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California Sea Otters—2007 Survey Count Reaches New High
Observers led by scientists from the U.S. Geological Survey (USGS) counted a total of 3,026 California sea otters during the 2007 spring survey, marking a record high and a 12.4-percent increase over the 2006 count of 2,692. The previous high was 2,825 sea otters in spring 2004. "The favorable viewing conditions—the best we've had in years during our spring surveys—likely contributed to the encouraging count," said survey organizer Brian Hatfield, a USGS biologist stationed in San Simeon, California. Also rising slightly is the latest 3-year running average—the average of the totals from the spring counts of 2005, 2006, and 2007—which is up 2.4 percent over the previous average, to 2,818 sea otters. To assess overall population trends, 3-year running averages of spring counts are used to reduce the influence of anomalously high or low counts during any particular year, as recommended by the U.S. Fish and Wildlife Service (USFWS)'s Southern Sea Otter Recovery Plan. "We are guardedly optimistic about the slight increase in this latest 3-year running average," said Lilian Carswell of USFWS, "although the population remains a considerable distance from the delisting threshold. For southern sea otters to be considered for delisting, the 3-year running averages would have to exceed 3,090 for 3 continuous years."
"While a high count is always better news than a low count, these counts have varied quite a lot in recent years," said USGS scientist Jim Estes, whose sea-otter expertise spans more than 3 decades. He pointed out that last year's count was on the low side, for example, and noted that "We cannot infer much about the population until there has been a sustained trend." Several segments of the coast surveyed this spring showed significant increases in the adult and subadult group of sea otters called independents. The greatest increase was 135 more independents this year for Monterey Bay. At the south end of the survey area, 39 independents were spotted east of Gaviota and 29 in the Naples Reef area, approximately 7 km west of Coal Oil Point (50 km east of Point Conception). By comparison, none were spotted east of Gaviota during the spring 2005 count, and only one in spring 2006. The spring 2007 California sea-otter survey was conducted May 2-17 and covered about 375 mi of California coast, from Point San Pedro in the north to Rincon Point in the south. Overall viewing conditions were more favorable than those during the spring 2006 survey. The annual spring survey is a cooperative effort of the USGS, the California Department of Fish and Game's Marine Wildlife Veterinary Care and Research Center, the Monterey Bay Aquarium, and many experienced and dedicated volunteers. The information gathered from spring surveys is used by Federal and State wildlife agencies in making management decisions about this small sea mammal. For additional information about the 2007 California sea-otter survey, visit URL http://www.werc.usgs.gov/otters/ca-surveyspr2007.htm.
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in this issue:
California Sea Otter Count Reaches New High
MIT Students Tour USGS Woods Hole Science Center Coastal-Hazards Research Featured in First USGS Podcast
Airborne-Lidar Technology and Applications Workshop
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U. S. Department of the Interior | U.S. Geological Survey
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