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
Shrimp and prawn as food Shrimp and prawn as food Shrimp and prawn are important types of seafood that are consumed worldwide. Although shrimp and prawns belong to different suborders of Decapoda, they are very similar in appearance and the terms are often used interchangeably in commercial farming and wild fisheries. A distinction is drawn in recent aquaculture literature, which increasingly uses the term "prawn" only for the freshwater forms of palaemonids and "shrimp" for the marine penaeids. In the United Kingdom, the word "prawn" is more common on menus than "shrimp"; the opposite is the case in North America. The term "prawn" is also