Abstract

The health status of coral communities on the island of Guadeloupe (Lesser Antilles) was estimated using a visual method developed by one of the authors, consisting of dividing coral communities into four classes according to the pressure they are under from macroalgae and siltation: 1) the reef habitat is almost devoid of macroalgae and signs of high siltation. The algal stand is represented by algal turf; 2) a population of macroalgae is installed on the bottom and (or) siltation appears on the bottom. Corals are unaffected by either of these phenomena; 3) macroalgae tend to invade coral colonies and (or) mud to cover them. Corals show many signs of necrosis due to one or the other of these phenomena; 4) macroalgae or fine sediments mainly cover coral populations. A few coral colonies remain. The study focused on 119 sites spread around the island of Guadeloupe between the surface and about 20 m deep. Sites were studied during 2023 and the first months of 2024 by divers trained to use this technique. The results show that 11% of the surveyed coral communities were in excellent condition (class 1); 51% were in good condition, but supported a large macroalgae population (class 2); 30% of the sites had coral communities colonized by macroalgae or more or less covered by mud. Finally, 2% of the sites support coral communities that have been destroyed.