Distribution, abundance, and microhabitat characterization of small juvenile corals at Palmyra Atoll
Distribution, abundance, and microhabitat characterization of small juvenile corals at Palmyra Atoll
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巴尔米拉环礁幼年珊瑚的分布、丰度和微生境特征
DOI：
10.3354/meps07787
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发表时间：
2009
影响因子：
2.5
通讯作者：
N. Knowlton
中科院分区：
文献类型：
--
作者：
Melissa S. Roth;N. Knowlton
幼年珊瑚是珊瑚种群动态的一个重要组成部分，但对其早期生命史阶段的生态和自然历史知之甚少。在人口统计调查中，小的幼年珊瑚往往与较大和较老的珊瑚分组，或由于其体积小和神秘的性质而被完全忽视。本研究描述了中太平洋帕尔米拉环礁小型幼年珊瑚（定义为直径≤5 mm的定居后珊瑚）的分布、丰度和微生境。一个潜水员操作的脉动蓝光和过滤系统被用来增强天然珊瑚荧光在白天，以帮助检测小的幼年珊瑚。幼鱼密度范围为0 ~ 59.5m-2，前礁幼鱼密度（21.9 ± 0.8m-2）是后礁幼鱼密度（2.4 ± 0.3m-2）的9倍多。最高的少年密度观察到在中间的采样范围在14米深的前礁。幼年珊瑚占所有生境和深度的珊瑚群落的31%以上，这导致了正偏态的大小频率分布。珊瑚碎石上幼年珊瑚的微生境最好描述为覆盖着甲壳珊瑚藻的凸面，半径20毫米内没有另一个珊瑚。本研究提供了小型幼年珊瑚的基本生态和自然历史信息，并显示了测量直径≤5 mm的珊瑚作为监测珊瑚种群和评估珊瑚礁环境变化的方法的可行性。
Juvenile corals are an important component of the population dynamics of corals, but little is known about the ecology and natural history of their early life-history stages. In demographic surveys, small juvenile corals are often grouped with larger and older corals or overlooked entirely due to their small size and cryptic nature. This study describes the distribution, abundance, and microhabitat of small juvenile corals, defined as post-settlement corals ≤5 mm in diameter, at Palmyra Atoll, Central Pacific. A diver-operated pulsating blue light and filter system was used to enhance innate coral fluorescence during daylight to aid in detecting small juvenile corals. Juvenile densities ranged from 0 to 59.5 m -2 and were more than 9 times higher on the fore reef (21.9 ± 0.8 m -2 ) than on the back reef (2.4 ± 0.3 m -2 ). The highest juvenile densities were observed in the middle of the sampled range at 14 m depth on the fore reef. Juvenile corals accounted for >31% of coral colonies in all habitats and depths, which resulted in positively skewed size-frequency distributions. The microhabitat of juvenile corals on coral rubble was best described as a convex surface covered with crustose coralline algae that lacked another coral within a 20 mm radius. This study provides basic ecology and natural history information of small juvenile corals and shows the feasibility of surveying corals ≤5 mm in diameter as a method for monitoring coral populations and assessing environmental changes on a coral reef.