California's Sea Otter Numbers Continue Slow Climb plus 1 more

[USGS Newsroom <oc_web@xxxxxxxx>]

Title: USGS Newsroom

California's Sea Otter Numbers Continue Slow Climb plus 1 more

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California's Sea Otter Numbers Continue Slow Climb

Posted: 12 Sep 2013 08:30 AM PDT

Note to editors: For interviews with California Department of Fish and Wildlife sea otter biologists, please contact Alexia Retallack to schedule. USGS biologist, Tim Tinker will be available for interviews on Thursday, September 12, 2013, near the Seymour Marine Discovery Center in Santa Cruz, Calif. Please contact Ben Landis to schedule.

SANTA CRUZ, Calif. — California sea otter numbers are up, according to the latest population survey led by federal, state and university scientists. The reasons: more pups — and the addition of San Nicolas Island sea otters to the population count. 

Since the 1980s, U.S. Geological Survey scientists have calculated an averaged population index each year for the southern sea otter — Enhydra lutris nereis — a federally listed threatened species found in California. For the 2013 report, USGS lists the population index as 2,941 (data online). 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. Fish and Wildlife Service. 

“Population growth in central California has faltered recently, so the fact that we’re seeing a slightly positive trend is a basis for cautious optimism,” says Tim Tinker, a biologist with the USGS Western Ecological Research Center who supervises the annual survey. “Certainly, sea otters have made an impressive recovery in California since their rediscovery here in the 1930s. But as their numbers expand along California’s coast, they are facing different ‘growing pains’ in different locales. Our research partnership is investigating the factors responsible for these local trends.”

Researchers from the USGS, California Department of Fish and Wildlife’s Office of Spill Prevention and Response, Monterey Bay Aquarium, University of California-Santa Cruz and other institutions collaborate annually to conduct the sea otter survey. The population index reported to USFWS is calculated as multiple year averages of raw data from annual surveys, to compensate for year-to-year variability in observation conditions, and to give scientists a more reliable picture of sea otter abundance trends.

“We counted a record number of pups this year, which led to the uptick in the 3-year average,” says USGS biologist Brian Hatfield, coordinator of the annual survey, “A high pup count is always encouraging, although the number of adult otters counted along the mainland was almost identical to last year’s count, so we’ll have to wait and see if the positive trend continues.” 

There is a second reason for the higher population index reported this year. In 2013, the equation for this population index was amended to add sea otters living at San Nicolas Island. One-hundred-and-forty sea otters were introduced to the island in the 1980s as part of a USFWS recovery experiment, but most of them returned to the mainland, died, or simply disappeared. USFWS completed an extensive review of the translocation program in December 2012, resulting in termination of the program. As a consequence, sea otters at San Nicolas Island are no longer considered to be an “experimental” population and will now be included as part of the California-wide population index for southern sea otter recovery. The population at the island is now at 59 individuals. 

Statewide Trends and Local Questions

USGS scientists also annually update a database of sea otter strandings — the number of dead, sick or injured sea otters recovered along California’s coast each year. In 2012, scientists from CDFW, USGS, Monterey Bay Aquarium and other institutions came across a total of 368 stranded sea otters.

This stranding number only accounts for sea otters that people find, and past research indicates that possibly less than 50% of sea otters that die in the wild end up on the beach. But efforts are made to examine each reported sea otter carcass, and a subset of fresh carcasses are sent to the CDFW Marine Wildlife Veterinary Care and Research Center, where scientists conduct necropsies to determine the primary causes of death and identify factors that may have contributed to the death of each animal. 

Data from both living and deceased sea otters continues to shed light on sea otter population ecology in different parts of the California coast. For example, a high proportion of sea otter carcasses recovered between Cayucos and Pismo Beach in recent years have white shark bite wounds, a potential explanation for the downward trend in sea otter numbers in that area. In Elkhorn Slough, a new study suggests that sea otter appetites for crabs can improve the health of seagrass beds. And at the southern end of their mainland range, researchers are observing sea otter feeding and movement behavior to understand their slow southward expansion.

“Overall trends are important, but they can mask problems that may be affecting only a portion of the population,” says Lilian Carswell, Southern Sea Otter Recovery Coordinator for USFWS. “These regional research projects help us understand the effects of local influences, whether human-caused or natural, and inform the overall southern sea otter recovery strategy.”

