Fisheries workers deter seals from the Ballard Locks using underwater pyrotechnics

If you’ve been to the Ballard Locks lately, you might have seen someone throwing what look like firecrackers into the water near the fish ladder.

The firecrackers are known as seal crackers—underwater pyrotechnic devices that deter seals from feasting on the large number of salmon running through the fish ladder right now.

Nicole Celestine from the U.S. Army Corps of Engineers tells My Ballard that as the number of salmon going through the locks increase, so do the number of predators—in this case, seals.

Lake Washington Fisheries co-managers—Washington Department of Fish and Wildlife (WDFW) and Muckleshoot Indian Tribe—work with the U.S. Army Corps of Engineers to reduce salmon predation.

“They do this by throwing (non-lethal)  seal crackers into Lake Washington, to train harbor seals and sea lions away from the fish ladder, and help salmon along their journey upstream to spawn,” Celestine told My Ballard in an email.

Each year, fisheries managers tracks all three salmon species—coho, Chinook, and sockeye—as they pass through their locks into freshwater for their annual migration. The WDFW and Muckleshoot Indian Tribe conduct the counts cooperatively to determine if there are sufficient sockeye open fishing season.

There’s been a lot of action at the fish ladder lately—just one week ago, 1,292 coho went through the locks in a single day. (You can check out the daily counts of all three species here.)

So if you see someone throwing what looks like regular firecrackers into the locks—don’t be alarmed—they’re just doing their jobs to keep the seals at bay.

Photo: File photo of the Ballard Locks fish ladder