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research"</title></head><body>
<div><font face="Lucida Grande">Rare beluga data show whales dive to
maximize meals<br>
UNIVERSITY OF WASHINGTON</font></div>
<div><font face="Lucida Grande">PUBLIC
RELEASE: 12-FEB-2016</font></div>
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>-----------------------------------Excerpts-------------------------<span
></span>--------</font></div>
<div><font face="Lucida Grande" size="-1">"They found the whales
most frequently dove to depths where Arctic cod congregate (200-300
meters or 650-1,000 feet), confirming these fish are a significant
source of food for belugas, and that the whales will dive to depths
that maximize their encounters with prey."</font></div>
<div><font face="Lucida Grande" size="-1"><br></font></div>
<div><font face="Lucida Grande" size="-1">"Both beluga
populations frequently dove to the bottom of the sea to feed on
bottom-dwelling organisms in the northern Bering Sea and Chukchi Sea,
but then dove in more mid-depth ranges along areas that sloped from
shallow to deep. They were likely looking for opportunities to eat
based on where prey was concentrated by oceanographic features, Hauser
said."</font></div>
<div><font face="Lucida Grande"
size="-1">-----------------------------------------------</font></div>
<div><font face="Lucida Grande" size="-2"><br></font></div>
<div><font face="Lucida Grande" size="-1">Children's singer and
songwriter Raffi may have brought beluga whales into popular culture
with his 1980 song "Baby Beluga," but surprisingly little is
actually known about the life and ecology of these elusive marine
mammals that live in some of the world's most remote, frigid
waters.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
Two distinct populations spend winters in the Bering Sea, then move
north as sea ice melts and open water allows them passage into the
Beaufort and Chukchi seas. There they feast on Arctic cod, frequently
diving to depths of 200 to 300 meters -- and sometimes over 900 meters
(0.5 miles) -- to find food.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
As the Arctic continues to change due to rising temperatures, melting
sea ice and human interest in developing oil and shipping routes, it's
important to understand belugas' baseline behavior, argue the authors
of a new paper published this winter in the journal<i> Marine Ecology
Progress Series</i>. Its authors drew upon a rare dataset that spans
15 years of dive information for 30 whales to produce a comprehensive
analysis of beluga migration and feeding patterns in the
Arctic.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
"This study gives us a benchmark of the distribution and foraging
patterns for these two beluga populations," said lead author
Donna Hauser, a doctoral student in the University of Washington's
School of Aquatic and Fishery Sciences. "However, there still
needs to be additional work to see how beluga behavior has changed in
concert with changing sea ice conditions in the
Arctic."</font></div>
<div><font face="Lucida Grande" size="-1"><br>
Beginning in 1993, researchers worked with Alaska Native communities
in Northwest Alaska and Aboriginal tribes in Canada to tag beluga
whales. The whales often swim close to shore during early summer,
making it possible to capture a whale and attach a satellite-linked
tag to the dorsal ridge along its back.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
The tags are designed to turn on when the whale surfaces to breathe,
then transmit locations and dive depth to a satellite that then relays
data back to researchers electronically. Tag technology has improved
over time, with one tag remaining on a whale and transmitting data for
18 months.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
"It's a really fantastic system for getting relatively
high-resolution information for these animals that spend most of their
time underwater and offshore," Hauser said. "In addition to
their inaccessibility, these populations use remote areas of the
Arctic, so they are generally hard animals to
research."</font></div>
<div><font face="Lucida Grande" size="-1"><br>
For this study, the researchers also looked at the distribution of
Arctic cod, a primary food source for both beluga populations, and
compared that data to the locations and depths where the whales dove.
They found the whales most frequently dove to depths where Arctic cod
congregate (200-300 meters or 650-1,000 feet), confirming these fish
are a significant source of food for belugas, and that the whales will
dive to depths that maximize their encounters with prey.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
The data evidenced this second finding by recording diving behavior
that was all over the map, literally. Both beluga populations
frequently dove to the bottom of the sea to feed on bottom-dwelling
organisms in the northern Bering Sea and Chukchi Sea, but then dove in
more mid-depth ranges along areas that sloped from shallow to deep.
They were likely looking for opportunities to eat based on where prey
was concentrated by oceanographic features, Hauser said.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
Ultimately, this study helps illuminate aspects of a yearly migration
that spans thousands of kilometers in a region that's experiencing
rapid change.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
"The results of this work can be used not only to understand
ecological relationships for Arctic top predators but also inform the
management of beluga whales, which are an important subsistence
resource for northern communities," said co-author Kristin
Laidre, a UW assistant professor of aquatic and fishery
sciences.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
The researchers will look next at how the timing of beluga fall
migration south may be affected by later sea ice freeze-up in the
northern Arctic under climate change.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
###<br>
Other co-authors are Sandra Parker-Stetter of UW aquatic and fishery
sciences and the Northwest Fisheries Science Center; John Horne of UW
aquatic and fishery sciences; Robert Suydam of Alaska's North Slope
Borough Department of Wildlife Management; and Pierre Richard of
Fisheries and Oceans Canada's Freshwater Institute.</font></div>
<div><font face="Lucida Grande" size="-1"><br>
Beluga tagging was funded and supported by a number of organizations,
including the Alaska Beluga Whale Committee, village of Point Lay,
North Slope Borough and National Marine Fisheries Service (see the
paper for a full list).</font></div>
<div><font face="Lucida Grande" size="-1"><br></font></div>
<div><font face="Lucida Grande" size="-1">Funding for Hauser's
analysis came from the National Science Foundation through UW's
Integrative Graduate Education and Research Traineeship (IGERT)
Program on Ocean Change.</font></div>
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<div><font face="Verdana" size="-2"
color="#000000">****************************************************<br
>
"Our results indicate that future reductions in Arctic sea ice
cover could significantly reduce available water in the American
west...."<br>
<br>
Jacob O. Sewall and Lisa Cirbus Sloan. Disappearing Arctic sea ice
reduces available water in the American west<br>
<i>GEOPHYSICAL RESEARCH LETTERS</i> VOL. 31,<b> 2004<br>
<br>
</b>*******************************************************<br>
" Š the proportion of the land surface in extreme drought is
predicted to increase from 1% for the present day to 30% by the end of
the twenty-first century." <br>
<br>
Eleanor J. Burke et al. Modeling the Recent Evolution of Global
Drought and Projections for the Twenty-First Century with the Hadley
Centre Climate Model.<i> JOURNAL OF HYDROMETEOROLOGY</i> OCTOBER<b>
2006<br>
<br>
</b>******************************************************<br>
"Linkages between northern high-latitude climate and precipitation
in the Sierra Nevada suggested here could indicate that, under
conditions of continued global warming, this drought-prone region may
experience a reduction in Pacific-sourced moisture."<br>
<br>
Jessica L. Oster et al. Late Pleistocene California droughts during
deglaciation and Arctic warming.<i> Earth and Planetary Science
Letters</i><b> 2009</b></font></div>
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