Widespread deoxygenation of temperate lakes
Widespread deoxygenation of temperate lakes
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DOI：
10.1038/s41586-021-03550-y
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发表时间：
2021-06-03
期刊：
影响因子：
64.8
通讯作者：
Rose, Kevin C.
中科院分区：
文献类型：
--
作者：
Jane, Stephen F.;Hansen, Gretchen J. A.;Rose, Kevin C.
水生系统中溶解氧的浓度有助于调节生物多样性(1,2)、营养物生物地球化学(3)、温室气体排放(4) 和饮用水质量(5)。沿海和海洋水域溶解氧浓度的长期下降与气候变暖和人类活动有关(6,7)，但人们对湖泊溶解氧浓度的变化知之甚少。尽管溶解氧的溶解度随着水温的升高而降低，但长期的湖泊轨迹很难预测。变暖的湖泊中的氧气损失可能会因分解的增强和更强的热分层(8,9)而放大，或者由于初级生产的增强(10)，氧气可能会增加。在这里，我们分析了总共 45,148 个溶解氧和温度剖面，并计算了 1941 年至 2017 年 393 个温带湖泊的趋势。我们发现溶解氧下降在地表和深水栖息地普遍存在。地表水的下降主要与水温升高时溶解度的降低有关，尽管在部分高产变暖湖泊中，地表水中的溶解氧有所增加，这可能是由于浮游植物产量的增加。相比之下，深水的下降与更强的热分层和水透明度的丧失有关，但与气体溶解度的变化无关。我们的研究结果表明，气候变化和水体透明度下降已经改变了湖泊的物理和化学环境。淡水中溶解氧的下降幅度是世界海洋中观测到的下降幅度的 2.75 至 9.3 倍(6,7)，可能威胁到重要的湖泊生态系统服务(2,3,5,11)。
The concentration of dissolved oxygen in aquatic systems helps to regulate biodiversity(1,2), nutrient biogeochemistry(3), greenhouse gas emissions(4), and the quality of drinking water(5). The long-term declines in dissolved oxygen concentrations in coastal and ocean waters have been linked to climate warming and human activity(6,7), but little is known about the changes in dissolved oxygen concentrations in lakes. Although the solubility of dissolved oxygen decreases with increasing water temperatures, long-term lake trajectories are difficult to predict. Oxygen losses in warming lakes may be amplified by enhanced decomposition and stronger thermal stratification(8,9) or oxygen may increase as a result of enhanced primary production(10). Here we analyse a combined total of 45,148 dissolved oxygen and temperature profiles and calculate trends for 393 temperate lakes that span 1941 to 2017. We find that a decline in dissolved oxygen is widespread in surface and deep-water habitats. The decline in surface waters is primarily associated with reduced solubility under warmer water temperatures, although dissolved oxygen in surface waters increased in a subset of highly productive warming lakes, probably owing to increasing production of phytoplankton. By contrast, the decline in deep waters is associated with stronger thermal stratification and loss of water clarity, but not with changes in gas solubility. Our results suggest that climate change and declining water clarity have altered the physical and chemical environment of lakes. Declines in dissolved oxygen in freshwater are 2.75 to 9.3 times greater than observed in the world's oceans(6,7) and could threaten essential lake ecosystem services(2,3,5,11).