On March 1st, the New England Aquarium aerial survey team spotted a gray whale thirty miles south of Nantucket – an extraordinarily rare sight as they have been extinct in the Atlantic for over 200 years. But in the last 15 years, some five gray whales have been seen in these waters, leading to speculation that whale behaviors are adapting as a result of climate change.
This whale is likely an adolescent male too young to be interested in female whales. When summering in the shallows of the Bering Sea, fattening up for fasting during the winter off Baja, California, he probably wandered off into the Northwest Passage. A possibility previously unheard of because of the thick layer of ice which normally forms in the passage, but in recent years, it’s been relatively ice-free due to rising global temperatures.
Once in the Arctic Ocean, the whale may have just gone with the flow. The Arctic Ocean empties into the broad Greenland Sea. Much of the Arctic Ocean has been open during the summer in recent decades. When cold weather returns in October, there is more sea ice formation. The salt is left out for ocean water to freeze at 32 degrees Fahrenheit, and the ice is fresh. Left behind is very cold, briny water that sinks to displace more nutrient-rich water from the Arctic to flow into the nutrient-poor Atlantic.
After feasting in the nutrient-rich waters, the well-fed gray whale heads south to warmer waters. Just this past December, a gray whale, likely the same whale, was seen in the waters off the coast of Florida.
The sandy, shoal-laden waters of Cape Cod and the Islands are much like the preferred winter habitat off of Baja, California, except colder with more dissolved oxygen and marine life. The gray whale is swimming on schedule to return to Arctic waters this summer. Whether he returns to the Atlantic or Pacific Ocean in September remains to be seen.
Whales are highly intelligent creatures, so we expect them to surprise scientists and researchers every once in a while. Sightings like these are a great reminder of their intelligence and resilience in the face of ever-changing conditions.
Steady on,
Rob
