What happens when large predators are selectively removed from a 

 reef — the snappers, groupers, barracudas, and sharks? Is a chain 

 of events set in motion that can be likened to certain food chains 

 on land? For ejtample, when hawks and owls are selectively killed 

 in a farm area, a notable increase, in small rodents frequently 

 results, and certain plants, especially grain crops, may be 

 markedly reduced. Where cougars and coyotes are eliminated, deer 

 and rabbits may become so common that vegetation is overgrazed, 

 to the ultimate detriment of the deer, rabbits, and an entire 

 ecosystem (Leopold, 1943, 1947; Clarke, 1954). What happens on a 

 reef where large predators are reduced in numbers? It is certain 

 that change occurs, but documentation of what happens remains to 

 be done. 



VI-172 



