The pollution of the marine environment by solid wastes, either directly introduced into the sea or discharged into the oceans from rivers or pipelines, is considered from the perspective of both their impacts and their regulation. The waste materials covered include dredged material, particulate wastes from sand/gravel extraction, and land reclamation, and industrial wastes including mining wastes, munitions, and plastics/litter. All solid wastes have significant physical impacts at the point of disposal when disposed of in bulk with consequentially significant biological impacts, particulary on the benthos. Depending on their composition, these wastes may also exert significant chemical effects through contamination by human activities, for example, by hazardous substances, organic materials with a high oxygen demand, elevated concentrations of nutrients, etc. Wastes disposed of directly at sea fall under international and national regulation whereas those discharged into the oceans from rivers or pipelines, fall only under national regulation.
Encyclopedia of Ocean Sciences, Volume , 1 January 2019,