Slots in dyke walls, won’t fix mulloway fishery

Congolli rather than mulloway are now the focus of restoration efforts in the Lower Lakes. In a 2011 article by Ruchira Talukdar from the Australian Conservation Foundation, this species common in estuaries in Tasmania, Victoria and southern NSW is incorrectly described as being on the verge of extinction and dependent on the Goolwa Barrage boat lock for passage to the Coorong to spawn. Ms Talukdar wrote: "Upstream over-extraction of water in the Murray-Darling Basin and the prolonged drought had left the Lower Lakes disconnected from the Coorong, dealing a killing blow to congolli breeding. The females couldn't make their downstream migration for the last four years. Fortunately for the congolli, the August 2010 floods sent enough water down the Murray-Darling to connect the Lakes to the Coorong. During a six-week rescue operation which ended in October 2010, the State Government enabled as many as 20,000 females to swim into the Coorong by using the Goolwa Barrage boat lock was used as a temporary fish passage."

What neither the media release from the Minister, nor the article published by the Conservation Foundation, admitted is that there are already fishways in the Murray Mouth barrages. They were built as part of the $60 million 'Sea to Hume Dam' project launched in 2003.

Monitoring of the fishways built a part of this initiative, including the Tauwitchere large vertical-slot, Tauwitchere small vertical-slot, Goolwa vertical-slot, Hunters Creek Vertical slot, and the Tauwitchere rock ramp showed 10,900 congolli moved through these structures during 2010 and 2011, with half of these fish using the rock-ramp. But the overwhelmingly dominant species using the fishways and rock-ramp were not congolli but rather the pest red fin perch and tiny ubiquitous Australian smelt (Retropinna semoni) with 442,675 and 455,089, respectively, recorded entering or leaving the fishways and rock-ramp over this period.

There is no shortage of money for building slots in dyke walls, and paying bureaucrats to count hundreds of thousands of insignificant tiny fish that wash between the slots, but there is a complete absence of honest reporting on the true state of the Lower Lakes fishery and what is most needed for its restoration.

What a shame.