Solving An Ecological Mystery

Ancient Aboriginal knowledge is helping to fill in the missing details of epic migrations made by Australia’s freshwater eel species.

- Angela Heathcote

EACH AUTUMN, the adults of two species of Australian eel – the longfin and southern shortfin eel (Anguilla reinhardtii and A. australis) – prepare for an epic journey to a location thought to be in the Coral Sea between Papua New Guinea and New Caledonia, where they breed and then die.

Starting from estuaries, dams and rivers along eastern Australia as well as ponds and wetlands in urban enclaves, such as Centennial Park, in Sydney, and Melbourne’s Royal Botanic Gardens, they can travel thousands of kilometres. Navigating their way through drains and stormwater networks can be a game of chance.

“When they have the urge to migrate they are determined and pretty resilient,” says ecologist Dr Jarod Lyon from the Victoria-based Arthur Rylah Institute for Environmental Research, which has carried out various studies on Australian eel populations since the 1970s. “Historically, they’ve been able to get past most barriers, as long as there’s enough rain.”

There’s plenty we don’t know about the migration of these eels. And much of what we do know comes from anecdotal evidence of eel fishers.