Response for project 199801400: Ocean Survival Of Salmonids

Comment on proposed FY 2006 budget

We request continuation of project 1998-01400; Ocean growth and survival of juvenile salmonids in the Columbia River plume in FY06. The Council staff Fiscal Year 2006 budget of $1, 820,600 is consistent with our expectations and needs to contract ship time, people, hydrologic model validation and application and analytical services to conduct the wide array of efforts to ascertain and describe the role of the Columbia River plume for growth and survival of juvenile salmon the leave the Columbia River basin to ocean rearing areas. The effort will allow an evaluation of the impact of hydropower activities on survival of juvenile salmon as they move into an ocean environment.

Accomplishments since the last review

Determined the yearly variation in abundance and distribution of salmon stocks, by ESU, and associated pelagic nekton community in the northern California Current, including the plume for the spring and late summer periods. Determined the yearly variation in zooplankton food resources in relation to change in physical characteristics of plume and northern California Current marine waters that affects growth and survival of juvenile salmon. Juvenile salmon distribution is determined by the size and direction of the Columbia River plume. The interaction with pelagic biologic fields (prey and predators) dictates survival success. Juvenile salmon are found to occupy only the shelf break, the extent of habitat moves toward shore as the summer season progresses Developed and validated a hydrologic model of the Columbia River plume. The model is being used to develop physical metrics of salmon habitat opportunity. This will be coupled to a hydrologic model of the Columbia River estuary which will provide a comprehensive view of the availability of salmon habitat under various natural and anthropogenic modifications in the region from Bonneville Dam through the coastal ocean. Assessed variation and benefit of enhanced growth in the plume in relation to variation in physical and biological features of the coastal and Columbia River plume environment. The CR plume offers refuge and food resources for smaller juvenile salmon to grow larger before moving to more oceanic habitats out of the plume. Determined that all ESU’s utilize the plume and distribute themselves along the coast differentially. All salmon ESU’s appear to go to different places along the coast. Juvenile salmon growth patterns reflect the extent and quality of good salmon habitat in the plume and along the coast. When ocean conditions are not as good, the extent of quality of habitat is less than when ocean conditions are good. Metrics of ocean conditions are now being developed.

FY 2006 goals and anticipated accomplishments

Through long-term and fine scale observations, describe interannual variations in the distribution, abundance, and performance (health and growth) of juvenile salmon in relation to temporal and spatial characteristics of physical and biological features associated with the Columbia River plume and the surrounding ocean. Describe, through observations, historical reconstruction, and numerical physical modeling, the temporal and spatial physical features of the Columbia River plume in relation to ocean conditions with the intent of defining and describing physical attributes of salmon habitat. Examine the relationship between ocean and plume conditions, river flow, and juvenile salmon production using biological models to identify critical relationships between food resources, predator-prey interactions, salmon growth and survival. Develop and analyze scenarios that describe changes in salmon survival as a function of Columbia River plume characteristics that may result from altered river flows due to climate and human-induced modifications, and/or from changing oceanic conditions. We will use physical and biophysical models of the plume to relate future FCRPS operations and ocean/climate conditions to salmon survival.

Subbasin planning

How is this project consistent with subbasin plans?

The project is consistent and implements focal species objectives for salmon to develop an understanding for emigrating salmon life history diversity and habitat use in the Columbia River plume (Lower Columbia River and Columbia River estuary Subbasin Plan Vol II pages A-224 Supplement to the Mainstem Lower Columbia River and Columbia River Estuary Subbasin Plan page 2-10, 2-17); to implement Habitat Improvement Strategies by striving to understand how salmonids utilize the plume habitat and develop a scientific basis for estimating species response to habitat quantity and quality and to protect and restore these critical habitats (Lower Columbia River and Columbia River estuary Subbasin Plan Vol II pages A-245; Supplement to the Mainstem Lower Columbia River and Columbia River Estuary Subbasin Plan page 2-3), and to reduce critical uncertainties by increasing genetic research to identify genotypic variation in habitat use, understanding salmonid estuary and plume ecology, including food-web dynamics, understand juveniles salmon migration patterns, and understand linkages between physical and biological processes sufficiently to predict salmon survival response to restoration activities (Lower Columbia River and Columbia River estuary Subbasin Plan Vol II pages A-262-3).

How do goals match subbasin plan priorities?

Key next steps are identified in the Supplement to the Mainstem Lower Columbia River and Columbia River Estuary Subbasin Plan (page 5-2) to 1) improve our understanding of estuarine (including the plume) processes and species habitat needs and interactions so that impacts of potential management actions can be anticipated 2) develop a model specific to the estuary and lower mainstem that quantifies relationships between habitat conditions and species responses 3) use the model to conduct reach by reach assessments of habitat conditions in the lower mainstem, estuary, and plume and identify those reaches that have the greatest protection or restoration needs and potential A key priority strategy identified in the Plan Overview of the Lower Columbia Salmon Recovery and Fish & Wildlife Subbasin Plan (page 17) is to improve knowledge of the interrelationship among fish, wildlife, and limiting habitat conditions in the estuary, plume, and lower mainstem as one of eight broad strategies to implement now.

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