Over the past thirteen years we have demonstrated that the distribution, abundance, and survival of juvenile Columbia River salmon in the northern California Current vary synchronously with variable ocean conditions.  Because of this new understanding, we have been able to develop a suite of physical, biological and ecological indicators of ocean conditions that are useful predictors of salmon survival and which are posted to our web-site semi-annually. These efforts now provide outlooks on returns one to two years in advance for coho and spring Chinook salmon. We continue to demonstrate that efforts by the Northwest Power and Conservation Council (NWPCC) and BPA to restore, rehabilitate, and enhance salmon production must be evaluated in terms of ocean conditions.

The primary goal of our work is to further understand how the ocean and Columbia River (CR) plume conditions affect juvenile salmonids, then predict, in a quantitative rat... her than qualitative manner, how changing ocean conditions will affect salmonid growth and survival and subsequent adult returns.  From this research we can recommend ways to link management actions to various river, plume and ocean conditions for effective management of salmon using an ecosystem approach.

By the end 2010, we will have 13 years of data on salmon abundance, distribution, and growth in relation to adult returns and ocean conditions.  Given the complexity of interactions between climate, ocean, and plume conditions, none of the years examined to date have provided a similar suite of conditions.  It is clear that we have not yet observed all possible or repeated environmental/oceanographic ecosystem combinations that support juvenile salmon.  Because of impending climate change impacts, a longer time series is needed for climate-salmon studies to provide sufficient statistical power to discern the key climate, ocean, and ecological factors that modulate salmon survival in the sea.  A longer time series, the limit of which remains unclear at this time, will improve our ability to help managers of the Columbia River Basin develop longer range assessments of climate change impacts on use of hatchery, habitat restoration, and altering river flows to restore endangered salmon populations.

Our efforts are built around the core hypothesis that early ocean growth and survival of Columbia River juvenile Chinook and coho salmon are determined through both bottom-up and top-down processes associated with productivity of coastal waters and the Columbia River plume habitat during spring and summer.  Through correlation analysis we will continue to validate current relationships described in our Summary of Findings to Date as well as further develop metrics relating to smolt-to-adult survival of specific populations of Columbia River Chinook and coho salmon with food distribution, abundance and quality, and distribution and abundance of potential predators.  In addition, we will link performance indices of salmon condition to indices of food quantity and quality within specific regions of the coastal ocean.  Statistical power is provided by generating a time series of sufficient duration that include the inevitable variability provided by the ocean environment.  

We will continue monitoring and initiate complimentary new research using an ecosystem approach consisting of three main objectives that together address hypotheses of bottom up processes, top-down processes, and Columbia River plume structure.  Our first objective centers on determining the distribution, growth and condition of juvenile Columbia River Chinook, coho salmon in the plume and their ocean environments with associated physical and biological features, and effects on salmon survival during spring-summer surveys.  This will be achieved by continuing our comprehensive time series of the distribution and abundance of juvenile salmon, stock structure, habitat usage, and growth and condition of juvenile salmonids in the northern California Current and the CR plume. This work includes 1) the oceanographic and salmon surveys in May, June and September from Newport, OR, to La Push, WA; 2) analysis of salmonid stock structure, stock origin and growth characteristics of various stocks; 3) analysis of factors causing mortality such as piscine and avian predators and diseases; and 4) analysis of food web structure through studies of composition of prey fields and the use of stomach and intestinal parasite community of juvenile salmon to quantify feeding habits.  The physical context for these surveys will be provided by CMOP products (mooring observations, daily circulation forecasts, and multi-year simulation circulation databases).  As a new effort, we will include Columbia River Basin steelhead, sockeye and chum salmon to identify linkages of growth and survival to ocean conditions.  Preliminary evaluation of interannual variation in adult sockeye salmon returns over the past 12 years reveal that they are not responding to ocean conditions in a similar manner as Chinook and coho salmon.

Our second objective relates to additional surveys that are more focused in space and time that adds critical pieces of information on predator impacts, specific food resources, biological condition, and means by which juvenile salmon exit the Columbia River estuary.  We will enhance sampling of salmon in the Columbia River estuary to measure condition (including their pathogen load) of juvenile salmon prior to entering the ocean.   We also will modify the piscine predator/forage fish survey (ongoing since 1998) to characterize the juvenile fish prey fields.  In addition, we will survey to measure the juvenile salmon consumption rate by avian predators in the plume frontal region and to further evaluate the oceanographic conditions that affect the transport of juvenile salmon from the estuary to the plume.

Our third objective is to synthesize the early ocean ecology of juvenile Columbia River Chinook and coho salmon, test mechanisms that control salmonid growth and survival, and produce ecological indices that forecast salmonid survival.  We will use simulation models, statistical analyses of climate, ocean and biological time series data and indices to produce improved river and salmon management advice.  Under this third objective, we will link those observations to management via three tasks: simulation modeling, tests of causal mechanisms, and forecasting.  We will continue our dedicated effort of computer simulation modeling that will use coupled bio-physical and population models to look at mechanisms related to ecosystem productivity (bottom-up), and predator-prey interactions (top-down).  Moreover, models will serve as tools for integrating data, hypothesis testing and carrying out “what if” model experiments.  Testing causal mechanisms that explain salmon survival during their first summer at sea using integrated bio-physical and statistical modeling.  Emphasis will be on relationships between spatial variations in growth and survival.  Finally, we will provide short-lead forecasts of return rates for Columbia River coho and Chinook salmon.  The goals of this task are to continue to develop and update our salmon forecasts and salmon forecasting web-page (http”//www.nwfsc.noaa.gov and click on “Ocean Conditions and Salmon Forecasting”).  Our forecasts are based on 15 indicators including basin-scale indicators, regional scale indicators, and local indicators.  To date, our indicators are based on ocean conditions or on lower trophic level organisms.  We will develop a set of performance indicators that index the salmon directly.  We will also leverage the influence of the plume on large-scale productivity in the shelf, obtained through interdisciplinary projects such as RISE (Hickey et al. 2010), to develop an index and regular forecasts for “plume influence on shelf productivity.”   Show More