八年前(2007年)在委内瑞拉的LosRoques群岛中,对Acroporapalmata的分布和状况进行了量化。目的是为该物种进行基线研究,将种群遗传学与人口统计数据相结合。结果表明,在10个调查地点中,至少有6个有可能恢复。在珊瑚相对丰富的地点,恢复潜力被认为很高,低患病率,遗传多样性高,和高的有性生殖率。然而,如上所述,Zubillaga等人。(2008)意识到的复苏仍然强烈依赖于当地和区域的压力源。2014年(本研究),在LosRoques重新评估了A.palmata的状态。我们将站点数量从原始基线研究中的10个增加到106个。这使我们能够评估整个MPA的人口状况。此外,我们还确定了可能阻碍人口恢复的当地威胁。这里,我们表明,A.palmata现在在整个公园的分布相对有限,仅发生在15%的调查网站中。在整个群岛中,大量的死亡殖民地很常见;结果表明,在过去的几十年中,该物种已经失去了其原始分布的近50%。记录的大多数珊瑚是大型成虫(~2米高),这表明这些较老的殖民地可能对本地和全球威胁不太敏感或更具弹性。然而,这些存活的菌落中有45%显示出部分死亡和活组织降解的证据。有趣的是,部分死亡率的最大增加发生在保护水平最低的部位([公式:见正文];df=4,p<0.05).这可能表明小规模海洋管理在协助珊瑚礁恢复方面具有积极作用。我们还记录了在先前被分类为具有高恢复潜力的位点中棕榈曲霉密度的显著降低([公式:参见文本];df=8;p<0.05)。这种持续下降的一种解释可能是由于在过去的10年里,在整个加勒比海地区发生了两次大规模的漂白事件,记录显示LosRoques的整体珊瑚覆盖率经历了前所未有的下降。因此,我们得出结论,尽管当地保护可以促进恢复,海洋变暖等全球威胁的影响可能会阻碍这种受威胁物种的恢复。
Eight years ago (2007), the distribution and
status of Acropora palmata was quantified throughout Los Roques archipelago in Venezuela. The aim was to produce a baseline study for this species which combined population genetics with demographic data. The results highlighted that A. palmata had the potential to recover in at least 6 out of 10 sites surveyed. Recovery potential was assumed to be high at sites with a relatively high abundance of the coral, low disease prevalence, high genetic diversity, and high rates of sexual reproduction. However, as noted, Zubillaga et al. (2008) realized recovery was still strongly dependent on local and regional stressors. In 2014 (this study), the
status of A. palmata was re-evaluated at Los Roques. We increased the number of sites from 10 in the original baseline study to 106. This allowed us to assess the population
status throughout the entirety of the MPA. Furthermore, we also identified local threats that may have hindered population recovery. Here, we show that A. palmata now has a relatively restricted distribution throughout the park, only occurring in 15% of the sites surveyed. Large stands of old dead colonies were common throughout the archipelago; a result which demonstrates that this species has lost almost 50% of its original distribution over the past decades. The majority of corals recorded were large adults (∼2 m height), suggesting that these older colonies might be less susceptible or more resilient to local and global threats. However, 45% of these surviving colonies showed evidence of partial mortality and degradation of living tissues. Interestingly, the greatest increase in partial mortality occurred at sites with the lowest levels of protection ([Formula: see text]; df = 4, p < 0.05). This may suggest there is a positive role of small scale marine management in assisting reef recovery. We also recorded a significant reduction ([Formula: see text]; df = 8; p < 0.05) in the density of A. palmata in sites that had previously been categorized as having a high potential for recovery. One explanation for this continued decline may be due to the fact that over the past 10 years, two massive bleaching events have occurred throughout the Caribbean with records showing that Los Roques has experienced unprecedented declines in overall coral cover. We therefore conclude that although local protection could promote recovery, the impacts from global threats such as ocean warming may hamper the recovery of this threatened species.