ON THE LAND Cod populations increasing
Some of the local most sort after fish, the Murray cod and Trout cod populations in the Murray Darling Basin are improving due to increased flows and better habitats.
Recent research undertaken by government agencies, universities and community groups have assisted the Murray–Darling Basin Authority (MDBA) to examine how populations of native fish species are tracking in the Basin.
MDBA Executive Director Environmental Management, Carl Binning said the evaluation showed some native fish populations have improved while others are remaining stable and only a small number are in decline.
“These results point to the Commonwealth and state environmental water managers’ increasing insight into how best to manage water in the future, building on the knowledge and expertise that has been gained over the first five years of the Basin Plan,” Mr Binning said.
“We know that water for the environment can be released at different rates, times and locations to help native fish breed and move through the Basin.
“It’s also really important to combine flows with other actions such as fish stocking and habitat restoration—it’s not all about flows.”
The data showed that environmental flows have resulted in more than 40 positive responses, including fish spawning and recruitment events.
“Through the Basin Plan, we aim to ensure there is enough water to look after river health and our native fish, while also supporting a productive river system,” Mr Binning said.
“In the Lower lakes, Congoli and Common galaxias are improving. Water for the environment has also improved spawning events for Golden perch, Murray cod and Silver perch.
“These results are promising – but there is more work to do to build native fish numbers after the significant fall in the numbers and distribution of native fish that has occurred for the past 150 years.
“Three species, the Yarra pygmy perch, the Purple-spotted gudgeon and the Southern pygmy perch, have been identified as in a decline.
“We can be hopeful given our recent track record. In the past three years nearly 300 flow events were provided by environmental water holders to support native fish species and about 90 per cent of these achieved their aim.
“Carp remain a key challenge in the Basin. The MDBA supports the National Carp Control Plan being developed by the Australian Government.”
These results form part of the Basin Plan Evaluation, which looks at progress since the plan was agreed in 2012.
The evaluation will also identify lessons learned to see how we can do things better into the future.
Further findings from the evaluation will be released over coming months.
Carp are the biggest threat to other species of fish in the Murray Darling Basin.