How Does Noise Pollution Affect Whales?

It has long been suspected that the noise pollution caused by human activity – from motor boats, shipping vessels and the suchlike – have an adverse effect on life below the waves. Whales, in particular, may be susceptible to this, due to the fact that they rely on sonar to communicate and, in some circumstances, navigate.

However, unlike the studies conducted on how noise pollution affects land and air animals, until now there has been little in the way of scientific evidence to corroborate those claims about whales. Aiming to change all that is Leigh Torres, a researcher from Oregon State University in the States, who wants to provide conclusive proof that noise pollution is damaging to whales through an extended period of study.

Drones and dung

Torres’ main methods of research are twofold: firstly, she uses the scope and high-definition imaging afforded by drones to gain a better overview of whale health and size than ever before, and secondly, she analyses their faecal matter for vital indicators which tell her about their genetics, diet and, most importantly, stress levels.

After locating a whale (not a difficult task off the Oregon coast, where grey whales are in abundance), Torres tries to identify any unique markings in order to individually document whale activity. She then flies a drone overhead to take aerial photos of the creature, in an attempt to see how fat it has grown. As a general rule of thumb, the fatter an animal, the less stressed it is.

Finally, she waits for the subject to digest its meal and defecate into the waters. Scooping up a sample of this faecal matter, she is able to examine genetic information contained within it to determine the whale’s gender and other data, as well as analysing hormones to get an idea of its stress levels.

Following on from 9/11

Torres hopes that her work will build on the ground-breaking study conducted in the immediate aftermath of the September 11^th terrorist attack in 2001. With the US government concerned about people and substances entering and leaving the country, all commercial transit routes were blocked for several days.

One of these was the shipping route leading to Saint John in New Brunswick, which just happened to be a popular breeding ground for baleen whales in the area. Scientists collecting faecal matter in this time period noted that the hormones of the whales showed unprecedentedly low levels of stress, presumably as a result of the absence of shipping vessels in the vicinity.

While Torres does not fear for the longevity of the healthy whales in the Oregon region, she hopes that her work can serve as a precursor to better understanding how noise pollution affects this gentle giant of the sea in other parts of the world, as well. In regions where pollution as a result of tropical rain storms is rampant, whales are on the brink of extinction, for example. The last thing they need is a manmade racket creating even more stressful problems for the future of their species.