Re: What do you call a person who studies dolphins and whales?

A person who studies dolphins and whales is called a Cetologist.  The 
scientific classification for the group that includes dolphins and whales 
is called the Cetacea, or Cetaceans (porpoises are also included in this 
group).  People who study the classifications and variety of species within 
this group may also consider themselves marine mammologists (the study of 
marine mammals, which would also include manatees and dugongs).

Sorry for the late reply!