Structures installed to modify hydrology in waterways such as culverts can cause fragmentation across intertidal and subtidal areas, leading to increased habitat patchiness of previous interconnected habitats. This study aimed to understand the potential impacts of a 268-m culvert on habitat parameters in a large tidal bay and a coastal lagoon in Southern California. We analyzed key habitat characteristics of both sites including water conditions and sediment characteristics as well as biotic communities including zooplankton, benthic macroinvertebrate, and fish communities. As compared to the tidal bay, the lagoon had more extreme temperature differences, decreased dissolved oxygen and salinity, and lower zooplankton abundance. The composition of zooplankton, benthic macroinvertebrates, and small fish communities also differed between the two habitats, suggesting higher habitat heterogeneity than might be expected given their proximity. Removing the culvert that connects these habitats and returning it to an earth-lined open channel would decrease fragmentation between the two habitats and improve trophic quality while retaining the estuarine characteristics of the overall system.

为改变水道中的水文而安装的结构（如涵洞）会导致潮间带和潮下带区域的破碎化，从而导致以前相互连接的栖息地的栖息地斑驳性增加。本研究旨在了解 268 米长的涵洞对南加州大型潮汐湾和沿海泻湖的栖息地参数的潜在影响。我们分析了两个地点的主要栖息地特征，包括水条件和沉积物特征以及生物群落，包括浮游动物、底栖大型无脊椎动物和鱼类群落。与潮汐湾相比，泻湖的温差更大，溶解氧和盐度降低，浮游动物丰度更低。浮游动物、底栖大型无脊椎动物、和小型鱼类群落在两个栖息地之间也存在差异，这表明栖息地异质性高于考虑到它们的接近程度所预期的情况。拆除连接这些栖息地的涵洞并将其返回到有土的明渠将减少两个栖息地之间的分裂并提高营养质量，同时保留整个系统的河口特征。