Dinâmica espaço-temporal da abundância do coral endêmico do Brasil mussismilia harttii Verrill (1868) no banco dos abrolhos BA.

Abstract

Coral reefs are among the most productive ecosystems in the world providing important ecosystem services for diverse human populations, and are home to several species forming a rich diversity. Studies show that reefs are experiencing declining coverage in different regions of the world. In Brazil these reefs are distributed from Amazonas to Espírito Santo with colonies that can reach the coast of São Paulo, they are priority areas for biodiversity conservation due to their small extent, their high levels of endemism and high rates of habitat loss. the objectives of this work are to quantify the dynamic time space of the relative coverage of the coral Mussismilia harttii in the main sites, reefs and habitats during the years 2006 to 2008 and 2013 to 2014, and also to verify the main influences that are causing the decline in the relative coverage of the coral Mussismilia harttii during the observed years. The data were worked with a 5-year timeline, and collections were made in the Abrolhos bank by researchers at 26 sites divided into 6 reefs with 3 types of habitats. One and two-factor analysis of variance (ANOVA) was carried out in order to find significant differences between the relative cover of the studied coral between reefs, habitats and years. A Boosted Regression Trees (BRT) model was also used to assess the relative influence of environmental and biotic variables on the relative cover of the coral. The highest coverage value found was on the reimbursement of Timbebas (1,8 ± 0,4 coverings), followed by a portion of the walls (1,1 ± 0,5 cover), in habitats the largest cover found was on the Top (1,5 ± 0,4 coverage), between the years there was no significant difference. The modeling explained 92.8% of the variations in the relative coverage of M. hartti, the highest value was in Depth (29.1%), followed by Palythoa (19.4%). The present work showed that the coral M. harttii had more coverage in shallow reefs, and the variables that most diminished its coverage were the depth and contact with the zoantid Palythoa caribaeorum.