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Joint USGS/NOAA Cruise Samples Contaminants near San Francisco
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Sampling sediments:
Dann Blackwood (Woods Hole) prepares a small van Veen grab to sample sediment from the Rigid-Hull Inflatable Boat aboard the NOAA ship McArthur near the Golden Gate Bridge. The nearshore sample will provide information about contaminants and sediment chemistry near the mouth of San Francisco Bay, thus rounding out the offshore sampling grid. Photograph by Gunnar Lauenstein (NOAA).
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The NOAA ship McArthur sailed from San Francisco on February 18 with a scientific party of chemists, geologists, and biologists from the USGS' Coastal and Marine Geology Program (CMGP), the National Oceanic and Atmospheric Administration (NOAA)'s Status and Trends Program, and NOAA's Marine Sanctuary Program. Thanks to the efforts of many, the USGS was able to assist NOAA in acquiring sediment samples on the California continental shelf and to obtain additional samples for USGS studies of contaminant transport in the Pacific Ocean offshore of San Francisco.
Mike Torresan (Menlo Park, CA) and Dann Blackwood (Woods Hole, MA) were asked to assist NOAA with deep-water sampling near San Francisco from February 28 to March 6. Ian Hartwell of NOAA did a great job as chief scientist. Marilyn ten Brink (Woods Hole) and Brian Edwards (Menlo Park) were instrumental in the planning of the cruise. Ellen Mecray and Joe Newell mobilized and shipped needed gear on short notice from Woods Hole. Mike Torresan and Sid Mitra collected and organized needed equipment and supplies from Menlo Park.
Ian Hartwell (left) and Mike Torresan subsample the upper surface of a sediment sample in a large van Veen grab. Photograph by Dann Blackwood. |
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Gunnar Lauenstein and Sabrina Varnam (NOAA) collect a subsample for grain-size analysis. Photograph by Dann Blackwood. |
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The collaborative cruise aimed to collect samples for measurement of sediment texture, chemical composition, and accumulation of contaminants on the continental shelf west of San Francisco and the city's Southwest Ocean Outfall, which discharges treated sewage and stormwater about 6 km (4 mi) offshore. Sediment-sampling stations were located in a grid designed to show the distribution and amounts of pollutants in the sediment and their transport off the shelf. Some of the contaminants being studied include trace metals, hydrocarbons, and pesticides. Samples will also be analyzed for pharmaceuticals, which are a growing threat to the environment and at this time are largely unregulated in septic treatment.
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Above left:
Doug Pirhalla (NOAA), Mike Torresan, and Ian Hartwell (left to right) "hang loose" on the way to the next station. Photograph by Dann Blackwood.
Above right:
Seaman Surveyor Leroy Jordan recovers the CTD (conductivity-temperature-depth) / water-sampler rosette. Water-sampling bottles form the outer ring of the rosette. A CTD recorder in the rosette's center records the conductivity, temperature, and depth of seawater from which each sample is taken. The water samples will be analyzed for chlorophyll content, a measure of biologic productivity in the water. Photograph by Dann Blackwood.
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This multidisciplinary project was successful for both USGS and NOAA scientists. All the priority sediment stations were sampled, as well as many of the secondary sites, and water-column sampling occurred concurrently. Ian Hartwell (NOAA), Brian Edwards, Mike Torresan, Sid Mitra, and Tom Lorenson (Menlo Park), and Marilyn ten Brink (Woods Hole) will analyze sediment samples along with photographs provided by Dann Blackwood (Woods Hole) of the sediment surface of each grab sample.
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May 2002
in this issue:
cover story:
Contaminants Sampling Cruise - San Francisco
Ground-Truthing Coral Reef Maps
Shorebird Migration
CO2 in Saline Aquifers
Early Earth Day in Florida
Honduras Coral Reef Documentary Online
Girl Scouts
University Job Fair
Sea-Level Rise Lecture
Massachusetts Sea-level Rise Briefing
New Directions Workshop
Floating Support Facility
Howell New Patuxent Director
WHFC Runners
Water-Column Optics Talks
Special Emphasis Program
New Employees
Mendenhall Fellow Presents Talk
May Publications List
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U. S. Department of the Interior | U.S. Geological Survey
