A long-term study showing the changes in habitat associations of polar bears in response to sea ice conditions in the southern Beaufort Sea has implications for polar bear management in Alaska.
Karyn Rode, a polar bear biologist with the U.S. Fish and Wildlife Service in Anchorage, Alaska and one of the study's authors, says data collected between 1979 and 2005 show that polar bears in the region are occurring more frequently on land and in open water and less frequently on ice during the fall. This means there are increased chances for human/bear interaction. The paper was published in the December issue of Arctic – the journal of the Arctic Institute of North America.
Polar bears were observed over the 27-year period by U.S. government Minerals Management Services staff as part of the fall bowhead whale aerial survey conducted annually in the southern Beaufort Sea. Ice conditions were also recorded.
Data showed that as ice conditions changed, bears were being found on different habitats. Between 1979 and 1987, 12% of bear sightings were associated with no ice. Between 1997 and 2005 however, 90% of bear sightings were associated with no ice.
"When bears were seen, they were more often seen in open water and on land than on sea ice. At the same time, changes were observed in ice, suggesting that these observations are connected," says Rode.
In addition, the number of bears sighted steadily increased from 138 bears in the years 1979-1987, to 271 bears between 1988 and 1996, and finally to 468 bears between 1997 and 2005. Rode warns that this study was not designed to estimate the number of bears using the nearshore area. Data were drawn from studies created to track bowhead whale migration routes, not polar bear populations. Therefore, it should not be concluded that more bears are occurring in the nearshore waters off the Southern Beaufort Sea coast.
However, Rode states that "Our results do suggest that bears that use the nearshore area are more likely to occur on land in recent years because their preferred habitat, sea ice, is unavailable.
"This is one of the few data sets available over such a long time frame. It shows there has been a shift in habitat use," she says.
In the Beaufort Sea region, there was less ice in 2005 than when the study period began in 1979. In general, freeze up is later and spring melt comes earlier with measurements showing since 1979 the summer melt period has increased by 13 days per decade. This is one reason for the region's rapid retreat of multi-year ice, which provides a thicker, more stable platform for hunting and denning.
This work is helpful in highlighting the need to proactively develop programs to manage bear-human interactions in coastal areas. Bear-human interactions in Native villages and with industry in Alaska have been on the rise in recent years.
This media release is part of the Promotion of Arctic Science, an Arctic Institute of North America project made possible with the generous support of the Government of Canada Program for International Polar Year.
The mission of the Arctic Institute of North America at the University of Calgary is to advance the study of the North American and circumpolar Arctic and to acquire, preserve and disseminate information on physical, environmental and social conditions in the North. More information can be found at www.arctic.ucalgary.ca
A new indicator for marine ecosystem changes: the diatom/dinoflagellate index
21.08.2017 | Leibniz-Institut für Ostseeforschung Warnemünde
Value from wastewater
16.08.2017 | Hochschule Landshut
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
24.08.2017 | Life Sciences
24.08.2017 | Life Sciences
24.08.2017 | Medical Engineering