Incidência, prevalência e progressão de doenças em corais de recifes rasos no nordeste do Brasil

Abstract

Coral diseases are known from the 1970s onwards, with the classification of Black Band disease. After the first descriptions, about twenty other diseases were cataloged and described for the most diverse oceans around the world over the next 45 years. However, little is known about the transmission mechanisms and development of these diseases, at what level they reach corals, genetically and cytologically. Thus, this study hoped to answer questions about this development, considering the prevalence and incidence of diseases found in northeastern Brazil, in individuals of the Siderastrea stellata stony coral and how they are affected internally and externally. Through monitoring studies, the dominance of two diseases previously registered for the South Atlantic was observed, White Plague disease and the Red Band disease. Both demonstrated a high mortality rate with rates exceeding 40% of individuals killed in the two areas studied. In addition, the diseases were rapidly progressing diseases, evolving an average of 4.5 cm^2 /month of tissue necrosis. When analyzed at the histological level, the tissues also showed signs of spawning out of season and necrosis in several stages as well as colonies of bacteria and fungi. The presence of epibionts among tissues was also observed, as was the case with cyanobacteria and diatoms. With this work, it is concluded that the monitoring of these diseases must be effective, and protective measures increasingly implemented. Corals that show disease symptoms are only a percentage of everything that is sick. Remediation and mitigation routes should be designed to avoid premature loss of coral reef areas, especially those with a high rate of endemism.