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San Francisco Bay, California is considered a mercury-impaired watershed. Elevated concentrations of mercury are found in water and sediment as well as fish and estuarine birds. Sources of mercury to the watershed since 1845 include sediment-associated mercury from mercury mining, mercury losses from gold amalgamation activities in mines of the Sierra Nevada, aerial deposition of mercury from global and regional emissions to air, and the direct discharge of mercury to Bay waters associated with the urbanization and industrialization of the estuary. We assessed historical trends in mercury bioaccumulation by measuring mercury concentrations in feathers of the endangered California Ridgway’s rail (formerly California...
Categories: Data;
Tags: California Ridgway's Rail,
Feathers,
Ice Cores,
Lake Tahoe,
Mercury, All tags...
San Francisco Bay,
Sediment,
Structural Equation Model,
USGS Science Data Catalog (SDC),
Wyoming, Fewer tags
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Tracklines and associated observations were mapped and analyzed using ArcMap (ESRI, Redlands, CA). GPS data were recorded in NAD27 map datum and projected to an USGS Albers Equal Area Conic map projection for presentation and subsequent density analyses. Concatenated GPS and observation data were then used to generate point and line coverages in ArcMap (ESRI, Redlands, CA). We designed a custom analytic tool using ArcMap Model Builder that allows for the construction and export of user-specified and effort-adjusted spatial binning of species observations along continuous trackines. For the purposes of this report, we calculated seabird density estimates and marine mammal counts along continuous 3.0-kilometer and...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: At-sea suvey,
California Current System,
Channel Islands,
Marine Bird,
marine mammals, All tags...
seabird,
southern California,
southern California Bight, Fewer tags
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The GIS shapefile "Census summary of southern sea otter 2016" provides a standardized tool for examining spatial patterns in abundance and demographic trends of the southern sea otter (Enhydra lutris nereis), based on data collected during the spring 2016 range-wide census. The USGS range-wide sea otter census has been undertaken twice a year since 1982, once in May and once in October, using consistent methodology involving both ground-based and aerial-based counts. The spring census is considered more accurate than the fall count, and provides the primary basis for gauging population trends by State and Federal management agencies. This Shape file includes a series of summary statistics derived from the raw census...
Categories: Data;
Types: Citation,
Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: California,
Central California Coast,
Coast,
Southern California Coast,
aerial counts, All tags...
biota,
environment,
habitat,
oceans,
sea otter census,
shore counts,
trends, Fewer tags
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The spring 2016 mainland sea otter count began on 1 May and was completed on 11 May. Overall viewing conditions this year were very good, being more favorable than those during the 2015 spring census (3.1 vs. 2.6, where 0=poor, 1=fair, 2=good, 3=very good, and 4=excellent) and contributed to the relatively short duration of the count. The surface canopies of kelp (Macrocystis sp.) were considered by most participants to be below normal for this time of year in the northern half of the range and about normal in the southern half. Sea otters along the mainland were surveyed (using a combination of ground-based and aerial-based surveys) from Pillar Point in San Mateo County in the north, to Rincon Point in the south...
Types: Citation;
Tags: California,
Central California Coast,
Coast,
Southern California Coast,
USGS Science Data Catalog (SDC), All tags...
aerial counts,
biota,
environment,
habitat,
oceans,
sea otter census,
shore counts,
trends, Fewer tags
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Background - Interest in developing alternative sources of renewable energy to reduce dependence on oil has increased in recent years. Some sources of renewable energy being considered will include power generation infrastructure and support activities located within continental shelf waters, and potentially within deeper waters off the U.S. Pacific coast and beyond state waters (i.e., outside three nautical miles). Currently, the Bureau of Ocean Energy Management (BOEM) is considering renewable energy proposals off the coast of Oregon, California, and Hawaii. From 1999–2002, the U.S. Geological Survey (USGS) and Humboldt State University (HSU) worked with BOEM (formely known as the Minerals Management Service,...
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