Everyone enjoys a good scratch. For a bowhead whale stretching up to 20 meters long and weighing as much as 75 tonnes in Canada\u2019s Arctic, the question is what to do about it. The unexpected solution lies within the shallow and relatively warm waters of Cumberland Sound, off southeastern Baffin Island in Nunavut.<\/p>\n
That\u2019s where bowheads from the Eastern Canada-West Greenland population gather in late summer to rub themselves on large rocks just below the water\u2019s surface.<\/p>\n
\u201cIt\u2019s like a day spa for the whales,\u201d explains Sarah Fortune, a doctoral candidate at the University of British Columbia who led the research. \u201cThink of it as using a pumice stone to get a callus off your foot, using the physical environment to help exfoliate the skin.\u201d<\/p>\n
In 2014, Fortune accompanied Fisheries and Oceans Canada scientists to research the diet and feeding behavior of bowheads in the rich habitat of Cumberland Sound. \u201cWhales were at the surface, rolling over, doing headstands, tails out of the water, occasionally making loud vocalizations. We\u2019d never seen this before,\u201d she says.<\/p>\n
The research team returned in August 2016 for further investigation\u2014this time with a drone\u2014and gathered conclusive evidence of what they had suspected: the whales were rubbing against rocks in water less than 10 meters deep as a way of removing dead skin.<\/p>\n
Of the 81 whales the scientists observed, all were molting. About 40 percent showed signs of rock rubbing, including linear, light-colored markings on their bodies from the friction.<\/p>\n