Shoal of Black Triggerfish, Melichthys niger, Christmas Island, Australia

View of massive die-off of black triggerfish on the beach on Ascension Island in the southern tropical Atlantic Ocean, South Atlantic Ocean

View of massive die-off of black triggerfish on the beach on Ascension Island in the southern tropical Atlantic Ocean, South Atlantic Ocean

Green algae (Caulerpa racemosa) and black durgon (Melichthys niger), schooling, St. Peter and St. Paul's rocks, Brazil, South America

Large school of black triggerfish (Melichthys niger), Hanauma Bay, Oahu, Hawaii, United States of America, Pacific

Black durgon (Melichthys niger), St. Peter and St. Paul's rocks, Brazil, South America

Black durgon (Melichthys niger), St. Peter and St. Paul's rocks, Brazil, South America

Green algae (Caulerpa racemosa) and black durgon (Melichthys niger), schooling, St. Peter and St. Paul's rocks, Brazil, South America

Black durgon (Melichthys niger) schooling, St. Peter and St. Paul's rocks, Brazil, South America

Schooling black durgon (Melichthys niger), and seafloor covered by Caulerpa sp., Peter and St. Paul's rocks, Brazil, South America

Green algae, Caulerpa racemosa and black durgon, Melichthys niger, schooling, St. Peter and St. Paul's rocks, Brazil, Atlantic Ocean

A young woman free diving with black triggerfish (Melichthys niger), Molokini Marine Preserve off the island of Maui, Maui, Hawaii, United States of America

Two young women free diving with black triggerfish (Melichthys niger), Molokini Marine Preserve off the island of Maui, Maui, Hawaii, United States of America

Slate pencil sea urchins (Heterocentrotus mammillatus) colour the foreground of this Hawaiian reef scene with a young woman free diving with black triggerfish (Melichthys niger), Molokini Marine Preserve off the island of Maui, Maui, Hawaii, United States of America