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
Lexile

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, from climate warming and a loss of sea ice.
 
The dive information on two U.S. Arctic Ocean beluga populations showed the white whales in the Chukchi and Beaufort seas. They were diving more than 2,950 feet.
 
The lead author of the study says it adds to the limited information scientists have on 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 in 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. The belugas have distinctive, bulbous structures on their forehead. Their 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 linked to satellites to whales. 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 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, trying to learn what habitat they 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 and found a correlation.
 
The whales likely made dives based on where prey was concentrated by oceanographic features such as 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 (95)
  • alexaf-ver
    2/25/2016 - 09:24 a.m.

    I find it surprising that researchers would need 15 years of data.

    • coreyh-hei
      3/23/2016 - 11:17 a.m.

      It is good because you have text evidence, but i think you should of put more sentences on your response to now what it is about.

    • josephc2-hei
      4/12/2016 - 02:55 p.m.

      very surprising :)

  • javantej2-hei
    2/25/2016 - 11:05 a.m.

    It took 15 yrs. of data because we needed to provide insight into the whale's foraging patterns in remote regions. Hauser and other researchers collected data from 30 whales in 15 yrs. Hauser and the other researchers matched dive information to data they had on the location of schools of Arctic cod and found a correlation.

  • coreyh-hei
    2/25/2016 - 11:05 a.m.

    they needed 15 years of data so that they could now where they live also see what they eat and. Also where they travel to and places like that.

  • xavionay-hei
    2/25/2016 - 11:10 a.m.

    The researchers needed 15 years of data to be sure that they could prove that these whales were diving to these depths.They also tag the whales so that way they can keep up with the whales.

  • emmem-hei
    2/25/2016 - 11:22 a.m.

    They needed 15 years worth of data, because they needed enough time to prove about the whales.The whales dove to great depths to reach the fish.They needed the time for them to dive,eat,etc.

  • emmem-hei
    2/25/2016 - 11:24 a.m.

    They needed 15 years worth of data because they needed enough time to prove the diving of they whales.They needed to show them diving,eating,etc.The whales like to go dive at great great depths to reach to fish.

  • jaydeno1-hei
    2/25/2016 - 12:04 p.m.

    The reason that researchers need over 15 years of data is because you would need all the data you can get. There fore, so it can be as precised as it can be.

  • yamiletj-hei
    2/25/2016 - 12:12 p.m.

    The researchers needed 15 years of data so they can make sure they see the whales eating patterns. Also what remote regions they stayed at.

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