Nitrogen loads explain primary productivity in estuaries at the ecosystem scale

摘要: Increased nutrient loads stimulate estuary primary productivity and can alter the structure function of biological communities within estuaries, particularly when producer groups respond differently to changes in availability. Here, relative influence riverine inputs nitrogen phosphorus were compared determine their contribution estuarine producers at large spatial scales. Indices demersal (extent macroalgae other vegetation, total shallow water area vegetated) planktonic (seasonally averaged chlorophyll concentration) derived whole-of-ecosystem scales 14 estuaries dispersed across a longitudinal gradient using aerial imaging, underwater videography situ monitoring. A model selection framework was used relate annual (total [TN], dissolved inorganic [DIN], [TP]), sediment (TSS), molar stoichiometric load ratios (TNM: TPM), residence times indices. Dissolved best predictor extent macroalgae, vegetation coverage, concentration chlorophyll. Rapid increases all three indices occurred ∼ 5–10 Mg km−2 yr−1. There some evidence that TNM: TPM, TP TSS informative covariates. Relative DIN loads, poor macroalgal These findings underscore critical role catchment-derived contributing scale support growing consensus (in addition phosphorus) must be managed effectively alleviate eutrophication estuaries.