Pre-historic marvel surviving tough times in our waters
THEY form a bizarre and mysterious link to our prehistoric past, and their survival can reveal a lot about health of our waterways.
A recent study shows populations of Australia’s ancient lungfish appear to be remaining stable in the mid-Brisbane River, a section of the river below the dam wall, meandering into the Mt Crosby Weir.
As part of a long-term environmental initiative, Seqwater, has been monitoring and documenting lungfish populations in various waterways for more than a decade.
Seqwater senior scientist Dr David Roberts said lungfish were ancient creatures that had
remained unchanged for more than 100 million years, predating the dinosaurs.
Dr Roberts said lungfish were named as such because, unlike most fish that only get their
oxygen by passing water through their gills, lungfish have developed lungs which allowed them to breath air.
Despite this, lungfish are listed as vulnerable, with degradation of habitat a major burden on their breeding and survival.
“We monitor lungfish downstream of our dams as barriers to movement and altered flow
regimens downstream of these dams have the potential to adversely affect lungfish and their
habitats and we want to make sure this isn’t happening,” Dr Roberts said.
“Our research is telling us that populations of lungfish are stable and while their habitats change year to year from droughts and floods, lungfish live for around 70 years, so they have the ability to wait out the bad years for when conditions improve again.
“We know a lot about what lungfish need to breed and we are embarking on programs to
improve the quality of the breeding habitats so that lungfish populations remain healthy.
“All our research is being used to develop a population model for this species so we can make
sure populations remain healthy long into the future.”
Researchers use electrofishing to safely catch fish and record the details before releasing them into the water, unharmed.
“We check the fish for previous microchip tags we placed on them during earlier research and
record details such as length and weight. If the fish is one we haven’t caught before, we insert
one of these tags so we can begin tracking it,” Dr Roberts said.
Dr Roberts said recent genetic studies had concluded the lungfish found in the Brisbane River
were likely to have been brought here from the Mary River.
“Back in the 1890s, lungfish were spread around different rivers across parts of south east
Queensland to increase their chances of surviving long-term,” Dr Roberts said.
“The future for Australian Lungfish is looking pretty good, as a protected species and global
natural treasure, we want to do as much as we can to make sure it stays around for good.”