The Wind River, a tributary to the Columbia River just above Bonneville Dam, is, at only 224 square miles, a substantially smaller drainage than the Yakima. It receives more precipitation and thus is dominated by forests and industrial timberlands. The Wind River has had some habitat restoration but nowhere near the extent of the Yakima, but that is also because the watershed is relatively undeveloped and in better shape than many other places within the Columbia Basin.
The Wind River received plants of hatchery summer steelhead (Skamania stock) until 1998, so the final year of return for most hatchery adults would have been 2000. Thus, 2001 was the first year without hatchery influence from smolts or adults. As we see in Figure 1, the wild population of summer steelhead in the Wind River did not decline to the extent that the Yakima’s did, nor is the rebound as great. During the hatchery period from 1989-2000 the average run size of wild winter steelhead was 531 fish, compared to 739 fish during the post-hatchery period (2001-2015). On average, that is about 200 more fish per year.
As was the case with the Yakima, the focus of our blog post last week, we don’t have the data or experimental design to parse out the specific effects that caused the increase in run size. We do know that marine survival improved in the later time period, but it is not possible to identify the relative influence of the specific causes that led to the increase in wild fish abundance in the post-hatchery years.
Ideally we could compare the Wind to other adjacent populations with hatcheries to parse out specific hatchery and environmental effects. This is difficult however because consistent data on run sizes is not available for the nearby Klickitat or Hood River summer runs (both of which have hatcheries). The only available data is for the Hood River winter run steelhead, which is only 13.5 miles away from the mouth of the Wind and has a hatchery program.
Run sizes for the Wind summers and Hood winters track closely in many years, but not all and as a result the Hood winter runs have declined from 2001-2013 while the Wind River population increased. This is interesting because many populations in the Columbia increased in abundance over that period as a result of improved marine survival and dam operations. Populations in the Hood and Wind presumably responded differently for a number of factors, but it is notable that research in the Hood River (Araki et al. 2009) found that spawning hatchery adults reduced the size of the wild population. The fact that the Wind summer population is doing better than it was with the hatchery and outperforming the nearby Hood winter run population underscores the need for a more thorough understanding of the processes driving these patterns.
Why is it important to understand the effects shaping wild steelhead populations in the Wind River and elsewhere? Because it has implications for angling opportunity. Wild steelhead in the Wind are listed as “Threatened” under the Endangered Species Act. A catch-and-release (C&R) season depends on the strength of the wild run size. Each year the Washington Department of Fish and Wildlife makes in-season run size estimates. The Department believes a run size of 500 wild steelhead is needed to open a fishery, but they don’t want effects of the fishery (incidental mortalities from C&R) to drive the population below that threshold so fisheries are not opened unless the in-season estimate is predicted to be at least 550 wild steelhead.
The threshold has only been in place since the steelhead were ESA-listed in 2006, but it is informative to understand what fishing opportunity would have been for the hatchery and post-hatchery time periods had the threshold been in place. That analysis reveals that the Wind River would have been open for sport angling 88% of the years (14 of 16 years) since the hatchery was closed compared to 42% of the years (5 of 12 years) when the hatchery was operating. While not a perfect comparison because the time periods are different, it is important because we recently conducted an extensive poll that indicates steelhead anglers are primarily concerned with being on the river. Strong wild populations can provide that type of C&R opportunity, while nearby rivers such as the Hood and Klickitat provide hatchery fish for harvest.
While the closure of the hatchery may have helped provide fishing opportunity after the ESA listing because of the more abundant wild run, there is a bigger, more important point to be made here. We don’t have more definitive data showing to what extent the hatchery closure led to an increase in the Wind’s wild steelhead population. This underscores the need for large-scale experiments to test the response of wild steelhead populations in watersheds with and without hatcheries over a sufficient period of time to answer critical management questions. In other words, we need wild-only rivers like the Wind as part of large-scale controlled experiments along with rivers with different hatchery treatments. Setting aside wild-only rivers is essential for this experiment to succeed, but there needs to be a sound experimental design and monitoring plan as well.
We applaud the Washington Department of Fish and Wildlife for designating the Wind River as a wild steelhead gene bank, in addition to other streams in the lower Columbia and the Olympic Peninsula. The Puget Sound wild steelhead gene banks should be designated shortly. To make the most of these designations, they should be part of a well-designed controlled experiment evaluating the relative performance of gene bank rivers and nearby rivers with hatcheries. After all, as anglers, don’t we want solid evidence to show what works and what doesn’t? Fishing – not to mention the prospects for wild steelhead recovery — will be better if we do.