scholarly journals Coral reef calcifiers buffer their response to ocean acidification using both bicarbonate and carbonate

2013 ◽  
Vol 280 (1753) ◽  
pp. 20122374 ◽  
Author(s):  
S. Comeau ◽  
R. C. Carpenter ◽  
P. J. Edmunds
Keyword(s):  
Coral Reef ◽  
Ocean Acidification ◽  
Conceptual Models ◽  
Sea Water ◽  
Empirical Support ◽  
Ion Concentration ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Carbonate Ion ◽  
Negative Effect

Central to evaluating the effects of ocean acidification (OA) on coral reefs is understanding how calcification is affected by the dissolution of CO 2 in sea water, which causes declines in carbonate ion concentration [CO 3 2− ] and increases in bicarbonate ion concentration [HCO 3 − ]. To address this topic, we manipulated [CO 3 2− ] and [HCO 3 − ] to test the effects on calcification of the coral Porites rus and the alga Hydrolithon onkodes , measured from the start to the end of a 15-day incubation, as well as in the day and night. [CO 3 2− ] played a significant role in light and dark calcification of P. rus , whereas [HCO 3 − ] mainly affected calcification in the light. Both [CO 3 2− ] and [HCO 3 − ] had a significant effect on the calcification of H. onkodes , but the strongest relationship was found with [CO 3 2− ]. Our results show that the negative effect of declining [CO 3 2− ] on the calcification of corals and algae can be partly mitigated by the use of HCO 3 − for calcification and perhaps photosynthesis. These results add empirical support to two conceptual models that can form a template for further research to account for the calcification response of corals and crustose coralline algae to OA.

The coral reef-dwelling Peneroplis spp. shows calcification resilience to ocean acidification conditions - results from culture experiments

2021 ◽  
Author(s):  
Laurie Charrieau ◽  
Katsunori Kimoto ◽  
Delphine Dissard ◽  
Beatrice Below ◽  
Kazuhiko Fujita ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Ocean Acidification ◽  
Sea Water ◽  
General Structure ◽  
Ion Concentration ◽  
Large Benthic Foraminifera ◽  
Carbonate Ion ◽  
Short Period

<p>Ocean acidification is a consequence of current anthropogenic climate changes. The concomitant decrease in pH and carbonate ion concentration in sea water may have severe impacts on calcifying organisms. Coral reefs are among the first ecosystems recognized vulnerable to ocean acidification. Within coral reefs, large benthic foraminifera (LBF) are major calcium carbonate producers.</p><p>The aim of this study was to evaluate the effects of varying pH on survival and calcification of the symbiont-bearing LBF species <em>Peneroplis</em> spp. We performed culture experiments to study their resistance to ocean acidification conditions, as well as their resilience once placed back under open ocean pH (7.9).</p><p>After three days, small signs of test decalcification were observed on specimens kept at pH 7.4, and severe test decalcification was observed on specimens kept at pH 6.9, with the inner organic lining clearly appearing. After 32 days under pH 7.4, similar strongly decalcified specimens were observed. All the specimens were alive at the end of the experiment. This result demonstrates the resistance of <em>Peneroplis </em>spp. to an acidified pH, at least on a short period of time.</p><p>After being partially decalcified, some of the living specimens were placed back at pH 7.9. After one month, the majority of the specimens showed recalcification features, mostly by addition of new chambers. The trace elements concentrations of the newly formed chambers were analysed by LA-ICPMS. Interestingly, more chambers were added when food was given, which highlights the crucial role of energy source in the recalcification process. Moreover, the newly formed chambers were most of the time abnormal, and the general structure of the tests was altered, with potential impacts on reproduction and in situ survival. In conclusion, if symbiont-bearing LBF show some resistance and resilience to lowered pH conditions, they will remain strongly affected by ocean acidification.</p>

Global warming offsets the ecophysiological stress of ocean acidification on temperate crustose coralline algae

2020 ◽  
Vol 157 ◽  
pp. 111324 ◽  
Author(s):  
Ju-Hyoung Kim ◽  
Nahyun Kim ◽  
Hanbi Moon ◽  
Sukyeon Lee ◽  
So Young Jeong ◽  
...  
Keyword(s):  
Global Warming ◽  
Ocean Acidification ◽  
Coralline Algae ◽  
Crustose Coralline Algae

scholarly journals Rapid multi-generational acclimation of coralline algal reproductive structures to ocean acidification

2021 ◽  
Vol 288 (1950) ◽  
Author(s):  
B. Moore ◽  
S. Comeau ◽  
M. Bekaert ◽  
A. Cossais ◽  
A. Purdy ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Growth Rates ◽  
Natural Habitat ◽  
Algal Growth ◽  
Coralline Algae ◽  
Reproductive Structures ◽  
Highly Sensitive ◽  
Negative Effect ◽  
Coral Reef Ecosystems

