Evidence of extensive reef development and high coral cover in nearshore environments: implications for understanding coral adaptation in turbid settings.
Evidence of extensive reef development and high coral cover in nearshore environments: implications for understanding coral adaptation in turbid settings.
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DOI：
10.1038/srep29616
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发表时间：
2016-07-19
影响因子：
4.6
通讯作者：
Daniell JJ
中科院分区：
文献类型：
--
作者：
Morgan KM;Perry CT;Smithers SG;Johnson JA;Daniell JJ
据报道，在过去的30年里，大堡礁（GBR）中部的平均珊瑚覆盖率下降了15%以上。在这里，我们提出了新的数据，记录了在研究较少的浑浊近岸地区（<10米深度）广泛的珊瑚礁发展，并表明这些珊瑚礁的珊瑚覆盖率平均为38%（是中陆架和外陆架珊瑚礁的两倍）。在调查的海底区域中，11%有明显的珊瑚礁或珊瑚群落覆盖。虽然调查区域代表了近岸区（15.5平方公里）的一小部分，但该珊瑚礁密度与在更宽的GBR大陆架上测量的密度（9%）相当。我们还表明，跨大陆架珊瑚覆盖下降与距离海岸（R2 = 0.596）。已确定的珊瑚分类群（21属）表现出明确的深度分层，密切对应的光衰减和海底地形，与珊瑚礁的发展局限于海底的前身床形。从这一有意义的空间尺度上测量的近岸珊瑚礁发生和生态的第一次评估的数据表明，这些珊瑚群落可能表现出意想不到的能力，以容忍记录的水质下降。事实上，这些浅水近岸珊瑚礁可能与深水（>30米）中光珊瑚礁有许多共同的特点，并可能具有类似的潜力，作为大规模扰动的避难所。
Mean coral cover has reportedly declined by over 15% during the last 30 years across the central Great Barrier Reef (GBR). Here, we present new data that documents widespread reef development within the more poorly studied turbid nearshore areas (<10 m depth), and show that coral cover on these reefs averages 38% (twice that reported on mid- and outer-shelf reefs). Of the surveyed seafloor area, 11% had distinct reef or coral community cover. Although the survey area represents a small subset of the nearshore zone (15.5 km2), this reef density is comparable to that measured across the wider GBR shelf (9%). We also show that cross-shelf coral cover declines with distance from the coast (R2 = 0.596). Identified coral taxa (21 genera) exhibited clear depth-stratification, corresponding closely to light attenuation and seafloor topography, with reefal development restricted to submarine antecedent bedforms. Data from this first assessment of nearshore reef occurrence and ecology measured across meaningful spatial scales suggests that these coral communities may exhibit an unexpected capacity to tolerate documented declines in water quality. Indeed, these shallow-water nearshore reefs may share many characteristics with their deep-water (>30 m) mesophotic equivalents and may have similar potential as refugia from large-scale disturbances.