As glaciers worldwide retreat due to climate change, managers of national parks need to know what’s on the horizon to prepare for the future. A new study from the 91̽�� and the National Park Service measures 38 years of change for glaciers in Kenai Fjords National Park, a stunning jewel about two hours south of Anchorage.

The , published Aug. 5 in The Journal of Glaciology, finds that 13 of the 19 glaciers show substantial retreat, four are relatively stable, and two have advanced. It also finds trends in which glacier types are disappearing fastest. The nearly 670,000-acre park hosts various glaciers: some terminate in the ocean, others in lakes or on land.

“These glaciers are a big draw for tourism in the park — they’re one of the main things that people come to see,” said lead author , a 91̽��doctoral student in Earth and space sciences. “Park managers had some information from satellite images, aerial photos, and repeat photography but they wanted a more complete understanding of changes over time.”

The data show that lake-terminating glaciers, which include the popular and , are retreating fastest. Bear Glacier retreated by 5 kilometers (3 miles) between 1984 to 2021, and Pedersen Glacier retreated by 3.2 kilometers (2 miles) during that period.

“In Alaska, much glacier retreat is being driven by climate change,” said Black, who will complete her doctoral degree at the 91̽��this month. “These glaciers are at really low elevation. It’s possibly causing them to get more rain in the winter rather than snow in addition to warming temperatures, which is consistent with other climate studies in this region.”

One surprising finding was that , which as a tidewater glacier terminates at the ocean, has advanced in recent years. Local boat operators had reported seeing newly exposed land near the glacier’s edge in 2020. But the new analysis shows that the overall glacier has been advancing for about 5 years, and appears to go through regular cycles of advance and retreat. The edges of most of the other tidewater glaciers were relatively stable over the study period.

The six land-terminating glaciers all showed intermediate response, with most retreating, especially in summer months, but at a slower rate than the lake-terminating glaciers. The only other glacier that advanced during the study period was land-terminating Paguna Glacier, which is covered in rock debris from a landslide caused by the 1964 Alaska earthquake. This debris insulates the glacier surface from melting.

To make the calculations, Black used 38 years of images captured by satellites in fall and spring to trace outlines for each of the 19 glaciers — a total of about 600 outlines. She visually inspected each image to map the position of the glacier’s edge. Black used a similar approach in recent to calculate the rate of retreat of marine-terminating glaciers in west Greenland.

The new data for Alaska provide a baseline to study how climate change — including warmer air temperatures, as well as changes in both the types and amount of precipitation — will continue to affect these glaciers. All the glaciers in the study are considered maritime glaciers because they are subject to the warm, wet maritime climate.

The study has immediate application for park managers. These numbers help to quantify the changes that have been occurring and will continue for the glaciers and their immediate environments.

“We can’t manage our lands well if we don’t understand the habitats and processes occurring on them,” said co-author Deborah Kurtz at the U.S. National Park Service in Seward, Alaska.

As the park’s Physical Science Program Manager, Kurtz is also interested in the changes to the surrounding river, lake and landscape ecosystems, and how to communicate those changes to the public.

“Interpretation and education are also an important part of the National Park Service mission,” Kurtz said. “These data will allow us to provide scientists and visitors with more details of the changes occurring at each specific glacier, helping everyone to better understand and appreciate the rate of landscape change we are experiencing in this region.”

This study was done as part of an internship originally intended to take place at Kenai Fjords National Park. Black instead did the research remotely from Seattle and visited local glaciers at Mount Rainier. Part of this research was funded by the National Park Service’s Future Park Leaders program, a partnership between the Ecological Society of America and the U.S. National Park Service.

For more information, contact Black at teblack@uw.edu and Kurtz at Deborah_kurtz@nps.gov.

Beginning May 1, Airlift Northwest will station a Turbo Commander aircraft in Juneau to allow the medical transport service to reach more people living in outlying rural communities in Southeast Alaska.

Airlift has served Southeast Alaska for over 30 years transporting critically ill or injured patients to specialty care in Anchorage or Seattle, and will continue this service. Airlift currently operates a Learjet, which has limitations landing in smaller communities due to shorter airport runways.

