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Richmond River Cod
The Richmond River cod was a form of ''Maccullochella'' cod, now believed to have been eastern freshwater cod, ''Maccullochella ikei'', that occurred naturally in the Richmond River system, an east coast river system in north-east New South Wales, Australia. Eastern freshwater cod in turn are a species of ''Maccullochella'' cod found in east coast drainages and originating from Murray cod, ''Maccullochella peelii'', that crossed the Great Dividing Range and entered east coast drainages from a river capture event between 0.62 and 1.62 million years ago (mean estimate 1.1 million years ago). Richmond River cod are extinct, from overfishing, habitat destruction including gross siltation, and whole-of-catchment scale bushfires and fish kill The term fish kill, known also as fish die-off, refers to a localized die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (2005) ''Plant Management in Fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maccullochella
''Maccullochella'' is a genus of large Australian predatory freshwater fish within the family Percichthyidae. The genus ''Maccullochella'' was named after an early Australian fish researcher with the surname ''McCulloch''. The ''Maccullochella'' species are called 'cod' in the vernacular. At the time of European settlement of Australia, members of the genus ''Maccullochella'' dominated the Murray-Darling river system ( Murray cod, ''M. peelii'', and trout cod, ''M. macquariensis'') and 4 East Coast river systems (eastern freshwater cod, ''M. ikei'', of the Clarence and Richmond Rivers, Brisbane River cod, ''Maccullochella'' sp., and Mary River cod, ''M. mariensis''). As large, long-lived, top-order predators with delayed sexual maturity and relatively low fecundity (fertility) ''Maccullochella'' species are extremely vulnerable to overfishing, siltation and other forms of habitat degradation, and river regulation by dams and weirs that alter river environments and negatively af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eastern Freshwater Cod
The eastern freshwater cod (''Maccullochella ikei''), also known as the eastern cod or Clarence River cod, is a large predatory freshwater fish of the genus ''Maccullochella'' and the family Percichthyidae, that occur in the coastal Clarence River system of north-eastern New South Wales. Eastern freshwater cod are closely related to the Murray cod of the Murray-Darling River system, and are considered an icon of the Clarence River system. A long-lived, slow-growing species, eastern freshwater cod are threatened by poaching .e. illegal take habitat degradation, catastrophic natural events such as bushfires, and inbreeding from low genetic diversity. They are currently classified as endangered and protected by law from human exploitation of any kind. Range Eastern freshwater cod are native to the Clarence River system in northern New South Wales, Australia. The Clarence River system is an extensive East Coast drainage with many tributaries of differing size. By Australian stan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richmond River
The Richmond River is a river situated in the Northern Rivers region of New South Wales, Australia. Course and features The river rises at the northern end of the Richmond Range, near its junction with the McPherson Range, on the Queensland/ New South Wales border, west of Mount Lindesay, and flows generally south east and north east, joined by twelve tributaries, including the Wilsons River, before reaching its mouth at its confluence with the Coral Sea of the South Pacific Ocean near Ballina; descending over its course. On its journey it passes through the towns of Kyogle, Casino, Coraki and Woodburn. Summerland Way is situated adjacent to much of the middle reaches of the course of Richmond River. At Ballina, the Pacific Highway crosses the river. The catchment area of the river is estimated at , which makes it the sixth largest catchment in New South Wales; and its floodplain has an area of over . History Aboriginal history The traditional custodians of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New South Wales
) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_date = Colony of New South Wales , established_title2 = Establishment , established_date2 = 26 January 1788 , established_title3 = Responsible government , established_date3 = 6 June 1856 , established_title4 = Federation , established_date4 = 1 January 1901 , named_for = Wales , demonym = , capital = Sydney , largest_city = capital , coordinates = , admin_center = 128 local government areas , admin_center_type = Administration , leader_title1 = Monarch , leader_name1 = Charles III , leader_title2 = Governor , leader_name2 = Margaret Beazley , leader_title3 = Premier , leader_name3 = Dominic Perrottet (Liberal) , national_representation = Parliament of Australia , national_representation_type1 = Senat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's List of countries and dependencies by area, sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a Megadiverse countries, megadiverse country, and its size gives it a wide variety of landscapes and climates, with Deserts of Australia, deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately Early human migrations#Nearby Oceania, 65,000 years ago, during the Last Glacial Period, last i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Dividing Range
