Filters: partyWithName: William M Perry (X) > partyWithName: Ecosystems (X)
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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...
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...
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,...
Sea otters are well-known tool users, employing objects such as rocks or shells to break open invertebrate prey. We used a series of generalized linear mixed effect models (GLMEs) to examine observational data on prey capture and tool use from 211 tagged individuals from five geographically defined study areas throughout the sea otter’s range in California. Our best supported model was able to explain 75% of the variation in the frequency of tool-use by individual sea otters with only ecological and demographic variables. In one study area, where sea otter food resources were abundant, all individuals had similar diets focusing on preferred prey items and used tools at low to moderate frequencies (4-38% of prey...
Categories: Data;
Tags: California,
USGS Science Data Catalog (SDC),
diet specialization,
foraging,
sea otter,
The spring 2015 mainland sea otter count began on 2 May and wasn’t completed until 2 July. The delay in finishing the census was due primarily to limited availability of the survey plane (because of the need for the plane during the oil spill in the Refugio State Beach area). Overall viewing conditions this year were more favorable than those during the 2014 spring census (View Score = 2.6 vs. 2.3, where 0=poor, 1=fair, 2=good, 3=very good, and 4=excellent). The surface canopies of kelp (Macrocystis sp.) were considered by most participants to be about normal for this time of year. Sea otters along the mainland were surveyed (using a combination of ground-based and aerial-based surveys) from Pillar Point...
Categories: Data;
Tags: California,
Central California Coast,
Coast,
Southern California Coast,
USGS Science Data Catalog (SDC),
The goal of this project was to primarily assess east-west connectivity across Route 67 and secondarily, north-south connectivity across Scripps Poway Parkway and Poway Road, two highly trafficked roads to the west of Route 67. We collected deer scat piles from both sides of these crossings in spring between March and June of 2015, and again in fall throughout October 2015. Collected pellets were extracted and amplified using protocols and loci developed by Bohonak and Mitelberg (2014). DNA fingerprinting results were used to investigate mule deer movement in the region directly by identifying individuals which had been captured multiple times throughout the study period. We also assessed movement indirectly through...
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