The whale found dead off South Carolina was an 11-year-old male that had been entangled at least since October, when it was sighted off Nantucket, Massachusetts, swimming with a fishing line caught in its mouth and extending past its tail, the fisheries service said in a news release.
The same entangled whale was seen again in mid-February off Florida, where a team of experts was dispatched but was unable to free the whale.
Conservationists worry that North Atlantic right whales are slipping closer to extinction as deaths in recent years have outpaced births.
However, the 2021 calving season has proven to be the best in years. Survey teams dispatched to search by air for right whale mothers and newborn calves have so far spotted 15 calves — the most reported since 2015.
The calving season typically goes until mid-April.