Cormorant Nest

A double-crested cormorant nest.

The Northwest Power and Conservation Council sent a letter to the U.S. Fish and Wildlife Service on Aug. 19 supporting a proposed rule that would allow permits to remove nests and kill double-crested cormorants that prey on hatchery fish and salmon and steelhead listed under the Endangered Species Act.

The support stems from the significant harm fish-eating birds cause on the number of juvenile salmon and steelhead that make it to the Pacific Ocean from the Columbia Basin.

"Predation by birds is now considered the dominant mortality factor limiting some ESA-listed species' survival, and a significant source of mortality of non-listed species," the letter stated. "This hamstrings the Northwest's significant annual taxpayer and Bonneville Power Administration-ratepayer investments (nearly $1 billion annually) to protect ESA-listed salmon and steelhead while simultaneously delivering a critical source of clean, carbon-free hydropower to the Northwest."

Council staff have reported that fish in the Snake and Columbia rivers pass more than a dozen colonies of birds that prey on fish through a 500-mile journey, affecting at least five ESA-listed species—Snake River sockeye, Snake River steelhead, Snake River spring/summer Chinook, upper Columbia steelhead and upper Columbia spring Chinook.

In one recent study, scientists found these colonies of nesting birds consume between one-third and one-half of upper Columbia steelhead smolts before they reach the ocean. The Council's letter noted the study found in some instances as much as 70 percent of upper Columbia steelhead smolts are dying from bird predation—more than all other causes of mortality combined, including dams, other predators and disease.

In its letter, the Council said the U.S. Fish and Wildlife Service's proposed rule will significantly help efforts to control fish-eating bird populations.

"This proposed rule complements a recently released draft Environmental Impact Statement on the operation of the Federal Columbia River Power System with a biological assessment that requires ESA consultation with NOAA Fisheries and USFWS this year," the letter stated.

K.C. Mehaffey covers fish issues for Clearing Up, and is editor of the NW Fishletter. She joined the NewsData writing team in February 2018. From lawsuits to scientific studies, she is enjoying the deep dive into the Columbia Basin's many fish topics.