As Ice Melts, Arctic Ecosystem Confronts Emboldened Killer Whales

The hunting grounds are apparently widening for one of "nature's most effective predators" reports the New York Times, warning of "potentially significant consequences for animals up and down the food chain...." "As sea ice has receded, killer whales — which are actually dolphins — are now venturing to parts of the sea that were once inaccessible, and spending more time in places they were once seen only sporadically," according to data presented by research scientist Brynn Kimber (who works in the National Oceanic and Atmospheric Administration's Marine Mammal Laboratory). Arctic sea ice has declined significantly in the four decades since satellite monitoring began. Roughly 75 percent of ice volume disappeared in the last 15 years alone, and the remaining ice is thinner and of poorer quality, said Amy Willoughby, a marine mammal biologist with NOAA's Alaska Fisheries Science Center. The loss of ice coupled with warming waters and atmospheric temperatures has affected every level of the Arctic ecosystem. Large mammals like polar bears have struggled to navigate shrinking habitats, while the marine algae at the base of the Arctic food chain blooms sooner and more abundantly than ever before. In recent years, scientists have noticed similar upheaval in the behavior of the region's marine mammals. Orca are feasting more often on bowhead whales. Scientists and Indigenous Arctic communities have noted a growing number of bowhead whale carcasses in the northeastern Chukchi and western Beaufort seas with signs of orca attack.... "Killer whales are really intelligent," said Cory Matthews, a research scientist with the Arctic region of Fisheries and Oceans Canada. "They consume really fast. If a new area opens up, they can get in there maybe within the next year and exploit a prey population that could be perhaps really slow to respond to those changes."

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