In a research paper just published in Proceedings of Royal Society B in London, whale researchers in a team led by the New England Aquarium discovered that large whales like people can show signs of increased chronic stress when exposed to elevated noise levels over prolonged periods of time.

Right whales have been called America’s urban whale. Their primary habitats up and down the East Coast of North America are all in or near major ports and shipping lanes. Here a right whale dives near a large ship in Canada’s Bay of Fundy. Credit: New England Aquarium

The findings were the result of an unplanned experiment in the aftermath of the 9/11 tragedy. At that time, whale researchers in Canada’s Bay of Fundy were routinely collecting feces from North Atlantic right whales to measure various stress hormones found in that excrement. In the immediate hours and days after 9/11, commercial transportation around the world was deliberately brought to a standstill to assess needed security measures. That included stopping shipping traffic into the Bay of Fundy which is both the principal summer feeding waters for right whales and also the home to the busy port of St. John, New Brunswick.

 
Right whales are the most endangered large whale in the Atlantic. There are only about 450 of these baleen whales left. Their low population is thought to be a product in part of multiple stressors in their environment. Unexpectedly after 9/11, whale researchers at Boston’s New England Aquarium discovered the first evidence of the effects of noise pollution on the chronic stress levels of these whales. Credit: New England Aquarium

That stand down of ship traffic resulted in a significant decrease in underwater noise and unintended experiment. Baleen whales communicate using low-frequency acoustic signals. Underwater noise from large ships overlaps communication sounds used by whales, and these noise levels have significantly increased, leading to concerns about effects on whales. This study shows that reduced ship traffic in the Bay of Fundy after September 11, 2001, resulted in a significant decrease in underwater noise. Reduced noise was associated with decreased levels of faecal stress hormones in right whales. This is the first evidence that exposure to ship noise is associated with chronic stress in whales, and has implications for baleen whales in heavy ship traffic areas. 


Right whale mothers give birth to their calves near the Florida/Georgia border during the winter months near the ports of Jacksonville and Savannah. In the spring, they bring their calves to Cape Cod Bay adjacent to the shipping lanes into Boston, and in the summer, they bring their calves to feed in the Bay of Fundy and the major shipping lanes into St. John, New Brunswick. Credit: Kara Mahoney Robinson

This important research has drawn international media attention. Follow the links to read additional coverage of the study in the UK's BBC, The Telegraph, Daily Mail, The Guardian, and the Associated Press and MSNBC.