North American whales face potential extinction as warming oceans force them into unsafe territory

Warm waters have pushed certain kinds of whales into unstable habitats, leading to a steep decline in births, a new study found.

North Atlantic whales are facing extinction, experts say, after observing no sign of newborns in the past year.

As the ocean water temperatures have risen, depleting their food supply, the whales have been migrating to cooler waters where new hazards and "nutritional stress" are taking a toll on their population size, a March study out of Cornell University said.

Whales are now venturing farther north into cooler Canadian waters where food is more plentiful, but where boats and fishing gear have proved dangerous.

"The fishing gear has not been specially designed to break away when whales are entangled, and there are no acoustic monitoring programs in place to force ships to slow down when whales are present," said Charles Greene, professor of oceanography at Cornell University.

Photos of the endangered whales: 

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Endangered North Atlantic right whales
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Endangered North Atlantic right whales
DUXBURY, MA - MAY 6: The fluke of a whale is seen in an aerial view of whales feeding off the shores of Duxbury Beach. There were groups of the North Atlantic right whales swimming off shore. The critically endangered animals are making a comeback since they were nearly hunted to extinction a century ago. They are also making a habit of appearing off the local coastline in the spring. The whales feed on copepods by opening their mouths as they swim through masses of the tiny, but fat-rich, creatures. (Photo by David L. Ryan/The Boston Globe via Getty Images)
DUXBURY, MA - MAY 6: A view of the Baleen which is a filter-feeder system inside the mouth of a right whale feeding off the shores of Duxbury Beach. There were groups of the North Atlantic right whales swimming off shore. The critically endangered animals are making a comeback since they were nearly hunted to extinction a century ago. They are also making a habit of appearing off the local coastline in the spring. The whales feed on copepods by opening their mouths as they swim through masses of the tiny, but fat-rich, creatures. (Photo by David L. Ryan/The Boston Globe via Getty Images)
DUXBURY, MA - MAY 6: The wakes of right whales can be see on the calm ocean waters off the shores of Duxbury Beach. There were groups of the North Atlantic right whales swimming off shore. The critically endangered animals are making a comeback since they were nearly hunted to extinction a century ago. They are also making a habit of appearing off the local coastline in the spring. The whales feed on copepods by opening their mouths as they swim through masses of the tiny, but fat-rich, creatures. (Photo by David L. Ryan/The Boston Globe via Getty Images)
DUXBURY, MA - MAY 6: An aerial view of a right whale erupting from the blow hole while feeding off the shores of Duxbury Beach. There were groups of the North Atlantic right whales swimming off shore. The critically endangered animals are making a comeback since they were nearly hunted to extinction a century ago. They are also making a habit of appearing off the local coastline in the spring. The whales feed on copepods by opening their mouths as they swim through masses of the tiny, but fat-rich, creatures. (Photo by David L. Ryan/The Boston Globe via Getty Images)
DUXBURY, MA - MAY 6: Aerial view of a whale's fluke off the shores of Duxbury Beach. There were groups of the North Atlantic right whales swimming off shore. The critically endangered animals are making a comeback since they were nearly hunted to extinction a century ago. They are also making a habit of appearing off the local coastline in the spring. The whales feed on copepods by opening their mouths as they swim through masses of the tiny, but fat-rich, creatures. (Photo by David L. Ryan/The Boston Globe via Getty Images)
CAPE COD BAY, MA - APRIL 12: A North Atlantic Right Whale sounds while feeding on plankton in Cape Cod Bay, off the coast of Provincetown. A team from the Provincetown Center for Coastal Studies, was researching the right whale's food supply today during their migration north. (Photo by Bill Greene/The Boston Globe via Getty Images)
391683 01: FILE PHOTO: A rare North Atlantic right whale surfaces June 27, 2001 off the coast of Massachusetts. Scientists launched a second rescue attempt July 10, 2001 to remove fishing line embedded in the infected jaw of the endangered 45-foot whale. (Photo by Getty Images)
Fin whale.Balaenotera physalus.Two whales feeding on a school of herring. Fish are escaping, jumping in the air; seabirds (Gulls and Shearwaters) are trying to catch fish. Both whales are turned on their right side; the throat pleats are distended. .Coast of New Brunswick, Canada, North Atlantic Ocean. (Photo by: Francois Gohier/VW Pics/UIG via Getty Images)
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Researchers said 17 right whales died last year, totaling more than 3.5 percent of the population. Right whales refer to three types of Eubalaena whales - the North Atlantic right whale, North Pacific right whale and the Southern right whale.

"Most of the dead whales that have been examined have exhibited evidence of the blunt trauma associated with ship strikes," Greene said.

Right whales eat Calanus finmarchicus, a species of copepods as their main form of nutrition. Scientists have tracked whale reproduction rates in correlation with the amount of available C. finmarchicus. Whale reproduction can vary greatly, Greene said, depending on the abundance of the copepods.

Recently, the researchers grew concerned with the spread of C. finmarchicus away from the Gulf of Maine as water temperatures rose, bringing the whales with them.

These northern waters are not safe for the whales, and the added "nutritional stress" has likely led to the decline in new calves.

"This elevated mortality in the population paints a bleak picture for this highly endangered species' future," he said.

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