Dozens of dolphins gathered in the deep bowl of John’s Pass to ride out Hurricane Irma; four are shown here. Bucking seas and cresting waves force dolphins to raise their heads higher than normal over the water surface to breathe without getting water in the blowhole. This extra effort can exhaust dolphins in stormy seas, especially calves.
What do dolphins do in a hurricane? No one knows. No one really even knows how dolphins respond to serious thunderstorms, other than the fact that rain on water is the loudest natural sound. No one out there is watching dolphins in a storm.
If a boater is caught in a serious storm at sea, passing dolphins are not a priority. The standard way to study dolphins, watching and recording from a small boat, is indeed “cumbersome” during storms.
However, there are other ways to brace the elements for clues about how dolphins act during hurricanes.
The day of Hurricane Irma, people on the John’s Pass Bridge saw dozens upon dozens of dolphins that had gathered in the deep bowl of water under the bridge. It was not possible to count them with precision. They were too active.
At any given time, 20 or 30 dolphins rolled to the surface to breathe. This was unusual. Typically, in heavy seas, dolphins stay submerged for longer periods than normal, as if the effort of surfacing to breathe is not worth the buffeting they get at the surface. As a result, you see dolphins in heavy seas far less often than in calm seas.
But the dolphins were so animated as Irma screamed past that many were visible at any given moment.
It makes sense that the dolphins left the shallow Intracoastal Waterway to weather the storm in the deeper bowl of John’s Pass. This is the place where they could get as far under the writhing sea surface as possible without traveling far out to sea. And I think this is part of the story of how dolphins act during hurricanes.
Another part of the story is unintended gatherings. On land, countless people evacuated their homes to wait out Irma in hurricane shelters, where they gathered in great numbers. But they did not gather because they sought one another’s company.
Similarly, it makes sense that individual dolphins headed for the deeper waters of John’s Pass to wait out Irma in an aquatic shelter. They probably did not gather because they sought one another’s company.
Once in John’s Pass, the dolphins were very animated. Is that because they were scared of the hurricane? No one knows. But I have seen plenty of pets scared witless by storms and fireworks.
A well-known behavior explains the dolphins’ animation: Each other. There is a direct relationship between the number of dolphins gathered together in an area of water and their level of animation. Specifically, the more dolphins, the more active they are.
There might be more to it during a hurricane. The shrieks of the storm may have compelled the dolphins to call to one another more loudly than normal to stay in touch. However, the writhing waters may have further compelled them to repeatedly check in with one another through physical proximity. This could account for their highly animated behavior at the surface.
Another clue is that they stayed in John’s Pass for several days after the storm. They made a marvelous sight: dozens and dozens of dolphins rolling at the surface without a single boat in view. Once the danger passed, they may have stayed to socialize. Dolphins are psychologically designed to socialize and are, after all, incurable opportunists.
A final clue about how dolphins act in hurricanes came from the hurricane season of 2005. We got out on the water as soon as possible after one of those hurricanes – does it matter which one? – and saw the same behavior: dozens and dozens of highly animated dolphins, as if checking in with each other in the wake of the storm. The only difference is that they were gathered just outside John’s Pass.
Dr. Weaver studies wild dolphins under federal permit 20346, National Oceanic and Atmospheric Administration. Send her an email at firstname.lastname@example.org or visit her website www.goodnaturedstatistics.com. NOAA advises anyone who sees a stranded dolphin in the Gulf of Mexico to call 877-942-5343 or 877-433-8299.