INDIANOLA — The Suquamish Tribe and the Washington State Department of Fish and Wildlife are working in concert to determine why 209 common murres and Pacific loons washed up dead on the Indianola beach Monday.

While there had been no apparent oil or gasoline spills in the area, residents started noticing the carcasses earlier this week, and tribal officials reported their findings to the state crews.

Suquamish Tribal Fisheries Biologist Paul Dorn said there could be a number of different reasons for the mass death, among them drowning, pollution, poisoned food or fishing via purse seining. He and other tribal workers helped collect the bodies and samples to send to the Fish and Wildlife laboratories to establish the cause of death.

“This is a hugely sad event,” he said. “These were not endangered birds, but they are not common either… We received calls Monday morning. We’re responding, but we don’t know the cause yet.”

Fish and Wildlife District Wildlife Biologist Greg Schirato said this is definitely not a case of bird flu, but there is a hotline open for residents to call if they see a large die-off similar to this one.

“This particular case is unusual,” he said. “In quite a few years, I’ve dealt with bird wash ups for quite a few years on this beach, and this one is different.”

Dorn said the bird carcasses he saw appeared to be in perfect health, without ruffled feathers or other signs of a struggle or contamination. An immediate reaction was to ascertain whether the birds ingested something that could prove to be fatal to other species in the area, and sound a warning to address it, he said.

Schirato said if the birds were poisoned, or ate something unusual, it would be found during the necropsy of the carcasses. If poisoning was the cause of death, steps would be taken to protect other species in the area.

“That is very, very rare though,” he said. “Birds die at a pretty high rate, and people always assume it’s poisoning, which is very rare.”

Birds can also get caught in storms, causing them to starve to death, which will also be reviewed during the necropsy. Results from the tests were returned Friday.

“Sunday or Monday are the next purse seining,” Dorn said of another reason the birds washed ashore dead. He said he would go along to see if there was anything about the process that could have killed the birds. Purse seining is a way of fishing by casting a rectangular net weighted at the bottom and buoyed at the top. It could have caused the birds to drown. Schirato said the Grover’s Creek Hatchery and Fishery had just opened for fishing, which can sometimes cause birds to drown going after bait in nets, but he has never seen something on this scale before.

“Since 1999, we have had birds wash up on shore,” he said, noting he’s seen four bird die offs besides this one. “Those are usually in the 30 to 40 range though, nothing like this… They get caught in the gill nets looking for bait. One of the tribal workers reporting this counted 209 birds in the water, and we picked up 191.”