I'd like to reference an argument presented here before when this same issue came up.<p>Japanese harvest ships slaughter thousands of dolphins each year, in a certain bay. Some escape. Next year, more olphins return to the bay and are caught, seemingly by surprise?<p>SO either, the escaped dolphins did not communicate the danger, were unable to communicate, or just didn't care what happened to other dolphins.<p>In any of those cases, do we have the duty to protect the lives of dolphins? Either they are not intelligent, not communicative, or have no racial ethic that values dolphin life. Why would we?