Lake-rich Arctic deltas differ biogeochemically from tundra lakes, and their role as sources and sinks of greenhouse gases remains poorly understood. Under-ice and open-water changes in methane (CH₄) storage (43 lakes, 2014), floating chamber measurements of total and diffusive CH₄ evasion to the atmosphere (6 lakes, 2014–2015), and water-column CH₄ oxidation (MOX) (6 lakes, 2014–2015) permitted evaluation of how CH₄ emissions vary among lakes with differing river-to-lake connection times within the Mackenzie Delta. CH₄ emissions during ice-out were considerable, followed by substantial declines as open-water progressed. Water-column MOX rates were highest after ice-out, and declined throughout open-water. After accounting for a strong effect of CH₄ substrate levels, MOX rates were inversely related to pH, which can increase to high levels during open-water because of high macrophyte production. Comparisons of water-column CH₄ storage versus open-water fluxes (6 lakes) showed that diffusive evasion plus MOX removed most CH₄ in the water columns every 1–2 days with only modest changes in storage, suggesting that counter-balancing water-column replenishment is substantial. Lakes with short river-connection times (i.e. most strongly autotrophic and strongly CO₂-absorbing in this delta) and thermokarst lakes contribute disproportionately to CH₄ flux, relative to lakes with long river-connection times. Thus, this great Arctic delta represents an important system of greenhouse-gas emitting lakes despite prior work showing their net absorption of CO₂ during open-water, and having a low landscape area of CO₂-saturated thermokarst lakes. Autotrophically absorbed CO₂ becomes labile carbon substrate, and is microbially shunted back to the atmosphere as the more potent greenhouse gas CH₄.

富含湖泊的北极三角洲在生物地球化学上与苔原湖泊不同，它们作为温室气体源和汇的作用仍然知之甚少。冰下和开放水域甲烷 (CH ₄ ) 储存的变化（43 个湖泊，2014 年）、浮室测量总和扩散 CH ₄逃逸到大气中（6 个湖泊，2014-2015 年）和水柱 CH ₄氧化 (MOX)（6 个湖泊，2014-2015 年）允许评估麦肯齐三角洲内具有不同河流到湖泊连接时间的湖泊之间的CH ₄排放如何变化。通道₄结冰期间的排放量相当可观，随后随着开放水域的进展而大幅下降。结冰后水体 MOX 率最高，并在整个开放水域下降。在考虑到 CH ₄底物水平的强烈影响后，MOX 速率与 pH 值呈负相关，在开放水域期间，由于大型植物产量高，pH 值可能会增加到高水平。水柱 CH ₄储存量与开放水域通量（6 个湖泊）的比较表明，扩散规避加 MOX每 1-2 天去除水柱中的大部分 CH ₄，储存量仅发生适度变化，这表明平衡水-色谱柱补充量很大。与河流连接时间短的湖泊（即最强烈的自养和强烈的 CO ₂- 吸收在这个三角洲）和热岩溶湖泊相对于河流连接时间长的湖泊对 CH ₄通量的贡献不成比例。因此，这个巨大的北极三角洲代表了一个重要的温室气体排放湖泊系统，尽管先前的工作表明它们在开阔水域期间对 CO ₂的净吸收，并且具有较低的 CO ₂饱和热岩溶湖泊景观面积。自养吸收的 CO ₂变成不稳定的碳底物，并通过微生物分流回大气，成为更有效的温室气体 CH ₄。