Millions of dollars have been spent to restore fish habitat in Western Washington.

Property owners pay taxes to local governments to control stormwater runoff.

State government and tribal fisheries have put huge investments into hatcheries.

“While all that has been going on, we’ve seen a precipitous decline in the survival rate of both hatchery fish as well as wild fish,” said Phil Anderson, director of the state Department of Fish and Wildlife.

That’s why the department, along with the Tulalip Tribes and 25 other organizations, are beginning a five-year study to determine why some species of salmon and trout are having trouble surviving their saltwater voyages.

The Salish Sea Marine Survival Project, as it’s called, is an international effort. Canadian groups are agreeing to pay half of the estimated, eventual $20 million cost of the study.

The decline has been seen in fish runs both in Washington and British Columbia.

“The fish don’t know there’s a border,” said Mike Crewson, fisheries enhancement biologist for the Tulalip Tribes.

The marine survival rate for many stocks of Chinook and coho salmon, along with steelhead, has dropped more than 90 percent over the past 30 years, according to Long Live the Kings, a Seattle-based non-profit group formed around fish preservation.

Numbers for sockeye, chum, and pink salmon have varied widely over the same time period.

For some reason, many of these anadromous fish — those that spawn in fresh water and spend most of their lives at sea — are not doing well in saltwater, particularly in the inland waters of Western Washington.

The Snohomish and Skagit river systems have been hit particularly hard, Crewson said.

While there’s a solid understanding of the factors affecting salmon survival in fresh water, according to Long Live the Kings, the issues in the marine environment are more complex.

From what is known so far, the survival problem has been traced to a combination of factors. Pollution, climate change, loss of habitat and increased consumption of salmon by seals and sea lions are all playing a part, Tulalip tribal officials have said.

Tribes and government agencies have been collecting information on their own, but it hasn’t yet been put together into context, Crewson said.

That will be one benefit of the new study — synthesizing the work done so far, he said. More research will be done as well.

The Tulalips, for example, have two smolt traps they use to catch young fish to track their progress and survival rates. The tribe already spends about $500,000 per year on fish survival programs and will increase their sampling efforts as part of this study, Crewson said.

Other studies more focused on certain areas, such as a joint effort between the Tulalips and the Nisqually tribe focusing on the Snohomish and Nisqually river systems, will be folded into the larger effort, Crewson said.

“The survival’s especially poor in Puget Sound (as opposed to the open ocean),” he said. “We’re trying to figure out what’s different in Puget Sound.”

The state recently appropriated nearly $800,000 toward the new study. The Pacific Salmon Foundation, a Canadian group, has raised $750,000 to support project activities north of the border. That group is serving as the organizer for efforts there, as is Long Live the Kings on the American side.

The Pacific Salmon Commission, a joint Canadian-American organization formed to implement treaty agreements, is putting in $175,000.

The rest of the money will be raised as the study progresses, officials said. A report and action plan is expected after five years.

Bill Sheets: 425-339-3439; sheets@heraldnet.com.