Climate change is transforming coral reef structures, with important yet largely unknown consequences for reef food webs. Crustaceans, molluscs, polychaetes, and other small motile invertebrates living as epifauna on coral habitats represent an essential trophic link between primary producers and a diverse and abundant invertivorous fish fauna. Here, we investigate variation in assemblages of motile epifaunal invertebrates on live coral and dead coral heavily overgrown by turf algae. Sampling was conducted 2–3 years following mass bleaching within the study region at four locations broadly spanning the distribution of corals on the eastern seaboard of Australia—along the northern and central Great Barrier Reef, and, adjacent to the central east coast, the Solitary Islands and offshore Elizabeth and Middleton Reefs (> 2000 km total distance). Epifaunal assemblages differed significantly between live and dead ‘turf-covered’ coral habitats, with overall density, biomass, and productivity of epifauna more than an order of magnitude greater on dead than on live coral. The size structure and composition of assemblages also differed: turf-covered dead coral supported greater abundances of small animals than live coral, notably harpacticoid copepods, while live coral assemblages had proportionally greater abundances of larger decapods. A ten-fold increase in secondary productivity of motile invertebrates is predicted as live corals are replaced by turf-covered dead coral, however, this productivity will predominantly be available as small harpacticoid copepod prey (size range: 0.125–0.25 mm). Associated flow-on effects through reef food webs are likely, as changes to epifauna will directly affect invertivore communities, which in turn potentially influence larger carnivores and other functional groups.

气候变化正在改变珊瑚礁结构，对珊瑚礁食物网产生重要但很大程度上未知的影响。甲壳类动物、软体动物、多毛类动物和其他小型活动无脊椎动物作为珊瑚栖息地的表皮动物群，代表初级生产者与多样化和丰富的反食鱼类群之间的重要营养联系。在这里，我们研究了活珊瑚和被草皮藻类严重过度生长的死珊瑚上的活动表层无脊椎动物组合的变化。采样是在研究区域内大规模漂白后 2-3 年进行的，四个地点的珊瑚分布广泛分布在澳大利亚东海岸——大堡礁北部和中部，以及与中东部海岸相邻的孤岛岛屿和近海伊丽莎白礁和米德尔顿礁（总距离 > 2000 公里）。活珊瑚和死珊瑚栖息地之间的附生动物组合存在显着差异，附生动物的总密度、生物量和生产力在死珊瑚上比活珊瑚高一个数量级以上。组合的大小结构和组成也不同：草皮覆盖的死珊瑚比活珊瑚支持更多的小动物，尤其是角足类桡足类，而活珊瑚组合则按比例增加更大的十足目动物。随着活珊瑚被草皮覆盖的死珊瑚所取代，预计活动无脊椎动物的二次生产力将增加十倍，然而，这种生产力将主要作为小型桡足类猎物（尺寸范围：0.125-0.25 毫米）获得。可能通过珊瑚礁食物网产生相关的流动效应，