This deliverable reports on Task 2.2 ‘Assembly of observations about microbiomes, plastics, the plastisphere and carbon fluxes’. It used protocols established in task 2.1 ‘Definition of common standards for the assembly of spatially explicit data’ to compile, quality-control and grid existing high-quality observations into a knowledge base of observations (D2.1). Data included into AtlantECO-BASE1 consisted of contributions from the five following data sources and tasks: Task 2.2.1 ‘Microbiome data from traditional microscopy (presence-absence, abundance and biomass)’, Task 2.2.2 ‘Microbiome data from state-of-the-art optical/imaging analysis’, Task 2.2.3 ‘Microbiome and plastisphere data from state-of-the-art genetic analyses’, Task 2.2.4 ‘Nano-, micro and macroplastics data from state-of-the-art sampling methods’, and Task 2.2.5 ‘Carbon flux data from estimated from high resolution bio-optical sensors’. Additional data contributions and mapping efforts from other partners and work packages (Task 2.3) are also included. A comprehensive list and description of all data sets collected can be found in the Appendix Tables to this document.