Terrigenous sediment impact on coral recruitment and growth affects the use of coral habitat by recruit parrotfishes (F. Scaridae)
Terrigenous sediment impact on coral recruitment and growth affects the use of coral habitat by recruit parrotfishes (F. Scaridae)
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DOI：
10.1007/s11852-013-0247-2
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发表时间：
2013-09-01
影响因子：
2.1
通讯作者：
Conklin, E.
中科院分区：
文献类型：
--
作者：
DeMartini, E.;Jokiel, P.;Conklin, E.
一些主要的人为压力源的影响发生在罕见的、不可预测的间隔；除非用空间代替时间，否则很难及时评价它们的影响。在本文中，我们沿着环境梯度用空间代替时间，以别名预测栖息地恢复的时间响应。本文描述了一项为期3年的研究，该研究结合了实地实验和对夏威夷西部Pelekane湾边缘珊瑚礁的描述性调查，该研究沿着Kohala流域间歇流的沉积梯度进行。这一退化的流域现在正在通过排除食草动物、生境工程和重新种植本地植物来恢复。在2010-2012年夏季，对沉积物陷阱、沉降板阵列、特有指状珊瑚的有标记分支、底栖生物组成调查、经济上重要的鹦嘴鱼的新种群密度以及新种群对珊瑚的相对利用情况进行了评估。正如预期的那样，沉积物积累速率降低，而所有珊瑚指标以及繁殖鱼类对珊瑚的密度、利用和偏好一般随着距离沉积物排放点的距离而增加。通过沉积物影响的分布（由单独的研究绘制）叠加大型成年鹦嘴鱼的招募丰度，使我们能够估计，例如，由于沉积物对招募鹦嘴鱼的影响而未实现的鹦嘴鱼资源的数量和价值。因此，我们的Pelekane湾案例研究说明了“空间换时间”替代如何有效地应用于评估潜在的水域对珊瑚礁资源的回收——在相当早于可能的珊瑚礁及其资源对流域恢复的时间响应的时候。
Some major anthropogenic stressors have impacts that occur at infrequent, unpredictable intervals; their effects are difficult to evaluate in a timely manner unless space is substituted for time. In this paper we substitute space for time along an environmental gradient that aliases a predicted temporal response to habitat restoration. We herein describe a 3-year study that combined field experiments and descriptive surveys of a fringing reef at Pelekane Bay, west Hawaii, along a sedimentation gradient from an intermittent stream that episodically discharges from the Kohala Watershed. This degraded watershed is now being restored by grazer exclusion, habitat engineering, and replanting of native flora. Sediment traps, arrays of settling plates, marked branches of endemic finger coral Porites compressa, together with surveys of benthic composition, densities of recruits of economically important parrotfishes, and the relative use of corals by fish recruits, were evaluated during the summers of 2010-2012. As expected, sediment accumulation rate decreased while all coral metrics and the densities, use, and preference of corals by recruit fishes generally increased with distance from the point of sediment discharge. Proportionate abundances of recruit through large adult-sized parrotfishes, overlayed on distributions (mapped by separate study) of sediment impact, allowed us to estimate, as an example, the amount and value of parrotfish rersources that are being unrealized because of sediment impacts on recruit parrotfish. Our Pelekane Bay case study thus illustrates how "space-for-time" substitution can be efficiently applied in an evaluation of potential watershed reclamation of reef resources-at a time considerably prior to likely temporal responses of the reef and its resources to watershed restoration.