Vertebrate and invertebrate taxa that serve as forage for predators play a critical role in coastal ecosystems by linking lower trophic levels to ecologically and economically valuable predators in upper trophic levels. We analyzed long-term data from multiple monitoring surveys in Chesapeake Bay and its major tributaries to evaluate patterns and relative abundances of forage at two spatial scales and to identify drivers of forage availability. Time series of forage abundances showed positive spatial correlation, becoming increasingly similar with declining distance between tributaries and regions of Chesapeake Bay. Statistical models were fit to identify relationships among forage taxa and climatic, biological, and environmental variables. Annual abundance indices of many forage taxa were higher in years when spring water temperatures warmed slowly, as indicated by an annual 5 °C degree-day warming index that represented the rate of warming during late winter/early spring. Forage indices also were related (in taxon-specific ways) to winter–spring chlorophyll concentration and freshwater discharge, and to three summer water quality variables: dissolved oxygen, salinity, and water temperature, in addition to a broad-scale climate indicator (Atlantic Multidecadal Oscillation). Our findings broadly demonstrate that bottom–up climate forcing acts to control at least some taxa at lower trophic levels in Chesapeake Bay. Ongoing phenological changes in regional climate and evidence of spatial dependence in responses of forage to environmental conditions underscore the likelihood that spatiotemporal foraging conditions for predator species will change under projected climate conditions.

脊椎动物和无脊椎动物类群作为捕食者的觅食，通过将较低营养级别与较高营养级别的具有生态和经济价值的捕食者联系起来，在沿海生态系统中发挥了关键作用。我们分析了切萨皮克湾及其主要支流的多次监测调查的长期数据，以评估两个空间尺度上的牧草格局和相对丰度，并确定了牧草可利用性的驱动因素。牧草丰度的时间序列显示出正的空间相关性，随着支流与切萨皮克湾地区之间距离的减小，变得越来越相似。统计模型适合于确定饲料类群与气候，生物和环境变量之间的关系。春季水温缓慢升高的年份中，许多饲草类群的年丰度指数较高，这可以通过代表冬末/初春的升温速率的每年5°C-天的升温指数来表明。饲料指数还（以分类群特定的方式）与冬季春季的叶绿素浓度和淡水排放量以及三个夏季水质变量（溶解氧，盐度和水温）相关，此外还有广泛的气候指标（大西洋多年代际振荡）。我们的发现广泛表明，自下而上的气候强迫作用在切萨皮克湾的较低营养级别上至少控制了一些分类单元。