It has been found, contrary to prevailing thought, that herbivorous fishes, particularly two species--Diplodus holbrooki and Lagodon rhomboides--are among the most common fishes of coastal and continental shelf habitats throughout the southeastern United States, and their feeding habits can dramatically affect the structure of hard-substrate benthic communities. These fish are also major prey species for commercially important species such as snapper and grouper, and may be a significant pathway of energy transfer from shallow nearshore waters to deeper offshore reefs. Experimental field studies will be conducted to assess 1) the interactions between different herbivorous fishes, the interactions between fishes and other herbivores, and the effects of these interactions on benthic community structure; and 2) the mechanisms that cause dramatic increases in the abundance of unpalatable brown seaweeds in the presence of herbivorous fishes. These data will then be compared with studies already completed on herbivorous fish in tropical communities.
