Fin whales are the second-largest animal on Earth after the blue whale, and the IUCN lists the species Vulnerable globally, with Massachusetts carrying its own S2, imperiled, rank on top of that. Most of the 162 records can’t be tied to any county, as you’d expect for sightings made offshore, and of those that can, Barnstable County on Cape Cod holds 12, close to Stellwagen Bank, one of the richest feeding grounds on the East Coast.
Records build through spring and peak from July through September, with a smaller April rise, tracking the months fin whales spend feeding inshore before moving to warmer breeding waters further south. Winter records drop to almost nothing, a genuine seasonal absence rather than a gap in who was out looking.
Full species profile
