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Seabird numbers: a surprising trend

seabird merganser

A merganser swims in Seattle waters.

Some dive while others cry as they fly above choppy waters in search of food in the pouring rain. It's a day for the annual winter seabird count along Puget Sound's near coasts, and the birds are in full form.

Rod Brown and Cathy Conolly, citizen scientists two, are tracking seabirds at a designated spot near Myrtle Edwards Park on the Elliott Bay waterfront. “We've got a merganser out here that's in breeding plumage with feathers coming off the back of its head and a nice showy crest,” says Brown, as he looks through binoculars. “It's showing off to other birds that might find that an attractive mate.” Conoly adjusts a spotting scope and sees a Barrow's Golden Eye. “It's this lovely black and white duck,” she says admiringly.

In a marine world where good news is often hard to find, an increase in winter seabirds is cause for celebration. Eighteen species along Puget Sound's near coasts are on the rise, including loons, surf scoters, buffleheads and rhinoceros auklets.

Since October, Brown and Conolly have come to this stormy observation site to count seabirds, and they will continue to do so as part of a Seattle Audubon inspired “citizen science” study that runs through April each year. A joint collaboration with NOAA, the Washington Department of Fish and Wildlife and others, the seven-year long project has tracked the visits of 18 seabird species and found an increased presence in 14 of them.

Those doing well include loons, rhinoceros auklets, cormorants and harlequin ducks. As the wind and rain pound the coastline, Brown takes out a compass and ruler to take bearings of the direction the seabirds have come from. “The first batch is 80 degrees on the ruler from the horizon,” he says, “and the second is 250 degrees.” Conolly notes the readings in scientist-designed charts as large flocks of surf scoters, as many as 800, line up in neat rows near a cargo ship in the Bay. The ship may be acting as a buffer to keep grain from a nearby terminal from washing out to sea.

The impressive number of surf scoters is something the two citizen scientists always try to count at this particular site. “This is the only observation point where you can see these large flocks,” says Conolly. Surf scoters are a significant portion of seabird life in Elliot Bay, she adds, the males sporting a distinctive black and white head in stark contract to an orange bill tip.

One hundred fifty trained volunteer citizen scientists have been counting seabirds from Deception Pass to Olympia and as far west as Cape Flaherty annually since 2007. The results were released in a new report, Using citizen science data to identify local hotspots of seabird occurrence.

The goal, says lead author Eric Ward of NOAA's Northwest Fisheries Science Center is “to establish a baseline of surveys in Puget Sound and try to identify whether species that have declined in the past are still declining, whether things have stabilized or whether some have increased.” A good example of those that have increased are rhinoceros auklets, results which dovetail with positive nesting surveys. Seabirds that remain in decline include western grebes, which have shown historic declines since the 1970s, red-necked grebes, white-winged scoters and brants. Interestingly, points out Ward, western grebes have become more abundant in coastal areas off the California current, which appear to have higher or more reliable food sources than Puget Sound.

Another author, Scott Pearson with Washington Department of Fish and Wildlire, says that while the center of gravity for many overwintering seabirds may have shifted to Northern California because of food, Puget Sound's center of gravity fluctuates because of variations in California currents and Alaska, as well as when the currents hit the continent. The strength of the two changes over time and results in mixed impacts on the base of the food web, phytoplankton. Ocean upwelling also plays a factor. Upwelling brings nutrient rich sediments to the surface. “Some waters can be warmer or colder and that can have big effects on both the strengths of the upwelling and also the amount of food available,” says Pearson.

Pearson, based in Olympia, notes that the citizen science study had varied results depending on whether seabird counts were in south Puget Sound or north Puget Sound. “Down here we're starting to see a lot more jelly fish whereas in the north people are seeing a lot more forage fish.” Initial studies by NOAA scientists, he says, show a relationship between jelly fish abundance, latitude and water clarity. Seattle is only a little farther north than Olympia, but the distance could make a difference when it comes to food supply. Pearson adds that in the north part of the Sound, the tidal exchange is stronger and there are far more fresh and seawater outlets, which can result in more abundant food supply.

Positive trends in seabird sightings, caution Ward and Pearson, don't always reflect increasing populations of seabirds in the area. Federally protected marbled murrelets, for instance, continue to decline across Washington. And many winter seabirds are migrants and do their nesting elsewhere. Nor is it clear just how much or how little traditional threats — such as contaminants, shoreline armoring, climate change or even derelict fishing gear — are having on winter seabirds.

But what seems clear from the rigorous data, says Seattle Audubon's Toby Ross, is that 14 species along Puget Sound's near shore are literally on the rise. “Seabirds are an intrinsic part of the ecosystem. So if there's something happening with the seabirds there's likely something else happening with their food, with water quality; it just goes on from there.”

It's all a part of the web, he says, the marine web, whose documentation on the seabird front wouldn't be possible without citizen scientists willing to count and observe month after month, October through April, for the last seven years.

If you're up on seabirds and willing to take a test to prove it, contact the Seattle Audubon Society. They plan to expand the project.

  

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Seabird numbers: a surprising trend