This limit to their distribution may be because of the large open expanse of ocean between this area and the Hawaiian Islands. Barracuda have a large gape and can feed on large fish by chopping them in half with their jaws. Their prey includes mullet, snapper, herring, sardines, grunts, jacks, mackerel and cephalopods. Species Diversity Tropical marine environments in general support greater diversity than temperate waters because marine life in general is favored by warm temperatures rather than cold. This relates to the physiology of animals and plants.
Coral reefs support more species per unit area than any other marine ecosystem.
Greater primary production translates to a greater food supply to support organisms. The organisms that live on and around reefs are specially adapted to efficiently and rapidly exploit nutrients and food as they become available. They occupy ecological niches which avoid competition for limited resources. Among these 3 sanctuaries, the Florida Keys has the greatest species diversity, with 378 total species. There is a wide variety of habitat types there to support a greater diversity of organisms.