In response to shoreline erosion and coastal wetland loss, living shorelines have been implemented as a natural alternative to shoreline hardening. In high wave energy systems, “hybrid” living shoreline designs incorporating large-scale breakwaters have been increasingly chosen to restore and conserve wetlands. However, evaluations of the effectiveness of breakwaters at preserving natural shorelines and promote the growth of shoreline plantings are limited. To evaluate the effectiveness of large-scale breakwaters at protecting or restoring marshes in high wave energy environments, we conducted an experimental planting and shoreline monitoring program landward of eight-year-old breakwaters and adjacent no breakwater sites along Bon Secour Bay, Alabama. Results showed that breakwaters help natural marsh to maintain its cover at a high level (70%), but have little impact on shoreline planting. Furthermore, breakwater presence reduced the pressure for upland migration, allowing natural marsh patches to expand seaward. Without breakwater protection, fringing marsh retreated upland significantly. Cumulatively, this study suggests that large-scale breakwaters could have an impact on preserving fringing marsh vegetation in high wave energy environments though their effectiveness into the future will require adaptive management in response to local sea-level rise.

为了应对海岸线侵蚀和沿海湿地丧失，已将活海岸线作为海岸线硬化的自然替代方案。在高波能系统中，越来越多地选择包含大型防波堤的“混合”生活海岸线设计来恢复和保护湿地。然而，对防波堤在保护自然海岸线和促进海岸线植物生长方面的有效性的评估是有限的。为了评估大型防波堤在高波能环境中保护或恢复沼泽的有效性，我们对阿拉巴马州邦赛库尔湾沿岸已有八年历史的防波堤和邻近的无防波堤地点进行了一项试验性种植和海岸线监测计划。结果表明，防波堤有助于天然沼泽将其覆盖率保持在较高水平 (70%)，但对岸线种植影响不大。此外，防波堤的存在降低了高地迁移的压力，使天然沼泽斑块向海扩展。在没有防波堤保护的情况下，边缘沼泽向高地退缩。总的来说，这项研究表明，大规模防波堤可能对保护高波能环境中的边缘沼泽植被产生影响，尽管它们在未来的有效性将需要针对当地海平面上升的适应性管理。