Scientists Say Arctic, Sea Ice Levels Linked With , Gray Whale Mass Die-Off Events.br LiveScience reports that scientists may have determined br the reason behind a series of mass deaths among br gray whales in the northeastern Pacific Ocean. .br According to a new study, scientists have linked recent br major mass mortality events with Arctic sea ice levels. .br According to a new study, scientists have linked recent br major mass mortality events with Arctic sea ice levels. .br Three major die-off events have br impacted gray whales off the coast br of North America since the 1980s.br Those events reduced the whale population br by 15 to 25 each time they occurred, br killing over 2,000 gray whales.br In 2019, the latest die-off event br started with over 70 gray whales washing br ashore dead in only six months.br Since then, a total of 688 are known br to have died, while the cause of br the event has remained unclear.br These are extreme population swings br that we did not expect to see in a large, br long-lived species like gray whales, Joshua Stewart, Study lead author and assistant professor at Oregon State University's Marine Mammal Institute, via LiveScience.br According to the new study, published in the journal 'Science,' changing conditions and fluctuations in sea ice levels in the Arctic may be responsible for these events. .br Sea ice cover and the amount of br available food may dictate how br the gray whale population fares. .br When the availability of their prey br in the Arctic is low and the whales br cannot reach their feeding areas because br of sea ice, the gray whale population br experiences rapid and major shocks, Joshua Stewart, Study lead author and assistant professor at Oregon State University's Marine Mammal Institute, via LiveScience.