A global diatom database - abundance, biovolume and biomass in the world ocean

• Published in: Earth System Science Data
• Main Authors: Leblanc, K, Aristegui, J, Armand, L, Assmy, P, Beker, B, Bode, A, Breton, E, Cornet, V, Gibson, J, Gosselin, M-P, Kopczynska, E, Marshall, H, Peloquin, J, Piontkovski, S, Poulton, AJ, Queguiner, B, Schiebel, R, Shipe, R, Stefels, J, van Leeuwe, MA, Varela, M, Widdicombe, C, Yallop, M
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2012
• Subjects: Biological Sciences; Ecology; Marine and Estuarine Ecology (incl. Marine Ichthyology); Arctic; Indian; Pacific; Southern Ocean; Phytoplankton
• Online Access: https://doi.org/10.5194/essd-4-149-2012; http://ecite.utas.edu.au/83471

Phytoplankton identification and abundance data are now commonly feedingplankton distribution databases worldwide. This study is a first attempt tocompile the largest possible body of data available from different databasesas well as from individual published or unpublished datasets regardingdiatom distribution in the world ocean. The data obtained originate fromtime series studies as well as spatial studies. This effort is supported bythe Marine Ecosystem Model Inter-Comparison Project (MAREMIP), which aims atbuilding consistent datasets for the main plankton functional types (PFTs) inorder to help validate biogeochemical ocean models by using carbon (C)biomass derived from abundance data. In this study we collected over 293 000individual geo-referenced data points with diatom abundances from bottle andnet sampling. Sampling site distribution was not homogeneous, with 58% ofdata in the Atlantic, 20% in the Arctic, 12% in the Pacific, 8% inthe Indian and 1% in the Southern Ocean. A total of 136 different generaand 607 different species were identified after spell checking and namecorrection. Only a small fraction of these data were also documented forbiovolumes and an even smaller fraction was converted to C biomass. As it isvirtually impossible to reconstruct everyone's method for biovolumecalculation, which is usually not indicated in the datasets, we decided toundertake the effort to document, for every distinct species, the minimumand maximum cell dimensions, and to convert all the available abundance datainto biovolumes and C biomass using a single standardized method.Statistical correction of the database was also adopted to exclude potentialoutliers and suspicious data points. The final database contains 90 648 datapoints with converted C biomass. Diatom C biomass calculated from cell sizesspans over eight orders of magnitude. The mean diatom biomass for individuallocations, dates and depths is 141.19 μg C l −1 , while the medianvalue is 11.16 μg C l −1 . Regarding biomass distribution, 19%of data are in the range 01 μg C l −1 , 29% in the range 110 μg C l −1 ,31% in the range 10100 μg C l −1 ,18% in the range 1001000 μg C l −1 , and only 3%> 1000 μg C l −1 . Interestingly, less than 50 speciescontributed to > 90% of global biomass, among which centricspecies were dominant. Thus, placing significant efforts on cell sizemeasurements, process studies and C quota calculations of these speciesshould considerably improve biomass estimates in the upcoming years. Afirst-order estimate of the diatom biomass for the global ocean ranges from444 to 582 Tg C, which converts to 3 to 4 Tmol Si and to an average Sibiomass turnover rate of 0.15 to 0.19 d −1 .Link to the dataset: doi:10.1594/PANGAEA.777384 .