Food webs in urban estuaries support valuable ecosystem services that are subject to a wide range of stressors that can degrade the structure of trophic networks. Multiple trophic pathways stabilize food webs by providing complementary diet resources for consumers but the consequences of urbanization on estuarine food webs are relatively unknown. In estuarine creeks across an urban-to-suburban gradient, we demonstrate trophic decoupling of benthic and pelagic pathways, trophic niche contraction, and increasing human health risk arising with the same factors that are associated with ecological degradation. This suggests an urban estuarine paradox—human activities often create larger volumes of deep water habitat, yet human activities also render much of this area unproductive with measurable opportunity costs to food webs. Our findings emphasize the shared consequences of environmental degradation for the ecological integrity of urban estuaries and the health of urban communities that rely on estuaries for sustenance.

城市河口的食物网支持有价值的生态系统服务，这些服务受到各种压力源的影响，这些压力源可能会破坏营养网络的结构。多种营养途径通过为消费者提供补充饮食资源来稳定食物网，但城市化对河口食物网的影响相对未知。在横跨城市到郊区梯度的河口小溪中，我们证明了底栖和远洋路径的营养脱钩、营养生态位收缩以及与生态退化相关的相同因素所引起的人类健康风险的增加。这表明了城市河口悖论——人类活动往往会创造更大体积的深水栖息地，但人类活动也使该地区的大部分地区变得生产力低下，对食物网造成了可衡量的机会成本。我们的研究结果强调了环境退化对城市河口生态完整性以及依赖河口维持生计的城市社区健康的共同后果。