Abstract
The scientific research on phytoplankton diversity has gained much interest the last years, for one due to the development of techniques that allowed picophytoplankton to be detected and enumerated. The picophytoplankter Micromonas pusilla has been shown to be a significant component of the picophytoplankton, occassionally even dominating the picophytoplankton community. It is, however, unclear how wide-spread this dominance of M. pusilla is. Furthermore, knowledge of regulatory role of virus infection for M. pusilla population dynamics, production and diversity is lacking. A study on the presence, significance and functionality of virus and host in the field is highly warranted. The present study will clarify the ecological importance of virus infection for M. pusilla through an integrated study assessing the occurrence and abundance of MpV, as well as the genetic diversity and clonal variation of MpV, and the impact of viruses on M. pusilla mortality and population dynamics. Different geographical locations will be studied on a temporal scale in order to allow unique and optimal insight into the contribution of M. pusilla and its specific viruses to C-flux within the pelagic food web. It will be for the first time that a detailed comparative study on the importance of M. pusilla and virus infection as regulating factor will be executed on such a spatially as well as temporarily scale. Newly developed techniques will be used to detecte and quantitate M. pusilla and specific virus. The present study will also explore the existence of distinct populations of MpV for the different study sites. The results of this timely proposed project will largely advance our comprehension of the importance of picophytoplankton and viral control of picophytoplankton population dynamics. The results are expected to provide new insights in our understanding of the functioning and structure of marine pelagic food webs and geochemical cycling. The obtained data will, furthermore, be essential for a more accurate evaluation of mathematical ecosystem models.
Netherlands