By Jessica Schremmer and Anita Ward
A jawless blood-sucking eel-like fish has surfaced in record numbers in the River Murray system, a new monitoring program has found.
Ninety-one pouched lamprey and four short-headed lamprey were recorded migrating up from South Australia’s Coorong through to the Murray River system between July and October last year – the highest amount ever monitored over winter.
The ancient and native species was feared to be on the brink of extinction after the Millennium Drought.
The Department for Environment and Water’s Program Leader for Coorong, Lower Lakes and Murray Mouth Adrienne Rumbelow said the Millennium Drought led to more than three years of disconnection of the Lower Murray river system.
“During those three years there was no migration for lampreys because there was no flow at the bottom of the River Murray system … there was no connection between freshwater and saltwater,” she said.
Lamprey are anadromous fish, which means they are born in freshwater, spend most of their adult life in the ocean before they migrate up freshwater rivers to spawn.
“After the drought, probably the next 45 years we were really struggling to find any lamprey in the system and we had some really big concerns about whether we lost a couple of species from the Murray-Darling Basin,” Ms Rumbelow said.
Fortunately, more consistent water flows into the Lower Murray River system through to the Coorong and Lower Lakes in the following years led to its recovery, with additional water for the environment aiding the living fossil in its migratory path.
“I think it’s a combination of flows at the right time of the year, and then a lot the locks and weirs and anabranches in the River Murray have now got fishways on them,” she said.
Source: https://www.abc.net.au/n
