Phytoplankton identification and abundance data\rare now commonly feeding plankton distribution databases\rworldwide. This study is a first attempt to compile the largest\rpossible body of data available from different databases as\rwell as from individual published or unpublished datasets\rregarding diatom distribution in the world ocean. The data\robtained originate from time series studies as well as spatial\rstudies. This effort is supported by the Marine Ecosystem Model Inter-Comparison Project (MAREMIP), which aims\rat building consistent datasets for the main plankton functional\rtypes (PFTs) in order to help validate biogeochemical\rocean models by using carbon (C) biomass derived from\rabundance data. In this study we collected over 293 000 individual\rgeo-referenced data points with diatom abundances\rfrom bottle and net sampling. Sampling site distribution was\rnot homogeneous, with 58% of data in the Atlantic, 20%\rin the Arctic, 12% in the Pacific, 8% in the Indian and 1%\rin the Southern Ocean. A total of 136 different genera and\r607 different species were identified after spell checking and\rname correction. Only a small fraction of these data were\ralso documented for biovolumes and an even smaller fraction\rwas converted to C biomass. As it is virtually impossible\rto reconstruct everyone’s method for biovolume calculation,\rwhich is usually not indicated in the datasets, we decided to\rundertake the effort to document, for every distinct species,\rthe minimum and maximum cell dimensions, and to convert\rall the available abundance data into biovolumes and C\rbiomass using a single standardized method. Statistical correction\rof the database was also adopted to exclude potential\routliers and suspicious data points. The final database contains\r90 648 data points with converted C biomass. Diatom\rC biomass calculated from cell sizes spans over eight orders\rof magnitude. The mean diatom biomass for individual locations,\rdates and depths is 141.19 μg Cl−1, while the median\rvalue is 11.16 μg Cl−1. Regarding biomass distribution,\r19% of data are in the range 0–1 μg Cl−1, 29% in the range\r1–10 μg Cl−1, 31% in the range 10–100 μg Cl−1, 18% in\rthe range 100–1000 μg Cl−1, and only 3% > 1000 μg Cl−1.\rInterestingly, less than 50 species contributed to >90% of\rglobal biomass, among which centric species were dominant.\rThus, placing significant efforts on cell size measurements,\rprocess studies and C quota calculations of these\rspecies should considerably improve biomass estimates in\rthe upcoming years. A first-order estimate of the diatom\rbiomass for the global ocean ranges from 444 to 582 Tg C,\rwhich converts to 3 to 4 Tmol Si and to an average Si\rbiomass turnover rate of 0.15 to 0.19 d−1. Link to the dataset:\rdoi:10.1594/PANGAEA.777384.
Gosselin, M.-P. (2012). A global diatom database – abundance, biovolume and biomass in the world ocean. Earth System Science Data Discussions, 5(1), 147–185. https://doi.org/10.5194/essdd-5-147-2012