Surf scoter (Melanitta perspicillata)
Shorebirds are showing up along a 25-mile stretch of beach on the Washington peninsula and are becoming stranded. Mostly scoters, many of the birds are dying and Olympic National Park rangers and wildlife officials do not why. I stumbled across this worrisome wildlife health issue, literally, last Sunday night (Sept. 13). We were driving south along the peninsula on Highway 101 and decided to stop for the night at Kalaloch campground, located on a bluff overlooking a sulky patch of Pacific Ocean.
After staking our tent, and wolfing down some dinner, we decided to go for a walk on the beach. Signs warned us that “beach logs kill!” as we descended down the bluff. The beach was like none I’d ever seen — which says a lot coming from a Florida native. It was jammed with beached logs, strewn like pick-up sticks in both directions as far as I could see. We carefully picked our way across the trunks of the massive logs, some of which had intact roots and some of which had been lopped off by chain saws.
It was high tide. Sand fleas attacked my bare legs every time I walked on the sand versus staying on the logs. It didn’t take much of an imagination to see how these logs could kill. If the tide came up suddenly, they could trap you. They may shift with the currents, pinning an unwary beach goer under water. Someone could slip trying to maneuver through them and then become caught. Though unique, they made me intensely uneasy. It was one of those moments where I realized that wild nature has an edge to it that is often too sharp and jagged to accommodate humans.
Female surf scoter
And then I saw the first surf scoter. Dusk had blurred into twilight and we were walking with our headlamp beams illuminating our paths. My beam swung over the bird, and I was immediately struck by how still she was. She sat in a patch of sand in an opening between log piles, about eight yards from the incoming tide line. Her head was wrapped back across her wing feathers, and her eyes shone with reflected light. She saw us, but made no effort to move. Sand swirled around her and grains were lodged in her feathers and coated her head and shovel-shaped beak. We did not touch her, but wondered aloud why she wasn’t moving and didn’t seem alarmed by our presence. Something told me she was sick. Wild birds simply don’t act like that, I thought.
A few yards down the beach, another surf scoter lay sprawled with her neck elongated in a death pose. She looked like she’d been dead for less than a day. Sand had made a ring around her body, and had nearly covered her legs and part of her throat. As we made our way back to the trail to the campground, I thought I saw two more dead female birds. It was eerie. Something was killing these birds.
The next morning, I found a park ranger and inquired about the stranded and dead birds. We were standing half-way down the trail to the beach, and he pointed to a a group of about six scoters sitting on the beach about 40 yards north from our position. He told me that they’d had a big storm about a week ago, and that the birds had begun showing up a few days after the storm on Friday, Sept. 11. They weren’t sure, he said, if they were just exhausted from the storm or if they were being struck by a disease.
On a hunch, I asked him if they suspected neurotoxin poisoning, something I’d heard about with sea lions on the Pacific Coast and that I knew altered animal behavior. He said that they weren’t ruling anything out, and that they had taken a few birds for necropsies and should know the results by Sept. 18. He told me that this had not happened before, in this area. It seemed to only be affecting surf scoters and white-winged scoters, he said, which eat shellfish. He also told me that many of the birds they’d found ill or dead seemed to be in the middle of their moult cycle, and that they may have been more vulnerable to a storm because of this. Lastly, he also told me that whatever was affecting the two species of scoter seemed to not be transmitted to other birds. They had observed gulls picking at the dead scoter remains, with no ill effects. Still, the park service was warning people not to touch stranded scoters or pick up their feathers.
Since my talk with the ranger, I found this article by UPI on the bird die-off, and a longer article ran in the Peninsula Daily.The second article states that many of the birds appeared to be dazed, which matched what I observed on the beach, and that many seemed to be “seizing” which makes me wonder if toxic algae is indeed the cause of their illness.
Ocean chlorophyl concentrations during a toxic algae bloom. (Click to enlarge.)
A cursory internet search for toxic algae blooms off Washington’s coast turned up some interesting tidbits. Five years ago, scientists identified a “hot spot” for toxic algae blooms caused by Pseudo-nitzschia (a genus of phytoplankton) in the waters between Vancouver Island (Bristish Columbia, Canada), and the Washington peninsula. Pseudo-nitzschia is a nasty diatom that produces a biotoxin called domoic acid. The acid accumulates in shellfish, anchovies and sardines — staple constituents of many marine mammals’ and marine birds’ diets — and is poisonous by causing amnesic shellfish poisoning (also called ASP). According to Wikipedia, “domoic acid especially damages the hippocampus and amygdaloid nucleus” in the brains of marine mammals, and causes damage by a chemical reaction that floods neurons with calcium leading to cell death.
The Visible Earth image (above) shows a 30-mile diameter bloom from Sept. 29, 2004, a size record for the Juan de Fuca straights. The NASA caption to this image also states, “Fed by cold ocean waters that rise from the ocean floor near the coast, phytoplankton blooms are frequent in this region, and some are toxic.” This past January, NOAA scientists published a paper in Limnology & Oceanography that identified why harmful algal blooms occur in this area. They wrote that a powerful 30-mile wide eddy swirls water between the Juan de Fuca straights, Vancouver Island and the Washington peninsula and that this eddy frequently contains significant background populations of Pseudo-nitzschia. Under certain conditions, toxic cells are moved from these background populations to nearshore sites, where blooms occur.
Some scientists postulate that toxic algae release their poisonous byproducts to inhibit competing species and garner nutritious resources for themselves. Other scientists insist that harmful algal blooms are merely the result of an over-proliferation of nutrients. Either way, the sick scoters I saw are very unlucky ducks, and many won’t finish their migration south from Alaska.
Wild Muse 