Human noise in the ocean is becoming a major concern. From sonar on our submarines, to cargo ship traffic, and even oil drilling rigs we are filling our oceans up with lots of unnatural noise. This human made noise is linked to altering the calling, foraging, and migration patterns for many marine species. Scientists also believe it is a reason there have been so many beached whales.
Here is a video that shows how different noises in the oceans sound, and how loud they really are.
EFFECTS OF SOUND ON WHALES
It seems as if whales and dolphins are the marine animals which are most affected by noisy oceans. Natural noise in the ocean from wind, waves, or other marine animals is a common occurrence, but they are not nearly as intense as noise from humans. The more intense and frequent noise causes stress to whales and contributes to them beaching themselves. Chris Clark, director of Cornell University’s Bioacoustics Research program, claims he has seen whales abandon a location because of noise, and that these locations sometimes contain a food source necessary for the whale’s survival.
Sound waves from military submarine sonar systems can get as loud as 235 decibels; they are able to travel hundreds of miles and can maintain an intensity of 140 decibels as far as 300 miles from the source.
Another example of human generated noise pollution are cargo ships. Cargo ships create ambient noise, also known as background noise. This is particularly concerning for low-frequency great whales. Right whales, which are an endangered species, have been proven to show noise from cargo ships constantly crossing the ocean is causing them stress.
Here is a video on the process of deep water oil rigging. Looking at this, it would be hard to believe that these rigs don’t make a ton of noise. It is understandable that hearing noise from these rigs constantly could cause stress to a whale or confuse it when considering they heavily rely on acoustics for survival.
RECENT BEACHED WHALE STORIES
On February 10th, 2017, New Zealand had over 600 Pilot whales wash ashore. Volunteers were able to save about 80 of the whales, who went on to join a nearby pod. Later that night the pod they joined got stranded on Farewell Spit. Although the cause of these whales stranding and beaching themselves is unknown, one inference is underwater noise. The loud sound waves that humans create can panic whales into surfacing too quickly or swimming into the shallows.
In May 2016, more than 20 whales beached themselves near San Felipe, Mexico. According to CBS NEWS, there were no signs of injuries noted on the whales, however, they seemed disoriented. Since the whales had no signs of injury, a possible cause is that noise pollution drove them out of deep water towards the beach.
Less than a year after 330 whales washed ashore on the Patagonian Inlet, and 70 whales were found on a beach in southern Chile. Although they are not the same species, this is a terrible trend that’s happening. These whales were smaller and had been dead for about 2 months before they were found.
Information in this chapter is thanks to contributions from Alana Olendorf
