A team of marine biologists from the University of Southampton (UK) announces the discovery, four kilometers below the surface of the sea, of mysterious traces on the ocean floor. Although not yet confirmed, these fingerprints may have been made by whales. If this is the case, then it could be a new record.
Where do these mysterious traces come from in a region of the Pacific Ocean targeted for the extraction of deep-sea polymetallic nodules? In 2015, the RRS James Cook, a marine research vessel, visited the area before a possible extraction, to characterize the species evolving in the water below. By analyzing the seabed, the researchers then came across a series of traces more than two meters long. These could not be attributed to humans, and seemed too deep to have been created by fish. What if these tracks had been left by whales?
“Further analysis revealed that the depressions were not randomly distributed or isolated, but that they formed curvilinear features or traces,” notes Dr. Leigh Marsh, the main instigator of the research. Similar tracks have been found elsewhere in the world, and have been attributed to whales in deep water. If this is the case, it would be a record for a marine mammal. Remember that the current record is held by two Cuvier’s beaked whales, observed at nearly 3,000 meters below the surface in 2014.
Beaked whales or sperm whales are known to hunt very deep under the ocean’s surface, or to avoid certain predators such as killer whales. But could they do something else? In shallower waters, some species of whales are known to rub on the ocean floor, for example to remove dead skin. Could this behavior also be observed in deep waters, and explain these mysterious traces?
“Like many discoveries in ocean exploration, these results were totally unplanned and resulted from applications of new technologies. The next step will be to provide more conclusive evidence that these whales are the basis of these traces, the researcher says. In the future, we hope to be able to sample the sediments in the tracks to see if whale skin cells are present or not. “