The number of urchins required was dependent on the amount of food available. Urchins also could not reach the disease in crevices between corals. The cyanobacteria involved in BBD require light for photosynthesis, and thus are restricted to shallow depths except on reefs with high water clarity. Because infections are often concentrated, it was believed that a reduction of the available light would be a viable method to eradicate a large number of infections simultaneously. At 40 percent light transmittance approximately half the corals were successfully treated, primarily those located in slightly deeper water.
Treatment is a temporary solution at best to a growing problem, however.
Scientists are working to determine what causes BBD to first appear on a reef, and develop management solutions to eliminate the source of the threats impacting coral reefs today.