Biological Science Technician (Field Assistant)
Email:
ezierdtsmith@usgs.gov
Office Phone:
650-329-4525
ORCID:
0000-0003-0787-1856
|
Arsenic (As) toxicity is a global environmental and health problem. There are both natural (eg volcanic activity) and anthropogenic sources of As (eg lead arsenate and copper arsenate were commonly used pesticides in the 1900’s). Aqueous levels of arsenic in the Klamath Basin (CA, OR), which has a volcanic origin, can exceed at some locations both the Oregon Department of Environmental Quality human health water quality criteria (2.1 ug/L) (Sturdevant, 2011) and the US EPA drinking water limit (10 ug/L) (US EPA., 2001). In this study, dissolved concentrations of As, copper (Cu) and lead (Pb) were measured in more than 30 sites within the Klamath Basin between May and October. Results from samples collected between...
Categories: Data;
Tags: Klamath,
Klamath County,
USGS Science Data Catalog (SDC),
Upper Klamath Lake,
Upper Klamath Lake, All tags...
arsenic,
copper,
dissolved metals,
environment,
geochemistry,
health,
hydrology,
hydrology,
lead,
mass spectroscopy,
salinity,
surface water (non-marine),
surface water quality,
water chemistry,
water pH,
water sampling,
water sampling,
water temperature, Fewer tags
|
Declining phytoplankton biomass and the resulting stress on the food web has been suggested as one contributor to the decline of Delta Smelt and other fish species in the San Francisco Bay (SFB) and the Sacramento San Joaquin River Delta. Filter feeding by two species of bivalves, Corbicula fluminea and Potamocorbula amurensis, has been shown to control phytoplankton growth rate in the SFB and Delta and both are thought to be partially responsible for the reduction in food for pelagic species. Phytoplankton growth rate is dependent on spatially and temporally varying nutrient concentrations, light availability, transport time, and pelagic and benthic grazing losses. Bivalve grazing has the potential to limit primary...
|
Trace-metal concentrations in sediment and in the clam Limecola petalum (World Register of Marine Species, 2020; formerly reported as Macoma balthica and M. petalum), clam reproductive activity, and benthic macroinvertebrate community structure were investigated in a mudflat located 1 kilometer south of the discharge of the Palo Alto Regional Water Quality Control Plant (PARWQCP) in south San Francisco Bay, California. This report includes data collected by the U.S. Geological Survey (USGS) starting in January 2019. These data append to long-term datasets extending back to 1974. This dataset supports the City of Palo Alto’s Near-Field Receiving-Water Monitoring Program, initiated in 1994. This data release is presented...
Tags: Benthos,
San Francisco Bay,
Silt-Clay,
USGS Science Data Catalog (SDC),
aluminum, All tags...
benthic ecosystems,
chromium,
copper,
iron,
mercury,
metal elements,
nickel,
salinity,
selenium,
silver,
zinc, Fewer tags
|
San Francisco Bay and Estuary is largely urbanized and developed, and the southern bay is the most urbanized with many sources of nutrients, many concerns that the system might become eutrophic, and many questions about how South Bay has maintained its relatively good health. The hypotheses for why South Bay is not eutrophic, where other bays have not been so fortunate, include high bivalve grazing that limits net phytoplankton growth and high turbidity which also limits the phytoplankton growth rate. Understanding the bivalve grazing rates in the south bay includes the necessity of understanding temporal and spatial distributions of bivalves. Despite the critical need to understand all controls on eutrophication,...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Biomass,
Bivalves,
Lower San Francisco Bay,
USGS Science Data Catalog (SDC),
benthic community, All tags...
benthic invertebrates,
benthos,
grazing rate,
recruitment, Fewer tags
|
The Benthic Lab investigates the benthic community throughout the San Francisco Bay and Sacramento Delta.
|
View more...
|
