Marine pollution is a primary cause of eutrophication of surface waters, in which excess nutrients, usually nitrates or phosphates, stimulate algae growth. Many potentially toxic chemicals adhere to tiny particles which are then taken up by plankton and benthic animals, most of which are either deposit feeders or filter feeders. In this way, the toxins are concentrated upward within ocean food chains. Many particles combine chemically in a manner highly depletive of oxygen, causing estuaries to become anoxic. When pesticides are incorporated into the marine ecosystem, they quickly become absorbed into marine food webs. Once in the food webs, these pesticides can
Malacological Society of London 1942. Molluscs range in size from cephalopods such as the octopus and giant squid to microscopic gastropod snails, and the Society is concerned with some 85,000 recognised extant species, which include 23 per cent of all named marine organisms as well as molluscs living in freshwater and terrestrial habitats. It is also interested in the species (including those of the two extinct classes of molluscs) preserved as fossils, which creates a relationship with the study of geology. In association with the Oxford University Press, the Society publishes the "Journal of Molluscan Studies", previously called "Proceedings of the Malacological Society", and