Beluga whales dive deep to eat This May 11, 2011 photo released by North Slope Borough and the National Oceanic and Atmospheric Administration (NOAA) shows a beluga whale pod in the Chukchi sea near Alaska. (Vicki Beaver/North Slope Borough/NOAA via AP/Thinkstock)
Beluga whales dive deep to eat
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Beluga whales off Alaska's northern coast like to hunt for Arctic cod. The whales will dive to great depths to reach the fish. That is according to data collected over 15 years. It provides insight into the whales' foraging patterns in the remote region.  Now the area is undergoing profound changes. Those include climate warming and a loss of sea ice.
 
The dive information was learned about two U.S. Arctic Ocean beluga populations.  It focused on the white belugas in the Chukchi and Beaufort seas. They can dive more than 2,950 feet.
 
The lead author of the study says it adds to the limited information scientists have. They want to learn about the diet and behavior of the two whale populations.
 
"It's sort of important to get some benchmarks. And some baseline information," said lead author Donna Hauser.  She is a doctoral student.  She attends the University of Washington's School of Aquatic and Fishery Sciences.
 
Belugas are small, toothed whales. They are born gray. They turn white as they age. They have muscular bodies. Belugas have distinctive, bulbous structures on their forehead. They have a thick blubber layer that can be 5 inches thick.
 
Male belugas grow as long as 15 feet. Females can be 12 feet. They feed on salmon, crab, shrimp, squid and clams. They also like small schooling fish. Those include herring, capelin, smelt and cod. The whales are hunted by Alaska Native subsistence hunters.
 
Alaska has five populations of beluga whales. Two spend winters in the Bering Sea.  When sea ice melts, they head through the Bering Strait. It takes them into the Chukchi or Beaufort seas.
 
During the study, researchers applied tags to whales. The tags were linked to satellites.  When tagged belugas surfaced to breathe, the tags would transmit locations and dive depths.
 
Hauser and other researchers looked at data collected from 30 whales. The whales were tagged over 15 years. The period was from 1997 to 2012. One retained a tag for 18 months.
 
Polar bears and Pacific walrus need sea ice as a platform for hunting. Beluga whales can move around the ice.
 
The researchers tracked belugas into feeding areas that formerly had been covered year-round with sea ice. The researchers want to learn what habitat the belugas use on their long migrations.
 
Without much information about the diet of belugas in the Arctic Ocean, Hauser and other researchers matched dive information to data they had on the location of schools of Arctic cod.  A correlation was found.
 
The whales likely made dives based on where prey was concentrated by oceanographic features. Those include undersea slopes from shallow to deep water, Hauser said. The whales commonly dove 650 to 1,000 feet.
 
"So we could confirm, for one thing, that there was this correspondence between the depths the Chukchi belugas were diving and the depths at which Arctic cod were most abundant," she said.
 
The tags attached to the belugas could record dives to 1,000 meters. That is 3,280 feet. One male beluga dove to 956 meters, or more than 3,100 feet, in the Canada Basin. The basin reaches depths of more than 10,000 feet. Researchers don't know why belugas would dive so deep there, Hauser said.
 
The research was published in the journal Marine Ecology Progress Series in December.

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CRITICAL THINKING QUESTION
Why did researchers need 15 years of data?
Write your answers in the comments section below


COMMENTS (13)
  • jamaurianr-hei
    2/25/2016 - 11:27 a.m.

    To see how long they can dive. The male can drive 956 feet long and the female can drive well I don't know how the female drive. The males can grow 15feet long and the female can grow about 12feet long.

  • sr-bla
    2/25/2016 - 01:06 p.m.

    I feel bad for the belugas whales because where they live there are not much ice burges to protect them.

    • williaml-hei
      2/25/2016 - 03:46 p.m.

      I can agree with your statement.

  • ms-bla
    2/25/2016 - 01:18 p.m.

    Wow what a cool animal.I think I just found my favorite whale.

    • amiahj-hei
      2/25/2016 - 04:00 p.m.

      You need to read the question over. That does not have anything to do with the question.

  • mariannae-hei
    2/25/2016 - 01:46 p.m.

    Researches needed 15 years of data because it provides insights into the whales' foraging patterns in the remote region.

  • dylanc1-hei
    2/25/2016 - 01:54 p.m.

    So they would have enough time to research the whales. Also because they could be rare in places.

  • angelar-hei
    2/25/2016 - 01:55 p.m.

    They need five years of data because all the Whales live deep down in the Ocean so they would be hard to find deep in the Ocean. They had to have the stuff to find the Whales. They would just wait it out.

  • nickr1-hei
    2/25/2016 - 03:34 p.m.

    Well the whales in the passage are very unique and so they are hard to get data on because they hide under icebergs so it is hard to find them and experiment on and they also go around 3,000 feet under the surface so they are hard animals to get information off of.

  • williaml-hei
    2/25/2016 - 03:45 p.m.

    To unlock all the whales secrets like how it moves. also they learnd how deep on of their wales were. (956 meters over 3100 feet)

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