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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]
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