Fish ladders give native fish a survival boost

28/5/03
In a first for Western Australia, native freshwater fish are being given a helping hand to overcome man-made barriers and reach new habitats.
Fisheries Minister Kim Chance today opened the Goodga River 'fish ladder' near Albany - one of two types of the unique invention being put to the test in local waterways to help fish 'climb' over obstacles such as weir walls.
"The Goodga River east of Albany is the only known waterway in WA where the rare trout minnow (Galaxias truttaceus) is found," Mr Chance said.
"But when a 1.5m high concrete gauging weir was installed several years ago, the fish were unable to travel upstream to valuable habitat and breeding areas, threatening their future.
"The purpose built 'vertical slot' fish ladder is helping overcome this."
A 'vertical slot ladder' is a gentle sloping concrete channel consisting of a series of connected water pools. It allows the trout minnow to slowly 'climb' the weir and swim upstream into previously inaccessible waters.
The remote fish ladder took several months to construct and cost about $50,000. The project was funded by a National Heritage Trust grant and the Department of Fisheries.
Engineering and on-the-ground project management was provided by the Waters and Rivers Commission.
The commission has also completed a fish ladder in Margaret River using a Department of Fisheries 'Fishcare' grant. The ladder was built following the construction of the Margaret River Weir.
"Several native species - including the primitive 'eel like' fish, lampreys - have been unable to negotiate the 1.4m climb over the wall to reach seasonal breeding areas," Mr Chance said.
"Many animals died from injuries, exhaustion or getting lost while attempting to climb over or around the weir.
"The ladder is a slowly graduating ramp made from rocks that mimic the environment by creating a series of step pools in which the fish can rest before negotiating the next gradual incline."
Mr Chance said the fish ladders were just one example of how the Department of Fisheries was working with the community to protect fish stocks.
"Fish ladders have been used with varying degrees of success in other parts of Australia," he said.
"WA's infant fish ladder program has been working with other States in order to avoid repeating their mistakes."
Minister's office: 9213 6700