In recent years, a large number of whales have stranded and died on several occasions in and around Scotland, most recently in the Orkney Islands where 77 pilot whales died recently, and before that in the Hebrides where 55 whales died about a year ago.
Of the 13 mass strandings of pilot whales that have occurred in the last 30 years, ten have occurred in the last decade, according to the Scottish Marine Animal Stranding Scheme at Glasgow University.
And according to Andrew Brownlow, who is leading the work on the project, this is because pilot whales are particularly inclined to follow a leader, reports the Guardian.
– There are so many parallels, both regarding the number of animals and regarding their behavior, he tells the newspaper.
May depend on people
With no indication that weather phenomena, solar storms, disease, hunger or the like would have increased at the same rate as the mass strandings, the researchers believe that the animals’ behavior is due to fear, which may have arisen as a stress reaction to loud noises.
A suspicion that can be proven by looking at tiny hair cells in the whales’ auditory bones, which sit deep inside their heads. But to be able to look at these, the hard bones must first lie in a chemical solution for up to a year.
In any case, however, Andrew Brownlow does not believe that sound is the only culprit in the drama, but that new prey and new movement patterns that accompany the warmer water temperatures also play a role.
– A large part of the animals at last year’s beaching were a large number of the animals pregnant or giving birth, which means that they use these waters as a calving area. But if these waters are particularly noisy, it causes big problems for animals that have a strong herd mentality and are easily frightened when they have to move in a new environment that is difficult to navigate, Brownlow told the Guardian.
Strandings affect the sea
Research since the 1980s has shown that noise pollution, ranging from seismic surveys of oil and gas resources to military sonar systems, has a harmful effect on whales and dolphins.
But even if Andrew Brownlow’s group cannot yet establish that the sound environment has anything to do with the strandings in question, it is known that the mass death of whales affects the sea negatively. And he therefore issues a sharp warning.
– We have to be very careful with what we do in these waters, because otherwise this will become a frighteningly common occurrence, he says.