Inriver Abundance of Copper River Chinook Salmon, a Comparison of Mark-Recapture and Sonar-Based Abundance Estimates - 2025-2027

Utilizing established two-sample mark-recapture techniques, the Native Village of Eyak Department of the Environment and Natural Resources will estimate the 2025-2027 annual inriver abundance of Copper River Chinook salmon. Simultaneously, utilizing high-resolution sonar at Miles Lake, the Alaska Department of Fish and Game will continue to develop length-based enumeration techniques for large Chinook salmon passage with separate funding. This project will compare the two datasets postseason to determine the best strategy for long-term population monitoring.

This data is required to maintain the subsistence allocation preference established in the Copper River Subsistence Salmon Fisheries Management plan (5 AAC 01.647). The preseason Chinook salmon forecast is dependent upon the inriver abundance estimate produced through this project, this project’s inseason data available through eyak.fishscan.com is used as one of several indices for inseason management of the inriver fisheries, and postseason system-wide escapement and total run size allow managers to assess the effectiveness of management in meeting the SEG established in the Copper River King Salmon Management Plan (5 AAC 24.361).