Estuaries act as nurseries for a wide variety of fish species, potentially providing vital foraging opportunities and refuge from predation for their juvenile residents. Yet, these dynamic environments are comprised of a mosaic of habitat types that span gradients of both salinity and physical habitat structure. Here, we present a novel use of size‐spectra analysis to infer nursery habitat function across the estuary habitat mosaic. Interpreting slope and intercept values of abundance against body mass size‐spectra regressions as indicators of predation risk and production, we constructed spectra for six distinct habitat types across the entire tidal influence of an unindustrialized estuary in coastal British Columbia. Based on catches of >200,000 individual fish representing 30 different species from April through September, the estuary rockweed mudflat habitat had the lowest size‐spectra slope and highest intercept, consistent with lower predation risk and higher production. Size‐spectra coefficients varied seasonally across the ecotone, indicating spatio‐temporal variation in key nursery functions. Size‐spectra can provide insight into key ecological processes of productivity and predation risk across dynamic aquatic habitats.

中文翻译：

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河口大小光谱分析：评估整个​​栖息地马赛克上的鱼苗场功能

河口充当各种鱼类的苗圃，可能为他们的未成年居民提供重要的觅食机会和避难所。然而，这些动态环境由跨越盐度和物理栖息地结构梯度的栖息地类型组成。在这里，我们介绍了一种新颖的使用大小光谱分析的方法来推断整个河口栖息地马赛克上的苗圃栖息地功能的方法。解释坡度和截留值的丰度与体重的关系-光谱回归作为捕食风险和生产的指标，我们为不列颠哥伦比亚省沿海未工业化河口的整个潮汐影响构建了六个不同栖息地类型的光谱。根据从4月到9月捕获的代表20种不同鱼类的200,000多条个体鱼，河口滩涂滩涂生境具有最小的光谱谱坡度和最高的截距，这与较低的捕食风险和较高的产量一致。整个过渡带的大小光谱系数随季节变化，表明苗圃的主要功能时空变化。大小光谱可以洞察动态水生生境中生产力和捕食风险的关键生态过程。