The Great Dividing Range, also known as the East Australian Cordillera or the Eastern Highlands, is a cordillera system in eastern Australia consisting of an expansive collection of mountain ranges, plateaus and rolling hills, that runs roughly parallel to the east coast of Australia and forms the fifth-longest land-based mountain chain in the world, and the longest entirely within a single country. It is mainland Australia's most substantial topographic feature and serves as the definitive watershed for the river systems in eastern Australia, hence the name. The Great Dividing Range stretches more than from Dauan Island in the Torres Strait off the northern tip of Cape York Peninsula, running the entire length of the eastern coastline through Queensland and New South Wales, then turning west across Victoria before finally fading into the Wimmera plains as rolling hills west of the Grampians region. The width of the Range varies from about to over .Shaw, John H., ''Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River Capture
Stream capture, river capture, river piracy or stream piracy is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream. This can happen for several reasons, including: *Tectonic earth movements, where the slope of the land changes, and the stream is tipped out of its former course *Natural damming, such as by a landslide or ice sheet *Erosion, either **Headward erosion of one stream valley upwards into another, or **Lateral erosion of a meander through the higher ground dividing the adjacent streams. **Within an area of karst topography, where streams may ''sink'', or flow underground (a sinking or losing stream) and then reappear in a nearby stream valley *Glacier retreat The additional water flowing down the capturing stream may accelerate erosion and encourage the development of a canyon (gorge). The now-dry valley of the original stream is known a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include: growth overfishing, recruitment overfishing, ecosystem overfishing. The ability of a fishery to recover from overfishing depends on whether its overall carrying capacity and the variety of ecological conditions are suitable for t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Destruction
Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby reducing biodiversity and species abundance. Habitat destruction is the leading cause of biodiversity loss. Fragmentation and loss of habitat have become one of the most important topics of research in ecology as they are major threats to the survival of endangered species. Activities such as harvesting natural resources, industrial production and urbanization are human contributions to habitat destruction. Pressure from agriculture is the principal human cause. Some others include mining, logging, trawling, and urban sprawl. Habitat destruction is currently considered the primary cause of species extinction worldwide. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introdu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltation
Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or permanent) of fine sediments on bottoms where they are undesirable. Siltation is most often caused by soil erosion or sediment spill. It is sometimes referred to by the ambiguous term "sediment pollution", which can also refer to a chemical contamination of sediments accumulated on the bottom, or to pollutants bound to sediment particles. Although "siltation" is not perfectly stringent, since it also includes particle sizes other than silt, it is preferred for its lack of ambiguity. Causes The origin of the increased sediment transport into an area may be erosion on land or activities in the water. In rural areas, the erosion source is typically soil degradation by intensive or inadequate agricultural practices, leading to soil eros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Kill
The term fish kill, known also as fish die-off, refers to a localized die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (2005) ''Plant Management in Florida's Waters.'' The most common cause is reduced oxygen in the water, which in turn may be due to factors such as drought, algae bloom, overpopulation, or a sustained increase in water temperature. Infectious diseases and parasites can also lead to fish kill. Toxicity is a real but far less common cause of fish kill. Fish kills are often the first visible signs of environmental stress and are usually investigated as a matter of urgency by environmental agencies to determine the cause of the kill. Many fish species have a relatively low tolerance of variations in environmental conditions and their death is often a potent indicator of problems in their environment that may be affecting other animals and plants and may have a direct impact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
