The counts made from shore are plotted on maps and then entered into a spatial database. 1118, Explore recent publications by USGS authors, Browse all of Pubs Warehouse by publication type and year, Descriptions of US Geological Survey Report Series. The 1914 data point is uncertain al- The aerial counts are entered directly into a geographic information system-linked database in the aircraft. Population Data Sources California Sea Otter Population By: Danny Hamilton. In coordination with the California Department of Fish and Game and other institutions, ongoing surveys and research continues to inform the southern sea otter recovery plan for the U.S. California’s Sea Otter Numbers Continue Slow Climb. Part or all of this report is presented in Portable Document Format Data Series According to data released Friday by the U.S. Geological Survey, there were 3,186 southern sea otters paddling the Pacific off California. Factors that can influence the count include viewing conditions, abundance and species composition of surface canopy kelp, observer experience, and distribution and movements of the animals. Sea otters play a vital role in the health and stability of the nearshore marine ecosystem as a keystone species CALIFORNIA SEA OTTER POPULATION ANNUAL SURVEY – survey history and methodology. Data from 1982 onward are counts made during annual spring surveys.Earlier data from counts and estimates using a variety of methods. California’s southern sea otter has been listed as a threatened species under the Endangered Species Act since 1977. 1. Population status of California sea otters. Yet despite an overall increase in sea otter abundance, sharks have been “taking a bite” out of the portion of the population that could fuel expansion into new areas. An estimate of otter population size in Alaska was 98,780 among the three populations in 2013 (USFWS, 2013) with observed annual growth rates in some areas reaching 16–20% (Bodkin et al., 1999; Estes, 1990). Southern sea otters, also called California sea otters, live in waters along the California coastline, ranging from San Mateo County in the north to Santa Barbara County in the south. Fish and Wildlife Service. A standardized method to survey sea otters was developed by WERC scientists and put into use in 1982 in California. A CDFW scientist using a telescope to search for sea otters. Fish and Wildlife Service’s Southern Sea Otter Recovery Plan recommends using to assess the sea otter population status, thus reducing the influence of anomalously high or low counts from any particular year (USFWS, 2003). OSTI.GOV Technical Report: Population status of California sea otters. 200 MARINE MAMMAL SCIENCE. Download the latest version of Adobe Reader, free of charge. PDF documents opened from your A .gov website belongs to an official government organization in the During the California Sea Otter Translocation Program Methodology Conclusions & Discussion ... contributed to the unsuccessful recovery efforts of the translocated population. Fish and Wildlife Service’s delisting threshold for a second straight year. Background: The California sea otter population, listed as threatened under the Endangered Species Act, has shown a slow and intermittent rate of recovery over recent years. WERC scientists conduct annual population surveys of the southern sea otter, a federally listed threatened species. The 2012 data suggests that California’s sea otter population is continuing its pattern of tepid recovery. Currently the southern sea otter population is estimated at just above 3,000 animals. browser may not display or print as intended. The sluggish recovery of the southern sea otter of California, a threatened population on the Endangered Species list, appears to have stalled once again. To reduce the influence of anomalously high or low counts during any particular year, three-year running averages -- commonly called a "population index" -- of the survey results are also used to assess whether the population is growing or declining. The information gathered will be used by federal and state wildlife agencies in making decisions about the management of this sea mammal. No data point selected. 1). Since 1982, a standardized method has been deployed to survey the sea otter population in California. Although the California sea otter population is declining, the geographic range of the population continues to expand both to the north and south. Fish and Wildlife Service, 2003) recommends using the 3-year running average of total counts as the official metric for monitoring trends, thereby reducing the influence of anomalously high In addition, the sea otter population size, density, and trajectory are all much greater in Alaska relative to California. Click here to learn more. Secure .gov websites use HTTPS Abstract: The GIS shapefile "Range extent of southern sea otters 2017" is a simple polyline representing the geographic distribution of the southern sea otter (Enhydra lutris nereis) in mainland California, based on data collected during the spring 2017 range-wide census. Fish and Wildlife Service. Browse the menu, click on the "Data and tools" tab, "News" tab, and "Related" tab to learn about sea otter biology and the annual California sea otter population survey. Official websites use .gov By con - trast, the sea otter population in California occupies less than 25% of its historic range (USFWS 2015), remains concentrated in the geographic center of … Since the 1980s, U.S. Geological Survey scientists have calculated a population index each year for the southern sea otter (Enhydra lutris nereis), a species federally listed as threatened. U.S. Geological Survey scientists say the latest 3-year average (2,813 sea otters) was 0.5 percent lower than last year, the first time the trend has been negative since the late 1990s. SANTA CRUZ, Calif. — The southern sea otter population continues its pattern of tepid recovery, according to the latest population survey led by U.S. Geological Survey, California Department of Fish and Game Office of Spill Prevention and Response and Monterey Bay Aquarium scientists. Fish and Wildlife Service. WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems. about viewing, downloading, and printing report files can be found here. Fish and Wildlife Service have decided to cancel this year's annual rangewide southern sea otter census. For southern sea otters to be considered for removal from threatened species listing, the population index would have to exceed 3,090 for three consecutive years, according to the threshold established under the Southern Sea Otter Recovery Plan by the U.S. California Sea Otter (Enhydra lutris nereis) Census Results, Spring 2019 By Brian B. Hatfield, Julie L. Yee, Michael C. Kenner, and Joseph A. 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