Arctic Beringia Fish Ecology

Studying the wild and wonderful fishes of northern Alaska

2023 Brooks Range Fish Fieldwork

During July-September 2023, the 2-person WCS fisheries crew collected fish from various waterbodies in the Brooks Range mountains of northern Alaska as part of a survey of baseline heavy metal and PFAS (also known as “forever chemicals”) in fish tissues. This baseline survey is necessary to assess current conditions before areas of the Brooks Range are potentially opened to industrial development, particularly in regards to the proposed Ambler Road and the Central Yukon EIS. The results from the project may inform fish consumption health advice for Indigenous and recreational fishers that commonly harvest fish from these waterbodies.

WCS Fisheries Technician Mike Lunde attempts to catch Arctic grayling for fish contaminant sampling along Nutirwik Creek in the Brooks Range mountains of northern Alaska
Brooks Range locations (green dots) and rivers (highlighted in green, Kobuk on left and Alatna on right) slated for WCS fish contaminants sampling in 2023

At all locations from the map above, we planned to collect aquatic vegetation, sediment, invertebrate, slimy sculpin, and large-bodied fish samples to assess for concentrations of arsenic, copper, lead, zinc, and mercury, heavy metals that can be harmful to human health when consumed in significant amounts.

Slimy sculpins caught in the Middle Fork Koyukuk River near Wiseman, AK. Sculpins are useful for contaminant analyses because they do not move far from one location during their lives, representing ideal sentinel organisms to assess local contamination. Water bodies in the Koyukuk and other drainages may be affected by a proposal to open lands along the Dalton Highway for industrial development (the preferred alternative in the draft Central Yukon EIS)

Sampling was successful at all locations, with many different species of fish collected including Arctic grayling, least cisco, burbot, lake trout, longnose sucker, inconnu, humpback whitefish, northern pike, and round whitefish.

USFWS Collaborator Wyatt Snodgrass with an inconnu (sheefish) caught on the Kobuk River to be assessed for contaminant concentrations. The Kobuk River would be affected by the proposed Ambler Road
WCS Fish Ecologist Kevin Fraley checks a tangle net for fish in an unnamed lake along the Dalton Highway
Longnose suckers collected in an unnamed lake along the Dalton Highway for the project. The lands around this lake would potentially be opened for resource development under the preferred alternative in the Central Yukon EIS
USFWS collaborator Wyatt Snodgrass remains upbeat despite difficult sampling conditions along the upper Kobuk River

Samples collected in 2023 are currently being processed in the laboratory and will be sent to an external lab for testing. Follow-on sampling for PFAS concentrations and addition of new waterbodies (John River, Alatna River, and Koyukuk River near Bettles, AK) will occur in summer 2024

Kevin Fraley

, , , ,

Leave a comment