Gray whales continue to wash up dead and emaciated, but causes remain elusive
A dead southern right whale washed up Monday on the shores of Alaska. (Photo illustration by Michael Laris/Wired)
In 2011, a researcher from the University of South Florida discovered that the vast majority of whale carcasses in Florida sink to the bottom of the water column and the stomach contents of most die with the carcass. The researcher discovered that the remaining carcasses would sink within a day of being discovered, in about half the cases. That same year, a Florida marine biologist found that in the Gulf of Mexico, as many as 40 percent of whale carcasses sank. The Florida researcher also discovered that some whales, particularly whales between 60 and 70 feet long, have been observed to be unable to right themselves during a deep dive.
Now, a new study, conducted by the University of Maine’s Fisheries Center, has discovered reasons why and where dead whales sink. It also found that dead whales also sink at different rates.
The study was conducted by a team from the University of Maine’s Fisheries Center. It was funded by the National Oceanic and Atmospheric Administration and the U.S. Geological Survey.
“We’ve been trying to figure out why they sink for the past ten years, and now we can answer the question,” the lead researcher, Joseph A. Conforte, said. “The answer is pretty simple once you understand what’s happening.”
Conforte said the key difference among species or individual whales is the depth at which they sink.
“For the most part, most whales are found dead,” he said. “But some whales are not; for example, humpback whales, which are typically found stranded, do not sink to the bottom of the water column. But we do find them often dead and have not yet been able to determine why. There is much more to learn about the behavior of these animals, especially the deep sea, and that’s what we are trying to do.”
The first question the researchers wanted to answer is, what is so different about the behavior of whales that cause them to sink to the bottom of the water column? The answer was simple: they are smaller than some other whales, which means they are less buoyant and have less ability to travel through the water column with the currents
