Seawater carbonate chemistry and microbial abundances, bacterial activity and extracellular enzyme activities

DOI

We investigated the effects of an increase in dissolved CO2 on the microbial communities of the Mediterranean Sea during two mesocosm experiments in two contrasting seasons: winter, at the peak of the annual phytoplankton bloom, and summer, under low nutrient conditions. The experiments included treatments with acidification and nutrient addition, and combinations of the two. We followed the effects of ocean acidification (OA) on the abundance of the main groups of microorganisms (diatoms, dinoflagellates, nanoeukaryotes, picoeukaryotes, cyanobacteria, and heterotrophic bacteria) and on bacterial activity, leucine incorporation, and extracellular enzyme activity. Our results showed a clear stimulation effect of OA on the abundance of small phytoplankton (pico- and nanoeukaryotes), independently of the season and nutrient availability. A large number of the measured variables showed significant positive effects of acidification in summer compared with winter, when the effects were sometimes negative. Effects of OA were more conspicuous when nutrient concentrations were low. Our results therefore suggest that microbial communities in oligotrophic waters are considerably affected by OA, whereas microbes in more productive waters are less affected. The overall enhancing effect of acidification on eukaryotic pico- and nanophytoplankton, in comparison with the non-significant or even negative response to nutrient-rich conditions of larger groups and autotrophic prokaryotes, suggests a shift towards medium-sized producers in a future acidified ocean.

In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2021) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2021-07-28.

Identifier
DOI https://doi.org/10.1594/PANGAEA.934302
Related Identifier https://doi.org/10.1093/icesjms/fsv130
Related Identifier https://cran.r-project.org/web/packages/seacarb/index.html
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.934302
Provenance
Creator Sala, M M; Aparicio, F L; Balagué, Vanessa; Boras, J A; Borrull, E; Cardelus, C; Cros, Lluisa; Gomes, Ana; Lopez-Sanz, Angel; Malits, A; Martinez, R A; Mestre, M; Movilla, Juancho; Sarmento, Hugo; Vazquez-Dominguez, E; Vaqué, Dolors; Pinhassi, J; Calbet, Albert; Calvo, Eva; Gasol, Josep M; Pelejero, Carles; Marrasé, Celia
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Contributor Yang, Yan
Publication Year 2016
Rights Creative Commons Attribution 4.0 International; https://creativecommons.org/licenses/by/4.0/
OpenAccess true
Representation
Language English
Resource Type Dataset
Format text/tab-separated-values
Size 3914 data points
Discipline Earth System Research
Spatial Coverage (2.800 LON, 41.667 LAT)