Description: It is expected that the calcification of foraminifera will be negatively affected by the ongoing acidification of the oceans. Compared to the open oceans, these organisms are subjected to much more adverse carbonate system conditions in coastal and estuarine environments such as the southwestern Baltic Sea, where benthic foraminifera are abundant. This study documents the seasonal changes of carbonate chemistry and the ensuing response of the foraminiferal community with bi-monthly resolution in Flensburg Fjord. In comparison to the surface pCO2, which is close to equilibrium with the atmosphere, we observed large seasonal fluctuations of pCO2 in the bottom and sediment pore waters. The sediment pore water pCO2 was constantly high during the entire year ranging from 1244 to 3324 µatm. Nevertheless, in contrast to the bottom water, sediment pore water was slightly supersaturated with respect to calcite as a consequence of higher alkalinity (AT) for most of the year. Foraminiferal assemblages were dominated by two calcareous species, Ammonia aomoriensis and Elphidium incertum, and the agglutinated Ammotium cassis. The one-year cycle was characterised by seasonal community shifts. Our results revealed that there is no dynamic response of foraminiferal population density and diversity to elevated sediment pore water pCO2. Surprisingly, the fluctuations of sediment pore water undersaturation (Omega calc) co-vary with the population densities of living Ammonia aomoriensis. Further, we observed that most of the tests of living calcifying foraminifera were intact. Only Ammonia aomorienis showed dissolution and recalcification structures on the tests, especially at undersaturated conditions. Therefore, the benthic community is subjected to high pCO2 and tolerates elevated levels as long as sediment pore water remains supersaturated. Model calculations inferred that increasing atmospheric CO2 concentrations will finally lead to a perennial undersaturation in sediment pore waters. Whereas benthic foraminifera indeed may cope with a high sediment pore water pCO2, the steady undersaturation of sediment pore waters would likely cause a significant higher mortality of the dominating Ammonia aomoriensis. This shift may eventually lead to changes in the benthic foraminiferal communities in Flensburg Fjord, as well as in other regions experiencing naturally undersaturated Omega calc levels.
Global identifier:
Doi(
"10.1594/PANGAEA.830063",
)
Measurements(
Measurements {
domain: Unspecified,
station: None,
measured_variables: [
"Identification",
"Species",
"Station label",
"LATITUDE",
"LONGITUDE",
"DEPTH, water",
"Date",
"Description",
"Number of individuals",
"Percentage",
"Number of species",
"Sample volume",
"Split",
"Population density",
"Shannon Diversity Index",
"Fishers alpha index of diversity",
"Percentage",
"Percentage",
"Percentage",
"Percentage",
"Diameter",
"Salinity",
"Temperature, water",
"Pressure, water",
"Alkalinity, total",
"Carbon, inorganic, dissolved",
"Partial pressure of carbon dioxide (water) at sea surface temperature (wet air)",
"Calcite saturation state",
"Carbonate system computation flag",
"pH, total scale",
"Carbon dioxide",
"Partial pressure of carbon dioxide (water) at sea surface temperature (wet air)",
"Fugacity of carbon dioxide (water) at sea surface temperature (wet air)",
"Bicarbonate ion",
"Carbonate ion",
"Aragonite saturation state",
"Calcite saturation state",
],
methods: [
"Calculated using CO2SYS",
"Calculated using CO2SYS",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
"Calculated using seacarb after Nisumaa et al. (2010)",
],
},
)
Dataset
Comment: In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) 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 2014-02-26.
Origins: /Wissenschaft/PANGAEA
Tags: Atmosphärische CO2-Konzentration ? Ammoniak ? Blei ? Meerestemperatur ? Geografische Koordinaten ? Bodenwasser ? Ozeanversauerung ? Benthos ? Gesamtkohlenstoff ? Kohlendioxid ? Salzgehalt ? Gewässerzustand ? Bevölkerungsdichte ? Populationsdichte ? Mortalität ? Studie ? Wasserprobe ? Sediment ? Meeresgewässer ? Wasser ? Modellierung ? Sedimentdynamik ? Atmosphäre ? Gewässer ? Ostsee ? Elphidium excavatum excavatum ? Reophax dentaliniformis ? Soft-bottom community ? Temperate ? Calcification/Dissolution ? Elphidium gerthi ? Ammonia aomoriensis ? Elphidium incertum ? Ammotium cassis ? Entire community ? Coast and continental shelf ? Community composition and diversity ? Field observation ? Growth/Morphology ? Elphidium albiumbilicatum ? Elphidium excavatum clavatum ?
Bounding boxes: 9.613999999999999° .. 9.8915° x 54.782000000000004° .. 54.84166999999999°
License: cc-by/3.0
Language: Englisch/English
Modified: 2022-12-15
Time ranges: 2009-06-01 - 2009-06-30
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