Columbia River Whitefish Management

A Decision Analysis of Adaptive Management Experiments for Columbia River Whitefish Management

BC Hydro

ESSA developed a decision analysis and adaptive management model for mountain whitefish (Prosopium williamsoni) downstream of the Hugh Keenleyside Dam (HKD) on the Columbia River that explicitly accounts for uncertainties in: 1) the stock-recruitment relationship; 2) spawning (January) and incubation (March) flows in the Columbia and Kootenay Rivers; and 3) foregone power revenues. The decision dealt with the benefits and costs of different spawning flows below the HKD because post-spawning flows often produce de-watering mortality of mountain whitefish eggs. We used Monte Carlo simulation for alternative experimental HKD flow operations and mark-recapture population abundance surveys to evaluate the value of collecting information on the egg-to-adult recruitment. With equal weighting on a wide range of alternative recruitment curves, the optimal HKD spawning flow was 60 kcfs.

Adaptive management results revealed that active adaptive flow experiments that generated stronger contrast in flows were superior to passive (low contrast flow) experiments over a wide range of assumptions. With adaptive management, the optimal flow could increase up to 80 kcfs if the population turned out to be insensitive to egg mortality. Under this assumption, active adaptive management experiments were able to “pay for themselves” within 10 years. However, if the population turned out to be sensitive to egg mortality, adaptive management revealed the larger biological risks but the optimal flow remained unchanged from 60 kcfs.

We also showed that experiments that only “look inward” on the treatment system have relatively low statistical power, highlighting the importance of simultaneously conducting monitoring on populations in reference systems.

Publications and Presentations

Alexander, C.A.D., C.N. Peters, D.R. Marmorek and P. Higgins. 2006. A decision analysis of flow management experiments for Columbia River mountain whitefish (Prosopium williamsoni ) management. Can. J. Fish Aquat. Sci. 63: 1142–1156.
[PDF - 650 kb]

Alexander, C.A.D., P. Higgins, D.R. Marmorek and C.N. Peters. 2002. A Decision Analysis of Adaptive Management Experiments for Columbia River Whitefish Management. A PowerPoint presentation prepared for BC Hydro.
[PPT- 296 kb]