Is there a Microbial Loop in Lake Baikal?

Abstract

The occurrence of a microbial loop in the pelagic environment is discussed with regard to hydrological and meteorological effects as well as to the planktological states during the seasons in lake Baikal. Strong local conditions due the melting ice and the sequence of the spring bloom indicate close local interactions between phytoplankton and bacteria. However, missing reports on micro-zooplankton and continuous reports of the roles of the individual organism groups involved in the microbial loop make is difficult to establish the way of matter flow in the lake as a general path. Further, sinking rates of diatoms do not allow a remineralisation of plankton-C and -N in the deep water in its upper photic levels. Thus, microbial mineralized nutrients will stay for long time in the abyssal area of the lake, which can be regarded responsible for its oligotrophic nature in the upper layers.

Keywords

• Lake Baikal
• limnology
• microbial loop