The Turbo Commander is better suited to land on shorter runways allowing improved access to the smaller community airports based in Gustavas, Haines, Hoonah, Kake, Prince of Wales Island and Skagway.

“Airlift Northwest is dedicated to saving lives by providing pre-hospital emergency treatment on the ground and in the air,” said Chris Martin, executive director. “In response to requests for improved access to medical transport from providers in Southeast Alaska, we are pleased to offer this new service.”

“The turboprop will allow us to access patients who, in the past, have had to make their way to an area where we could get them in the Learjet. Now we won’t see that delay,” said Dr. Richard Utarnachitt, medical director for Airlift.

Patient care will be provided by two critical care nurses with current certifications in advanced skills for cardiac life support, pediatric life support, neonatal resuscitation and trauma care.

Airlift Northwest, an entity of 91̽��Medicine, provides medical transport to critically ill and injured adults and children throughout the Pacific Northwest and beyond. It operates six bases in Washington and Alaska.

Airlift also announced recently that it will permanently base a Turbo Commander aircraft in Yakima to provide communities in Central Washington with improved access to urgent medical transport. Communities served by the Yakima-based crew include Wenatchee, Ellensburg, Omak, Moses Lake, the Tri-Cities, Sunnyside, Toppenish and other Central Washington locations.

Scientists in the past 20 years have recognized that salmon stocks vary not only year to year, but also on decades-long time cycles. One example is the 30-year to 80-year booms and busts in salmon runs in Alaska and on the West Coast driven by the climate pattern known as the Pacific Decadal Oscillation.

Now work led by 91̽�� researchers reveals those decadal cycles may overlay even more important, centuries-long conditions, or regimes, that influence fish productivity. Cycles lasting up to 200 years were found while examining 500-year records of salmon abundance in Southwest Alaska. Natural variations in the abundance of spawning salmon are as large those due to human harvest.

“We’ve been able to reconstruct what salmon runs looked like before the start of commercial fishing. But rather than finding a flat baseline – some sort of long-term average run size – we’ve found that salmon runs fluctuated hugely, even before commercial fishing started. That these strong or weak periods could persist for sometimes hundreds of years means we need to reconsider what we think of as ‘normal’ for salmon stocks,” said Lauren Rogers, who did this work while earning her doctorate in at the 91̽��and is now a post-doctoral researcher with the University of Oslo, Norway.

Rogers is the lead author of a on the findings in the Jan. 14 online early edition of the .

“Surprisingly, salmon populations in the same regions do not all show the same changes through time. It is clear that the salmon returning to different rivers march to the beat of a different – slow – drummer,” said , 91̽��professor of aquatic and fishery sciences and co-author of the paper.

“The implications for management are profound,” Schindler said. “While it is convenient to assume that ecosystems have a constant static capacity for producing fish, or any natural resource, our data demonstrate clearly that capacity is anything but stationary. Thus, management must be ready to reduce harvesting when ecosystems become unexpectedly less productive and allow increased harvesting when ecosystems shift to more productive regimes.

“Management should also allow, and probably even encourage, fishers to move among rivers to exploit salmon populations that are particularly productive. It is not realistic to assume that all rivers in a region will perform equally well or poorly all the time,” he said.

The researchers examined sediment cores collected from 20 sockeye nursery lakes within 16 major watersheds in southwestern Alaska, including those of Bristol Bay. The scientists homed in on the isotopic signature of nitrogen that salmon accumulate in the ocean and leave behind in lake sediments when they die: When there was a lot of such nitrogen in the sediments, it meant returning runs during that time period were abundant; when there was little, runs had declined.

Climate is not the only reason for long-term changes in salmon abundance. Changes in food webs, diseases or other factors might be involved; however, at present, there are no clear explanations for the factors that cause the long-term variability observed in this study.

Most, but not all, of the lakes examined showed declines in the kind of nitrogen the scientists were tracking beginning around 1900, once commercial fisheries had developed. However, earlier fluctuations showed that natural processes had at times reduced salmon densities as much as recent commercial fisheries, the co-authors said.

