Dynamics of coral reef benthic assemblages of the Abrolhos Bank, eastern Brazil: inferences on natural and anthropogenic drivers

PLoS One. 2013;8(1):e54260. doi: 10.1371/journal.pone.0054260. Epub 2013 Jan 24.

Abstract

The Abrolhos Bank (eastern Brazil) encompasses the largest and richest coral reefs of the South Atlantic. Coral reef benthic assemblages of the region were monitored from 2003 to 2008. Two habitats (pinnacles' tops and walls) were sampled per site with 3-10 sites sampled within different reef areas. Different methodologies were applied in two distinct sampling periods: 2003-2005 and 2006-2008. Spatial coverage and taxonomic resolution were lower in the former than in the latter period. Benthic assemblages differed markedly in the smallest spatial scale, with greater differences recorded between habitats. Management regimes and biomass of fish functional groups (roving and territorial herbivores) had minor influences on benthic assemblages. These results suggest that local environmental factors such as light, depth and substrate inclination exert a stronger influence on the structure of benthic assemblages than protection from fishing. Reef walls of unprotected coastal reefs showed highest coral cover values, with a major contribution of Montastraea cavernosa (a sediment resistant species that may benefit from low light levels). An overall negative relationship between fleshy macroalgae and slow-growing reef-building organisms (i.e. scleractinians and crustose calcareous algae) was recorded, suggesting competition between these organisms. The opposite trend (i.e. positive relationships) was recorded for turf algae and the two reef-building organisms, suggesting beneficial interactions and/or co-occurrence mediated by unexplored factors. Turf algae cover increased across the region between 2006 and 2008, while scleractinian cover showed no change. The need of a continued and standardized monitoring program, aimed at understanding drivers of change in community patterns, as well as to subsidize sound adaptive conservation and management measures, is highlighted.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anthozoa / physiology*
  • Anthozoa / radiation effects
  • Biodiversity
  • Biomass
  • Brazil
  • Conservation of Natural Resources
  • Coral Reefs*
  • Fishes / physiology
  • Food Chain
  • Herbivory / physiology
  • Light
  • Seaweed / physiology
  • Seaweed / radiation effects

Grants and funding

Financial support was provided by the Conselho Nacional de Desenvolvimento Científico e Tecnológico/Pro-Abrolhos Project (#420219/2005-6) and Conservation International (CI). This is a contribution of the CI's Marine Management Areas Science Program, Brazil Node, and Rede Abrolhos/SISBIOTA (MCT/CNPq/CAPES/FAPES). RLM, FLT and GMAF acknowledge individual grants from CNPq and FAPERJ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.