Actions taken under the Spirit of the Salmon Plan have contributed to a more optimistic outlook for the Columbia River Basin’s anadromous fish. Generally the trends indicate some large stocks of salmon and sturgeon have stabilized or increased over the last decade (Figures 2, 13, 18, 19 and the figure shown in We Have Halted the Salmon’s Decline).
While full analyses of individual fish stocks are beyond the scope of this Update, mainstem data do indicate mostly positive prospects for our ability to recover salmon, lamprey and sturgeon.
Mainstem data on large units of fish (as shown, for example, in We Have Halted the Salmon’s Decline) are collected for a variety of management purposes, including harvest regulation and monitoring fish passage through the hydrosystem. Mainstem data are not necessarily collected to assess trends in specific wild stocks. But they can be useful to gain an understanding of the status of larger management units and can provide insight into the status of finer level groups of fish.
Figures 7, 8, 14, 15, 16, 17, and 18 show data specific to natural origin stocks that indicate a general uptick in rebuilding natural spawners since their lowest run sizes in the 1990s. Similarly, Figures 7 and 8 show progress in rebuilding steelhead salmon since their lowest returns in the mid-1990s.
Our ability to evaluate trends for specific stocks using mainstem data is limited in large part to reconstructing run sizes of different salmon populations. Changes in abundance are difficult to correlate with specific actions taken to recover fish because of the numerous factors that affect their survival.
However, most natural-origin stocks, including Pacific lamprey and white sturgeon, remain well below historical levels. The lamprey population has yet to move toward recovery (Figure 14). The decline of Columbia River white sturgeon between Bonneville and McNary dams has generally stabilized, but populations levels overall are still not at restoration levels (Appendix D Sturgeon Abundance). The numbers of most natural origin fish caution us that much more work lies ahead.
For upriver spring chinook, some increase in the overall returns to the Columbia River has occurred since 1979 (Figure 1). Most of the spring chinook, however, are of hatchery origin.
Run sizes of upper Columbia summer chinook have increased since 1979 (Figure 2), but the trend has been relatively flat since 2001.
Bonneville Pool tule fall chinook (Figure 3) are mostly hatchery origin fish returning to Spring Creek Hatchery. With the exception of 2006 and 2007, run sizes of Spring Creek tules have generally increased since 1986. There are no data on the river mouth returns of any natural origin tules from tributaries that flow into the Columbia between Bonneville and McNary dams (Zone 6)..
The mid-Columbia bright fall chinook stock (Figure 4) are primarily hatchery origin fish returning to Little White Salmon, Klickitat and Umatilla hatcheries. This group also includes small numbers of naturally spawning fish in Zone 6 tributaries outside the Deschutes River. There have been some increases in the run sizes for this group since the 1990s. Significant increases might not be expected since hatchery production has remained relatively stable. There are no data on the river mouth run sizes of any natural origin fish in this group.
With the exception of 2007, run sizes of upriver bright fall chinook stock (Figure 5) have generally increased relative to the 1990s. This upriver bright fall chinook group is comprised of natural origin fish from the Deschutes River and all hatchery and natural origin fish from areas upstream of McNary Dam including the Snake and Yakima rivers. A significant portion of this group is natural origin fish from the Hanford Reach.
While a couple years have had strong returns, no real increasing trend is apparent for the clipped and unclipped Skamania steelhead stock (Figure 6). Most of the unclipped steelhead are presumed to be natural origin fish. (Biologists consider unclipped fish to be a reasonable index of wild run sizes and have a long history of clipped and unclipped dam counts for steelhead but not for other stocks.) These summer run steelhead pass Bonneville Dam from April 1 through June 30. They may be primarily destined for tributaries downstream of McNary Dam. (It is not possible to reconstruct upriver steelhead runs at the river mouth.)
Since the 1980s and 1990s, a slight increasing trend has occurred in counts of Group A Index steelhead (Figure 7). These are steelhead measuring less than 78 cm fork length that pass Bonneville Dam from July 1 through October 31. These fish can be destined for anywhere in the basin. The majority of the unclipped fish are presumed to be natural origin fish.
No increase in the abundance trend of unclipped Group B Index steelhead has been seen since the 1980s (Figure 8). These steelhead measure 78 cm or greater and pass Bonneville between July 1 and October 31. They are presumed to be primarily destined for areas in the upper Clearwater Basin and in the Middle Fork Salmon River. Around 20-25% of the unclipped fish in recent years may be hatchery origin fish from supplementation programs in the Clearwater Basin.
