The East Coast Whale Die-Offs: Unraveling the Causes

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In early December of 2016, the carcasses of juvenile humpback whales began turning up in the busy waters around the mouth of Virginia’s Chesapeake Bay.

In early December of 2016, the carcasses of juvenile humpback whales began turning up in the busy waters around the mouth of Virginia’s Chesapeake Bay. By the end of February, 10 animals had been found within about a 200-mile stretch of coast between Virginia and North Carolina.

Though scientists did not yet know it, the spate of deaths marked the start of an “unusual mortality event” (UME) for humpback whales. Such episodes, which are codified in the Marine Mammal Protection Act, involve unexpected strandings and a “significant die-off” of any marine mammal population. (A “stranding” can describe both a live or a deceased animal.)

After a decline in strandings in 2021, a dramatic spike appears to once again be underway. Between December 1, 2022 and March 1, 2023, 16 humpbacks have stranded on or near shorelines from North Carolina to New York, the highest number ever recorded during that particular three-month period. Ten of the whales have been found on beaches in, or just offshore from, New Jersey and New York. (Other whale species, including four critically endangered North Atlantic right whales, have also stranded along the U.S. East Coast since January.

Read more at: Yale Environment 360

A dead humpback whale in Lido Beach, New York on January 31, 2023. (Photo Credit: Seth Wenig / AP Photo)