The 'opera house'-style nets - so named because its shape resembles the Sydney landmark - will be outlawed across all Victorian waterways from July 2019, Agriculture Minister Jaala Pulford announced on Monday.

"Opera house nets have been placing our platypus population at risk and so it's time for us to embrace different fishing gear," Ms Pulford said.

The nets have been a popular net for catching yabbies but inadvertently trapped platypus, drowning the air-breathing, web-footed mammals.

Already banned in or near public Victorian fishing holes, but permitted in private dams, the nets will be totally outlawed from mid-2019.

Victoria's full-scale ban on the "cruel traps" has been hailed as a win for native species.

"It's widely recognised that yabby traps cause animals an agonising death by drowning," People for the Ethical Treatment of Animals spokeswoman Emily Rice said.

"And when mothers are caught, their young are left to starve to death, wiping out entire families."

Department of Environment data recently revealed all 13 recorded platypus drownings in state rivers, streams, creeks and dams in 2017 were caused by illegally used set-and-forget nets.

Many platypus deaths also likely go unreported, meaning the true cost of opera nets is probably far greater.

Victorian fishers will be able to trade in the problematic yabby nets for a more wildlife-friendly trap, which needs to be manned.

Ms Pulford said trials showed the replacement nets would "catch just as many yabbies without impacting our precious wildlife".

Fishers caught using opera house nets face a maximum fine of $38,000 or up to two years in prison.

Australian Associated Press