Overfishing, nutrient-fuelled hypoxia and habitat destruction have reduced oyster populations to a fraction of their former abundance. Over the past two decades there has been a widespread effort to restore oyster reefs and develop oyster aquaculture. Yet it remains unclear how re-introduction of large oyster populations will change coastal biogeochemistry. Of particular interest is whether oysters may help offset excess nitrogen loading, which is responsible for widespread coastal water quality degradation, low oxygen conditions and biodiversity declines. Here we used a meta-analysis approach to assess how oysters alter inorganic nutrient cycling, with a focus on nitrogen removal. Additionally, we examined how oysters alter greenhouse gas emissions. We demonstrate that oysters enhance removal of excess nitrogen by stimulating denitrification, promote efficient nutrient recycling and may have a negligible greenhouse gas footprint. Further, oyster reefs and oyster aquaculture appear to have similar biogeochemical function, suggesting the potential for sustainable production of animal protein alongside environmental restoration.

过度捕捞，以养分为动力的缺氧和栖息地的破坏使牡蛎种群减少到以前的数量的一小部分。在过去的二十年中，人们进行了广泛的努力来恢复牡蛎礁和发展牡蛎养殖。然而，尚不清楚重新引入大牡蛎种群将如何改变沿海生物地球化学。特别令人感兴趣的是牡蛎是否可以帮助抵消过量的氮负荷，这是造成沿海水质普遍下降，低氧条件和生物多样性下降的原因。在这里，我们使用荟萃分析方法评估牡蛎如何改变无机养分循环，重点是脱氮。此外，我们研究了牡蛎如何改变温室气体排放。我们证明牡蛎通过刺激反硝化作用来增强去除多余氮的能力，促进有效的养分循环利用，并且温室气体足迹可以忽略不计。此外，牡蛎礁和牡蛎养殖业似乎具有相似的生物地球化学功能，这表明在环境恢复的同时可持续生产动物蛋白的潜力。