Columbia Estuary Data Development Program (CREDDP)

The Columbia River Estuary Data Development Program (CREDDP), a federally-funded research program, began in 1978 and was completed in 1984. The purpose of the program was to provide a foundation of scientific knowledge about the estuary and to provide information useful in managing land and water resources through the public planning and permitting processes. The program was initiated by local governments and citizens who saw a need for a better information base for use in managing natural resources and in planning for development. In response to these concerns, the Governors of the states of Oregon and Washington requested in 1974 that the Pacific Northwest River Basins Commission (PNRBC) undertake an interdisciplinary ecological study of the estuary. At approximately the same time, local governments and port  districts formed the Columbia River Estuary Study Taskforce (CREST) to develop a regional management plan for the estuary.

CREDDP was designed to meet the needs of those groups who were expected to be the principal users of the information being developed. One such group consists of local government officials, planning commissions, CREST, state and federal agencies, permit applicants, and others involved in planning and permitting activities. The other major anticipated user group includes research scientists and educational institutions. For planning purposes, an understanding of the ecology of the estuary is particularly important, and CREDDP has been designed with this in mind. Ecological research focuses on the linkages among different elements in the food web and the influence on the food web of such physical processes as currents, sediment transport and salinity intrusion. Such an ecosystem view of the estuary is  necessary to predict the effects of estuarine alterations on natural resources. 

CREDDP research was divided into thirteen projects, called work units. Three work units, Emergent Plant Primary Production, Benthic Primary Production, and Water Column Primary Production, dealt with the plant life which, through photosynthesis and uptake of chemical nutrients, forms the base of the estuarine food web. The goals of these work units were to describe and map the productivity and biomass patterns of the estuary's primary producers and to describe the relationship of physical factors to primary producers and their productivity levels. The higher trophic levels in the estuarine food web were the focus of seven CREDDP work units: Zooplankton and Larval Fish, Benthic Infauna, Epibenthic Organisms, Fish, Avifauna, Wildlife, and Marine Mammals. The goals of these work units were to describe and map the abundance patterns of the invertebrate and vertebrate species and to describe these species' relationships to relevant physical factors. The other three work units, Sedimentation and Shoaling, Currentsand Simulation, dealt with physical processes. The work unit goals were to characterize and map bottom sediment distribution, to characterize sediment transport, to determine the causes of bathymetric change, and to determine and model circulation patterns, vertical mixing and salinity patterns.

Final reports on all thirteen work units were published, in addition to a comprensive synthesis entitled The Dynamics of the Columbia River Estuarine Ecosystem. These reports, as well as other descriptive publications produced by the CREDDP project are available below. The Estuary Parternship also houses some of the raw and processed data developed by the work unit researchers. This information can be made available upon request. Please contact Keith Marcoe at, or 503 226 1565 X230.


Descriptive Guides/Indices


Map Atlases


Work Unit Reports: Estuarine Food Web, Plant Life

Work Unit Reports: Estuarine Food Web, Higher Trophic Levels

Work Unit Reports: Physical Processes