Bird Distribution and Abundance - Ocean Survival of Salmonids

A study to evaluate the role of changing ocean conditions on growth and survival of juvenile salmon from the Columbia River basin as they enter the Columbia River plume and Pacific Northwest coastal habitats. Adult returns vary dramatically (over 10 fold) as a result of changing (good or bad) ocean conditions juveniles experience. Evaluating the benefit of restoration efforts in the Columbia River to restore endangered salmon populations needs to consider ocean conditions as a contributing factor to recovery. This is a large collaborative project with contributions from NWFSC, Oregon State University, and Oregon Health and Science University.

The work focuses on three objectives:

1) Determining the distribution, growth, and condition of juvenile Columbia River Chinook and coho salmon in the plume and their ocean environments with associated physical and biological features, and effects on salmon survival via regular spring and summer surveys.

2) Using additional focused surveys to obtain critical pieces of information on predator impacts, specific food resources, biological condition, and means by which juvenile salmon exit the Columbia River estuary.

3) Synthesizing 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.

This project provides critical information on marine survival to the Columbia River salmonid management community (hydrosystem, harvest, hatchery, and habitat management) provides environmental indicators useful for forecasting salmon returns, and provides a greater understanding of ecological controls on salmon populations. This is a long-term monitoring and research project initiated in 1998.

Species, abundance, and distribution of birds during salmon surveys.