Scientists at the Narrandera Fisheries Centre in NSW have bred the endangered Macquarie perch for the first time in captivity.
“Using a new novel approach involving the construction of an ‘artificial stream’ Industry & Investment NSW has been able to coax captive perch into thinking they were in a natural environment and as a result, both male and female Macquarie perch have reached breeding condition for the first time in captivity,” NSW Minister for Primary Industries Steve Whan said.
“To date past attempts to breed captive Macquarie perch have not been successful, as mature fish have not been able to reach breeding condition in captivity.”
Previously scientists had relied on capturing spawning-run fish from the wild – a practice best avoided for an endangered species such as Macquarie perch.
The first Macquarie perch eggs hatched at Narrandera Fisheries Centre in November and it is expected several hundred juvenile Macquarie perch will be ready for release into the wild in early 2011.
One-day-old Macquarie perch larvae
“This breakthrough has only been made possible after two years of preparation and research by the committed team involved with the project.
“I&I NSW staff also drew on valuable advice from the Department of Primary Industries in Victoria (who have successfully artificially bred spawning-run Macquarie perch in the past), and Native Fish Australia on how to obtain viable eggs and sperm from the captive fish and fertilise them in the hatchery,” said Whan.
Dr Dean Gilligan from I&I NSW said the captive fish used for the successful breeding program were from a remnant population of endangered Macquarie perch, rescued from the upper Lachlan catchment after their habitat was threatened by the recent introduction of redfin perch.
“We captured 122 Macquarie perch from the population in case of catastrophic collapse of the population in the wild,” he said.
“These fish were being held in captivity at the Narrandera Fisheries Centre until a safe haven could be established and they could be reintroduced back into the wild.”
Dr Gilligan said Macquarie perch populations began to crash by the mid 1900s, most likely due to habitat degradation associated with river regulation, fish passage barriers, land clearing and associated sedimentation and other forms of water pollution. The species has also suffered from competition for resources with, and exposure to diseases from, introduced fish species.
“By the 1970s, Macquarie perch were considered to be seriously threatened with extinction,” he said.
“Since then, the species has continued to decline, with populations considered viable as recently as 2005 having now declined or disappeared.
“Only a small number of self-sustaining populations remain and the species is now endangered at a State and National level.
“But now, with this breakthrough, I&I NSW will be able to look at developing and implementing a conservation stocking program in those parts of the Murray-Darling Basin where their populations are diminished or have become locally extinct.”
This research has been supported with funds from the Recreational Freshwater Fishing Trust.
