Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, P.O. Box 65, FI-00014, University of Helsinki, Finland.
Water Res. 2019 Sep 1;160:206-208. doi: 10.1016/j.watres.2019.05.074. Epub 2019 May 23.
Phosphorus (P) is the main nutrient that causes eutrophication in fresh waters. The majority of P in lake ecosystems is usually stored in the bottom sediment, hence P cycling from the sediment into the water column can significantly and negatively impact water quality. However, sediment nutrients are not taken into account, for instance, in the ecological status assessment determined by the European Water Framework Directive. This encourages lake managers to improve the water quality at the expense of the sediment; for example, chemical inactivation of P has been applied to the sediment in numerous lakes for rapid water quality improvement. While this may generate immediate results, inactivation of sediment P may in fact delay the long-term recovery of lake ecosystems and inhibit the re-use of nutrients. In some specific cases, these rapid restoration efforts that compromise sediment quality are justified. Nevertheless, we should aim for a general strategy that can promote permanent recovery of lake ecosystems - including their sediments. The support for such restoration activities may be difficult to find, since the tangible outcome is realized only after long periods of time.
磷（P）是导致淡水富营养化的主要营养物质。湖泊生态系统中的大部分磷通常储存在底部沉积物中，因此，沉积物中的磷向水柱中的循环会对水质产生显著的负面影响。然而，沉积物中的养分通常不会被考虑在内，例如，在欧洲水框架指令确定的生态状况评估中就没有考虑到这一点。这鼓励湖泊管理者为了改善水质而牺牲沉积物；例如，已经在众多湖泊中应用化学方法使磷失活，以迅速改善水质。虽然这可能会产生立竿见影的效果，但实际上，沉积物中磷的失活可能会延迟湖泊生态系统的长期恢复，并抑制养分的再利用。在某些特定情况下，这些损害沉积物质量的快速恢复措施是合理的。然而，我们应该制定一个能够促进湖泊生态系统——包括其沉积物——永久恢复的一般性策略。这种恢复活动的支持可能很难找到，因为只有在很长一段时间后才能看到有形的结果。
