This is a Beluga Whale (Delphinaptera leucas) that lived in the St. Lawrence River. During a time when some researchers were studying the Beluga population in that location, "Pascolio" was a young male who often went over to the little boats to see the researchers.

To learn more about Beluga Whales in the St. Lawrence River, as well some information and insight into these amazing animals, I suggest reading: Beluga: A Farewell to Whales, by Dr. Pierre Beland.