The pair of whales featured in this photographic series are unusual in that one has black pectoral fins, and the other’s pectoral fins are white. Stevenson estimates that less than 5% of whales seen in Bermuda have black pectoral fins.
However, it is the reverse in the North Pacific where almost all of the humpback whales have black pectoral fins and very few have white pectoral fins. “You wonder whether some of the black-finned whales from the North Pacific have crossed over Northern Canada and joined this population,” says Stevenson. “It would be easier and easier for this to have happened as global warming means that the ice pack up north is less of an impediment.”