Wild steelhead returns to Lower Granite Dam have generally increased in abundance compared to the lowest return years in the 1990s (Figure 9). The pattern is similar to the pattern of wild steelhead data at Bonneville even after mainstem fisheries have occurred.
There appears to be a slight increasing trend for winter steelhead compared to the 1990s (Figure 10). Because of inconsistent counts in the winter, it is difficult to be certain of this trend. Winter steelhead are destined for tributaries between Bonneville and The Dalles dams. Almost all unclipped fish are presumed to be natural origin fish.
While overall returns of unclipped steelhead are stable or increasing, some individual stocks may not be doing as well. For example, Figure 11 shows data on spawner estimates for John Day River steelhead based on redd counts. These data indicate a continued decreasing trend for this stock. (Data for other individual stocks are not always readily available.)
Figures 6, 7, 8, 9, and 10 show some limited progress toward recovering the total wild numbers of steelhead, although Figure 11 suggests there may be continued concerns with individual stocks. Because data are not available on the trends or status of individual ESA-listed Distinct Population Segments (DPSs) at Bonneville Dam, it is difficult to assess progress toward delisting.
In recent years, Columbia river-mouth run sizes of sockeye show a strong increasing trend (Figure 12). Most sockeye are destined for the Okanagan River. Sockeye are a mix of hatchery and natural origin fish. There are no river mouth estimates of total natural origin fish.
Run sizes of upriver coho have generally been larger than run sizes prior to 2000, except for 1986 (Figure 13). (Upriver coho are not reconstructed to the river mouth.) The 2012 count, however, was the lowest since 2000. There are no estimates of total natural origin upriver coho, so it is not possible to determine any trend in natural-origin coho run sizes.
Figure 14 shows just how far the numbers of Pacific lamprey, an important subsistence and cultural resource, have fallen in recent years. Once returning to the Columbia River and its tributaries by the millions, lamprey returns were at an all-time daytime low of 6,234 in 2010.
For information about white sturgeon population abundance trends, see Appendix D.
With the exception of three years in the early 2000s, natural-origin Snake River spring/summer chinook have made little improvement since the 1980s (Figure 15). These data showing Columbia river-mouth run sizes include Clearwater Basin natural-origin fish, which are not ESA-listed.
Figure 16 shows the number of wild Snake River spring/summer chinook at Lower Granite Dam. These data indicate that as with the river mouth run sizes, there has been an increase in run sizes since the lowest return years in the mid-1990s. The pattern at Lower Granite is unchanged compared to the pattern at the river mouth even after mainstem fisheries have occurred.
Figure 17 shows Columbia River mouth run sizes for natural origin upper Columbia spring chinook. These fish are destined for areas upstream of Priest Rapids Dam. The number of these fish has decreased since the 1980s; and thus no progress has been made towards recovering them. They are listed as endangered under the ESA.
Considerable progress has been made in restoring the abundance of Snake River fall chinook (Figure 18). Hatchery and natural-origin fish are collected for hatchery broodstock so the escapement to spawning areas upstream is less than the numbers of fish arriving at Lower Granite Dam where they are counted. However, quality and quantity of habitat continue to constrain natural production. To meet ongoing mitigation needs, maintenance of the supplementation program is required.
Progress has been made in reintroducing coho in the upper basin (Figure 19). These data include both hatchery- and natural-origin fish. Coho upstream of the Hood River Bridge are not ESA-listed, and upstream groups are products of tribal reintroduction efforts. Data on natural-origin coho in the Hood River, which are part of the Lower Columbia ESU, are not readily available.
Stanley Basin Snake River sockeye are listed as endangered under the ESA. In some years, no sockeye spawned naturally in the Stanley Basin, and a captive brood program supported the entire run. The majority of the run are hatchery-origin fish. In recent years, the total return, including a few natural-origin fish, has shown an increase (Figure 20), which probably reduces the short-term threat of extinction at least to some degree. With total returns of sockeye to the Stanley Basin remaining at less than 1,500, these fish clearly remain in dire condition.
Figure 21 shows data on tributary returns of spring chinook in the Umatilla and Walla Walla rivers and depicts progress in reintroducing spring chinook to these rivers. The trend for natural-origin spring chinook in the Umatilla River, however, does not show continued increases. Data specific to natural-origin fish in the Walla Walla were not available for this report.
While progress has been made in reintroducing extirpated salmon stocks, very limited headway has been made in the overall restoration of upriver salmon and lamprey populations to fulfill treaty-reserved rights to take fish at all usual and accustomed fishing places.