“We expected to detect a signal of commercial fishing – fisheries remove a lot of the salmon, and thus salmon nitrogen, that would have otherwise ended up in the sediments. But we were surprised to find that previous returns of salmon to rivers varied just as dramatically,” Rogers said.

As the paper said, “Interestingly these same fluctuations also highlight that salmon stocks have the capacity to rebuild naturally following prolonged periods with low densities, suggesting a strong resilience of salmon to natural and anthropogenic depletion processes. Indeed, total salmon production (catch plus escapements) has been relatively high in recent years for most sockeye salmon stocks in southwestern Alaska, despite a century of intense harvesting.”

Other co-authors are Peter Lisi and Gordon Holtgrieve with the UW, Peter Leavitt and Lynda Bunting with University of Regina, Canada, Bruce Finney with Idaho State University, Daniel Selbie with Fisheries and Oceans Canada, Canada, Guangjie Chen with Yunnan Normal University, China, Irene Gregory-Eaves with McGill University, Canada, and Mark Lisac and Patrick Walsh with Togiak National Wildlife Refuge, Alaska.

Funding was provided by the Gordon and Betty Moore Foundation, the National Science Foundation, the U.S. Fish and Wildlife Service and the Natural Sciences and Engineering Research Council of Canada.

###

For more information:
Rogers,
Schindler, 206-616-6724, deschind@uw.edu

The work was undertaken at a time when the fundamental biology of salmon was poorly known and there were no long-term studies integrating salmon and their ecosystems in a holistic manner, Thomas P. Quinn, 91̽��professor of aquatic and fishery sciences wrote in a of the program and the five field camps 91̽��established.

“Many basic techniques for counting salmon and understanding their life-history patterns were developed at these camps, and the data were used for the management of the salmon runs,” he wrote.

Today commercial fishing on sockeye salmon in Alaska is well-managed and the populations produced from the lakes and spawning grounds are near pre-fishing levels of abundance, 91̽��scientists say.

The program encompasses not just fisheries management, but work on ecology and evolution as well. One of the program’s strengths is that from the beginning 91̽��scientists and staff collected basic information about climate, hydrology, insects, plankton and other fish, something that distinguishes the data set from other salmon monitoring records. The program used an “ecosystem approach” long before the term became fashionable.

The techniques developed and insights gained about Alaska sockeye salmon have been applied to Pacific salmon all along the West coast. Because of the the contributions to conservation of fishery resources, the just awarded the program the Carl R. Sullivan Fishery Conservation Award, one of the society’s most prestigious awards according to William Fisher, society president.

“The Alaska Salmon Program at the 91̽�� was selected for this award because this program is without question one of the most outstanding models anywhere of a working laboratory,” he said. “With its direct connections to local communities and the global community, the program provides amazing educational and scientific outreach.”

The award was presented Aug. 20 in St. Paul, Minn., at the society’s annual meeting.

Field work is conducted from five 91̽��camps in the Wood, Kvichak and Chignik river watersheds in western Alaska. The program is funded by the National Science Foundation, the Gordon and Betty Moore Foundation and the Alaska salmon processing industry.

This summer’s field work, by Quinn and 91̽��aquatic and fishery sciences professors Ray Hilborn and Daniel Schindler, involve half dozen fisheries staff, eight undergraduates and about 10 graduate students looking at such things as:

• The role of the sockeye return in maintaining the resident fish such as
  rainbow trout,  char and grayling
• The evolutionary  pressures of fish size given the tradeoff between sexual
  selection and bear predation
• The process of local adaptation to different kinds of spawning habitat
• Understanding how watershed complexity affects sustainability of fisheries
• Reconstructing prehistorical salmon population dynamics based on traces in lake sediments
• Understanding how climate variation affects salmon population dynamics
• Using genetics to identify the river of origin of the fish and using that information to reconstruct the number of fish returning to each river.

The genetic work involves 91̽��faculty members Lorenz Hauser, Jim Seeb and Lisa Seeb.