Entomopathogenic fungi can attack suitable scales and completely overgrow them. The corals could then overgrow the hills, forming cays and reefs. The nutrient rich sediment also facilitates algae growth, which can overgrow the corals. The corals could then overgrow the submerged hills, to form the present cays and reefs. They have been observed to overgrow reefs in a carpet formation. Some lengths of the system were drained or allowed to overgrow with vegetation.