Hydrophysical, hydrochemical, and other data were collected from CTD and pump casts in the Columbia River Estuary from 09 July 1996 to 06 March 1998. Data was collected as part of the Columbia River Land-Margin Ecosystem Research (LMER) Project. Data include water depths, temperatures, salinities, sigma-thetas, optical backscattering, chlorophyll a concentrations, beam attenuations, and percent transmissivities of pure water. CTD data, unless otherwise noted, were taken on the downcast and the resulting salinity and temperature profiles were used to select pump depths on the following upcast.

Chemical, phytoplankton, and other data were collected from the Columbia River estuary from 16 June 1999 to 29 June 1999. Data were collected from R/V Robert Gordon Sproul, R/V Clifford Barnes, and fixed platforms as part of the Land-Margin Ecosystem Research (LMER) and the Columbia River Estuarine Turbidity Maximum Research Program (CRETMRP). Data were collected by pump casts and include water depths, temperatures, salinities, percent transmissivities, beam attenuations, and rates of primary production per hour. Data also include concentrations of chlorophyll a, phaeopigments, particulate organic carbon, particulate nitrogen, and particulate organic nitrogen.

This dataset includes the 1990, 1991 and 1992 Phytoplankton and Geochemical data from the Columbia River Turbidity Maximum (CRETM) / Land Margin Ecosystem Research Program (LMER). There are 2 metadata files, 3 station data files, 3 phytoplankton data files, and 3 geochemical data files, which were extracted from Station data files. The metadata files explain the parameters found within the phytoplankton and geochemical data sets.

This collection includes station and environmental datasets from pump casts and associated CTD casts collected for the Columbia River LMER and Columbia River Turbidity Maximum (CRETM) projects. Pump cast sampling, and associated CTD casts took place from a fixed vessel during one 28-35 day cruise per year in 1990, 1991, 1992, 1995, and 1996. During 1997 and early 1998, there were 2 week "seasonal" cruises in May, July, and October (1997) and February to March (1998). During 1999, sampling was conducted for two weeks in June on the Columbia River and for two weeks in July on the Fraser River in British Columbia, Canada.

A two-week field operation was conducted in the John Day Reservoir on the Columbia River to image the floor of the pool, to measure the distribution and thickness of post-impoundment sediment, and to verify these geophysical data with video photography and bottom sediment samples. The field program was a cooperative effort between the USGS Coastal and Marine Geology Team of the Geologic Division and the USGS Columbia River Research Laboratory of the Biological Resources Division. The data collection was completed aboard the R/V ESTERO during September 13-27, 2000. The interest in sediment accumulation in the reservoir was two-fold. First, it was unknown how effective this reservoir was as a sediment trap to material that otherwise would have been transported down-river to the estuary and eventually to the ocean. The recent erosion of beaches along the Washington coast has been attributed to a decreased contribution of sediment from the Columbia River to the coastal system due to the damming of the river. Second, sediment accumulation on the floors of reservoirs along the Columbia River has been suggested to be diminishing salmon spawning grounds. The extent of changes in habitat since construction of the John Day Dam, however, had not been documented. Common data sets were needed to address both of these questions, and for these reasons this geophysical and sampling program was undertaken.

This dataset comprises Columbia River current data from 1967 to 1973 collected from current meters attached to buoys as part of the AEC sponsored Columbia River Project, including current speed and direction, and U and V vectors.

Current meter data were collected using moored current meter casts in the Columbia River estuary - Washington/Oregon from August 13, 1979 to September 27, 1984. Data were submitted by Oregon State University as part of the Low Level Waste Ocean Disposal project. Data were processed by NODC to the NODC standard Current Meter Data (F015) format. The F015 format is used for time series measurements of ocean currents. These data are obtained from current meter moorings and represent Eulerian method of current measurement, i.e., the meters are deployed at a fixed point and measure flow past a sensor. Position, bottom depth, sensor depth, and meter characteristics are reported for each station. The data record comprises values of east-west (u) and north-south (v) current vector components at specified date and time. Current direction is defined as the direction toward which the water is flowing with positive directions east and north and negative directions west and south. Data values may be subject to averaging or filtering and are typically reported at 10-15 minute time intervals. Water temperature, pressure, and conductivity or salinity may also be reported. A text record is available for optional comments.