Abstract
Phytoplankton production is dynamic and the occurrence of blooms is hard to predict. This is partly because basic knowledge on population genetic patterns, and how species/populations propagate is lacking. We use the diatom Skeletonema marinoi as a model organism, and we differentiate populations by microsatellite markers. We have found that genetically differentiated populations of S. marinoi succeed each other in a seasonal manner. The population encountered at a particular season is well adapted to their habitat, e.g. in respect of hydrography, grazing pressure or competing species. We have also found that for some populations, propagation by resuspended benthic resting stages is an important strategy. On large spatial scales we have found that populations of S. marinoi are genetically differentiated. In the second phase of this project I will investigate the gene flow among populations along the Swedish west coast. Samples will be collected together with regional monitoring programs. From each location single cells will be isolated and monoclonal cultures established. DNA will be extracted from exponentially growing cultures and used as template in PCR reactions. Subsequently each individual clone will be genotyped and population diversity and differentiation will be estimated. Temporal and spatial data generated from this project will be incorporated into dispersal models and geographic and seasonal hot spots for algal blooms will be identified.
Sweden