_version_ 1867171817824714752
author Yamamoto, Shoji
Kayanne, Hajime
Terai, Makoto
Watanabe, Atsushi
Kato, Ken
Negishi, Akira
Nozaki, Ken
author_facet Yamamoto, Shoji
Kayanne, Hajime
Terai, Makoto
Watanabe, Atsushi
Kato, Ken
Negishi, Akira
Nozaki, Ken
collection Datos científicos de ciencias marinas y ambientales
contents Acidification of the oceans by increasing anthropogenic CO2 emissions will cause a decrease in biogenic calcification and an increase in carbonate dissolution. Previous studies have suggested that carbonate dissolution will occur in polar regions and in the deep sea where saturation state with respect to carbonate minerals (Omega) will be <1 by 2100. Recent reports demonstrate nocturnal carbonate dissolution of reefs, despite a Omega a (aragonite saturation state) value of >1. This is probably related to the dissolution of reef carbonate (Mg-calcite), which is more soluble than aragonite. However, the threshold of Omega for the dissolution of natural sediments has not been clearly determined. We designed an experimental dissolution system with conditions mimicking those of a natural coral reef, and measured the dissolution rates of aragonite in corals, and of Mg-calcite excreted by other marine organisms, under conditions of Omega a > 1, with controlled seawater pCO2. The experimental data show that dissolution of bulk carbonate sediments sampled from a coral reef occurs at Omega a values of 3.7 to 3.8. Mg-calcite derived from foraminifera and coralline algae dissolves at Omega a values between 3.0 and 3.2, and coralline aragonite starts to dissolve when Omega a = 1.0. We show that nocturnal carbonate dissolution of coral reefs occurs mainly by the dissolution of foraminiferans and coralline algae in reef sediments.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_820200
institution PANGAEA
language en
publishDate 2012
publisher PANGAEA
record_format pangaea
spellingShingle Seawater carbonate chemistry and net dissolution rate for experiment of Shiraho reef
Yamamoto, Shoji
Kayanne, Hajime
Terai, Makoto
Watanabe, Atsushi
Kato, Ken
Negishi, Akira
Nozaki, Ken
Alkalinity, total; Aragonite saturation state; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcification/Dissolution; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, partial pressure; Coast and continental shelf; Dissolution rate; Duration; Entire community; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Infrared gas analyzer (NDIR); Laboratory experiment; North Pacific; OA-ICC; Ocean acidification; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH, total scale; Potentiometric titration; Rocky-shore community; Salinity; Sample mass; Shirahoreef; Standardized to a constant salinity; Temperate; Temperature, water; Treatment; Water volume
Acidification of the oceans by increasing anthropogenic CO2 emissions will cause a decrease in biogenic calcification and an increase in carbonate dissolution. Previous studies have suggested that carbonate dissolution will occur in polar regions and in the deep sea where saturation state with respect to carbonate minerals (Omega) will be <1 by 2100. Recent reports demonstrate nocturnal carbonate dissolution of reefs, despite a Omega a (aragonite saturation state) value of >1. This is probably related to the dissolution of reef carbonate (Mg-calcite), which is more soluble than aragonite. However, the threshold of Omega for the dissolution of natural sediments has not been clearly determined. We designed an experimental dissolution system with conditions mimicking those of a natural coral reef, and measured the dissolution rates of aragonite in corals, and of Mg-calcite excreted by other marine organisms, under conditions of Omega a > 1, with controlled seawater pCO2. The experimental data show that dissolution of bulk carbonate sediments sampled from a coral reef occurs at Omega a values of 3.7 to 3.8. Mg-calcite derived from foraminifera and coralline algae dissolves at Omega a values between 3.0 and 3.2, and coralline aragonite starts to dissolve when Omega a = 1.0. We show that nocturnal carbonate dissolution of coral reefs occurs mainly by the dissolution of foraminiferans and coralline algae in reef sediments.
title Seawater carbonate chemistry and net dissolution rate for experiment of Shiraho reef
topic Alkalinity, total; Aragonite saturation state; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcification/Dissolution; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, partial pressure; Coast and continental shelf; Dissolution rate; Duration; Entire community; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Infrared gas analyzer (NDIR); Laboratory experiment; North Pacific; OA-ICC; Ocean acidification; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH, total scale; Potentiometric titration; Rocky-shore community; Salinity; Sample mass; Shirahoreef; Standardized to a constant salinity; Temperate; Temperature, water; Treatment; Water volume
url https://doi.org/10.1594/PANGAEA.820200