College of Water Sciences, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming 650034, Yunnan Province, China.
College of Water Sciences, Beijing Normal University, Beijing 100875, China; State Key Laboratory of Environment Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Kunming 650034, Yunnan Province, China.
Sci Total Environ. 2017 Dec 1;601-602:1544-1555. doi: 10.1016/j.scitotenv.2017.05.265. Epub 2017 Jun 9.
In this study, we made the first estimate of the annual dissolved organic phosphorus (DOP) load to Lake Erhai, a typical mesotrophic-eutrophic lake in China. We also evaluated what proportion of DOP was bioavailable using enzymatically hydrolyzable phosphorus (EHP), and further assessed the potential impacts of DOP on lake water quality. We estimated that the annual DOP load into Lake Erhai accounted for nearly 50% of total dissolved phosphorus, while EHP accounted for about 30% of the bioavailable phosphorus (BAP) pool. The DOP load increased and accounted for a greater proportion of total dissolved phosphorus and BAP loads during the wet season, and helped maintain algal blooms. Inflowing rivers were the main source of DOP with high bioavailability to Lake Erhai, especially in the wet season. The EHP concentrations of the inflowing rivers were positively correlated with algal biomass. The observation suggests that, as a significant source of BAP, the contribution of the DOP load to eutrophication of the lake should not be ignored, especially given the low soluble reactive phosphorus concentrations in the lake water during the algal biomass period. Information on the contributions from different pollution sources is needed to support the development of effective P pollution control strategies. Short-term strategies to protect Lake Erhai include better management of the inflowing rivers, especially in the northern part during the wet season, while, over the long-term, strategies to decrease P release from lake sediments should be considered.
本研究首次估算了进入中国典型中营养-富营养湖泊洱海的年溶解性有机磷（DOP）负荷。我们还利用可酶解磷（EHP）评估了 DOP 的可利用比例，并进一步评估了 DOP 对湖泊水质的潜在影响。我们估计洱海的年 DOP 负荷占总溶解磷的近 50%，而 EHP 占生物有效磷（BAP）库的约 30%。在雨季，DOP 负荷增加，占总溶解磷和 BAP 负荷的比例更大，并有助于维持藻类大量繁殖。流入河流是洱海 DOP 的主要来源，特别是在雨季，具有较高的生物可利用性。流入河流的 EHP 浓度与藻类生物量呈正相关。这一观察表明，作为 BAP 的重要来源，DOP 负荷对湖泊富营养化的贡献不应被忽视，特别是考虑到藻类生物量期间湖水可溶性反应磷浓度较低。需要了解不同污染源的贡献信息，以支持制定有效的磷污染控制策略。保护洱海的短期策略包括更好地管理流入河流，特别是在雨季的北部地区，而从长期来看，应考虑减少湖泊沉积物中磷释放的策略。
