Coral survey by "manta tow"

The "manta tow" technique consists in towing an observer behind a boat at slow speed. The observer clutches to a large wooden slate linked tot the boat by a rope. The observer writes the coral cover down on a sheet of paper on the slate along the (every 2 minutes).

Plaquette Manta Two

The coral cover is estimated through 5 surface categories occupied by live corals: 0 - 10 - 30 - 50 -75 - 100 %. The records are taken for 4 sections of 500 m, 2 on each side of the Photo-quadrat coral transect.

Comparing those two methods (photo-quadrat and manta tow) showed that the quadrats are a very good estimates of the kilometer of reef surrounding them. Until 2002, the "manta tow" technique were used on a regular basis. Since then, it is only used in case of major environmental change like biological proliferation (such as the crown of thorn starfish or Acanthaster planci).

Interactive map


1)  2024-09-02 15:22
Nuku Hiva
2)  2024-09-04
3)  2024-09-09 15:26
Série Galzin
4)  2024-09-30 15:23
5)  2024-11-05 15:23