Extreme Variations of pCO2 and pH in a Macrophyte Meadow of the Baltic Sea in Summer: Evidence of the Effect of Photosynthesis and Local Upwelling
Saderne, V.; Fietzek, P.; Herman, P.M.J. (2013). Extreme Variations of pCO2 and pH in a Macrophyte Meadow of the Baltic Sea in Summer: Evidence of the Effect of Photosynthesis and Local Upwelling. PLoS One 8(4). dx.doi.org/10.1371/journal.pone.0062689
In: PLoS One. Public Library of Science: San Francisco. ISSN 1932-6203; e-ISSN 1932-6203, more
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| Authors | | Top |
- Saderne, V.
- Fietzek, P.
- Herman, P.M.J., more
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| Abstract |
The impact of ocean acidification on benthic habitats is a major preoccupation of the scientific community. However, the natural variability of pCO2 and pH in those habitats remains understudied, especially in temperate areas. In this study we investigated temporal variations of the carbonate system in nearshore macrophyte meadows of the western Baltic Sea. These are key benthic ecosystems, providing spawning and nursery areas as well as food to numerous commercially important species. In situ pCO2, pH (total scale), salinity and PAR irradiance were measured with a continuous recording sensor package dropped in a shallow macrophyte meadow (Eckernforde bay, western Baltic Sea) during three different weeks in July pCO2 and PAR only), August and September 2011. The mean (+/- SD) pCO2 in July was 3836117 mu atm. The mean (+/- SD) pCO2 and pH(tot) in August were 239 +/- 20 mu atm and 8.22 +/- 0.1, respectively. The mean (+/- SD) pCO2 and pHtot in September were 1082 +/- 711 mu atm and 7.83 +/- 0.40, respectively. Daily variations of pCO2 due to photosynthesis and respiration (difference between daily maximum and minimum) were of the same order of magnitude: 281 +/- 88 mu atm, 219 +/- 89 mu atm and 1488 +/- 574 mu atm in July, August and September respectively. The observed variations of pCO2 were explained through a statistical model considering wind direction and speed together with PAR irradiance. At a time scale of days to weeks, local upwelling of elevated pCO(2) water masses with offshore winds drives the variation. Within days, primary production is responsible. The results demonstrate the high variability of the carbonate system in nearshore macrophyte meadows depending on meteorology and biological activities. We highlight the need to incorporate these variations in future pCO2 scenarios and experimental designs for nearshore habitats. |
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