Francis Parchaso
Francis Parchaso is a Biologist for the USGS Water Resources Mission Area.
Science and Products
Filter Total Items: 47
Near-field receiving water monitoring of a benthic community near the Palo Alto Water Quality Control Plant in South San Francisco Bay: February 1974 through December 2002
Analyses of the benthic community structure over a 28-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinal clam Macoma balthica from the same area. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundanc
Authors
Michelle K. Shouse, Francis Parcheso, Janet K. Thompson
Assessing toxicant effects in a complex estuary--A case study of effects of silver on reproduction in the bivalve, Potamocurbula amurensis, in San Francisco Bay
Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the cla
Authors
Cynthia L. Brown, Francis Parchaso, Janet K. Thompson, Samuel N. Luoma
Sediment-water interactions affecting dissolved-mercury distributions in Camp Far West Reservoir, California
No abstract available.
Authors
James S. Kuwabara, Charles N. Alpers, Mark Marvin-DiPasquale, Brent R. Topping, James L. Carter, A. Robin Stewart, Steven V. Fend, Francis Parcheso, Gerald E. Moon, David P. Krabbenhoft
Flux of dissolved forms of mercury across the sediment-water interface in Lahontan Reservoir, Nevada
No abstract available.
Authors
James S. Kuwabara, Mark Marvin-DiPasquale, Wayne Praskins, Earl Byron, Brent R. Topping, James L. Carter, Steven V. Fend, Francis Parcheso, David P. Krabbenhoft, Mae S. Gustin
Influence of hydrologic processes on reproduction of the introduced bivalve Potamocorbula amurensis in northern San Francisco Bay, California
Monthly censusing of reproductive condition of the Asian clam Potamocorbula amurensis at four sites in northern San Francisco Bay over a 9-yr period revealed year-to-year differences in local reproductive activity that are associated with patterns of hydrologic variability. Between 1989 and 1992, Northern California experienced a drought, whereas the period between 1993 and 1998 was marked by a mi
Authors
Francis Parchaso, Janet K. Thompson
Near field receiving water monitoring of benthic community near the Palo Alto Water Quality Control Plant in south San Francisco Bay: February 1974 through December 2000
Analyses of the benthic community structure over a 26-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinal clam Macoma balthica from the same area. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundanc
Authors
Janet K. Thompson, Francis Parcheso, Michelle K. Shouse
Benthic flux of dissolved nickel into the water column of south San Francisco Bay
Field and laboratory studies were conducted between April, 1998 and May, 1999 to provide the first direct measurements of the benthic flux of dissolved (0.2-micron filtered) nickel between the bottom sediment and water column at three sites in the southern component of San Francisco Bay (South Bay), California. Dissolved nickel and predominant ligands (represented by dissolved organic carbon, and
Authors
B.R. Topping, J.S. Kuwabara, Francis Parcheso, S.W. Hager, A.J. Arnsberg, Fred Murphy
Behind the energetics of the asiatic clam, Potamocorbula amurensis, in San Francisco Bay
The Asian clam (Potamocorbula amurensis) has played a key role in the food web of northern San Francisco Bay since its invasion in the fall of 1986. It has been associated with a dramatic decline in primary production, loss of a zooplankton species and a native mysid shrimp, the probable decline in striped bass, and has introduced alternative pathways for contaminant cycling in the bay food web.
Authors
Janet K. Thompson, Francis Parchaso
In situ ecosystem effects of trace contaminants in San Francisco Bay Estuary - The necessary link to establishing water quality standards II
No abstract available.
Authors
Francis Parcheso, C. L. Brown, J.K. Thompson, S.L. Luoma
In situ ecosystem effects of trace contaminants in the San Francisco Bay Estuary; the necessary link to establishing water quality standards
No abstract available.
Authors
J.K. Thompson, Francis Parcheso, C. L. Brown, S. N. Luoma
Seasonal reproduction of Potamocorbula amurensis in San Francisco Bay, California
No abstract available.
