The first salmon returning to the island in recent years was spotted this week at the mouth of Ravine Creek between the Washington State Ferry maintenance yard and Waterfront Park.

Even more exciting for local salmon enthusiasts is that the fish was a Chinook – a species rarely seen on the island.

“Goes to show you that nature can prove you wrong every time,” said Deborah Rudnick, ecologist for the Bainbridge Island Watershed Council.

The fish was spotted by the city’s shoreline planner, Ryan Ericson, who sent a picture to Suqamish Tribe’s Paul Dorn, who confirmed the species as Chinook.

Ravine Creek is a documented area for Coho and Chum salmon by the Washington Department of Fish and Wildlife. The presence of Chinook, however, has been documented on the island’s shorelines through the city’s beach seine program, which confirms that the species uses the island nearshore.

Rudnick said the Chinook spotting is an example of how colonization can work as stray fish end up outside of their native streams. If the habitat is right they may contribute new genes to a stream’s population.

The spotting is important to the ongoing research about the salmon reproductive strategies to maintain biodiversity, according to a memo from City Manager Brenda Bauer to the City Council.

Rudnick said she doesn’t expect the breed to spawn in island creeks because the species prefers a larger river system.

Salmon restoration has been a major process for the watershed council, a nonprofit organization under the auspices of Sustainable Bainbridge. It has been working on the city’s property at Cooper Creek near the Head of the Bay to try and revive the historically strong run that ended more than 50 years ago as island development increased.

Now in the third year of a four-year project, the Suquamish Tribe has provided between 13,000 and 15,000 chum salmon fry every year from its Cowling Creek Hatchery, along with food and expertise to care for them. Volunteers sign up to care and monitor the fish throughout the year.

The work began in 2001 when the city removed the in-ground concrete that was used when the creek was a potable water source for the city of Winslow. The survival rate for salmon is still dismal, with just 1 percent of 10,000 fish expected to make it back to the stream after their four-year life cycle. But rebuilding the salmon population is an ongoing endeavor for many local volunteers.