Survey Methodology

• The annual population index is calculated from visual surveys conducted along the California coastline by researchers, students and volunteers from USGS, CDFW’s Office of Spill Prevention and Response, Monterey Bay Aquarium, UC Santa Cruz, USFWS, U.S. Bureau of Ocean Energy Management, and Santa Barbara Zoo.
• Surveys are conducted via telescope observations from shore and via low-flying aircraft, typically from April through June. This year, the surveyed coastline spanned Point San Pedro in San Mateo County, south to Rincon Point near the Santa Barbara/Ventura County line, and also included San Nicolas Island.
• The annual survey was interrupted in 2011, when weather conditions prevented the mainland survey’s completion.

Sea Otter Facts

• Sea otters were presumed extinct in California after the fur trade years, but were rediscovered in the 1930’s by the public, when as few as 50 animals were documented persisting in nearshore areas off the coast of Big Sur.
• Sea otters are considered a keystone species of the kelp ecosystem because they prey on herbivorous invertebrates that, if left unchecked, can decimate kelp beds and the fish habitat they provide.
• Scientists also study sea otters as an indicator of nearshore ecosystem health, since sea otters feed and live near the coast and often are the first predators exposed to pollutants and pathogens washed down from coastlands, such as the microbial toxin microcystin.
• The public can report sightings of stranded sea otters to institutions listed on this webpage.

Rural Well-Being in the Prairie Pothole Region

Posted: 12 Sep 2013 06:47 AM PDT

Linking Land-Use and Economics

Land-use in the Prairie Pothole Region (PPR) of the northern Great Plains has been shifting at an extraordinary rate, including changes in agriculture practices, the recent boom in petroleum production, and rising tourism, according to a new U.S. Geological Survey report. 

The report examines how economic variables and rural development are linked to land use in the region and suggests that while agriculture remains an important economic, social and cultural driver, the long-term economic health of the PPR is dependent on a strong off-farm economy as well. 

"This report shows that policymakers and land managers may want to think holistically about land-use change and understand the linkages between their decisions and aspects of community well-being," said William Gascoigne, the USGS scientist who led the study. "We set out to produce the most comprehensive report regarding land conditions, economic influence, and rural community well-being in the PPR to help inform their decisions." 

The report showed that although a vast amount of land in the PPR remains in farming -- still a major employer in select counties -- technological advances in agriculture and a depressed off-farm economy are threatening the economic contribution of this industry. 

"We found that a strong farm economy and the persistence of family farms are just as, if not more so, dependent on a strong off-farm economy and labor market," Gascoigne said. "Although each community is unique, modern rural-development must go beyond agriculture and take sight of other aspects of rural communities, including what attracts people to the area."

The newly released USGS report and fact sheet also demonstrated that native prairie grassland remains in decline, a large portion of lands enrolled in the U.S. Department of Agriculture's Conservation Reserve Program (CRP) are once again being cultivated, and expanding petroleum production has just moved North Dakota past Alaska as the number two oil producer in the nation. 

While agriculture and oil production are major economic players, the report also noted that tourism — largely wildlife-based in this region — is a top-three industry in both of the Dakotas and is growing at above the national average in these states.  

"The farming community has long understood that diversity in agricultural operations is critical to economic productivity," said Rick Nelson, coordinator for the Plains and Prairie Potholes Landscape Conservation Cooperative (LCC), which funded the study. "Local policy makers also know that tourism activities and outdoor recreation are key components of a healthy local economy. It is less understood how this economic activity is threatened by land-use change and loss of habitat. This study helps to quantify how an investment of time and resources in strengthening the nonfarm rural economy may greatly assist local governing officials as they work to support agriculture in the community."

The study conservatively estimates that expenditures on hunting and wildlife viewing are estimated to be contributing close to 10,000 jobs, $760 million in labor income, and $450 million in output to the regional economy. In addition, operational spending by the U.S. Fish and Wildlife Service National Refuge System and the Partners for Fish and Wildlife Program, including perennial habitat restoration, are supporting close to another 900 jobs, $40 million in labor income, and $50 million in output in the region. 

The PPR extends into areas of both the United States and Canada where midgrass and tallgrass prairies contain thousands of shallow wetlands known as potholes, which are essential habitat for millions of migrating ducks and other birds each year. 

The LCC is a federal, state, and nongovernmental partnership working to understand the interaction among the economic, social and biological values of conservation to PPR communities. 

The Plains and Prairie Potholes LCC is responsible for identifying, prioritizing, and supporting research that addresses scientific uncertainties related to broad-scale natural resources challenges impacting the northern Great Plains and prairie pothole region of the United States and Canada. Visit the Plains and Prairie Potholes LCC for additional information on the mission, vision and activities.