EDMONDS — Every year, Ruth Blaikie waits for the visitors to return to Shell Creek.

“Like clockwork, they come — between Halloween and Thanksgiving,” she said. “When the salmon return, they spawn in our back yard.”

The creek has a natural run of chum salmon, and coho have been seen there, too.

Members of the Students Saving Salmon club at Edmonds-Woodway High School wanted to know more about the creek’s salmon runs and began their work in the fall. Some of it involved going door to door to 28 homes, talking to Blaikie and her neighbors about the types of fish that could be seen in the creek.

They handed out information sheets to homeowners to identify what kind of salmon were in the stream and what they could do to protect the habitat. They also asked for reports back on how many fish they’d seen.

“They all cared quite a bit about the salmon in their back yards,” said Malia Clark, the club’s vice president. Some were worried about the decline in salmon populations, she said.

One of the club’s goals is to find out how far upstream the salmon go and where they spawn, said Joe Scordino, a retired deputy regional administrator for the National Oceanic and Atmospheric Administration and a club advisor.

“There’s really a lack of information on when the fish do arrive, when the spawning period is, and how that varies year to year,” Scordino said.

The information gathered will go into a database compiled by the students so people will know more about potential future effects on salmon runs, he said.

Some homeowners already are aware, telling students they don’t use fertilizer on their lawns because of the problems it could create for the creek and the salmon, club member Jared Yu said.

Students asked people who lived along the creek if they’d be willing to have native plants added to their yard to improve the habitat.

“I said, ‘Yes, of course,’ ” Blaikie said. “I think we might want to plant some things to create more shade.”

The names of 13 people interested in the project were given to Sound Salmon Solutions, which has a grant for obtaining native trees and plants. The students might help plant them in the future.

Blaikie invited the students into her back yard to see the creek. “They were taking film of the salmon under water,” she said.

The group got a first-hand look at one of the creek’s biggest barriers to salmon migration: a five-foot-high wall with shallow water on the other side.

“It’s sort of a waterfall that comes out of a culvert and prevents a lot of salmon from going over it and extending their run,” Clark said.

Coho probably could work their way upstream, “but with real shallow water they don’t have any room to propel themselves,” Scordino said.

The homeowner whose property surrounds the wall is willing to work with the students on making improvements to ease salmon passage, “but I think the process will be pretty complicated,” Clark said.

Eventually, the group hopes to submit grant requests for a restoration project to create a passage for fish to navigate farther upstream. But that is not as easy as it sounds. Some grants require the property owner to be involved, while others will only work with government agencies, Scordino said.

So far now, the students are compiling information to determine where and when there are problems.

That provides the basics “so you can start planning restoration where necessary,” Scordino said. “It provides a solid base to assess how well your local environment is doing for salmon.”

Earlier this month, the students conducted monitoring of three creeks — Shell, Shellabarger and Willow — as well as in Edmonds Marsh.

They tested for indicators of the water’s health, such as the levels of dissolved oxygen, acidity and salinity. That testing is planned to continue monthly.

Results showed the oxygen levels in Shell Creek were good for spawning, Scordino said. Students used a sophisticated meter provided by the Hubbard Foundation to do the work.

A grant from Sound Salmon Solutions will pay for quarterly tests for petroleum compounds and heavy metals in the same three creeks and the marsh next year.

The information will be shared with the city of Edmonds. Students plan to make a presentation to the Edmonds City Council early next year.

Clark, a senior, said she’s always liked science but never before had been involved in hands-on field work.

“I enjoyed it,” she said. “I wish we could see more salmon running in the creeks.”

Yu, a senior pursuing an International Baccalaureate diploma, said he became interested in joining Students Saving Salmon during his junior year, after hearing about it from his biology teacher.

“This project has really been an opportunity to have an active role in the community and help out — that’s what makes the club so great,” he said.

Sharon Salyer: 425-339-3486; salyer@heraldnet.com.