Composition and Patterns of Taxa Assemblages in the Western Channel Assessed by 18S Sequencing, Microscopy and Flow Cytometry

Plankton monitoring by microscopy offers a long-term ecological perspective of plankton communities, but detection approaches are uniquely biased. Genetic identification marine has become standard is still not used in routine monitoring. This study assesses the value that genetic methods bring to microscopic and flow cytometry Western (English) Channel. An 18S high throughput sequencing (HTS) diversity survey taxa was performed on samples collected from an automated Water Microplankton Sampler (WaMS) deployed Continuous Recorder platform (CPR) 2011–2012. detected contrasting complementary assemblages surveys, mostly composed smaller or naked thin-walled taxa, with most phytoplankton being under 10 µm infrequently recorded other surveys. Most genetically-detected were mixotrophic heterotrophic. In comparison counts CPR Channel Observatory station L4, only 8–12 taxonomic families common all three them dinoflagellates, bias towards larger diatoms dinoflagellate Additional quantitative real-time PCR two potentially harmful pelagophyte, Aureococcus anophagefferens four Pseudo-nitzschia 2011–2013. revealed growth A. elevated summer 2011, whilst appearance delicatissima February year contrasted it’s timing at coastal station. Smaller measured had distinct seasonality abundance mid-Atlantic compared regions reflecting conditions.