Noise Pollution and Whale Behavior
In the oceans, where distances can be long and visibility can be short, many animal species rely on sound to communicate, navigate, and monitor their surroundings. The haunting cries and clicks of whales are both beautiful and vital to their survival. Using “songs” cetaceans can communicate with one another across several hundred kilometers of ocean. Whale sonar allows the animals to find food, safely travel along irregular coastlines, and migrate to and from breeding and feeding grounds. Some whales uses bursts of loud noise to drive and confuse their prey.
These activities are becoming more and more difficult as manmade noise in the sea has increased dramatically. Ship traffic, oil and gas exploration, scientific research activities, and the use of military sonar and communications equipment have caused an increase in ambient marine noise of two orders of magnitude in the last 60 years.
Recent studies suggest that noise pollution can harm whales directly by damaging their hearing, and in extreme cases, causing internal bleeding and death. More commonly, it appears that excessive or prolonged noise can cause behavioral changes that interfere with the health and survival of the animals.
When whales strand, or beach themselves, they often die. Death may be due to the factors that drove them ashore initially, or to exposure and dehydration and organ damage caused by the unsupported weight of their own bodies.