Platypuses, native water rats and other species are drowning in illegal traps left in Canberra's lakes.
The latest victims were a breeding pair of native golden-bellied water rats found dead in a opera house style yabby net.
The limp bodies of these freshwater aquatic mammals, which play a similar ecological role to otters in the Australian environment, were found at Yarramundi Reach on the southern shore of Lake Burley Griffin.
ACT Parks and Conservation Environment director Daniel Iglesias said the traps were invisible "killing machines" and they were sadly fairly widespread.
"We don't know how many nets are in use but what we do know is while these nets are illegal for use in the ACT you can buy them quite readily," he said.
The yabby or opera house traps are illegal for use in any public waterway in the ACT and are only legal for use west of the Newell Highway, which runs through Narrandera.
Penalties for illegal use in the ACT are high as $7000 but the government said prosecuting such cases was difficult.
"There are significant fines for people we are able to determine are using, in possession of [the nets], or killing the native animals," Mr Iglesias said.
Broadening public understanding about the illegal nets and their hazards was the government's best strategy to avoid future tragedies like this.
Mr Iglesias said the public should intervene and retrieve nets if they spotted them.
To avoid any confusion and make sure they are not wrongfully implicated by being in possession of a net near a waterway, report their location on the Access Canberra hotline 132 281.
ACT aquatic ecologist Matt Beitzel said 12 illegal traps had been found when Upper Stranger pond in Tuggeranong was drained. A dead turtle was found in one of them.
He said the abandoned gear led to "ghost-fishing" in ACT waterways as the nets and tackle smothered habitat and entangled fish and other aquatic life.
Canberra Fishermans' Cub president Glen Malam said anglers were largely doing the right thing and respecting the environment but the real issue was misunderstanding the laws and not comprehending the ongoing damage the traps could do.
"It is a bit confusing for ACT anglers to be able to see them on the shelves and then not be able to use them," he said. "It is a problem."
Mr Malam said there was an education gap as no license was required for fishing in the ACT.
"We need to look at better education. People just aren't aware it is illegal to do that. That is the core of the problem. And also they are easily lost and they are quite a cheap item."
National Capital Authority chief executive Malcolm Snow said the authority supported responsible fishing on Lake Burley Griffin.
"We're disappointed to see the images of native water rats (Hydromys chrysogaster) that were found dead in an illegal trap in Yarramundi Reach on the southern shore of Lake Burley Griffin," he said.
