Comment on An additional challenge of Lake Kivu in Central Africa – upward movement of the chemoclines by Finn Hirslund

In a paper published earlier this year, Hirslund suggested to release degassed deepwater from methane harvesting to the surface layer of Lake Kivu in order to counteract an observed slow rising of the chemoclines in the lake. In this comment, we present strong evidence for the presence of subaquatic springs in the lake that maintain the chemoclines at their present levels. Furthermore, the observed changes in the stratification do not call for urgent action. We therefore strongly advise against the proposed measures, which would most probably be harmful for the ecosystem, and instead propose to further monitor the development of the stratification in the lake.