Resting stages and ecology: Environmental cues and ecological significance

Workshop Plankton Resting Stages: ecological, evolutionary and geological perspectives, 5-8 October 2015, Hanko Peninsula, FinlandPlanktonic microalgae inhabit freshwater, brackish water and seawater environments and play a key role as phototrophs in the aquatic systems. The life cycles of most microalgal species are complex, with stages characterized by radically different morphologies and highly diverse environmental interactions. The two most common life stages are planktonic vegetative cells and benthic resting forms such as cysts or spores. During the planktonic stage, growth typically occurs in the water column, but for many species this is an ephemeral one. By contrast, resting stages remain dormant in sediments, where they are able to withstand adverse conditions until internal biological requirements and environmental conditions favour re-establishment of the vegetative form. However, despite the well-appreciated relevance of the different life-cycle strategies of microalgae with respect to their population dynamics, the full life cycle has been determined in only a few cases and for most species little is known about benthic resting forms and their interactions with the environment. Likewise, the factors that trigger transitions between the different life stages have yet to be identified. Here, we review current knowledge on the life-cycle strategies of major groups of microalgae and present an overview of the significance of life-cycle characteristics for algal bloom dynamicsPeer Reviewe