Rescuers have been working to free an entangled female North Atlantic right whale, one of the many that have made their seasonal arrival in waters south of the Vineyard and in Cape Cod Bay to feed.
About 25 North Atlantic right whales gathered south of the Vineyard last week, marking an early-season sighting.
A decomposed whale that washed up on Chappaquiddick last month has been identified as a North Atlantic right whale, adding to the death toll.
The deaths of 13 North Atlantic right whales in the United States and Canada this year is being considered an unusual mortality event, triggering an investigation into the cause.