Are these the last of the Baltic Sea harbor porpoises? We humans kill porpoises by the way we exploit the marine environment. Very few of us are aware that these creatures even exist. Even fewer of us realize that these mammals are our Baltic Sea neighbours. Scientists study their biology and behaviour. They diagnose diseases and injuries. They are learning how to provide physiotherapy. Educating people who earn their living from the sea, especially fishermen and sailors, plays a big role in saving the harbor porpoise. The survival of these endangered animals depends solely on our common will to save them.