PORT GAMBLE, Wash. — About 50% of young steelhead trout die while trying to navigate their way through the Hood Canal Bridge, but a new piece of equipment, installed Monday, could alleviate that.
The Hood Canal Bridge is a floating bridge.
Many would think fish would have no problem swimming under it but a lot of them do.
"Researchers realized that young steelhead were going missing and presumed dying near the bridge," said Shaara Ainsley with Long Live the Kings, a non-profit salmon and steelhead recovery organization.
The concrete pontoons holding the bridge up sit about 15 feet below the water's surface.
Juvenile steelhead and some salmon swim closer to the surface when migrating.
NOAA scientists believe the southeast corner of the bridge acts as a barrier that tends to trap fish and make them an easy meal for seals.
"When the fish encounter the bridge it's like a large wall to them," said Ainsley. "In the process of milling about and trying to figure out how to get around the bridge, they were getting picked off by harbor seals."
Now, a 70,000 pound, $1.6 million fish guidance structure called a fillet is attached to that corner.
It essentially blocks the corner off and keeps the fish from getting stuck.
"It will create a flat surface to guide fish around that corner so they won't get lost and confused," said Ainsley. "It will prevent seals from using that corner to corral them."
Researchers will tag the fish and use an underwater camera to observe them during the migration season to determine whether the fillet is having a positive impact.
"Hopefully, what we'll see is when it's in place is there will be higher survival and less predation by seals," said Ainsley.
If researchers determine the system works they hope to build three more fillets and install them on the other three corners of the Hood Canal Bridge.