The tide may be turning for endangered fish species in Victoria. 

New sampling by Melbourne Water has seen a large influx in juvenile Australian Grayling in the Tarago River.

It is likely linked to recent wet conditions supporting breeding in autumn.

The Grayling is a protected fish, meaning it is illegal to catch them.

Melbourne Water’s Environmental Water Delivery Lead Sarah Gaskill said about 150 fish of differing species have been previously tagged in the area and listening stations placed along the river using the innovative Passive Integrated Transponder (PIT) technology.

“When a tagged fish passes a listening post, our live tracking system receives a signal in real time,” she said. 

“We can link this back to conditions in the waterway to understand what flows they need to move and when. This helps us determine when to deliver extra environmental water flows from the Tarago reservoir upstream to help support their lifecycles.”

The intel appears to be working, with the latest sampling by Melbourne Water over a five-day period in March showing 44 young Grayling in the area, indicating a good breeding response in 2019.

“This is an exciting development in how we track the endangered Grayling’s health and helps provide optimum conditions for its survival and reproduction,” Ms Gaskill said.

The team also uncovered much healthier numbers of other species in the river than previously seen, which is further good news on the river’s biodiversity health, including: 42 Tupong (quadrupled numbers), 27 Short-finned Eels (more than triple), and 42 Common Galaxias (double previous sightings).

For now, Melbourne Water will closely monitor autumn flows in the river to observe the downstream movement of the fish to spawn. They will be tracked on every part of their epic swim by technology monitoring their life cycles.

The studies were undertaken in conjunction with the Arthur Rylah Institute.