Northern fur Seals on Pribilof Islands of Alaska

Roughly 50% of the world’s northern fur seals breed in the eastern Bering Sea on the Pribilof Islands of Alaska. The species has a rich history of exploitation for its luxurious fur and while various subpopulations have experienced periods of stability and recovery from sealing activities, today the overall population is declining. Many explanations for population decline have been proposed: predation, conflict with commercial fisheries, reduced prey abundance/quality, and warming seas. My research focuses on establishing a tool for wildlife managers that is both accurate and cost effective. To do this I tagged adult female northern fur seals with radio transmitter tags that are capable of telling me how long mother seals spend foraging at sea as well as how long they spend on shore nursing their pup. The longer mom spends foraging at sea, the longer her pup is left alone onshore fasting without food, inevitably losing weight if left alone for too long. Previous studies have linked pup weight to survival, noting that pups who wean heavier have a greater chance of surviving their first winter without mom. I suspect that when prey is hard to find, or other conditions are unfavorable like warm ocean temperatures, mother’s spend extra time searching for food. In conjunction with foraging trip duration measurements, we weigh the pups and have shown that indeed, when mom spends extended times foraging, her pups lose weight. Because we know survival increases with weight, in years when mom’s spend extra time foraging, we may expect survival to decline. This relationship suggests that maternal foraging trip durations can be used as an inexpensive tool of evaluating reproductive success in a depleted marine mammal species.

Greg Merrill (UAA) applies a radio transmitter to the flipper of an adult female northern fur seal on St. George Islands, AK, to track the animal’s time foraging at sea. NMFS Permit #14327-01.

Greg Merrill (UAA) waits to tag a female northern fur seal on St. George island as John Edwards (NOAA Alaska Ecosystems Program) and Greg Balogh (NOAA Alaska Regional Office) safely restrain the animal in a neoprene vest. NMFS Permit #14327-01. Photo credit: Rebekah Leverty.

An Arctic fox observes the tagging crew weighing an adult female on a northern fur seal breading colony. Look closely at the boulders in the background. A lot of them are seals! NMFS Permit #14327-01.

Harnessed to a cliff edge, Greg Merrill (UAA) uses a spotting scope to identify tagged northern fur seals hauled out on the breeding rookery below.

An adult female northern fur seal cautiously spies on the activities of the tagging team. NMFS Permit #14327-01. Photo Credit: Greg Merrill

A needle in a haystack: UAA researchers are on the hunt for ticks in Alaska

Summer in the Land of the Midnight Sun means Alaskans are hitting trails in full force with family, friends and their canine companions. However, the great outdoors comes with its own risks and happy hikers know to be prepared for whatever may be lurking in the woods, like bears or moose. But what about bugs? And we’re not talking about the mosquito kind. Turns out there’s something far worse than mosquito bites — and that’s being bitten by a tick.

As summers in the state have trended warmer over the last decade or so, the number of tick sightings in Alaska have started to increase. Although the Last Frontier has its own hearty tick populations native to the state, the concern in recent years is that nonnative species found in the Lower 48 may start migrating north.

North Slope biologists make room for the loons

Loons are a boon for bioresearch. Much like the canary in the coal mine, the health of these top aquatic predators can translate to an entire ecosystem.

“If there are changes in the environment, from way down to fish and plankton, it will bio-accumulate to a loon,” explained Hannah Uher-Koch, a graduate student in biological sciences at University of Alaska Anchorage. That makes these migratory birds — like the yellow-billed loon, which frequently flirts with inclusion on the endangered species list — a valuable research subject in a changing landscape.

Loons are study-worthy subjects because they’re highly specialized birds, and thus more prone to disturbance. With feet far back on the body, loons are anatomically built for swimming and diving. A minor disturbance can jolt a loon into the relative safety of the water, leaving eggs on the shoreline vulnerable to predators. A series of major disturbances — like the abrupt introduction of a round-the-clock oil pad — could force enough loons from nests to affect an entire generation. Industry and wildlife can coexist, though. Habituated loons now nest near the oilfields of Kuparuk and Alpine. That just makes the sustainable and managed introduction of industry even more important in the NPRA.

Counting sheep in the Chugach Mountains

A biology student at University of Alaska Anchorage (UAA), Metherell spent most of his summer deep in Chugach State Park, observing and recording Dall sheep behavior for days at a time. He spent so much time with sheep that, by August, he could identify individual personalities among the herd.

“[It’s been] an amazing opportunity as an undergraduate student,” he said

So far, the team knows the number of Dall sheep are shrinking in Chugach State Park. The population has halved in the past few decades. Lohuis determined nothing abnormal was killing the sheep; there were just fewer being born. Dial, meanwhile, determined that warming temperatures and longer growing seasons allowed vegetation like alders and willows to creep up the mountainside, cutting off the alpine tundra that Dall sheep love to snack on.

(Photo: Courtesy of Luke Metherell/Alaska Department of Fish and Game)