Benthic flow environments affect recruitment of Crassostrea virginica larvae to an intertidal oyster reef
Benthic flow environments affect recruitment of Crassostrea virginica larvae to an intertidal oyster reef
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底栖流动环境影响弗吉尼亚巨牡蛎幼虫向潮间带牡蛎礁的招募
DOI：
10.3354/meps09882
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发表时间：
2012
影响因子：
2.5
通讯作者：
M. Reidenbach
中科院分区：
文献类型：
--
作者：
Elizabeth R. Whitman;M. Reidenbach
为加强美国维吉尼亚海岸线牡蛎种群的恢复工作，重点是创造适合幼虫招募、存活和生长的海底栖息地。为了确定底栖生物流动过程如何影响幼虫的招募、速度和繁殖，我们收集了多个潮间带底栖动物表面的数据，包括一个泥床、一个翡翠牡蛎礁和两个修复地点，这些修复地点包括沉积的弗吉尼亚牡蛎壳或相对较大的蒲公英螺壳。用来衡量珊瑚礁水动力粗糙度的阻力系数CD的平均估计值被发现比修复地点的阻力系数大2倍，比泥床的阻力系数大5倍。增强的流体剪切增加了礁体上方的峰值雷诺应力和垂直动量输运，但在单个牡蛎之间的间隙区域，速度和湍流都降低了。不同三角形底栖粗糙度的幼虫安置板被用来模拟沿牡蛎礁发现的自然地形变异性。最大的幼虫招募发生在高粗糙度地形之间的间隙区域，在那里，作用于驱逐幼虫的剪应力被发现比沿着暴露的表面小20倍。与牡蛎壳修复地点相比，在流体力学更粗糙的螺壳上也发现了更大的招募。结果表明，修复工作应考虑创建类似于已建立的牡蛎礁的三维海底地形，以提供水动力条件和安置面，以促进幼虫的招募，防止被沉积物埋葬，并提供躲避捕食的避难所。
Restoration efforts to enhance Crassostrea virginica oyster populations along the Vir- ginia, USA, coastline focus on creating benthic habitat suitable for larval recruitment, survival, and growth. To determine how benthic flow processes affect larval recruitment, velocity and tur- bulence we collected data over multiple intertidal benthic surfaces including a mud bed, a C. vir- ginica oyster reef, and 2 restoration sites comprised of deposited C. virginica oyster shell or the relatively larger Busycotypus canaliculatus whelk shell. Mean estimates of the drag coefficient, CD, used as a measure of hydrodynamic roughness over the C. virginica reef were found to be 2 times greater than over the restoration sites and 5 times greater than over the mud bed. Enhanced fluid shear increased both peak Reynolds stresses and vertical momentum transport above the reef, but within the interstitial areas between individual oysters, velocities and turbulence were reduced. Larval settlement plates of varying triangular-shaped benthic roughness were used to mimic the natural topographic variability found along oyster reefs. The greatest larval recruitment occurred along interstitial regions between high-roughness topography, where shear stresses, which act to dislodge larvae, were found to be up to 20 times smaller than along exposed surfaces. Greater recruitment was also found on the more hydrodynamically rough whelk shell compared to the oyster shell restoration site. Results suggests that restoration efforts should consider creat- ing 3-dimensional benthic topography similar to established oyster reefs to provide hydrodynamic conditions and settlement surfaces that promote larval recruitment, prevent burial by sediment, and provide refuge from predation.