Description: Information on recent biomass distribution and biogeography of photosynthetic marine protists with adequate temporal and spatial resolution is urgently needed to better understand consequences of environmental change for marine ecosystems. Here we introduce and review a molecular-based observation strategy for high resolution assessment of these protists in space and time. It is the result of extensive technology developments, adaptations and evaluations which are documented in a number of different publications and the results of recently accomplished field testing, which are introduced in this review. The observation strategy is organized at four different levels. At level 1, samples are collected at high spatio-temporal resolution using the remote-controlled automated filtration system AUTOFIM. Resulting samples can either be preserved for later laboratory analyses, or directly subjected to molecular surveillance of key species aboard the ship via an automated biosensor system or quantitative polymerase chain reaction (level 2). Preserved samples are analyzed at the next observational levels in the laboratory (level 3 and 4). This involves at level 3 molecular fingerprinting methods for a quick and reliable overview of differences in protist community composition. Finally, selected samples can be used to generate a detailed analysis of taxonomic protist composition via the latest Next Generation Sequencing Technology (NGS) at level 4. An overall integrated dataset of the results based on the different analyses provides comprehensive information on the diversity and biogeography of protists, including all related size classes. At the same time the cost effort of the observation is optimized in respect to analysis effort and time.

Description: This talk is based on recent discoveries regarding spatial biogeography of Phaeocystis spp. via molecular monitoring in the North Sea, North Atlantic, Fram Strait and Central Arctic Ocean. The cosmopolitan micro algal genus Phaeocystis plays a crucial role in the ecology and biogeochemistry in nearly all marine ecosystems. It harbors three bloom- and colony-forming species, two cold and one `warm` water species. All three species: P. pouchetii in the Arctic, P. antarctica in the Southern Ocean and P. globosa in cold/warm temperate and tropical waters, are known to be key species within their habitats. P. pouchetii and P. globosa are believed to be species complexes. P. globosa has been physiologically widely studied, indicating eurythermal features due to a broad temperature span from -4 °C to more than +20 °C. This arises the question if present day populations of P. globosa could be dispersed via oceanic current regimes into the Arctic Ocean which is known to be an open oceanic system. Does P. globosa have the guts to enter the Arctic?