Evaluation of Long-Term Changes in Klamath Basin Chinook Populations From Dam Removal and Restoration Anadromy Versus No Action
Title: Evaluation of Long-Term Changes in Klamath Basin Chinook Populations From Dam Removal and Restoration Anadromy Versus No Action
Category: Technical Memo
File: Hendrix_2012_0057_Evaluation-of-dam-removal-and-restoration.pdf
Updated Date: 09.01.2017
Author(s)/Source(s): Noble Hendrix
Publication Date: 2012-Aug-07
Focal Topic: Dam Removal, Salmon
Location: Klamath Basin
Watershed Code: 180102
Decision makers are often faced with having to make a decision without perfect information (Berger 2006, Hilborn and Walters 1992). Decision theory may facilitate this process by providing a framework for evaluating alternative decisions under uncertainty (Berger 2006). By uncertainty, we are most often referring to alternative states of nature (i.e., the set of conditions over which the decision maker has no control). For example, two
states of nature concerning the chance of rain tomorrow are: 1) that it will rain tomorrow or 2) that it will not rain tomorrow. Alternative actions may then be evaluated in light of the uncertain state of nature. Returning
to the rain example, assume that there are two possible actions being considered: 1) bring and umbrella and 2) do not bring an umbrella. One can then evaluate the two actions given the probability of rain obtained, say,
via a weather forecast. Ultimately, the goal of being explicit about the uncertain states of nature and the actions is to make an informed decision. Here the states of nature were binary, but they may also be a much broader
set of conditions that are not under the control of decision makers. In the context of fisheries management these may be biological rates such as the inherent productivity of a species or physical conditions such as
variability in the environment. Here I analyze two alternative actions pertaining to a Chinook salmon (Oncorhynchus tshawytscha) population in the Klamath Basin under uncertain states of nature. This analysis informs the determination by the Secretary of the Interior (Secretarial Determination) regarding the removal of four mainstem dams on the Klamath River (for more information, pleases see klamathrestoration.gov).
dam removal, chinook