters is 11,000 metric tons per year (Unger and Harrison 2016; European Commission 2018a; Ingeborg and Gabrielson 2018) compared to 15,604 metric tons per year from single-use plastics.
From collection: From Pollution to Solution: A Global Assessment of Marine Litter and Plastic Pollution