Instituto de Ciencias de la Tierra, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
Marine Science Institute, University of California at Santa Barbara, CA, USA.
Sci Total Environ. 2021 Feb 10;755(Pt 2):142573. doi: 10.1016/j.scitotenv.2020.142573. Epub 2020 Sep 29.
Coastal armoring is widely applied to coastal ecosystems, such as sandy beaches, in response to shoreline erosion and threats to infrastructure. Use of armoring is expected to increase due to coastal population growth and effects of climate change. An increased understanding of armoring effects on those ecosystems and the services they provide is needed for impact assessments and the design of these structures. We investigated the following hypotheses: 1) impacts of coastal armoring on beach macroinvertebrates increase from lower to upper intertidal zones and 2) location of an armoring structure on beach profiles affects the number of intertidal zones, using comparative surveys of armored and unarmored beach sections in Chile and California. The effects of armoring were greater for upper intertidal (talitrid amphipods) and mid-intertidal species (cirolanid isopods) than for lower shore fauna (hippid crabs). Our surveys of sections of armoring structures located higher and lower on the beach profile (with and without interactions with waves and tides), showed loss of upper zone talitrid amphipods and mid-zone isopods and a reduction of lower zone hippid crabs in sections where the structures were lower on the beach profile and interacted with waves, compared to non-interacting sections. Our results support the hypothesis that impacts of armoring on intertidal macroinvertebrates increase from the lower to the upper intertidal zones of sandy beaches and also suggest that the relative position of an armoring structure on the beach profile, determines the number of intertidal zones it affects. Our findings also imply that by altering the position of existing armoring structures on the shore profile and increasing the amount of interaction with waves and tides, sea level rise and regional factors, such as coseismic coastal subsidence, can be expected to exacerbate the impacts of these widely used coastal defense structures on sandy beach ecosystems.
护岸广泛应用于沿海生态系统，如沙滩，以应对海岸线侵蚀和基础设施面临的威胁。由于沿海地区人口增长和气候变化的影响，预计护岸的使用将会增加。为了进行影响评估和设计这些结构，需要更好地了解护岸对这些生态系统及其提供的服务的影响。我们调查了以下假设：1）沿海护岸对海滩大型无脊椎动物的影响从上潮带到中潮带增加，2）护岸结构在海滩剖面中的位置会影响潮间带的数量，我们在智利和加利福尼亚对有护岸和无护岸的海滩剖面进行了比较调查。护岸对潮间带大型无脊椎动物（跳尾目甲壳动物）和中潮带物种（潮蟹目等足动物）的影响大于低潮带动物（涟蟹目十足目动物）。我们对位于海滩剖面较高和较低位置的护岸结构（与波浪和潮汐相互作用和不相互作用）的部分进行了调查，与不相互作用的部分相比，结构位于海滩剖面较低位置并与波浪相互作用的部分，上潮带跳尾目甲壳动物和中潮带潮蟹目等足动物减少，而低潮带涟蟹目十足目动物减少。我们的研究结果支持护岸对潮间带大型无脊椎动物的影响从上潮带增加到中潮带的假设，并且还表明护岸结构在海滩剖面的相对位置决定了它影响的潮间带数量。我们的研究结果还表明，通过改变现有护岸结构在海岸剖面中的位置，并增加与波浪和潮汐的相互作用，海平面上升和区域因素（如地震引起的海岸下沉）可能会加剧这些广泛使用的沿海防御结构对沙滩生态系统的影响。
