Icefield to Ocean

Credit to the Alaska Climate Science Center and their partners.

Icefield to Ocean describes the ecological connections in glacier-dominated landscapes. The following numbered descriptions correlate to the numbers on the diagram above.

Coastal Alaska and British Columbia glaciers are melting faster than almost any other glaciers on Earth. Glaciers are central to many natural processes and economic activities in this region. Changes in coastal icefields and glaciers can have a ripple effect down through the watershed all the way to the ocean.

1. Life on Ice

On the surface, within, and underneath—glaciers are full of life. The glacier surface collects organic matter and is home to diverse microbial communities. Runoff from glaciers provides bioavailable carbon to downstream ecosystems.

2. Melting Away

Rates of glacier loss are projected to increase in the region, with a 26–36 % reduction of total glacier volume by the end of the century.

3. Rain or Snow?

As temperatures warm in this temperate climate, more precipitation is falling as rain instead of snow. This is already affecting the economically valuable yellow-cedar trees. Over longer time scales, this shift could lead to further declines in glacier mass.

4. Fjord of Life

Calving action and the release of cold, fresh water from tidewater glaciers creates turbidity in the water. This mixing makes fjords a unique habitat for krill, fish, sea birds and marine mammals like seals.

5. Driving Currents and Productivity

Freshwater runoff from glaciers helps drive the Alaska Coastal Current. This current carries heat, nutrients, and organisms towards the Arctic. Glacier runoff also adds rock derived elements such as phosphorus and iron to marine ecosystems, which fuels phytoplankton growth at the bottom of the food chain.

6. Supporting the Salmon

The effects of glacier runoff on rivers and estuaries help create ideal habitats for salmon. It is estimated that salmon fisheries provide almost $1 billion per year in economic benefits to Southeast Alaska.

7. Going with the Flow

About 50% of the freshwater runoff into the Gulf of Alaska comes from glaciers. Watersheds with glacier ice are different from those without—they have unique physical and biological properties that support different organisms.

Links to Learn More

Icefield to Ocean poster

About Icefield to Ocean: What Glacier Change Might Mean for the Future of Alaska

Icefield to Ocean, Alaska Coastal Rainforest Center, University of Alaska Southeast

Icefield to Ocean factsheet, U.S. Geological Survey, Alaska Science Center

From Icefield to Ocean: Impacts of Glacier Change in Alaska (video recording of presentation)

O'Neel, S. et al. 2015. Icefield -to-Ocean Linkages across the Northern Pacific Coastal Temperate Rainforest Ecosystem. Bioscience 65(5):499-512.