- Spanish National Research Council Spain
- The University of Texas System United States
- University of California, San Diego United States
- University of East Anglia United Kingdom
- Fisheries and Oceans Canada Canada
- University of Hawaiʻi Sea Grant United States
- University of California System United States
- Texas A&M University United States
- University of California San Diego, Scripps Institution of Oceanography United States
- Bedford Institute of Oceanography Canada
- Instituto de Ciencias Marinas de Andalucía Spain
- Scripps Institution of Oceanography, University of California San Diego, US United States
- Scripps Institution of Oceanography United States
- Université du Québec à Rimouski Canada
- Scripps Institution of Oceanography United States
- University of Concepción Chile
- Monterey Bay Aquarium Research Institute United States
- University of Connecticut United States
- Texas A & M University United States
The smallest marine phytoplankton, collectively termed picophytoplankton, have been routinely enumerated by flow cytometry since the late 1980s during cruises throughout most of the world ocean. We compiled a database of 40 946 data points, with separate abundance entries for Prochlorococcus, Synechococcus and picoeukaryotes. We use average conversion factors for each of the three groups to convert the abundance data to carbon biomass. After gridding with 1° spacing, the database covers 2.4% of the ocean surface area, with the best data coverage in the North Atlantic, the South Pacific and North Indian basins, and at least some data in all other basins. The average picophytoplankton biomass is 12 ± 22 μg C l−1 or 1.9 g C m−2. We estimate a total global picophytoplankton biomass of 0.53–1.32 Pg C (17–39% Prochlorococcus, 12–15% Synechococcus and 49–69% picoeukaryotes), with an intermediate/best estimate of 0.74 Pg C. Future efforts in this area of research should focus on reporting calibrated cell size and collecting data in undersampled regions. http://doi.pangaea.de/10.1594/PANGAEA.777385