| | Rainbow Trout Rainbow trout ( Oncorhynchus mykiss ) and brown trout ( Salmo trutta ) have a long history of aquaculture and rainbow trout is one of the few species of fish which may be regarded as truly domesticated. Rainbow trout originate from western North America, while brown trout are native to Europe. In 1995, world aquaculture production of rainbow trout was approximately 360,000 tonnes, valued at approximately US $1.3 billion, while the total global production for all salmonids (including smelts) was approximately 943,000 tonnes and US $3.7 billion species whereas brown trout are generally grown only for recreational fishing. Brown TroutBrown trout have been in Western Australian waters since 1931 and rainbow trout since 1942. Both species of trout were originally introduced to our waters to provide food and recreational fishing, there being no large freshwater native species in southern areas except for the native catfish ( Tandanus bostocki ). As trout came from cooler, temperate climates, their distribution in WA is restricted to the south-west corner of the State. In 1935, a hatchery was developed at Pemberton in the south-west of WA, for breeding both brown and rainbow trout. The hatchery is now operated by the Department of Fisheries as part of the South West Freshwater Research and Aquaculture Centre (SWFRAC) and provides juvenile and yearling rainbow and brown trout for stocking of public rivers and dams for recreational fishing, to farmers to stock their dams, to fish farms for commercial trout grow-out, and for saline inland aquaculture of rainbow trout. There is a small established trout aquaculture industry in Western Australia. Currently, there are three farms commercially producing trout in WA and this low number of producers prevents the release of specific trout production data (see Cole et al., 1999). The commercial production from the aquaculture of trout in WA had reached 40 tonnes per annum, valued at around $400,000 (McNee et al., 1993). However, due to the reduced number of commercial farms and the diversion of production for fish-out (pay to fish) operations, the local industry has contracted. Australia-wide, over 9,000 tonnes of trout and salmon were produced in 1997/98, worth more than A$75 million (ABARE 1998). Rainbow trout (also called 'ocean trout') are produced in sea cages in Tasmania, but over 2,000 tonnes of rainbow trout were produced from land-based culture with a value of A$12.7 million, mostly from Victoria. Only land-based trout culture is practised in Western Australia. Attempts to farm rainbow trout in sea cages off the south coast have been limited by warm water temperatures, the lack of sheltered sites and poor public reception. However, alternative sites for large-scale production of rainbow trout are currently being examined. | |