The future of coral reef ecosystems is under threat because vital reef-accreting species such as coralline algae are highly susceptible to ocean acidification. Although ocean acidification is known to reduce coralline algal growth rates, its direct effects on the development of coralline algal reproductive structures (conceptacles) is largely unknown. Furthermore, the long-term, multi-generational response of coralline algae to ocean acidification is extremely understudied. Here, we investigate how mean pH, pH variability and the pH regime experienced in their natural habitat affect coralline algal conceptacle abundance and size across six generations of exposure. We show that second-generation coralline algae exposed to ocean acidification treatments had conceptacle abundances 60% lower than those kept in present-day conditions, suggesting that conceptacle development is initially highly sensitive to ocean acidification. However, this negative effect of ocean acidification on conceptacle abundance disappears after three generations of exposure. Moreover, we show that this transgenerational acclimation of conceptacle development is not facilitated by a trade-off with reduced investment in growth, as higher conceptacle abundances are associated with crusts with faster growth rates. These results indicate that the potential reproductive output of coralline algae may be sustained under future ocean acidification.

scholarly journals Low recruitment due to altered settlement substrata as primary constraint for coral communities under ocean acidification

2017 ◽  
Vol 284 (1862) ◽  
pp. 20171536 ◽  
Author(s):  
Katharina E. Fabricius ◽  
Sam H. C. Noonan ◽  
David Abrego ◽  
Lindsay Harrington ◽  
Glenn De'ath
Keyword(s):  
Coral Reefs ◽  
Ocean Acidification ◽  
Field Experiments ◽  
Later Life ◽  
Coralline Algae ◽  
Life Stages ◽  
Crustose Coralline Algae ◽  
Coral Recruitment ◽  
Recovery Potential ◽  
Coral Communities

The future of coral reefs under increasing CO 2 depends on their capacity to recover from disturbances. To predict the recovery potential of coral communities that are fully acclimatized to elevated CO 2 , we compared the relative success of coral recruitment and later life stages at two volcanic CO 2 seeps and adjacent control sites in Papua New Guinea. Our field experiments showed that the effects of ocean acidification (OA) on coral recruitment rates were up to an order of magnitude greater than the effects on the survival and growth of established corals. Settlement rates, recruit and juvenile densities were best predicted by the presence of crustose coralline algae, as opposed to the direct effects of seawater CO 2 . Offspring from high CO 2 acclimatized parents had similarly impaired settlement rates as offspring from control parents. For most coral taxa, field data showed no evidence of cumulative and compounding detrimental effects of high CO 2 on successive life stages, and three taxa showed improved adult performance at high CO 2 that compensated for their low recruitment rates. Our data suggest that severely declining capacity for reefs to recover, due to altered settlement substrata and reduced coral recruitment, is likely to become a dominant mechanism of how OA will alter coral reefs.

scholarly journals Impact of carbonate saturation on large Caribbean benthic foraminifera assemblages

2018 ◽  
Author(s):  
Ana Martinez ◽  
Laura Hernández-Terrones ◽  
Mario Rebolledo-Vieyra ◽  
Adina Paytan
Keyword(s):  
Ocean Acidification ◽  
Benthic Foraminifera ◽  
Atmospheric Carbon Dioxide ◽  
Inorganic Carbon ◽  
Low Ph ◽  
Ion Concentration ◽  
Relative Distribution ◽  
Submarine Springs ◽  
Carbonate Ion ◽  
Calcite Saturation

Abstract. Increasing atmospheric carbon dioxide and its dissolution in seawater have reduced ocean pH and carbonate ion concentration with potential implications to calcifying organisms. To assess the response of Caribbean benthic foraminifera to low carbonate saturation conditions, we analyzed benthic foraminifera abundance and relative distribution in proximity to low carbonate saturation submarine springs and at adjacent control sites. Our results show that the total abundance of benthic foraminifera is significantly lower at the low pH low calcite saturation submarine springs than at control sites, despite higher concentrations of inorganic carbon at the spring sites. The relative abundance of symbiont-bearing foraminifera and agglutinated foraminifera was higher at the low pH low calcite saturation submarine springs compared to control sites. These differences indicate that non-symbiont bearing heterotrophic calcareous foraminifera are more sensitive to the effects of ocean acidification than non-calcifying and symbiont bearing foraminifera, suggesting that future ocean acidification may impact natural benthic foraminifera populations.

scholarly journals Ocean acidification does not affect magnesium composition or dolomite formation in living crustose coralline algae, <i>Porolithon onkodes</i> in an experimental system

2015 ◽  
Vol 12 (2) ◽  
pp. 1373-1404 ◽  
Author(s):  
M. C. Nash ◽  
S. Uthicke ◽  
A. P. Negri ◽  
N. E. Cantin
Keyword(s):  
Ocean Acidification ◽  
Experimental System ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Experimental Conditions ◽  
Pco2 Treatment ◽  
Wide Range ◽  
Dolomite Formation ◽  
Time Frames ◽  
Near Future

