Multi-year persistence of beach habitat degradation from nourishment using coarse shelly sediments.
Multi-year persistence of beach habitat degradation from nourishment using coarse shelly sediments.
复制标题
由于粗贝壳沉积物的滋养，海滩栖息地退化多年持续。
DOI：
10.1016/j.scitotenv.2014.04.046
复制
发表时间：
2014
期刊：
影响因子：
--
通讯作者：
G. A. Johnson
中科院分区：
文献类型：
--
作者：
C. Peterson;M. Bishop;Linda M. D'Anna;G. A. Johnson
海滩营养越来越多地用于保护公共海滩舒适设施和沿海财产免受侵蚀和风暴破坏。如果海滩营养使用的填充沉积物在沉积学上不同于原生海滩砂，则可能会对桑迪海滩无脊椎动物及其生态系统服务造成压力干扰。然而，影响持续多久尚不清楚，因为营养后的监测通常只持续几个月。在这里，监测延长了3-4年后，每两个空间上分离，复制营养项目使用非天然粗沉积物。在这两个填充事件之后，砾石大小的颗粒和贝壳碎片对海滩沉积物的贡献得到了加强，尽管随着时间的推移而减少，但与3-4年监测结束时的对照地点相比，仍然很高，包括在低潮间带和冲刷区，底栖大型无脊椎动物集中。因此，两种动物区系内的无脊椎动物，吸器类端足类和Donaxspp.，在整个3-4年的营养后期间，显示出抑制的密度。相比之下，Emerita talpoida，仅在第一年和第二年的初夏，在营养海滩上显示出比对照海滩低的密度，而多毛类对营养几乎没有反应。营养对无脊椎动物的总体影响与其捕食者丰度的多年减少相匹配。鬼蟹丰度被抑制营养海滩的影响消失，只有第四个夏天。觅食滨鸟的数量在第一个项目后的4年和第二个项目后的2年都很低。我们的研究结果挑战的观点，即海滩营养是环境友好的，证明应用不自然的粗糙和贝壳沉积物可以作为一个压力干扰，以降低海滩栖息地和其营养服务的滨鸟2-4年。认识到营养后的恢复可能是缓慢的，仅监测几个月影响的研究是不够的。
Beach nourishment is increasingly used to protect public beach amenity and coastal property from erosion and storm damage. Where beach nourishment uses fill sediments that differ in sedimentology from native beach sands, press disturbances to sandy beach invertebrates and their ecosystem services can occur. How long impacts persist is, however, unclear because monitoring after nourishment typically only extends for several months. Here, monitoring was extended for 3–4 years following each of two spatially separated, replicate nourishment projects using unnaturally coarse sediments. Following both fill events, the contribution to beach sediments of gravel-sized particles and shell fragments was enhanced, and although diminishing through time, remained elevated as compared to control sites at the end of 3–4 years of monitoring, including in the low intertidal and swash zones, where benthic macroinvertebrates concentrate. Consequently, two infaunal invertebrates, haustoriid amphipods andDonaxspp., exhibited suppressed densities over the entire post-nourishment period of 3–4 years.Emerita talpoida, by contrast, exhibited lower densities on nourished than control beaches only in the early summer of the first and second years and polychaetes exhibited little response to nourishment. The overall impact to invertebrates of nourishment was matched by multi-year reductions in abundances of their predators. Ghost crab abundances were suppressed on nourished beaches with impacts disappearing only by the fourth summer. Counts of foraging shorebirds were depressed for 4 years after the first project and 2 years after the second project. Our results challenge the view that beach nourishment is environmentally benign by demonstrating that application of unnaturally coarse and shelly sediments can serve as a press disturbance to degrade the beach habitat and its trophic services to shorebirds for 2–4 years. Recognizing that recovery following nourishment can be slow, studies that monitor impacts for only several months are inadequate.