While Prime Minister Stephen Harper says the fate of Enbridge's proposed pipeline from the Alberta oilsands to tankers on the British Columbia coast will be based on science and not politics, documents show some of that science isn't forthcoming.

And critics say there is no time for the science to be completed before a federal deadline for the environmental assessment currently underway.

Documents filed with the National Energy Board show the environmental review panel studying the Northern Gateway project asked Fisheries and Oceans Canada for risk assessments for the bodies of water the proposed pipeline will cross. The pipeline is to traverse nearly 1,000 streams and rivers in the upper Fraser, Skeena and Kitimat watersheds.

The department didn't have them.

"As DFO has not conducted a complete review of all proposed crossings, we are unable to submit a comprehensive list as requested; however, this work will continue and, should the project be approved, our review will continue into the regulatory permitting phase," DFO wrote in a five-page letter dated June 6, 2012.

The response went on to say there "may be differences of opinion" between the company and the department on the risk posed by the pipeline at some crossings. It provided two examples of crossings of tributaries to the Kitimat River where Enbridge rated the risk as low but Fisheries rated it medium to high.

DFO said the federal ministry will continue to work with the company to determine the risk level and level of mitigation required.

"DFO is of the view that the risk posed by the project to fish and fish habitat can be managed through appropriate mitigation and compensation measures," said the department's response.

"Under the current regulatory regime, DFO will ensure that prior to any regulatory approvals, the appropriate mitigation measures to protect fish and fish habitat will be based on the final risk assessment rating that will be determined by DFO."

Earlier this month, Harper told reporters in Vancouver that "decisions on these kinds of projects are made through an independent evaluation conducted by scientists into the economic costs and risks that are associated with the project, and that's how we conduct our business."

He went on to say "the only way that government can handle controversial projects of this manner is to ensure that things are evaluated on an independent basis, scientifically, and not simply on political criteria."

But the federal government recently sent letters to 92 habitat staff members within Fisheries and Oceans in B.C., telling them that their positions will be cut. Thirty-two of them will be laid off outright.

The cuts will mean the department in B.C. has half the habitat staff it had a decade ago.

All but five of the province's fisheries field offices will be cut as part of a $79 million -- 5.8 per cent -- cut to the department's operational budget, including the offices in Prince George and Smithers that would have had the lead in monitoring pipeline effects.

The marine contaminant group that would have been involved in a spill in B.C. has been disbanded and the fisheries and environmental legislation gutted, said Otto Langer, a retired fisheries department scientist.

"He (Harper) says the science will make the decision. Well he's basically disembowelled the science," said Langer. "It's a cruel hoax that they're pulling over on the public."

Former federal Liberal fisheries minister David Anderson agrees.

Given the Dec. 31, 2013, deadline set by the federal government, Anderson said scientists in the Fisheries Department simply don't have time to complete any substantial scientific study of the project.

"You can't do these studies on the spur of the moment. It takes time to do them," Anderson said. "And the federal Fisheries have just been subjected to the most remarkable cuts, so you're in the throes of reorganization and reassessment and re-assigning people, and on top of it you throw them a major, major request for resources and work.

"It can't be done."

The department has three major projects in B.C. currently undergoing federal environmental assessment: Northern Gateway, a massive hydroelectric project called the Site C dam, and a gold-copper mine near Williams Lake, B.C., that was previously rejected following a federal environmental review.

Dr. Steve Hrudey, who was chairman of the Royal Society of Canada's expert panel on the environmental impact of the oil sands two years ago, said it is normal for the company asking for environmental approval -- in this case Enbridge -- to provide the information in question in the review process.

"They have to foot the bill," said Hrudey, who was also involved in more than two dozen reviews over 17 years as a member and then chairman of the Alberta Environmental Appeals board.

The project proponent pays consultants to prepare studies and reports required by the review board, the relevent federal departments look at those reports, respond with questions and comments of their own, and the panel then goes back to the proponent with those questions and requests for further information.

There may be several cycles of this back-and-forth.

"In the end DFO will say 'No, it's what we think it is and therefore you have to take measures we feel are appropriate for that rating,"' Hrudey said.

But if the department's ability to do the studies itself is questionable, some scientists fear the process will unfold without independent scientific study.

"It (the response from Fisheries to the panel) implies that the request to the joint review panel will not be answerable until after a decision has been made, until after the project has been approved," said Jeffrey Hutchings, a marine biologist at Dalhousie University.

"This seems, from a science perspective, a rather indefensible position in so far as a key part of the environmental review process is to evaluate the degree to which the pipeline will affect fish habitat."

A spokesperson for the panel said there has been no further request for information from DFO, and no further information is expected.

The federal department said a spokesperson was not available for an interview, but provided a statement via email saying Fisheries is providing advice to the assessment panel on the potential impacts of the project on fish and fish habitat.

"Fisheries and Oceans Canada has provided its assessment and is of the view that the risk posed by the project to fish and fish habitat in the freshwater and marine environments can be managed by the proponent through appropriate mitigation and compensation measures," said the email, which echoed the response sent to the panel.

"The Department notes in its submission that the proponent has conducted a reasonable ecological risk assessment and provided useful information on the risks that an oil spill (in either marine or freshwater) would pose to fisheries resources."

Hutchings found it odd that they're so sure.

"Well, how can you make that judgment when you have not yet conducted a complete review of all proposed crossings?" he said. "Again, from a science perspective, I don't see how it's possible to be able to draw that conclusion."

The proposed Northern Gateway is a $6-billion project expected to spur $270 billion in economic growth in Canada over 30 years.