Five populations are considered: algae, corals, molluscs, echinoderms and fish.
Only the macro-algae occurring along the year are taken into account. The seasonal ones (Boodlea, Hydroclathrus and Chnoospora) are not studied because the object of this survey is to analyse the long term variability of populations. The macro-algae are studied to the genus level because of the difficulties encountered to identify them to the species level. They are studied at the points 2 and 3 on the map below.
The studied corals belong to the Madrepores (class Anthozoa) and to the Hydocoals (class Hydrozoa). The corals are identified to the genus level because of the complex systematic of corals. They are studied at the points 1, 2, 3 and 6 of the map below.
The molluscs "testacés" and "épigés" (living at the surface of the substrate or near) and "endogés" (living deeper in the substrate) of a size larger than 5 mm have been counted. The parasites molluscs (family Eulimidae) are not taken into account. The studied molluscs belong to the Gasteropods (Prosobranch and Opistobranch) and to the Bivalves. They are studied at the points 2 and 3 on the map below.
For the echinoderms, only the species living next to the surface of the substrate belonging to the Echinidae and to the Holoturidae have been counted. They are studied at the points 2 and 3 on the map below.
All the fish species have been counted but without the size (age) estimates contrary to the ATPP. Size estimates started in 2008 for this program. The whole fish community in the all the water column from the seabed to the surface is taken into account, matching all the visible fish. All the observed fish are identified to the species level and counted. They are studied at the points 2, 3, 5 and for some species at the point 6 on the map below.