This collection of data from the planktonnet image repository comprises 5 individual planktonnet collections.Heincke 461 - POGO Cruise 2016: This collection is the result of an AWI/POGO cruise (HE461) in the Southern North Sea, sampling plankton on three transects from the island of Helgoland towards the Elbe and Eider estuaries as well as in a northeasterly direction towards the open North Sea. Within a 4 day period, each of the transects was sampled twice. HE461 is the second AWI-Pogo cruise in the North Sea (see collections HE443 and HE 484)North Sea, Helgoland Phytoplankton: This is a collection of phytoplankton and microzooplankton images that have been collected at the island of Helgoland. The collection was assembled to illustrate the current Helgoland phytoplankton checklist. More images resulting from samples analysed for the Helgoland Roads longterm data series are also now being added.North Sea, Waddensea Station Sylt Phytoplankton: This is a collection of phytoplankton images, mostly diatoms and dinoflagellate,s taken in the framework of the Waddensea station's Long-term monitoring programme in the Wadden Sea. The station is part of the Alfred-Wegener Institute for Polar and Marine Research (see also Helgoland collections). This set of images also contains the collection of Dr. Gerhard Drebes that was recently transferred to an electronic format. This collection contains series of images of the whole cell cycle of many phytoplankton species and spans almost 40 years. This is a hisotoric dataset that we archive to preserve it. With many images more than 40 years old we cannot guarantee correct identification.North Sea, Helgoland Roads Phytoplankton Monitoring: This image collection contains images taken from net samples and Utermöhl chambers during count operations and biodiversity assessments for the Helgoland Roads phytoplankton monitoring series.NOSOAT 2016: Description: This Collection documents the the Phytoplankton communityencountered in Polarstern cruise PS102 which started at the port of Bremerhaven and continued through the English Channel, Bay of Biscay and then along the African West Coast to Capetown. The NOSOAT cruise hosted a cohort of Students on a physical oceanography Course. However during the cruise Phytoplankton samples were also taken and analyzed upon return to Bremerhaven. The results are presented here. The cruise was funded jointly by POGO and the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research