Jun 10 2016

Southeast Alaska Climate & Water Resources Workshop Reveals Answers and New Questions

The Tongass National Forest spans 17 million acres, making it the largest national forest in America. This temperate rain forest is intertwined with lakes, rivers, and streams that are home to a variety of freshwater and saltwater fish.

Many of Alaska’s landscapes are changing due to climate change, and the Tongass National Forest is no exception.

Stakeholders, community leaders, and researchers gathered for a workshop on April 12th-15th to address changes in the Tongass National Forest’s water systems and what that could mean for the future.

“All aspects of hydrology are going to be affected by climate change,” says Jeremy Littell, research ecologist at the U.S. Geological Survey (USGS) and lead research scientist at the Alaska Climate Science Center (AK CSC).

At the workshop, Littell and other participants discussed several hydrological changes that could be due to a warming climate. However, identifying a definitive driver of change for the majority of water bodies is challenging since water temperature data in the Tongass is limited.

“We don’t know if all bodies of water show an increase in temperature because many are unmeasured,” explains Littell. “That was part of the workshop focus.”

Workshop participants also discussed how hydrological changes could impact water and other natural resources in the region.

For example, increasing air and water temperatures could cause a delay in ice formation and earlier ice melt. Changes in the rate and timing of ice melt is significant because higher amounts of fresh water could be flushed into stream systems. This could change water temperatures, water currents, and the availability of valuable nutrients, such as phosphorus and carbon, which in turn- could impact fish populations and subsistence harvesting. 

Subsistence was another key issue discussed at the workshop.

Many Southeast Alaskans use the forest’s variety of fish as a main food source. Research presented during the workshop revealed that certain species of fish, such as salmon, are migrating earlier due to changes in water conditions.

Participants also discussed the observed changes in the size of sockeye salmon. As to the cause of this, Littell explains that very little data exists for streams over a long period of time for researchers to determine if these changes are related to climate change.

The workshop brought together data and information that was collected by researchers, land managers, locals, and other workshop participants. Through the discussions, the participants were able to identify and bridge some gaps in the data.

“Many small efforts can add up,” says Littell.

But he added that this probably won’t be the last workshop and that it’s certainly not the end of the discussion.