This Fish Transect Coral Reef Research underwater video of fish surveys shows how to count fish underwater and was taken during the Farasan Islands Expedition to the Red Sea.
About a Fish Transect
At each research location on the reefs in the Farasan Islands a team of six divers leaves the Golden Shadow in a small boat to conduct habitat and fish surveys at up to three sites per day. The four habitat survey divers enter the water first to deploy two 50m long transect tapes on the bottom along a specific depth contour. About 30 minutes later, after the photo transects of the habitat have been completed, the two fish survey divers descend to the bottom and conduct a census of the fish along one of the 50m transect lines. Each divers counts the number and size of each species of fish they see in a 2m wide strip along their side of the transect line, that extends from the bottom to the surface.