Megaripples are current-generated seafloor bedforms of well-sorted sand or gravel and wavelengths over 1 m. In this aquatic eddy covariance study, we measured large rates of benthic primary production and respiration for a shallow-water sandy megaripple field exposed to strong tidally driven currents and intense sunlight. Current and light were the main short-term drivers of a highly dynamic oxygen exchange. Daytime oxygen release as high as 300 mmol m⁻² d⁻¹ and nighttime oxygen uptake up to −100 mmol m⁻² d⁻¹ were likely sustained by current-driven transport of oxygen, nutrients, and organic matter (fuel) into and out of the sand and superimposed by rapid internal cycling. Seasonal differences in temperature (45%) and light (69%) between April and September were the main long-term drivers of substantially greater rates of gross primary production and respiration in September. The megaripples functioned as an intense metabolic hotspot with carbon cycling rates larger than those of most near-shore sediments.

中文翻译：

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沿海海洋巨波纹场是具有高度动态氧交换的代谢热点

巨型波纹是当前产生的海底床形，由精选的沙子或砾石组成，波长超过 1 m。在这项水生涡流协方差研究中，我们测量了暴露于强烈潮汐驱动洋流和强烈阳光下的浅水沙质巨波纹场的底栖初级生产力和呼吸速率。电流和光是高动态氧气交换的主要短期驱动因素。白天氧气释放量高达 300 mmol m ^-2  d ^-1，夜间氧气吸收量高达 -100 mmol m ^-2  d ^{-1 ，}这很可能是通过电流驱动的氧气、营养物和有机物（燃料）输送到和脱离沙子并通过快速内部循环叠加。4 月至 9 月之间温度（45%）和光照（69%）的季节性差异是 9 月份初级生产总值和呼吸速率大幅提高的主要长期驱动因素。巨型波纹是一个强烈的代谢热点，其碳循环速率比大多数近岸沉积物的碳循环速率要大。