PDF(Pubmed)
Abstract：
Since about the turn of the millennium, octocorals have been increasing in abundance on Caribbean reefs. The mechanisms underlying this trend have not been resolved, but the emergent species assemblage appears to be more resilient than the scleractinians they are replacing. The sea fan Gorgonia ventalina is an iconic species in the contemporary octocoral fauna, and here its population dynamics are described from St. John, US Virgin Islands, from 2013 to 2019. Mean densities of G. ventalina at Yawzi Point (9-m depth) varied from 1.4-1.5 colonies m-2, and their mean heights from 24-30 cm; nearby at Tektite (14-m depth), they varied from 0.6-0.8 colonies m-2 and from 25-33 cm. These reefs were impacted by two Category 5 hurricanes in 2017, but neither the density of G. ventalina, the density of their recruits (< 5-cm tall), nor the height of colonies, differed among years, although growth was depressed after the hurricanes. Nevertheless, at Tektite, colony height trended upwards over time, in part because colonies 10.1-20 cm tall were reduced in abundance after the hurricanes. These trends were sustained without density-associated effects mediating recruitment or self-thinning of adults. The dynamics of G. ventalina over seven years reveals the high resilience of this species that will contribute to the persistence of octocorals as a dominant state on Caribbean reefs.
摘要：
从大约千年之交开始，加勒比珊瑚礁上的octocorals一直在增加。这一趋势背后的机制尚未得到解决，但是新兴的物种组合似乎比它们正在取代的巩膜动物更具弹性。海扇Gorgoniaventalina是当代八珊瑚动物群中的标志性物种，这里的人口动态描述来自圣约翰，美属维尔京群岛,从2013年到2019年。YawziPoint的G.ventalina的平均密度（深度9m）从1.4-1.5个菌落m-2变化，其平均高度从24-30cm变化；在Tektite（深度14m）附近，它们的菌落m-2和25-33厘米不等。这些珊瑚礁在2017年受到两次5级飓风的影响，但既不是G.ventalina的密度，他们新兵的密度(<5厘米高)，也不是殖民地的高度，不同的年份，尽管飓风过后增长受到抑制。然而，在Tektite,菌落高度随着时间的推移呈上升趋势，部分原因是飓风过后，高10.1-20厘米的殖民地数量减少了。这些趋势得以持续，没有密度相关效应介导成年人的招募或自我稀释。G.ventalina的动态超过七年，揭示了该物种的高复原力，这将有助于八角珊瑚作为加勒比海珊瑚礁上的主要国家的持续存在。
