Boston Harbor marks first harbor porpoise sighting of the year

March 21 (UPI) -- Experts said a video showing a harbor porpoise visiting Boston Harbor is a strong sign that spring has finally sprung.

Boston resident Jen Richardson posted a video to Twitter showing what she identified as a "dolphin" swimming close to shore Monday morning in Boston Harbor.

Tony LaCasse, a spokesman for the New England Aquarium, said the harbor porpoise is the first to be sighted this year, a good sign that spring is on the way.

"We have harbor porpoises come into Boston Harbor every spring," LaCasse told Boston.com.

He said the porpoises make frequent visits to the harbor, but the animals, the smallest members of the dolphin family, often go unnoticed because they surface only briefly for air.