Tara Oceans imaging dataset for N2-fixers

Tara Oceans expeditions were designed for studying plankton ecosystems at global scale. The first expeditions took place between 2009 and 2013 and this dataset represents a subset of the imaging dataset annotated as N2-fixers using two different methods. The first method corresponds to Environmental High-Content Fluorescent Microscopy image data generated by the EMBL Advanced Light Microscopy Facility. This subset included images annotated as diatom-diazotroph associations, Trichodesmium filaments and other N2-fixers when analysing 61 samples collected using a microplankton net (20-180 ?m mesh size) at 48 different stations. The second method corresponds to images generated in situ by an Underwater Vision Profiler 5 (UVP5, Hydroptics, France) mounted on the Rosette Vertical Sampling System. This system allows to illuminate precisely calibrated volumes of water and capture images during the descent. The UVP5 was operated in situ and was designed to detect and count objects of >100 ?m in length and to identify those of >600 ?m in size, and the current specific subset correspond to images annotated as Trichodesmium colonies (fusiform-shaped colonies usually referred to as ‘tufts’ or round-shaped colonies called ‘puffs).