Recovering Trout Cod in the Ovens River A threatened species success story Background The Murray-Darling Authority (MDBA), Victorian Fisheries Authority (VFA) and the Arthur Rylah Institute Trout Cod (Maccullochella macquariensis) is a (ARI) have collaborated to reintroduce Trout Cod back (up to 850mm length, 16kg weight) riverine fish into waterways where they previously existed. native to the mid reaches of the Murray-Darling Basin Consequently, Trout Cod were re-introduced into a (MDB). Once widespread and abundant, the species number of locations within the MDB (and elsewhere), has suffered a major decline in its distribution and including the lower-mid reaches of the Ovens River. abundance, particularly in the 1970s and 1980s due to Ecology and Life-history threatening processes including the removal of woody debris, flow regulation and dam construction. By the late Cod have a preference for faster-flowing deep 1980s, only a single, naturally occurring population was waters with abundant instream woody habitat. They are known to exist, in the Murray River between Yarrawonga a lie-in-wait apex predator, show strong site fidelity and to Cobram. are renowned for their aggression and fighting qualities A national recovery plan for Cod (DSE 2008) as a sport fish. Trout Cod sexually mature at 3-5 years, outlines a range of objectives and actions for this and adults undertake a spawning migration in spring critically endangered species. An Ovens River Trout (October and November) over 10’s of km’s. The species Cod Recovery program (DCNR 1994) has also been lays adhesive eggs in nests, which are guarded by the developed, which includes the following broad male until they hatch. Larvae drift downstream for four to objectives: five days. Survival of larvae and juveniles is correlated Develop suitable breeding techniques with years of higher flow variability in summer and Develop a translocation strategy autumn. Educate anglers to tell the difference between Murray Cod and Trout Cod. Monitor the Trout Cod population Figure 1: A juvenile Trout Cod caught in the Ovens River (Photo: Undertake research into the biology/ecology of the ARI) species.
Recovering Trout Cod in the Ovens River A threatened species success story Background Trout Cod (Maccullochella macquariensis) is a (up to 850mm length, 16kg weight) riverine fish native to the mid reaches of the Murray-Darling Basin (MDB). Once widespread and abundant, the species has suffered a major decline in its distribution and abundance, particularly in the 1970s and 1980s due to threatening processes including the removal of woody debris, flow regulation and dam construction. By the late 1980s, only a single, naturally occurring population was known to exist, in the Murray River between Yarrawonga to Cobram. A national recovery plan for Cod (DSE 2008) outlines a range of objectives and actions for this critically endangered species. An Ovens River Trout Cod Recovery program (DCNR 1994) has also been developed, which includes the following broad objectives: Develop suitable breeding techniques Develop a translocation strategy Educate anglers to tell the difference between Murray Cod and Trout Cod. Monitor the Trout Cod population Undertake research into the biology/ecology of the species. The Murray-Darling Authority (MDBA), Victorian Fisheries Authority (VFA) and the Arthur Rylah Institute (ARI) have collaborated to reintroduce Trout Cod back into waterways where they previously existed. Consequently, Trout Cod were re-introduced into a number of locations within the MDB (and elsewhere), including the lower-mid reaches of the Ovens River. Ecology and Life-history Cod have a preference for faster-flowing deep waters with abundant instream woody habitat. They are a lie-in-wait apex predator, show strong site fidelity and are renowned for their aggression and fighting qualities as a sport fish. Trout Cod sexually mature at 3-5 years, and adults undertake a spawning migration in spring (October and November) over 10’s of km’s. The species lays adhesive eggs in nests, which are guarded by the male until they hatch. Larvae drift downstream for four to five days. Survival of larvae and juveniles is correlated with years of higher flow variability in summer and autumn. Figure 1: A juvenile Trout Cod caught in the Ovens River (Photo: ARI)