Identification and Population Counts

The populations of fish, scleractinian corals and indicator species of invertebrates are counted during the course of a PCRF reef study.

FISH
Reef fish are counted during 4 x 45 minute dives, usually by two divers. Fish are identified to species level and numbers sighted during each dive are documented.

CORALS
Scleractinian corals are identified to genus level (since in many cases it is impossible to identify to species level without taking samples from the reef for microscopic analysis). Coral diversity is noted within the video transect areas. These areas are chosen to be representative of the diversity of the reef in general.

INVERTEBRATES
Three species of invertebrate are studied, their populations being counted during the course of a 45 minute dive by 2 divers over a given area of the reef. These are the long-spined sea urchin, Diadema, the crown-of-thorns seastar, Acanthaster planci and the giant clam.