In:
Biogeosciences, Copernicus GmbH, Vol. 19, No. 22 ( 2022-11-22), p. 5269-5285
Abstract:
Abstract. Ocean acidification (OA) is expected to negatively affect many
ecologically important organisms. Here we report the response of Caribbean
benthic foraminiferal assemblages to naturally discharging low-pH waters
with a composition similar to that expected for the end of the 21st
century. At low pH ∼ 7.8 and low saturation state with respect
to calcite (Ωcalcite 〈 4), the relative abundance of
hyaline, agglutinated, and symbiont-bearing species increased, indicating
higher resistance to potential carbonate chemistry changes. Diversity and
other taxonomical metrics (i.e., richness, abundance, and evenness) declined
steeply with decreasing pH despite exposure of this ecosystem to low-pH
conditions for millennia, suggesting that tropical foraminiferal communities
will be negatively impacted under acidification scenarios SSP3-7.0 (Shared
Socioeconomic Pathways) and
SSP5-8.5. The species Archaias angulatus, a major contributor to sediment production in the
Caribbean, was able to calcify at more extreme conditions (7.1 pH) than those
projected for the late 21st century, but the calcified tests had a
lower average density than those exposed to higher-pH conditions (7.96),
indicating that reef foraminiferal carbonate production might decrease this
century. Smaller foraminifera were particularly sensitive to low pH, and our
results demonstrate their potential use to monitor OA conditions.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-19-5269-2022
DOI:
10.5194/bg-19-5269-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2158181-2
