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Researcher(s):
Shiloh Psujek Sara Goldstein Creagan Lydon
ENVS course(s): 220 Initiated: November 2014 Completed: December 2014 Go to project site
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Chinook Salmon (aka. King Salmon) are classified as endangered or threatened species. They reside in the Pacific Northwest, particularly in Oregon, California, Idaho and Washington. Chinook have an especially hard life cycle, where they migrate from fresh water, the Pacific ocean and back upstream. This leaves the population prone to many potential dangers and habitat changes. Over the past century, many Oregon/Washington rivers have experienced anthropogenic alterations. In the early 1900s-- half a century before the environmentalist and animal rights movements reached their crescendos, dams were being constructed almost yearly. In Oregon, Chinook Salmon are listed as threatened, except in the Upper Columbia River where they listed as endangered, we would like to situated our project in this area. We would like to pose the following question to frame our project here: Can restorative law and policy help recover endangered populations? The following question we developed to focus the our project: How has dam construction and restorative law and policy affected spawning populations in upper reaches of the Columbia River?
The two variables we chose to use for extensive and intensive methods were "spawners" (the number of salmon that return to spawn per season) and "fraction wild" (the fraction of the total spawners that are natural origin wild fish).
For our initial, "extensive" methods we planned to preform time series analysis through data visualization. We harvested raw data from NOAA and generated graphs using Excel. We looked at these two variables for 5 different basins categorized as Chinook critical habitats. These basins are all in or close to Oregon. We analyzed these results through the lens of possibly one of the most important events related to the Chinook Species: March 1999, when all of these Chinook ESUs were listed under the Endangered Species Act.
For our subsequent, "intensive" methods we planned to focus on Upper Columbia River Chinook, due to the fact they are endangered, while the other salmon ESUs are listed as threatened. We will create similar graphs for the three rivers which make up this upper reach: the Methow, Entiat and Wenatchee rivers. We plan on preforming narrative analysis of these time series results. This means looking at many more significant events than the date they were listed under the Endangered Species Act to more deeply understand how the fluctuations of spawners and the fraction of wild spawners may correspond with any anthropogenic action. We will examining events in significant regulative action (law and policy), and relevant dam construction to see if there are any interesting trends and relationships.
From our initial, "extensive" time series analysis of Chinook spawning populations in five different Washington and Oregon basins, we can draw a few interesting conclusions. Directly after Chinook were listed as "endangered" in 1999 there are observable increase in number of spawners and an average significant decrease in fraction of wild spawners. Without more informative metadata and statistical analysis we cannot determine whether or not we found a causal relationship, but these results are particularly important for further inquiry into the efficiency of the Endangered Species Act.
From our subsequent, "intensive" analysis of our variables against our narrative timeline of dam construction and restorative law we noticed relationships with the data as well. At the construction of all dams we observe a subsequent decreasing trend. For the following dams: Priest Rapids, Hills, Rocky Reach, Wanapum, Wells and John Day (with the exception of Wenatchee spawners) there were tiny negative slopes, but they weren’t extremely significant and may not even appear if the data was smoother. Zosel (with the exception of Methow spawners) and Dryden Dams had very visible, subsequent decreases spawning numbers. We cannot be certain that these two instances represents correlation or causation, but seems to be an important connection. After the Chinook ESU was listed in 1999, we observe a dramatic spike in spawners for the Methow and Wenatchee Rivers, while the Entiat has a slight increase. The law and policy related events in 2005 and 2011 don’t seem to be related to any visible trends. Results of narrative time series analysis on Fraction Wild showed no relationships. Again, we cannot claim that these relationships are causal, especially since we only partially-smoothed the data. With further investigation into conservation programs, hatcheries and hydroelectric impacts however, another project with more time and resources might be able to paint a better picture of how these variables interact.