Eyak Lake 60 ° 33' 9.387" N 145 ° 40' 18.385" East of Cordova, Alaska
Science & Memory
is a project of the University of Oregon School of Journalism and Communication with a mission to tell complex stories of climate and environment throughout the Pacific Northwest and beyond. Faculty and students explore topics such as salmon and other species, human experience in a changing world, and environmental issues related to climate. Cordova, Alaska and Eyak Lake serves as a destination for some of this work.
Eyak Lake, a force of both life and prosperity for the organisms and culture of Cordova, is an important focal point of this project.
This Eyak Lake data story is organized in 3 chapters:
- Data of PLACE to offer context,
- Data of LIFE from sky to water,
- Data of ENVIRONMENTAL CHANGE to consider complexity.
13,000 acre feet = approximately 425 million gallons
Of the many sources that feed Eyak Lake, the largest single contributor is to the northeast via Scott Glacier, a 15-mile long glacier covering 25 square miles in the Chugach Mountains.
To the south, Eyak Lake drains into Eyak River which flows for six miles before entering the western Copper River Delta, eventually reaching the Gulf of Alaska.
The temperate rainforests surrounding Eyak Lake show the interchange between forest and ocean, and these natal coastal rainforest streams make an ideal spawning site for Pacific salmon. The path from Eyak River to Eyak Lake to Power Creek is the principal salmon spawning route of Eyak Lake.
Eyak Lake is home to a rich variety of plants, birds and wildlife, and ten key fish species. One of the most sought after natural resources is salmon. Eyak Lake serves as a vital salmon spawning site, with 1.4 million salmon harvested annually at the mouth of the Eyak River
Power Creek is an 11-mile stream fed by Scott Glacier that extends from the northeastern tip of Eyak Lake. Here, salmon both build the strength to survive in marine waters and eventually return to spawn. As snow and glaciers melt, the stream fills with sediment and turquoise water. This makes it challenging for fish to see their prey, meaning excess glacier runoff threatens the survival of salmon.
Trumpeter Swan (Olor buccinator) Approximately 10% of the world's trumpeter swans nest in the Copper River Delta area in the spring. About 100 swans winter over on Eyak Lake.
Dusky Canada Geese (Branta canadensis occidentalis) "Duskies" --in long term decline because of habitat changes--nest in the Copper River Delta and winter in the Willamette Valley area near Eugene, Oregon
Migratory Birds Approximately 4.5-5 million use the Copper River Delta as a migratory stopover. Over 235 species of birds have been identified during this migration.
Scavenger Birds Scavengers play an important role in an evolving ecosystem. By eating carrion and "cleaning" the environment, they add to ecosystem vitality. In Alaska, this means a symbiotic relationship with bears and larger birds.
BEARS
BROWN BEARS (Ursus arctos) Alaska's brown bears number upwards of 30,000 with density in the Chugach area thought to be highest in late summer and early fall as salmon come into streams. In the lower 48 states, brown bears are called grizzlies; in Alaska, the brown bear is the largest of the charismatic megafauna.
Brown bears grow up to 1500 pounds and range in color from light cinnamon to dark brown. Litter sizes range from one to four, with twins being most common.
Brown bears are often seen along Power Creek, the northern area of Eyak Lake.
BLACK BEARS (Ursus americanus) in Alaska are the most common bear species in the state. In the Eyak Lake area, black bears can be found near the lake in summer and fall. They hibernate approximately five months; longer in colder climes. Warming temperature trends affect hibernation and food availability, which in turn affect ability to mate and how long mothers rear young.
Black bears grow up to 350 pounds and are the most abundant bear species.
SITKA SPRUCE Picea sitchensis The Sitka Spruce is the state tree of Alaska and the tallest conifer in the world. Researchers find that Sitkas near salmon spawning streams often contain the DNA of salmon as the nitrogen content of decaying fish is absorbed by the tree.
SALMONBERRY Rubus spectabilis Rich in Vitamin C, salmonberries range from yellow to deep red and are found throughout the Chugach mountain range.
FIREWEED Chamaenerion angustifolium is known for tall stalks blooming from bottom to top. The stalk and flowers have a long history of use in traditional knowledge. Fireweed blooms along Eyak Lake and around Cordova roadways.
SALMON
Five varieties of salmon are found in the Prince William Sound area: King (Chinook), Coho (Silver), Sockeye (Reds), Chum (Dogs), and Pink (Humpies).
Eyak Lake andPower Creek waters in July teem with Sockeye returning to the nascent streams. Chum and Pink also enter Eyak Lake during the season.
Salmon live an average of 4 to 5 years, traveling from their nascent stream to the ocean, then back to spawn and die. As they return to Eyak Lake and find their way up Power Creek.
DECAY
Salmon and their many predators play a key role in nutrient transport for a healthy ecosystem. Fry and fingerling live in decomposing carcasses of adult fish. The carcasses also supply important nitrogen to the ecosystem of trees and plants along streams. Woodland species play a key role in helping decomposition.
Coastal temperate rainforests allow for dramatic reciprocity of forests and ocean. After salmon move through boreal forest streams to return to their nascent spawning ground, they die; their decomposing bodies become rich nutrients for new growth in the forest. Bears, eagles, ravens, crows, and gulls eat salmon and the carcasses and droppings from those species become part of the salmon-to-forest cycle. Research on Sitka spruce indicate salmon DNA in tree rings.
GROUND AND WATER
RETREATING GLACIERS IN THE EYAK LAKE REGION
“How the climate has been changing over the past few decades of anthropogenic influence really has manifest itself quite well. It provides tangible evidence for how climate change is affecting the landscapes.”
Shad O'Neel, head of the glacier research program at the USGS Alaska Science Center on retreating Alaskan glaciers, in "Alaska's Glaciers are Retreating" Climate Wire September 30, 2016
NASA Landsat satellites found that over the past century permafrost in Alaska has warmed up to 7 degrees, and researchers from the University of Alaska, Fairbanks, say it could lose more than 60 percent of its current permafrost mass.
RISING TEMPERATURES
ELODEA AND A CHANGING LAKE
The U.S. Forest Service is continuing to monitor the spread of Elodea in the Copper River Delta and is studying an herbicide to try to stop its spread. It will run tests of the herbicide again this year.
ELODEA Elodea canadensis commonly known as waterweed, is an invasive plant that was first spotted in Alaska in Eyak Lake in 1982. The plant has since spread to other parts of the state, threatening native plants species and altering habitats as it grows. The U.S. Forest Service uses both removal and herbicide to combat this process, but Elodea can proliferate from just a fragment of a plant.
ECONOMIC IMPACT
According to Alaska Department of Fish and Game reports in the last decade, biologists have estimated Eyak Lake provides an annual ex-vessel value for commercial harvests between $955,435 to $1,572,784.
CREDITS & SOURCES
Designed by Paige DePaepe
All photos and video from the Science & Memory team of students and faculty.
