Restoration

TU Science: Salmon, forests, floodplains, and carbon on Alaska’s Kenai Peninsula

The science field team along Resurrection Creek (L to R): Jordan Fields, TU’s Aquatic Resiliency Scientist; Luna Aldana, a summer science intern; Helen Neville, TU’s Senior Scientist; and Jack Kreisler, summer science staff.

Trout Unlimited is working with a broad coalition of partners to restore the aptly named Resurrection Creek on Alaska’s Kenai Peninsula. Resurrection Creek was a locus of gold mining activity in Alaska in the early 20th century. Prospecting river gravels left some lucky few richer, many others without much to show for their efforts but stories of moiling for gold under the midnight sun but left the river and its floodplain were certainly poorer. Mine tailing piles lined Resurrection Creek’s banks for miles – turning a once verdant stream that supported all five salmon species into a straight channel that removed much of the stream’s spawning and rearing habitat.

Surveying locations for soil cores along a recently restored section of Resurrection Creek.

Restoration has focused on removing those tailing piles and reuniting the river with its floodplain and the Kenai’s wild forest for the first time in nearly a century. The unique collaboration at this site between Trout Unlimited, the U.S. Forest Serivce, NOAA Fisheries,  the National Forest Foundation, Kinross Alaska and Hope Mining Company has resulted in one of the most successful restorations ever undertaken in The Last Frontier.

Helen Neville, TU’s senior scientist, hammers a soil core into the floodplain soil along an undisturbed section of the stream that the team is using a ‘natural reference’ to compare carbon storage in the degraded and restored reaches.

Now, TU’s National Science Team has seen still greater opportunity in the site: in rewatering the formerly degraded floodplain, the restoration may also sequester and store carbon, acting as a ‘Natural Climate Solution’. As part of a broader project to measure carbon sequestration at restoration sites across the nation, TU’s Senior Scientist, Helen Neville, and Aquatic Resiliency Scientist, Jordan Fields, travelled to Resurrection Creek this summer to measure the carbon currently stored across the site. This work is made possible by funding from Allen Family Philanthropies.

Jordan Fields points to a piece of buried wood in a deep soil core. Floodplains can store lots of carbon in their soils because of high inputs of biomass that are then quickly buried by sediment before that biomass can decay, leading to longterm storage.

Assisted in the field by TU Summer Science staff members, Jack Kreisler and Luna Aldana, Jordan and Helen collected soil cores, measured biomass density in riparian forests using high-resolution multi-spectral drones, and surveyed the density of large dead wood on the floodplain. The carbon in each of these three ‘pools’ will be summed to arrive at an estimate of the total carbon stock at the site. A Carbon stock refers to the amount of carbon stored there now – money in the bank, so to say. The team also collected unique measurements of isotopes in the soils at Resurrection Creek to determine the sequestration rate in soils. A sequestration rate refers to the pace at which carbon is taken from the atmosphere and stored in biomass or soils. In this way, sequestration comprises the deposits that build up the account balance of the carbon stock over time.

Drone imagery collected at Resurrection Creek in the summer of 2025 of the active mining (unrestored) area, the area currently being restored, an earlier restored earlier (in 2006), and a natural area never disturbed by mining.

Directly measuring sequestration is a new and novel technique, enabled by TU’s partnership on this work with Dr. Josh Landis at Dartmouth College, who developed the method. The results are still forthcoming, but the Science Team is certain that the restoration at Resurrection Creek is a ‘no-regrets’ natural climate solution strategy. For even if sequestration is slower than anticipated, TU’s restoration work here – and everywhere – is never about just one element, be it carbon or trout habitat, but rather about ensuring the health of aquatic ecosystems in the long run. At Resurrection Creek, the reports are already encouraging: all five salmon species have returned to recently restored reaches. Perhaps, carbon will follow the salmon. If so, this site on The Last Frontier would be at the very cutting edge, one of the first sites globally at which floodplain carbon sequestration has been directly linked to restoration.

By Jordan Fields.