Ascending galaxies (Symbols brevipinnis) at Curl Curl Creek, Manly Vale. Environmentalists fear the impact on the type of contaminated runoff from a school construction site.Photo: Greg Wallis
Local environmentalists fear a ‘wonder fish’ has been wiped out from its Sydney habitat by botched construction work at a nearby government secondary school.
The climbing galaxies (Symbols brevipinnis) belongs to a species lineage dating back to Gondwanaland. The fish was only identified in 1998 in the Manly Dam region of northern Sydney – the northernmost known location of the fish in Australia.
The fish breathes through its skin and uses large pectoral and pelvic fins as suction cups to even climb waterfalls. Elsewhere, fish larvae depend on reaching the sea to feed, but this population had somehow survived being contained by the dam.
However, heavy rains last month caused a flood of sediment from the Forest high school facility to Curl Curl Creek, the last waterway in Sydney populated by the climbing galaxies. More than two weeks later, the creek remains murky, conditions that will likely limit the fish’s ability to catch mayflies and other insects.
“I would hate to think that this will be the final end on our watch, after 90 million years,” says Malcolm Fisher, vice-chairman of the Save Manly Dam Catchment Committee (SMDCC).
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“We can’t say for sure whether it survived or not,” Fisher said. “But it’s a huge blow, you would have to think, when you see the condition of that water.”
The Northern Beaches Council has also warned that more silt disposal is possible. It told SMDCC treasurer Ann Collins on January 25 – more than a week after the first event – that a nearby sediment basin “appeared to be at full strength and would not be able to handle another major rain event” , according to the correspondence. by Guardian Australia.
The New South Wales Environment Protection Authority said it sent staff on January 19 and 22 to confirm the silting of the creek and its source, Forest High School. Initial investigations revealed the school works, although additional sources of sludge may have been found.
“We have advised the contractor and the NSW Department of Education to take immediate action to prevent water pollution,” a spokesperson said. “The discoloration of the water can last for some time until it flushes naturally, because the sludge consists of fine clay.”
The EPA “has not been monitoring the population of ascending galaxies,” the spokesperson said, while the council was the appropriate body to conduct any kind of oversight. But “at this stage it appears that no aquatic life has been affected by the incident.”
The Education Department, for its part, said its work was not responsible for the silting, even though it was the only party asked to take action by the EPA.
“Contractor ADCO, responsible for The Forest Secondary School construction site in Allambie Heights, carried out inspections following a report from the Environmental Protection Authority (EPA) of suspected sludge runoff at Manly Dam,” a spokesperson for the agency said. department.
Fisher said the Education Department had raided nearby Manly Creek several years ago with its public school work in Manly Vale.
“There is absolutely no other source for all that siltation in Curl Curl creek than the cleared Forest High School property,” he said.
However, environmental advocates doubt whether the EPA or other authorities such as the Northern Beaches Council will actually measure any changes, including examining whether the nocturnal fish have survived.
“How do they know there won’t be any impacts to those creeks?” SMDCC Treasurer Ann Collins said. “We should regularly measure what it looks like – or what the content of all the different chemicals and things like that are.”
The Curl Curl Creek was classified as having the highest level of environmental importance, and its protection should be a priority for both local and state governments. “There’s really only three or four on all the northern beaches,” Collins said.
“There is no management plan that actually provides certainty about this [the fish] stays there, she said. “You just feel like you’re hitting your head [a wall].”
The fish has caused a stir before, including being at the center of “a major conflict between conservationists and developers” in 1999, the Australian Museum says on its website. That was just a year after its discovery by scientist Andrew Lo.
His son, Nathan Lo, professor of evolutionary biology at the University of Sydney’s school of life and environmental sciences, says there are good reasons to be concerned about the fish’s fate.
“We know very little about the biology of the fish, and that silt discharge would not normally occur in this type of environment,” Lo said. “[It] could emphasize not only the climbing galaxies, but also other aquatic environments.”
“For that reason, runoff events should be avoided as they could affect the survival of the population,” he said.
Reintroduction of the species was possible, but any new population would have to develop the ability to survive while cut off from the sea. Moreover, “it would probably be a costly exercise to reintroduce these, so it is better to stop these types of run-off events in the first place,” Lo said.
The Manly Dam bushland region is home to at least six threatened mammal species, including the eastern pygmy possum, a recent diversity survey has found. It is also home to the critically endangered Seaforth mintbush among its 1,120 plant species, and the endangered Duffys Forest ecological community.
Collins notes that a nearby facility wants 75 additional parking spaces, which will result in the loss of trees, including some in the Duffys Forest ecological community. Such work would create a new threat of salinization.
This includes plans for 24 luxury retirement homes in the area, as well as new mountain bike trails that the municipality and cyclists are looking for.
“What was already very, very rare seems to be getting in the way of every other development that occurs,” Fisher said.
Collins said it’s time for governments to draw the line if the climbing galaxies and other rare species are to survive there.
“No, you have to think differently,” she said. “You can still do your things, but you have to do it [them] A different kind of.”