Sea-based marine litter originates – accidently, from normal operations and from deliberate discarding – from maritime activities such as shipping, fishing, offshore installations or dumping of refuse at sea. Sea-based marine litter seems to correlate with busy shipping routes. The fishing grounds tend to concentrate discarded fishing gear, but fishing ‘waste’ can additionally be transported from long distances with prevailing winds and currents. During the storms damaged structures of aquaculture can release significant amount of plastic litter.
Table 3. Some common marine litter items that can be originated from multiple sources and pathways (modified from JRC 2016).