Fishers operating in Victoria, Australis's east say their catch is down by as much as 80% since the start of seismic testing in the area.
Tyson Pollard and his father Tony have been octopus fishing for 3 years, and their catch is sent from Lakes Entrance to Melbourne and Sydney.
But, in recent months, the pair's haul has plummeted.
"Our catch rates are down by approximately 80% over the past 3, 4 months," Pollard said.
Pollard said he noticed a change when two large ships started surveying for oil and gas in his usual fishing area.
"New Year's Eve, the bushfires in our region meant we had to evacuate. New Year's Day, the seismic ship activity started," he said.
Several fishermen in the area have been compensated for their losses because of the testing, but the concerns of the industry go beyond money.
The controversial surveying technique has been used around Australia to look for oil and gas, but some environmentalists and scientists have warned the effects on marine life could be deadly.
The region became the latest epicentre of the testing debate after a bid to map the Great Australian Bight faltered earlier this year.
French Company Surveying Bass Strait
French-owned company CGG is using sonar to make 3D models of seabeds.
Loud airwaves are pulsed down into the ocean and bounced back to uncover the presence of oil and gas.
Seismic testing has been proposed around Australia, including near Newcastle, Bass Strait, and the Great Australian Bight.
CGG said its approach had indirect environmental benefits in that it "reduces the number of wells required to produce the resources that are discovered."
The company has a plan to survey 11,100 km2 of commonwealth waters by the end of June.
The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) regulates the conduct of offshore oil and gas companies.
It rejected CGG's first application because of a lack of consultation with fishers in the area.
CGG responded by devising a compensation scheme that saw fishers paid out for reductions in catches.
Five of 29 Fishers Compensated
Simon Boag represents fishers as the executive officer of the South Eastern Trawl Fishing Industry Association.
"We're waving our arms now, saying we think catches are down a third, and we think that the scientific study that's happening will show it's a lot more than that immediately behind the survey area," he said.
"I think things are bad enough that the surveying should be put on hold."
Boag said he has had to fight hard to find out how many fishers have actually been paid under the compensation scheme.
By the end of May, 5 months into the 6-month project, only five of 29 fishers who entered claims had been paid.
"The system CGG were using [to assess the claims] changed early on when they realized how much they were going to have to pay out," Boag said.
Fishers and CGG agreed trawlers should mitigate catch reductions by moving out of the affected areas.
"They're now saying fishermen need to go back to the area that's being surveyed, but doing that is dangerous and illegal," Boag said.
"So then they're moving away and, in that case, CGG is saying, 'You've moved away, so you're not eligible for compensation.' "