The ocean surface is often calm and peaceful, but the waters below can be full of noise. It is NOT a quiet place.
Off the coast of Massachusetts in the waters of the Stellwagen Bank National Marine Sanctuary, researchers are conducting a noise inventory. This will help them understand the effects of both natural and human-produced noises on marine animals, including the endangered North Atlantic right whale.
Marine mammals, such as whales and dolphins, rely on their ears more than their eyes to survive. Sound travels very quickly and over great distances under water. So marine mammals produce sounds to communicate with each other and to obtain information about their surroundings. In the ocean, natural sounds come from rainfall, breaking waves, wind, and movements of the seafloor like landslides or earthquakes. Human-produced sounds come from a number of sources, such as commercial fishing boats and tankers.
Each day hundreds of boats and tankers pass through the Sanctuary headed for Boston or other nearby ports generating a lot of underwater noise. To determine the impact of all these noises, researchers are using several methods to monitor marine animal behavior. Recording units called pop-ups have been deployed in the waters of the Sanctuary. They record sounds 24 hours a day. Pop-ups can detect, locate, and track sounds made by whales and fish.
Together with aerial surveys and ship tracking information from the U.S. Coast Guard, researchers can determine where the animals are and how they may be responding to different noises. Some whales are temporarily tagged, so researchers can follow their movements and record the sounds they make as they perform different behaviors. What impact does all this noise have on the behavior of endangered whales?
Will it affect their ability to survive and reproduce? Researchers are studying the data to find out. In the meantime, maybe humans can help lower the volume.