Authors
Francis Parchaso
Science and Products
Filter Total Items: 47
Near-field receiving water monitoring of a benthic community near the Palo Alto Water Quality Control Plant in South San Francisco Bay: February 1974 through December 2002
Analyses of the benthic community structure over a 28-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinal clam Macoma balthica from the same area. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundanc
Authors
Michelle K. Shouse, Francis Parcheso, Janet K. Thompson
Assessing toxicant effects in a complex estuary--A case study of effects of silver on reproduction in the bivalve, Potamocurbula amurensis, in San Francisco Bay
Contaminant exposures in natural systems can be highly variable. This variability is superimposed upon cyclic variability in biological processes. Together, these factors can confound determination of contaminant effects. Long term, multidisciplined studies with high frequency sampling can be effective in overcoming such obstacles. While studying trace metal contamination in the tissues of the cla
Authors
Cynthia L. Brown, Francis Parchaso, Janet K. Thompson, Samuel N. Luoma
Sediment-water interactions affecting dissolved-mercury distributions in Camp Far West Reservoir, California
No abstract available.
Authors
James S. Kuwabara, Charles N. Alpers, Mark Marvin-DiPasquale, Brent R. Topping, James L. Carter, A. Robin Stewart, Steven V. Fend, Francis Parcheso, Gerald E. Moon, David P. Krabbenhoft
Flux of dissolved forms of mercury across the sediment-water interface in Lahontan Reservoir, Nevada
No abstract available.
Authors
James S. Kuwabara, Mark Marvin-DiPasquale, Wayne Praskins, Earl Byron, Brent R. Topping, James L. Carter, Steven V. Fend, Francis Parcheso, David P. Krabbenhoft, Mae S. Gustin
Influence of hydrologic processes on reproduction of the introduced bivalve Potamocorbula amurensis in northern San Francisco Bay, California
Monthly censusing of reproductive condition of the Asian clam Potamocorbula amurensis at four sites in northern San Francisco Bay over a 9-yr period revealed year-to-year differences in local reproductive activity that are associated with patterns of hydrologic variability. Between 1989 and 1992, Northern California experienced a drought, whereas the period between 1993 and 1998 was marked by a mi
Authors
Francis Parchaso, Janet K. Thompson
Near field receiving water monitoring of benthic community near the Palo Alto Water Quality Control Plant in south San Francisco Bay: February 1974 through December 2000
Analyses of the benthic community structure over a 26-year period show that changes in the community have occurred concurrent with reduced concentrations of metals in the sediment and in the tissues of the biosentinal clam Macoma balthica from the same area. The community has shifted from being dominated by several opportunistic species to a community where the species are more similar in abundanc
Authors
Janet K. Thompson, Francis Parcheso, Michelle K. Shouse
Benthic flux of dissolved nickel into the water column of south San Francisco Bay
Field and laboratory studies were conducted between April, 1998 and May, 1999 to provide the first direct measurements of the benthic flux of dissolved (0.2-micron filtered) nickel between the bottom sediment and water column at three sites in the southern component of San Francisco Bay (South Bay), California. Dissolved nickel and predominant ligands (represented by dissolved organic carbon, and
Authors
B.R. Topping, J.S. Kuwabara, Francis Parcheso, S.W. Hager, A.J. Arnsberg, Fred Murphy
Behind the energetics of the asiatic clam, Potamocorbula amurensis, in San Francisco Bay
The Asian clam (Potamocorbula amurensis) has played a key role in the food web of northern San Francisco Bay since its invasion in the fall of 1986. It has been associated with a dramatic decline in primary production, loss of a zooplankton species and a native mysid shrimp, the probable decline in striped bass, and has introduced alternative pathways for contaminant cycling in the bay food web.
Authors
Janet K. Thompson, Francis Parchaso
In situ ecosystem effects of trace contaminants in San Francisco Bay Estuary - The necessary link to establishing water quality standards II
No abstract available.
Authors
Francis Parcheso, C. L. Brown, J.K. Thompson, S.L. Luoma
In situ ecosystem effects of trace contaminants in the San Francisco Bay Estuary; the necessary link to establishing water quality standards
No abstract available.
Authors
J.K. Thompson, Francis Parcheso, C. L. Brown, S. N. Luoma
Seasonal reproduction of Potamocorbula amurensis in San Francisco Bay, California
No abstract available.
Authors
Francis Parchaso