A positive picture is being painted for researchers looking into the health of glaucous-winged gulls on the Salish Sea.
"I don't want to jump the gun here, but the view from health indicators – we're getting a pretty good idea that these gulls are healthy, they are thriving in the Salish Sea thus far," said Dr. Mark Hipfner, Salish Sea Gull Project lead with Environment and Climate Change Canada. "We haven't finished and we haven't gone over the contaminants data yet so there still could be some surprises."
Started in 2020, the five-year project is designed to establish ecological baselines for gull health in the Salish Sea. With field work completed, researchers will now be analyzing contaminant levels and pathogens in local gulls and comparing those findings with gull populations elsewhere.
Hipfner said the physiological health indicators and blood work analyzed all point to normal levels.
"The Salish Sea is a heavily urbanized marine ecosystem unlike other parts of the province so that's really the key piece," he explained. "The Salish Sea is also a very important wintering area for gulls all over the continent, so it's important from a conservation and ecological perspective that the Salish Sea remain healthy for the birds that depend on the environment."
Preliminary data on the tagged gulls have indicated that the species are a part of three distinct populations, one in the the Bering Sea and the Aleutian Islands, one in the Gulf of Alaska and northern B.C., and one in southern B.C. and Washington, which represent the native gull population.
"Most of the gulls that we catch in the Salish Sea in the winter are the local type birds, but we do get individuals from the populations in Alaska … and the Bering Sea in the winter. So it gives you the idea that it's a pretty important area that the gulls are travelling that far to spend winter in the Salish Sea."
In terms of behaviour, one particular theme researchers have noticed is the number of gulls moving into cities including Vancouver, Victoria and Seattle is increasing, while the number nesting in more natural habitats is decreasing. Hipfner said this points to the gulls "making a decision" to move into the city.
"We think the reason is that they're much safer from bald eagles in the city," he said. "You don't see bald eagles if you're walking along False Creek in Vancouver … it's not an environment they can adapt to the same way the gulls can."
Hipfner said a final report is expected to be released within 12-18 months, with several papers planned for release in the next six months including ones on health metrics and genomics.
Following the ending of the gull project, Hipfner said researchers intend to continue with gull tagging, shifting the focus from habitat use and health to the importance of the herring spawn in the annual cycle.
Anyone who sees a tagged gull is encouraged to submit a photo or report the location and the tag colour through an online form or via e-mail to mark.hipfner@ec.gc.ca.
