Project Goals
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Kintama Research is working to construct an ocean tracking array for measuring the movements and survival of fish as small as salmon smolts along the west coast of North America & establish the relevance of such a tool for addressing important resource management issues.  In particular, an important goal is to develop an ability to allow the assessment of early marine survival and ocean movements for Columbia River salmon stocks.  In 2006, we began direct measurements of the survival of Snake & Yakima R ROR spring chinook smolts, and also compared the relative survival and performance of transported vs ROR Snake R smolts.

Earlier work using PIT tags and more recent work done by Dr Carl Schreck using acoustically tagged smolts showed that survival to Bonneville Dam or to the Columbia river mouth, respectively, have been very high, raising critical questions about why Columbia River Chinook have very low smolt-to-adult survival rates.  Largely as a result of the inability to find sufficient mortality in the Columbia R hydrosystem to account for the very low adult returns, the hypothesis arose that delayed mortality must occur for various Columbia River Chinook as a result of the the operation of the hydrosystem, but that this delayed (or latent) mortality is not manifest until the salmon smolts pass by all the dams.  An alternative hypothesis is that differences in smolt-to-adult returns (SARS, or more simply, marine survival) might be better explained by differences in the marine life history of different salmon stocks.  

This project seeks to provide objective information as to where Columbia River Chinook salmon smolts migrate to in the sea, and key information on the rates of marine mortality during the initial phase of the marine life cycle.  These data will be used in an explicit test of the PATH hypothesis that delayed mortality due to the hydrosystem is the cause of the problem, and secondly will be used to assess the efficacy of transport to boost salmon returns.  Successful demonstration of the application of the array to Columbia River salmon recovery issues would address a number of key RPAs which existing approaches cannot adequately address.  Given the record salmon returns to the Columbia River in several years since the ocean climate changes of 1999, a critical issue for successful salmon management is to distinguish the true effects on salmon returns caused by the operation of the hydrosystem from those due to ocean climate change.  The POST (Pacific Ocean Shelft Tracking) array is designed to be able to separate marine from freshwater impacts on salmon, and to localize the regions of the coast where mortality is high.

Snake River and upper Columbia River spring chinook salmon smolts must migrate through a series of 8 to 9 hydropower dams, respectively, in order to reach the Columbia estuary, and subsequently the Pacific Ocean.  Much of the recent research on survival rate trends, differential mortality, and recovery actions for Columbia and Snake River spring chinook assumes that there is a common ocean effect on juvenile survival (Budy et al. 2002; Deriso et al. 2001) and that the varying conservation status of Columbia River salmon is largely attributed to the development of the hydrosystem (Schaller et al. 1999).  Although there has been a growing recognition of the importance of ocean survival to Columbia River salmon stocks (Deriso et al. 2001; Kareiva et al. 2000; Scheuerell and Williams 2005) and therefore the need to incorporate ocean survival rates into survival models (Peters and Marmorek 2001), a technical means of addressing the key questions has been lacking.

In 2006, the POST Columbia River spring chinook survival study used acoustic telemetry to directly measure early marine survival from two populations of spring chinook in the Columbia River Basin, and to test two major hypotheses:
1. Is additional “latent” or “delayed” mortality experienced after Snake River smolts pass the eight dams they encounter as in-river migrants?  If so, this would be evidence for the PATH hypothesis that cumulative stress from multiple dam passage is reducing the productivity of important Snake River chinook stocks.
2. Does transporting/barging of chinook smolts improve early marine survival rates over run of river smolts?  If so, then transporting smolts down-river should provide a boost to adult return rates, reducing extinction risk.

To test the first hypothesis we will compare survival of Snake River spring chinook (from Dworshak National Fish Hatchery), which migrate through eight dams, with that of Yakima River chinook (from the Cle Elum Supplementation and Research Facility).  The Yakima population enters the Columbia River just upstream of the confluence of the Columbia and Snake Rivers, and only migrates through the four mainstem Columbia River dams.  This stock was chosen for comparison because historically it has had about a 5.2 times greater smolt to adult return rate (SAR) than the Snake River chinook (Cle Elum SAR's from Bosch and Fast 2006; Dworshak NFH SARs from CSS 2006).  This component of the work will be conducted by tagging and releasing two groups of N=200 tagged smolts from each stock, timed so that they will co-migrate down the length of the river and then out to sea in order to compare surival.  The study will be repeated in each of three years, 2007-09.

Our 2006 study allows us to contrast the survival of two stocks whose migration through the mainstem Columbia is similar, and where the major difference between stocks is in the extensive additional in-river migration that Snake River smolts must undertake past the four contentious Snake River dams.  The 2006 pilot study was technically successful in demonstrating that the approach works, and also did not find evidence for the PATH hypothesis that a difference in survival develops between the two stocks subsequent to passing Bonneville Dam.

The second hypothesis (that barging improves survival to adult return) is confined to the Snake River stock alone, as collection for barging of salmon smolts occurs only in the lower Snake River.  To test if barging improves the survival rates of these fish, we will contrast the lower river and early marine survival of two groups of N=100 transported smolts with the survival of the same two groups of run of river (ROR) Snake R spring chinook smolts used in the comparison with the Yakima R stock in Hypothesis #1.

Bosch, B., and D. Fast.  2006.  "Yakima/Klickitat Fisheries Project; Monitoring and Evaluation", 2005-2006 Annual Report, Project No. 199506325, 222 electronic pages, (BPA Report DOE/BP-00022449-1).

Budy, P., G. P. Thiede, N. Bouwes, C. E. Petrosky, and H. Schaller.  2002.  Evidence linking delayed mortality of Snake River salmon to their earlier hydrosystem experience. North American Journal of Fisheries Management 22:35-51.

CSS.  2006.  “Comparative Survival Study (CSS) of PIT-tagged Spring/Summer Chinook and PIT-tagged Summer Steelhead”, 2006 Annual Report (BPA Contract #19960200).

Deriso, R. B., D. R. Marmorek, and I. J. Parnell.  2001.  Retrospective patterns of differential mortality and common year-effects experienced by spring and summer chinook salmon (Oncorhynchus tshawytscha) of the Columbia River. Canadian Journal of Fisheries and Aquatic Sciences 58:2419-2430.

Kareiva, P., M. Marvier, and M. Mcclure.  2000.  Recovery and management options for spring/summer chinook salmon in the Columbia River Basin. Science 290:977-979.

Peters, C. N., and D. R. Marmorek.  2001.  Application of decision analysis to evaluate recovery actions for threatened Snake River spring and summer chinook salmon (Oncorhynchus tshawytscha). Canadian Journal of Fisheries and Aquatic Sciences 58:2431-2446.

Scheuerell, M. D., and J. G. Williams.  2005.  Forecasting climate-induced changes in the survival of Snake River spring/summer Chinook salmon (Oncorhynchus tshawytscha). Fisheries Oceanography 14:448-457.