A new study suggests the Canadian government may not be doing enough to monitor its Pacific salmon stocks.

The study from Simon Fraser University researchers found that visits by Fisheries and Oceans Canada to spawning streams have been steadily declining since the 1980s.

But it's more than just budget cuts. Michael Price, a fisheries biologist at SFU and co-author of the study, says the DFO's approach has been inconsistent and poorly targeted.

"Even given whatever budget they have, they haven't really taken a very strategic approach to monitoring," Price said.

"If we're not on those spawning streams checking on [salmon populations], they may not be able to carry on and spawn, and they may become extirpated in the future."

Adams River Sockeye

Sockeye salmon are bright red by the time they reach the spawning grounds of the Adams River near Kamloops, B.C. (Clive Bryson)

Visits down by two-thirds since the '80s

The study was published in the Canadian Journal of Fisheries and Aquatic Sciences, and found that in 2014 DFO staff visted less than 500 spawning streams.

In the mid 1980s, Price said, staff were visiting more than 1500 streams a year.

Price says it's important to visit streams to track things like population, disease events, stream blockages and more.

"We can determine trends over time, which is a very important thing," he said.

Scientists have categorized B.C.'s salmon population into distinct populations known as conservation units. More than 400 have been identified in the province.

Price says some of these conservation units have been extensively monitored, but others have been virtually ignored.

The study suggests the health of about half of all B.C. salmon conservation units cannot be properly assessed under the current monitoring regime.

Policies not being followed

Price argues these shortcomings are in direct violation of the Wild Salmon Policy, a guiding document for salmon management which he says the DFO hasn't fully implemented since its introduction in 2005.

He says there has been no formal assessment of individual population healths, which is one of the policy's key commitments. One of the study's main recommendations is that the DFO take steps to formally implement all aspects of the policy.

"It's been 12 years since this formative policy has come in, and yet there is still no plan to implement it," Price said.

Fisheries and Oceans Canada have not return requests for comment.

With files from CBC Radio One's The Early Edition.