As a young girl, I was terrified watching Alfred Hitchcock’s “The Birds” and to this day prefer not to get too close to anything with a sharp beak. In the Columbia Basin, we have our own scary bird problem. Double-crested cormorants and terns are devouring young salmon making their way downstream to the ocean from the upper Columbia and Snake rivers.
Making matters worse, many of these fish are salmon and steelhead listed for protection under the Endangered Species Act (ESA). Northwest citizens have spent billions ($14 billion to-date) to pay for improvements at the dams and to restore habitat in order to protect these fish.
A recent Draft Environmental Impact Statement (DEIS) from the U.S. Army Corps of Engineers proposes “culling” (shooting) about 16,000 of these birds located on Sand Island in the estuary (about 20 percent of the population), to reduce predation on endangered salmon. Many don’t like the idea of killing birds to protect fish, but the case to do so is compelling. Northwest citizens are spending an enormous amount to protect salmon species. They need to know their investment will be protected—not wasted or undermined because reasonable controls weren’t put in place to limit the impact of predatory birds.
Quite simply, there are too many birds and they are eating too many ESA-listed salmon and steelhead. The Corps reports that the number of breeding pairs of double-crested cormorants increased from 100 in 1989 to approximately 15,000 in 2013. In fact, Sand Island, which was created from dredge materials the Corps deposited as part of creating the Columbia and Snake navigation channel, houses the largest colony of double-crested cormorants in North America. From their perch on East Sand Island, these birds take and eat 11 million young salmon a year.
To put double-crested cormorant predation in perspective, the mortality rate salmon experience passing through Bonneville Dam was around 2.7 percent in 2011. For steelhead feasting upon by cormorants, the mortality rate is 6.7 percent, according to a recent NOAA analysis. And, the DEIS notes, in certain years bird predation can cause mortality rates of 11 to 17 percent for some Columbia River salmonid groups. That’s three to four times higher than what salmon experience at Bonneville Dam.
The Corps has conducted extensive research and tried myriad non-lethal methods to address the problem: “Social attraction” in which decoys and bird calls are used to persuade birds to relocate away from Sand Island; human hazing and visual deterrents; reducing by 75% their nesting habitat; and even radio-tagging and moving the birds.
Nothing has worked. For example, following rigorous hazing efforts, fully 98% of all radio and satellite-tagged birds returned and remained in the Columbia estuary for the 2012–2013 nesting season. These birds know a good meal ticket when they see it.
It’s indisputable that cormorant and tern predation is resulting in a huge loss of young salmon heading out to sea. It’s appropriate, then, that the latest ESA federal salmon protection plan (also called the Biological Opinion) requires the Corps to develop and carry out a management plan to reduce avian predation. As distasteful as culling may be, the agency must act— aggressively – for the salmon’s sake.