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Chinese Mitten Crab Surveys of San Joaquin River Basin and Suisun Marsh, California, 2000
- Juvenile Chinese mitten crabs (Eriocheir sinensis) are known to use both brackish and freshwater habitats as rearing areas.
- The objectives of this study were to examine the habitat use and potential effects of mitten crabs in the freshwater habitats of the San Joaquin River drainage.
- Monthly surveys using baited traps in the San Joaquin River were done from June through November 2000 and in the Suisun Marsh from August through October 2000.
- No mitten crabs were caught in the San Joaquin River Basin and only one mitten crab was caught in Suisun Marsh.
- It is unclear whether the failure to capture mitten crabs in the San Joaquin River Basin and Suisun Marsh was due to ineffective trapping methods, or represents a general downward trend in populations of juvenile mitten crabs in these potential rearing areas or a temporary decline related to year-class strength.
- Available data (since 1998) ... indicate a downward trend in the number of crabs.
Science Support for Wetland Restoration in the Napa-Sonoma Salt Ponds, San Francisco Bay Estuary
- The San Francisco Bay estuary has experienced tremendous human population growth during the past 150 years and a subsequent loss of natural habitats and degradation of water quality.
- More than 91% of the tidal wetlands has been lost to reclamation for farmland, salt evaporation ponds, and residential or industrial propert.
- Many native species dependent on tidal wetlands are now endangered or candidate species for listing.
The goal of this research project was to examine the ecological and hydrological function of the Napa-Sonoma salt ponds and their importance for waterbirds, including integrated studies on primary productivity, macroinvertebrates, plants, and fishes. This progress report presents the preliminary research results from the first year of the fieldwork.
Linkage of Bioaccumulation and Biological Effects to Changes in Pollutant Loads in South San Francisco Bay
This poster answers the questions:
- What are the long-term (1977-1997) trends of metals in the sediments and clams near the outfall of the Palo Alto Regional Water Quality Control Plant (PARWQP)?
- Can point-source inputs be distinguished from non-point-source contributions?
- Does metal exposure affect the reproductive capability in South Bay clams?
The History and Effects of Exotic Species in San Francisco Bay
Learn about:
- what an exotic species is,
- how they got to San Francisco Bay in the first place,
- what damage they've done,
- what they're doing now, and
- what the future holds...
Primary Production in San Francisco Bay
Primary Production is the synthesis of new plant matter by microscopic plants (algae) through the process of photosynthesis. Learn how USGS scientists measure algae in the Bay and how its total mass can be compared to that of Humphrey, the humpback whale
Managing Coastal Resources of the U.S.
Based on over 20 years study of San Francisco Bay, USGS scientists highlight their findings concerning nutrient enrichment and toxic and biological contamination. There are important practical lessons for policymakers.
"Steps of improved wastewater treatment have gradually reduced the inputs of toxic metals to San Francisco Bay. USGS monitoring has shown that these investments to remove contaminants have resulted in improvements in some indicators of biological health, such as metal concentrations in clams living near a wastewater discharge."
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![[USGS]](/peth04/20041025103509im_/http://www.sfbay.wr.usgs.gov/access/images/usgslogoSFB.gif)