The Aleutian Island Struggle

The 2018 Steller sea lion aerial survey struggle is real

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November 14, 2018
Katie Luxa
Biologist

 

Earlier this summer, NOAA scientists partnered with NOAA’s Aircraft Operations Center to conduct our annual aerial survey of Steller sea lions in Alaska. You can check out this post to read more about our aerial surveys.

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Overhead view of the camera system installed in the NOAA Twin Otter. Photo credit: Katie Luxa

Our trip began in Anchorage on June 19, where my co-workers and I met the pilots, mechanic, and – most importantly – the Twin Otter airplane that would be our office for the next three and a half weeks. The first order of business was to install our survey equipment: an array of 3 digital cameras mounted in the belly of the plane and a computer that controls the mount system.

The next task was to plan the flight to our first destination. Despite our ability to cover a lot of ground in the Twin Otter, Steller sea lion sites are spread out over more than 2,500 miles of coastline and weather conditions aren’t always favorable enough to fly safely and capture high-quality images. For these reasons, we split sites into two survey areas: Southeast Alaska and the Gulf of Alaska are surveyed in odd-numbered years and the Aleutian Islands are surveyed in even-numbered years. This year, an Aleutian Island survey year, flights would be based out of Dutch Harbor (Unalaska Island) and Adak Island.

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Dutch Harbor is approximately 800 miles southwest of Anchorage; it is the #1 commercial fishing port in the United States and was featured in the TV show “Deadliest Catch”. Adak is another 440 miles west of Dutch Harbor, and is the site of a US naval air facility that closed in 1997. At its peak, there were up to 5,000 troops and their families living in Adak – they even had a McDonald’s! Our area of highest priority was around Adak and so we hoped to start the survey on a high note and visit those sites first. Unfortunately, the weather forecast didn’t look great, so we headed to Dutch Harbor instead.

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Aerial view of Adak (most of the homes in the image are empty). Photo credit: Katie Luxa

Once we settled in Dutch Harbor, it was time to start planning survey flights. We use an app called ForeFlight to upload a list of GPS locations for known Steller sea lion sites and draw a route from point to point; the route can then be shared with the pilots, who use the same app in the plane. Depending on how close the sites are to one another and how many passes are needed to photograph the sea lions, it’s possible to visit more than 30 sites in a single flight. We try to come up with a few potential flights each day, because being flexible is key to a successful survey.

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Discussing that day’s flight options in Adak. Photo credit: Ben Hou

And, boy, this year was all about flexibility! We had unusually poor weather, including many days with low “ceilings” (height of the cloud layer) or gusting winds that made it impossible for us to fly. And when we were in the air, we often spent our survey flights “hunting and pecking” for sites that weren’t covered by fog. Despite our weather difficulties, though, we were still able to survey over 130 sites and take over 13,000 photos!

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Bogoslof Island is a breeding site for both Steller sea lions and northern fur seals. The steam rising from the island is due to recent volcanic activity. Photo credit: Morgan Lynn

There were also some true highlights on this year’s survey. As Katie mentioned in an earlier post, we surveyed Bogoslof Island, which was completely transformed by a series of volcanic eruptions starting in December 2016. Compared to our aerial survey in 2016, the island had more than tripled in size and was still steaming! Bogoslof is one of the few places in Alaska where both Steller sea lions and northern fur seals breed, and it was amazing to see them there again, after such dramatic changes to the landscape.

Through the fall and winter, we’ll continue the important task of counting sea lions in this year’s images – and keep our fingers crossed for fair weather in 2019!


I’m a research scientist with the University of Washington’s Joint Institute for the Study of the Atmosphere and Ocean. I study food habits of Steller sea lions and northern fur seals, as well as Steller sea lion population abundance and survival, at the Alaska Fisheries Science Center. I’ve worked at the Center since 2008. I received my undergraduate degree in Marine Science from the Southampton College of Long Island University and my Master’s degree from Western Washington University.

Author: Steller Watch

Blog for Steller Watch, a Zooniverse.org Project https://www.zooniverse.org/projects/sweenkl/steller-watch