Padrão de branqueamento de Siderastrea stellata (Verril, 1868) em dois complexos recifais areníticos do Atlântico Sul

• Autor(a) principal: Correia, Louize Freyre da Costa
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/43292
• topic: Siderastrea stellata; Siderastrea stellata; Ecossistemas recifais; Reef ecosystems,; Branqueamento de corais; Coral bleaching; Interação entre os Organismos Marinhos e os Parâmetros Ambientais, Variáveis Físicas da Água do Mar, Ecologia.

The reef ecosystems are among the most diverse on the planet, shelter about 25% of marine biodiversity and act in global chemical balance of carbon. Corals, important components of the reef are considered bio-indicators of climate variations. Such invertebrates may lose pigmentation which is one of the responses to a changing environment, resulting in the known bleaching phenomenon. In Pirangi and Maracajaú reefs was conducted monitoring of coral bleaching stony more abundant, Siderastrea stellata (Verril, 1868), associated with abiotic data such as temperature, transparency and salinity of the water. The data collection in both reefs were performed every 2 months during the year 2015. Were selected 18 colonies of stony corals species Siderastrea stellata, divided into three size classes (measured diameter), totaling six colonies per class size in Maracajaú and Pirangi: small colonies (<5 cm), medium (5-10 cm) and large (> 10 cm). Bleaching measured between the two reefs was distinct and Maracajaú had the highest values. It was also analyzed the bleaching of size classes and the smaller colonies had higher levels of bleaching, also more pronounced in Maracajaú. In both areas there was a decrease bleaching throughout the year and the mean bleach similarly varied throughout the year with Pirangi always exhibited lower rates. The 9 bleaching was associated with changes in transparency and salinity of the water, regardless of the reef analyzed. The highest rates of bleaching found in smaller colonies may indicate greater fragility of those justified by the smaller diameter, and consequently fewer zooxanthellae, providing less resistance to the colonies. Overall, in September there was a decrease of bleaching levels and at this time there is an increase in winds that cause greater sediment suspension, increasing the turbidity of the water. This situation differs from that found in literature, in which corals whiten more forward to sedimentation. The less transparency and salinity of the water found in Pirangi related to minor coral bleaching, compared to Maracajaú suggests that the colonies may be more suited to such constant adverse conditions and therefore has less bleaching. Another aspect to be considered on Maracajaú is that the stronger bleaching may be the result of increased penetration of ultraviolet rays due to the transparency of water, which also causes whitening. It is considered that the Brazilian corals are more resistant to environmental disturbances and stress and therefore the ideal conditions established in the literature for the proper development of corals, does not apply perfectly those of the coast of Brazil.