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Water for the environment: wetlands |
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The Fish of NSW Wetlands
The wetlands of NSW provide feeding, spawning and nursery sites for many species of fish. In fact, they are essential to the survival of many freshwater fish including Murray Cod, Golden Perch, Silver Perch and Catfish (Billyard, 2000). Most freshwater fish are not confined to wetlands, but are dependent upon them, directly or indirectly, for particular parts of their life cycle. The habitat requirements of adults are also often very different to the requirements of juveniles. Some fish remain in freshwater all of their lives. Others may or must spend a part of their lives at sea. Some have life cycles that involve migrations from fresh to salt water, or vice-versa in order to spawn. These species are called diadromous fish. There are still other fish species that spend their entire lives at sea. Due to the great range of wetland types in NSW, from freshwater to marine, all three types of fish can be found in the wetlands of NSW. [ TOP ]
NSW Fisheries is the principle agency responsible for the management of the fish resources of NSW. [ TOP ]
Many of the activities that adversely affect NSW wetlands also directly or indirectly impact on those fish populations dependent on them for particular parts of their life cycle. One of the most significant activities is river regulation. The large dams that have been built in many river systems in NSW store water that would have previously flooded wetlands further down the system. In many cases this has prevented the spawning of some native species as well as a reduction in the survival of young fish. With less water flowing into wetlands there has been a significant reduction in the movement of fish into and out of wetlands. There has also been a disruption in the cycling of nutrients as well as wetland productivity. In other cases wetlands that were previously characterised by cycles of wetting and drying are now permanently inundated. Regulatory structures also impede the passage of migratory species such as the Golden Perch and the Australian Bass. There are many other activities that have led to the decline of fish populations in NSW. They include, but are not limited to: water pollution; dredging and reclamation; water abstraction; the intermittent opening of coastal lagoons; aquaculture; the construction of roads, bridges, culverts, causeways and similar structures; the removal of snags, boulders or rocks; clearing of riparian or floodplain vegetation; the construction of breakwaters, jetties and similar structures; commercial and recreational fishing; and, erosion and sedimentation. [ TOP ]
In the NSW Fisheries, Aquatic Habitat Management and Fish Conservation - Policy and Guidelines (1998), the following categories are given for fish that have been moved from and within their natural ranges. Exotic species are those species brought into Australia from a foreign country, that are known to only occur in captivity within the aquarium trade in Australia. Alien species are those species brought into Australia from a foreign country, that have established wild populations in Australia. Introduced species refers to those native species that have been transferred into areas that are outside their natural range. Translocated species refers to native species that have been transferred into other localities within their natural range. [ TOP ]
Threatened Species Legislation that provides for the protection of all threatened fish and marine plants in NSW was included as Part 7a of the Fisheries Management Act in July 1998. Within the legislation fish are actually defined to include all aquatic animals at any stage in their life cycle. The provisions mirror those in the Threatened Species Conservation Act 1995 (administered by the NSW NPWS). As of September 1999, seven species had been declared as threatened under the legislation. These seven fish and their habitats are afforded special consideration in planning decisions. Protected Species NSW Fisheries has also prohibited the capture of some rare freshwater and marine species in order to ensure their protection. [ TOP ]
Details of some of fish species commonly found in NSW wetlands are provided below. Clear notes are given to indicate where a particular fish species is most likely to be found, whether it is threatened or protected, and some of the major activities that may be affecting populations.
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Best Reference Website - NSW Fisheries General & Field Guides
Conservation & Management
Threatened species
Introduced species
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| Copyright © 2000 - NSW Department of Natural Resources www.naturalresources.nsw.gov.au |
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