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Salmon study nets ‘a big wow’

The city-led effort finds that young fish aren’t behaving like anyone believed.

Nets cast from the island’s shore have drawn a startling catch.

Besides capturing, cataloging and releasing almost 60 species of sea life, a city-led study has netted data that shows Puget Sound salmon aren’t behaving as many expect – suggesting that government protections are falling short for the most sensitive salmon species.

“It’s all a big ‘wow,’” said island resident and marine habitat specialist Jim Brennan. “This is new information. We’re seeing that salmon are not doing what we thought and that the regulations there to protect them are not really protecting them.”

In a joint effort by the City of Bainbridge Island, the Suquamish Tribe and the state Department of Fish and Wildlife, a corps of volunteers logged over a thousand hours casting more than 150 nets along the island’s shore between 2002 and 2004.

The “beach seining” project was meant to gather a simple baseline of raw data. But the recently compiled results surprised city shoreline planner and project lead Peter Namtvedt Best.

“This was to just answer some basic questions because we don’t really have a good idea of how many or what kinds of critters are out there,” he said. “But what we’ve heard about chinook and other salmon is not what we’re learning from this study.”

Summer home

Even salmon are flocking to Bainbridge Island for the the quiet life.

Nets drawn from the island’s shore during the beach seining study found that numerous salmon from Northwest hatcheries are bucking the assumption that young salmon leave streams and make a beeline for the ocean. Many salmon are hanging out off the island’s shores for much longer than expected.

“There’s the book of thought that says salmon take a right and head out to the ocean,” Best said. “But these salmon didn’t read that book. Salmon are coming down here from all over the place.”

Because hatchery salmon are tagged, Best and other study participants were able to trace the origins of many chinook and coho caught in nets off Bainbridge. Typically released from river-based farms, fish were thought to spend about 18 days in Puget Sound before plunging into the Pacific.

“But some of the these salmon we found had been in the sound for 165 days,” Best said. “And that raises some interesting questions.”

Best guesses that the salmon could be seeking the more readily available food and protected environments common on off-shore habitats. It could also mean salmon are having a tougher time thriving in the ocean.

“Do fish exhibit preferences and actively search for certain habitats, food resources and geographical areas or are they just milling about, flowing with the currents and opportunistically eating whatever they come across?” he asked.

Marine habitat specialist Jim Brennan doesn’t know the answer for sure, but said salmon are also hanging out longer in other parts of the sound, including Vashon Island and south Snohomish County.

“It’s a big jigsaw puzzle and this is another piece,” he said. “I don’t know why they’re doing this, but it does mean they are subject to the affects of all that we do to the sound for a longer period of time. They are subject to our water quality, habitats, food supply a lot longer and this could affect their ability to thrive.”

The young salmon off the Bainbridge coast are also rushing to the island with remarkable speed, Best said. At least one young salmon released from British Columbia hatcheries reached the island’s waters in a matter of days, he said.

Brennan said studies he conducted for King County found similar results, with young salmon traveling nearly an equal distance to reach Vashon.

“We’re talking about small fish, the size of your finger,” Best said. “How is it physically possible to travel that distance in a matter of days?”

Best and Brennan surmise the salmon could be hitching rides on fast currents that zip them through 80 miles of Puget Sound water in a couple days.

The results also beg the question of whether this odd travel itinerary is widespread in wild salmon.

“There is the often-stated question of whether wild and hatchery behave the same,” Best said. “The only (hatchery) species that are tagged are coho and chinook, so it’s hard to know about other species, but it’s reasonable to think there is some behavior difference.”

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