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

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 highe...阿布洛霍斯滩（Abrolhos Bank）坐落于巴西东部，是南大西洋规模最大、物种多样性最高的珊瑚礁群。2003至2008年间，研究人员对该区域的珊瑚礁底栖群落（benthic assemblages）开展了长期监测。每个采样点均针对两种生境开展采样：海峰顶部与礁壁，并在不同礁区布设3至10个采样点。两个独立采样时段（2003-2005年与2006-2008年）采用了不同的采样方法。相较于后一采样时段，前一阶段的空间覆盖范围与分类学分辨率均更低。底栖群落在最小空间尺度上呈现出显著差异，其中不同生境间的群落差异最为突出。管理政策与鱼类功能群（漫游型与领地型植食性鱼类）的生物量，对底栖群落的影响相对微弱。研究结果表明，相较于捕捞保护措施，光照、水深与基底倾角等局域环境因子对底栖群落结构的塑造作用更强。未受保护的近岸礁壁呈现出更高的……