Walking Fish Reach Another Milestone

The trial release of the 156 captive-reared juvenile spotted handfish - a species that walks across the bottom on leg-like fins - is a milestone in the Recovery Plan for the species, say CSIRO marine biologists, Barry Bruce and Mark Green.

Spotted handfish are the first Australian marine fish to be listed as endangered under the Commonwealth Endangered Species Protection Act.

"This is a significant step in the overall conservation effort for this species" says Mr Bruce, who leads the project in its quest to secure the few remaining populations of this rare and threatened Australian fish.

"The information gained from this trial will help establish whether reintroduction is a viable strategy to help spotted handfish populations recover. Similar trials at other localities in the Derwent will also provide valuable information on the causes of the species decline," he says.

It has taken three years to develop a successful method to rear these fish in captivity according to Project Officer, Mark Green.

"This success is due to the dedication of the small team involved with maintaining the fish in captivity," Mr Green says.

Tasmania's Minister for Primary Industries, Water and Environment, Mr David Llewellyn, says the return of the captive-bred fish is a red-letter achievement in an important environmental program.

"This success is a result of strong co-operation between several government and community-based agencies working together towards preserving our natural marine environment," Mr Llewellyn says.

The juveniles were bred at the Tasmanian Aquaculture and Fisheries Institute's laboratories at Taroona, near Hobart.

Mr Green says that central to the breeding success has been -

· a regular cleaning routine and close monitoring of the water quality in the rearing systems· the development of an artificial substrate around which female handfish could lay their eggs, and· identifying and supplying suitable natural food for the juveniles.

Despite the project's success, any future captive breeding may hinge on finding funds to replace an air-conditioning unit used to cool the handfish nursery with a more suitable chiller system.

"The existing air-conditioning unit has been pushed to the limit, particularly during the critical summer period - we lost fish when it failed to maintain a suitable temperature," Mr Green says.

The objectives of the Recovery Plan, funded under the Federal Government's Natural Heritage Trust, are to monitor current populations of spotted handfish, determine the causes for their decline and implement strategies to help their populations recover.

Organisations participating in the recovery project include CSIRO Marine Research, Environment Australia, the Department of Primary Industries, Water and the Environment, the Tasmanian Aquaculture and Fisheries Institute, the University of Tasmania, the Hobart Ports Corporation, and the Tasmanian Conservation Trust.

More information: Nick.Goldie@nap.csiro.au