A highly threatened fish, which grows no more than 8cm in length, is returning to the Lower Murray in numbers not seen since the Millennium Drought according to the Department for Environment and Water (DEW).
Project Officer for Coorong, Lower Lakes and Murray Mouth for the DEW, Kirsty Wedge said the successful return of the Southern Pygmy Perch was attributed to a combination of adequate river flows, careful water level management and healthy wetland habitats.
“The Southern Pygmy Perch is a small fish that occupies the fringing wetlands of Lake Alexandrina in the Lower Murray,” Ms Wedge said.
“The health of these wetlands is highly dependent on careful management of water levels controlled by operating gates at five barrages, which also stop sea water entering the lakes from the Coorong,” she said.
Ms Wedge said Southern Pygmy Perch disappeared from the Lower Lakes in 2008 during the Millennium Drought, but thanks to carefully planned reintroductions coordinated by the Molecular Ecology Lab at Flinders University along with other organisations, informed lake level management and delivery of water for the environment, populations of the threatened fish were now improving.
She said monitoring undertaken as part of the Murray-Darling Basin Authority’s The Living Murray program recorded high numbers of Southern Pygmy Perch in the March 2022 survey – the highest of any year since the Millennium Drought.
“This was enhanced by increased River Murray flows, combined with delivery of water for the environment, which increased water levels in the Lower Lakes, extending the fish breeding season,” Ms Wedge said.