Abstract. There are concerns that Mg-calcite crustose coralline algae (CCA), which are key reef builders on coral reefs, will be most susceptible to increased rates of dissolution under higher pCO2 and ocean acidification. Due to the higher solubility of Mg-calcite, it has been hypothesized that magnesium concentrations in CCA Mg-calcite will decrease as the ocean acidifies, and that this decrease will make their skeletons more chemically stable. In addition to Mg-calcite, CCA Porolithon onkodes the predominant encrusting species on tropical reefs, can have dolomite (Ca0.5Mg0.5CO3) infilling cell spaces which increases their stability. However, nothing is known about how bio-mineralised dolomite formation responds to higher pCO2. Using P. onkodes grown for 3 and 6 months in tank experiments, we aimed to determine (1) if mol % MgCO3 in new crust and new settlement affected by increasing pCO2 levels (365, 444, 676 and 904 ppm), (2) whether bio-mineralised dolomite formed within these time frames, and (3) if so, whether this was effected by pCO2. Our results show there was no significant effect of pCO2 on mol % MgCO3 in any sample set, indicating an absence of a plastic response under a wide range of experimental conditions. Dolomite within the CCA cells formed within 3 months and dolomite abundance did not vary significantly with pCO2 treatment. While evidence mounts that climate change will impact many sensitive coral and CCA species, the results from this study indicate that reef-building P. onkodes will continue to form stabilising dolomite infill under near-future acidification conditions, thereby retaining its higher resistance to dissolution.

scholarly journals Re-evaluating the health of coral reef communities: baselines and evidence for human impacts across the central Pacific

2016 ◽  
Vol 283 (1822) ◽  
pp. 20151985 ◽  
Author(s):  
Jennifer E. Smith ◽  
Rusty Brainard ◽  
Amanda Carter ◽  
Saray Grillo ◽  
Clinton Edwards ◽  
...  
Keyword(s):  
Coral Reef ◽  
Human Impacts ◽  
Phase Shifts ◽  
Coralline Algae ◽  
Human Populations ◽  
Limited Information ◽  
Crustose Coralline Algae ◽  
Central Pacific ◽  
Reef Communities ◽  
Coral Reef Communities

Numerous studies have documented declines in the abundance of reef-building corals over the last several decades and in some but not all cases, phase shifts to dominance by macroalgae have occurred. These assessments, however, often ignore the remainder of the benthos and thus provide limited information on the present-day structure and function of coral reef communities. Here, using an unprecedentedly large dataset collected within the last 10 years across 56 islands spanning five archipelagos in the central Pacific, we examine how benthic reef communities differ in the presence and absence of human populations. Using islands as replicates, we examine whether benthic community structure is associated with human habitation within and among archipelagos and across latitude. While there was no evidence for coral to macroalgal phase shifts across our dataset we did find that the majority of reefs on inhabited islands were dominated by fleshy non-reef-building organisms (turf algae, fleshy macroalgae and non-calcifying invertebrates). By contrast, benthic communities from uninhabited islands were more variable but in general supported more calcifiers and active reef builders (stony corals and crustose coralline algae). Our results suggest that cumulative human impacts across the central Pacific may be causing a reduction in the abundance of reef builders resulting in island scale phase shifts to dominance by fleshy organisms.

scholarly journals Effect of carbonate ion concentration and irradiance on calcification in planktonic foraminifera

2010 ◽  
Vol 7 (1) ◽  
pp. 247-255 ◽  
Author(s):  
F. Lombard ◽  
R. E. da Rocha ◽  
J. Bijma ◽  
J.-P. Gattuso
Keyword(s):  
Ocean Acidification ◽  
Planktonic Foraminifera ◽  
High Light ◽  
Ion Concentration ◽  
Low Light ◽  
Calcification Rate ◽  
Shell Size ◽  
Shell Weight ◽  
Carbonate Ion ◽  
Orbulina Universa

Abstract. The effect of carbonate ion concentration ([CO32−]) on calcification rates estimated from shell size and weight was investigated in the planktonic foraminifera Orbulina universa and Globigerinoides sacculifer. Experiments on G. sacculifer were conducted under two irradiance levels (35 and 335 μmol photons m−2 s−1). Calcification was ca. 30% lower under low light than under high light, irrespective of the [CO32−]. Both O. universa and G. sacculifer exhibited reduced final shell weight and calcification rate under low [CO32−]. For the [CO32−] expected at the end of the century, the calcification rates of these two species are projected to be 6 to 13% lower than the present conditions, while the final shell weights are reduced by 20 to 27% for O. universa and by 4 to 6% for G. sacculifer. These results indicate that ocean acidification would impact on calcite production by foraminifera and may decrease the calcite flux contribution from these organisms.

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