Estuarine sediments are important sites for the interception, processing, and retention of organic matter, prior to its export to the coastal oceans. Stimulated microbial co-metabolism (priming) potentially increases export of refractory organic matter through increased production of hydrolytic enzymes. Using the microphytobenthos community to directly introduce a pulse of labile carbon into sediment, we traced a priming effect and assessed the decomposition and export of preexisting organic matter. We show enhanced efflux of preexisting carbon from intertidal sediments enriched with water column nutrients. Nutrient enrichment increased production of labile microphytobenthos carbon, which stimulated degradation of previously unavailable organic matter and led to increased liberation of “old” (6855 ± 120 years BP) refractory carbon as dissolved organic carbon (DOC). These enhanced DOC effluxes occurred at a scale that decreases estimates for global organic carbon burial in coastal systems and should be considered as an impact of eutrophication on estuarine carbon budgets.

中文翻译：

---

富营养化沉积物上的光亮：营养物质的丰富刺激了储存有机物的出口。

河口沉积物是有机物在出口到沿海海洋之前的重要场所，用于拦截，加工和保留有机物。刺激的微生物共代谢（引发）可能通过增加水解酶的产生来增加难治性有机物的出口。我们使用微底栖动物群落直接将不稳定的碳脉冲引入沉积物中，从而追踪了启动效应并评估了已有有机物的分解和输出。我们显示出潮间带富含水柱养分的沉积物中已有碳的外排量增加。营养富集增加了不稳定的微底栖动物碳的产量，从而刺激了先前无法获得的有机物质的降解，并导致“旧”（6855±120年BP）难熔碳作为溶解有机碳（DOC）的释放增加。这些增加的DOC排放量以减少对沿海系统全球有机碳埋藏的估计的规模发生，应被视为富营养化对河口碳预算的影响。