Freshwater fish

[Extract] Fish are an important component of the fauna of aquatic ecosystems of northern Australia. They contribute substantially to the overall biodiversity in the region and are critical components of riverine and wetland food webs. Fish occur at all secondary levels of food webs, consuming primary production (algae, terrestrial detritus and fruits) and planktonic and epibenthic insects and crustaceans, as well as other fish. They also figure prominently in the diet of other aquatic or semiaquatic organisms, such as snakes and monitor lizards, waterbirds, crocodiles and, of course, people. Fish also shift carbon produced in one area (e.g. floodplains) to other areas as they move between upstream tributaries or downstream estuaries and near-shore marine environments. Fish are economically important (e.g. the commercial and recreational barramundi fisheries of northern Australia), as well as spiritually and culturally vital in the lives of Indigenous people of the north