A new report on Pacific salmon stocks warns that the number of fish returning to British Columbia rivers could be at their lowest levels in 50 years.

In its third annual salmon assessment, The David Suzuki Foundation is giving Pacific stocks a "yellow" listing, which means there are sustainability issues that need to be taken seriously.

SeaChoice, a conservation group that was commissioned to write the 2008 study, uses a traffic light system to rank sustainable seafood options. Species with the lowest numbers would get a red rating.

David Suzuki Foundation aquatic biologist Jeffery Young says there are two issues affecting the overall status of the fish: Widespread decline in numbers and habitat loss from things like logging, mining and urban development.

"We've also had some fisheries mismanagement issues where we've opened some risky fisheries, primarily before the 1990s," he explained.

"We're still dealing with a very poor time for salmon and our fisheries are still not resilient to that challenge."

The foundation advises consumers to eat yellow-listed fish sparingly -- and to learn more about the source of the fish they are purchasing.

"We do not have enough people enforcing habitat," Young added. "We're kind of reducing our efforts there and that's a huge problem."

The Nass River sockeye salmon is considered a better choice than other yellow-listed wild salmon species. While still yellow overall, the Fraser River and Skeena River sockeye salmon have serious challenges this year.

When shopping for salmon, Young admits it can be difficult to know where the salmon comes from.

He says Canada should follow in the footsteps of the United States where companies say on the label which river the salmon is from.

When this information is not available, he suggests a simple solution -- ask an employee at the store.

For more information on the 2008 Pacific Salmon Ratings, visit the SeaChoice website at www.seachoice.org. To find out more about Pacific salmon under threat and solutions to their recovery, visit www.davidsuzuki.org.