Whales living in coastal areas, like right whales and humpbacks, communicate using sound. But unlike deep water whales, these coastal whales have quieter vocalizations that travel tens rather than hundreds or thousands of miles.

Chris Clark has placed hydrophones in Cape Cod Bay to locate vocalizing whales and track their movements.

As a result of these studies, ships have begun to slow down as they approach areas with whales, greatly reducing the amount of noise they make.