Bivalve farming was usually considered as a CO₂ source through respiration and calcification, but recent studies suggest its potential as a CO₂ sink, prompting exploration of its inclusion in carbon markets. Here we reviewed the scientific basis behind this idea and found that it is not supported by observational and experimental studies. This idea indeed arises from carbon budget models that are based on theoretical misconceptions regarding seawater carbonate chemistry. The main misunderstanding consists of assuming that the carbon trapped in the shell originates from atmospheric CO₂ when it mostly comes from (bi)carbonate ions. While these ions originate from atmospheric CO₂ through the erosion of minerals over geological time scales, their incorporation into shells does not prompt short-term CO₂ compensation. The opposite occurs—calcification releases CO₂ in seawater and limits or even prevents the uptake of atmospheric CO₂. Some authors suggest that considering the bivalve farm ecosystem could change the perspective on the source/sink issue but there is no evidence for that now. Most ecosystem-based carbon budget models rely on several unverified assumptions and estimates. Although challenging, field measurements must be conducted for monitoring, reporting, and verifying atmospheric CO₂ uptake before qualifying for carbon credits. To achieve scientific consensus, we need reinforcing measurement-based studies of CO₂ fluxes in shellfish ecosystems, integrating carbon balance models with observational and experimental science, and fostering interdisciplinary collaboration. Although bivalve farming provides numerous environmental benefits and is vital for sustainable aquaculture, there is currently no evidence that it contributes to CO₂ capture.

中文翻译：

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破解神话：双壳类农业不是二氧化碳汇


双壳类养殖通常被认为是通过呼吸和钙化作用产生的 CO₂ 来源，但最近的研究表明，它有可能成为 CO₂ 汇，促使人们探索将其纳入碳市场。在这里，我们回顾了这一想法背后的科学依据，发现它没有得到观察和实验研究的支持。这个想法确实源于碳收支模型，这些模型基于对海水碳酸盐化学的理论误解。主要的误解包括假设壳层中的碳来自大气中的 CO₂，而它主要来自（双）碳酸根离子。虽然这些离子通过地质时间尺度上的矿物侵蚀源自大气中的 CO₂，但它们掺入壳层并不会促使短期的 CO₂ 补偿。相反的情况是，钙化会在海水中释放 CO₂，限制甚至阻止大气中 CO₂ 的吸收。一些作者认为，考虑双壳类农场生态系统可能会改变对源/汇问题的看法，但现在没有证据证明这一点。大多数基于生态系统的碳收支模型都依赖于几个未经验证的假设和估计。尽管具有挑战性，但在获得碳信用额度之前，必须进行现场测量以监测、报告和验证大气中的 CO₂ 吸收。为了达成科学共识，我们需要加强对贝类生态系统中 CO₂ 通量的基于测量的研究，将碳平衡模型与观测和实验科学相结合，并促进跨学科合作。 尽管双壳类养殖提供了许多环境效益，并且对可持续水产养殖至关重要，但目前没有证据表明它_{有助于二氧化碳捕获}。