The structures that they build protect our shorelines from storm surge and waves, and the biological systems that they house filter the water and make it safer for us to work and play.
它们打造的结构保护了我们的海岸线 不受风暴潮和海浪的侵袭， 而且这种生态系统能过滤海水， 让我们能安全地在水里工作和玩耍。