Canada’s Bay of Fundy is located on the east coast of North America, tucked between Maine, New Brunswick, and Nova Scotia. It’s a common home to a number of ships and active ports, at least on a typical day. But September 11, 2001, was not a typical day. The attacks on the United States brought sea traffic throughout the region to a crawl as authorities rushed to ensure the safety of ships, their passengers, and their cargo. That slowdown lasted a couple of days and unintentionally created unique conditions for scientific inquiry.

For example, it helped researchers discover that whales were really stressed out.

The Bay of Fundy is a seasonal feeding ground for a few species of whales, whose populations spike in the summer and into the early fall. As a relatively enclosed body of water, the Bay of Fundy lends itself well to the study of these creatures. In September 2001, two teams of researchers were independently conducting whale-focused experiments in the area. One was collecting recordings of whale songs, to learn more about how whales communicate. The other was collecting whale feces, which, while gross, can be used to tell us more about whale diet and nutrition by measuring various hormone levels found within the stool samples. (The things we do in furtherance of science.)

Nearly a decade after 9/11, a group led by scientists from the New England Aquarium in Boston noticed that these two experiments provided a rare opportunity. For years, as the New York Times reported, we’ve known that whales “communicate with acoustic signals at low frequency, the range of many noises from ships” and that “whales move off, reduce their own calls and otherwise respond to ship noise.” Some researchers believed that whales were moving away because ship noise caused them stress, but there was no good way to test this theory. Incredibly, the 9/11 data provided a rare insight into the question.

When whales get stressed, they release a hormone that, ultimately, they excrete in their feces. Because researchers were collecting the poop on 9/11 and the days previous and subsequent, the science community had data on the relative stress levels of the Bay of Fundy whales during that time. What it shows is that the whales were pretty relaxed on the days after the attack—or, at least, more relaxed than they were in the days prior.

From the same time period, we also have data measuring the amount of low-frequency acoustic signals in the Bay that week—again, from before and after 9/11. We already knew that ship traffic came to a near-halt, so it shouldn’t be surprising that the amount of underwater noise also dropped dramatically. One could say that it was, relatively speaking, rather peaceful if you were a whale.

Whether the whales’ stress levels are important, though, is harder to determine. Since the conditions of this experiment were accidental, researchers can’t repeat the tests. One of the researchers pointed out, in the words of the Associated Press, that it is “unclear how much chronic stress from noise the whales can take before the population is affected, largely because it’s impossible to conduct controlled experiments on fifty-ton animals.” So for now, we’ll likely keep stressing out the whales.

Bonus Fact

Life as a college student can be stressful, too, especially around finals. A few schools have found a cute solution—puppies. The schools bring in trained therapy animals to take some of the edge off.

Excerpted from Now I Know More Copyright © 2014 by Dan Lewis and published by F+W Media, Inc. Used by permission of the publisher. All rights reserved.