Fish kill tied to algal bloom and influx of eagles

Dozens of eagles have been spotted swooping over the waters of Crescent Beach with their talons outstretched and their beaks ready to carry off shiny perch.

According to Russel Barsh, director for the Lopez-based laboratories Kwiaht,…the eagles, seagulls and herons are gathering on the beach to feed on fish killed by a massive algal bloom. Barsh who sampled and analyzed the bloom on Sunday, said it was made up almost entirely of Heterosigma akashiwo, a tiny organism implicated in fish kills in western Washington and the Pacific Coast. A bloom also occurred on Shoal Bay on Lopez last week.

“It is unclear how or why Heterosigma kills fish,” Barsh said in a recent press release. “One possibility is that dense clouds of this tiny organism simply pack up inside the gills of fish, like a sand storm, and make breathing difficult.”

Kim Secunda, a volunteer for Kwiaht’s Indian Island Marine Health Observatory, saw at least dozen eagles feasting on dead fish along the tide line last Monday. Most of the fish were shiner perch, a schooling fish species that congregates each summer around Indian Island to reproduce. According to Barsh these small fish are especially vulnerable to low oxygen levels.

He added that birds are not in danger by eating the fish. The organism causing the fish die off is not toxic, just a physical problem affecting the gills of fish. Barsh has sent samples to NOAA’s Northwest Fisheries Science Center for further study.


What can be harmful to the eagles is the influx of people watching the eagles in action. Shona Aitken, education coordinator for Wolf Hollow, warns islanders to be aware of the birds while driving as they are prone to swooping down and could be injured by your windshield. She also recommends not getting too close to the animals especially since it’s breeding season and many eagles are bringing food back to their young.

“Use a long lens so you are not affecting their behaviors,” said Shona about photographing wildlife.

She added that these birds may be beautiful to observe, but they are also fierce predators. The biggest birds are females and the average weight of local bald eagles is about 10 to 12 pounds.

“People are pretty amazed when they hear that,” she said.

She guesses that these predators of the sky will be seen at Crescent Beach until the fish are gone.

“They are taking advantage of this bonanza,” she said.


Photo caption: A bald eagle at Crescent beach. — Image Credit: Contributed Photo/ Amy Masters

Cali Bagby

View original article at: Fish kill tied to algal bloom and influx of eagles

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