Keith Ashfield's office says speculation over changes to the Fisheries Act are inaccurate. (CBC)

Pressure is mounting on Fredericton MP and federal Fisheries Minister Keith Ashfield over possible changes to protection of fish and fish habitat.

His office says those policies in the Fisheries Act are under review to better reflect Canadian priorities.

The act currently requires companies pursuing large and small developments, from oil pipelines to road culvert construction, to prove their plans preserve fish habitat in waterways, marshes, gravel beds and the banks and vegetation along waterways.

The material suggests there are plans to revise the Fisheries Act so that Ottawa would be responsible for fish, but not for their surrounding habitat.

Scientists say excluding the word "habitat" would cripple the act.

'Basically it's almost open season on many habitats in Canada'—Otto Langer, biologist

Some worry that will mean gutting the Fisheries Act.

Otto Langer is the retired federal Fisheries and Oceans scientist who says he was leaked draft changes a couple of weeks ago by insiders in the department.

“The government wants to remove the condition that one shall not harm habitat to one shall not have an adverse effect on fish of value economically, culturally and ecologically,” Langer said.

Those conditions are difficult, ambiguous and indirect, Langer said.

“Do polar bears, do eagles catch those fish? Are they part of an overall food chain to benefit man? Culturally, are they important if First Nations doesn't fish them? Economically they're not important because there's no sports fishery or commercial fishery." Langer said. "So basically it's almost open season on many habitats in Canada.”

Langer said he suspects the government may be considering the move in order to speed up the environmental review process.

“I think it all boiled to the surface with the Enbridge pipeline where [Stephen] Harper and [Joe] Oliver said ‘We're going to expedite this pipeline.’ People just aren't going to be able to line up at public assessment processes and slow down such industrial development. Every time you get harmed habitat, it triggered a Canadian Environmental Assessment review.”

Langer is one of 625 scientists speaking out against the idea.

There are ways to improve the efficiency of environmental reviews, he said, but the government should talk to Canadians about it first.

Current speculation over the changes is inaccurate, according to Ashfield's office.