Whale deaths off New Jersey, across East Coast are causing alarm. Here's a detailed look

Since Dec. 1, 23 whales have been found dead along the Atlantic Coast , part of a trend in unusually high deaths among three whale species since 2016-2017. The National Oceanic and Atmospheric Administration is investigating “unusual mortality” events for humpback whales, North Atlantic right whales and minke whales.

Many of the deaths are from still-unknown causes, but necropsies have shown many of the whales died from boat collisions and fishing gear entanglements.

This article originally appeared on USA TODAY: Whale deaths off New Jersey, across East Coast are causing alarm. Here's a detailed look