Crews from the Center for Coastal Studies were able to disentangle a large fin whale east of Boston Wednesday.The nearly 60-foot-long whale was spotted by a tuna spotter pilot swimming with a large loop of fishing rope and buoys lodged in its mouth on Stellwagen Bank.That pilot alerted the center and stayed with the animal until the Marine Animal Entanglement Response team could arrive at the scene.Responders threw a grappling hook overboard with 60 feet of line and a large buoy to help dislodge the entanglement.When the whale dove, it dragged the buoy with it and allowed the grappling hook to cut through the loop of fishing ropes. The MAER team repeated this process a second time to shorten the leftover rope on each side of the whale's mouth but decided not to repeat the action a third time, leaving a small portion to be shredded naturally. The whale was first seen entangled by recreational boaters on Saturday.Fin whales are the largest species of whale commonly seen off of the coast of New England, reaching lengths of up to 75 feet and weighing up to 60 tons. They are considered a federally endangered species. Reports of entanglements with this species of whale are relatively rare due in part to its reluctance to surface. This particular whale had not been seen since October 2015, the Center said.The Center for Coastal Studies is urging all mariners to report any entanglement sightings of whales, sea turtles, and all other marine animals immediately to the Entanglement Response Hotline at 1-800-900-3622.