Eyak Lake A Science & Memory Data Story

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.

Average annual temperature of Eyak Lake is 42ºF. Average annual rainfall is 148.37 inches. Average annual snowfall in the area is 100 inches.

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.

1.4 million salmon harvested annually from the Copper River Delta area

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

11 Miles of Power Creek feeds Eyak Lake

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.

The Power Creek culverts, installed in 2008, facilitate the passage of fish and connect a variety of spawning and rearing habitats.

BIRDS & WILDLIFE

Bald Eagle (Haliaeetus leucocephalus) The Alaskan bald eagle population is estimated at 30,000 birds. These birds of prey are the largest bird of prey in the state, with an average wingspan of up to 8 feet and weighing 8-14 pounds.

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.

"Humpies"
Sockeye

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.

The humble Russian Black Slug works to decompose the corpse of a salmon.

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.

Reciprocity

Salmon are key species in this ecosystem, providing food for predators, key nutrients for soil and forests, and economic vibrance for coastal communities. Careful management of salmon fisheries and streams by tribal and governmental institutions is crucial.

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

June 2017 marks 18 months out of the last 20 months with mean Alaska statewide temperatures at or above normal.

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.

The glacier and river systems feeding Eyak Lake become our home as we study and explore the Cordova area. We marvel at this region and what it gives the world.

CREDITS & SOURCES

Designed by Paige DePaepe

All photos and video from the Science & Memory team of students and faculty.

Report Abuse

If you feel that this video content violates the Adobe Terms of Use, you may report this content by filling out this quick form.

To report a Copyright Violation, please follow Section 17 in the Terms of Use.