TY - CHAP
T1 - Response of emMarginopora vertebralis/em (emForaminifera/em) from Laucala Bay, Fiji, to Changing Ocean pH
AU - Naidu, Roselyn
AU - Hallock, Pamela
AU - Erez, Jonathan
AU - Maata, Matakite
AU - Muller, Pamela Hallock
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Increased CO 2 emissions into the atmosphere lead to increased concentrations of dissolved CO 2 in the ocean. A chemical reaction between the dissolved CO 2 and seawater produces HCO 3 − , CO 3 2− and H + ions. These H + ions increase the acidity of seawater and decrease the pH. Increased acidity and decreased availability of CO 3 2− ion affect calcite and aragonite production by marine calcifiers in the ocean. To assess potential responses of the larger benthic foraminifer Marginopora vertebralis to ocean acidification, we performed growth experiments at three pH levels [7.5, 7.8, 8.1 (ambient seawater)] for 11 weeks. Specimens were stained with the fluorescent compound Calcein ( ̴40 µmole/l) prior to treatment, allowing identification of calcite added during the treatment period. At pH 8.1, specimens increased their test weight by 8.4%, at pH 7.8 growth was 4.2%, and at pH 7.5, growth was only 3.2%. These differences represent a significant relationship between ocean pH and test growth (i.e., calcification). In addition, several specimens in the pH 8.1 treatment underwent asexual reproduction during the experiment, while no reproduction was observed in the pH 7.8 or 7.5 treatments. These results indicate that ocean acidification predicted to occur by the end of the 21st century will cause a decline in population densities of Marginopora vertebralis in their natural environment, as consequences of both reduced growth rates and rates of reproduction. And because the tests of these foraminifers are important components of carbonate sediments on coral cays and tropical beaches, a decline in their rates of sediment production will exacerbate the consequences of rising sea level.
AB - Increased CO 2 emissions into the atmosphere lead to increased concentrations of dissolved CO 2 in the ocean. A chemical reaction between the dissolved CO 2 and seawater produces HCO 3 − , CO 3 2− and H + ions. These H + ions increase the acidity of seawater and decrease the pH. Increased acidity and decreased availability of CO 3 2− ion affect calcite and aragonite production by marine calcifiers in the ocean. To assess potential responses of the larger benthic foraminifer Marginopora vertebralis to ocean acidification, we performed growth experiments at three pH levels [7.5, 7.8, 8.1 (ambient seawater)] for 11 weeks. Specimens were stained with the fluorescent compound Calcein ( ̴40 µmole/l) prior to treatment, allowing identification of calcite added during the treatment period. At pH 8.1, specimens increased their test weight by 8.4%, at pH 7.8 growth was 4.2%, and at pH 7.5, growth was only 3.2%. These differences represent a significant relationship between ocean pH and test growth (i.e., calcification). In addition, several specimens in the pH 8.1 treatment underwent asexual reproduction during the experiment, while no reproduction was observed in the pH 7.8 or 7.5 treatments. These results indicate that ocean acidification predicted to occur by the end of the 21st century will cause a decline in population densities of Marginopora vertebralis in their natural environment, as consequences of both reduced growth rates and rates of reproduction. And because the tests of these foraminifers are important components of carbonate sediments on coral cays and tropical beaches, a decline in their rates of sediment production will exacerbate the consequences of rising sea level.
KW - benthic foraminifera
KW - climate change
KW - growth
KW - laucala bay
KW - ocean acidification
KW - ph
UR - https://digitalcommons.usf.edu/msc_facpub/902
UR - https://doi.org/10.1007/978-3-319-50094-2_8
U2 - 10.1007/978-3-319-50094-2_8
DO - 10.1007/978-3-319-50094-2_8
M3 - Chapter
BT - Climate Change Adaptation in Pacific Countries
ER -