Ocean Acidification Reduces Skeletal Density of Hardground‐Forming High‐Latitude Crustose Coralline Algae

2021 ◽  
Vol 48 (5) ◽  
Author(s):  
B. Williams ◽  
P. T. W. Chan ◽  
I. T. Westfield ◽  
D. B. Rasher ◽  
J. Ries
Keyword(s):  
Ocean Acidification ◽  
High Latitude ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Skeletal Density

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

Recent density decline in wild-collected subarctic crustose coralline algae reveals climate change signature

Geology ◽  
2019 ◽  
Vol 48 (3) ◽  
pp. 226-230 ◽  
Author(s):  
P.T.W. Chan ◽  
J. Halfar ◽  
W.H. Adey ◽  
P.A. Lebednik ◽  
R. Steneck ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Benthic Communities ◽  
Crustose Coralline Alga ◽  
Coralline Algae ◽  
Co2 Uptake ◽  
Strong Correlations ◽  
Crustose Coralline Algae ◽  
Skeletal Density ◽  
Surface Ocean

Abstract Warming surface ocean temperatures combined with the continued diffusion of atmospheric CO2 into seawater have been shown to have detrimental impacts on calcareous marine organisms in tropical and temperate localities. However, greater oceanic CO2 uptake in higher latitudes may present a higher oceanic acidification risk to carbonate organisms residing in Arctic and subarctic habitats. This is especially true for crustose coralline algae that build their skeletons using high-Mg calcite, which is among the least stable and most soluble of the carbonate minerals. Here we present a century-long annually resolved growth, density, and calcification rate record from the crustose coralline alga Clathromorphum nereostratum, a dominant calcifier in Pacific Arctic and subarctic benthic communities. Specimens were collected from the Aleutian Islands, Alaska (USA), a region that has undergone a long-term decline of 0.08 ± 0.01 pH units since the late 19th century. Growth and calcification rates remain relatively stable throughout the record, but skeletal densities have declined substantially since A.D. 1983. Strong correlations to warming sea-surface temperatures indicate that temperature stress may play a significant role in influencing the ability of corallines to calcify. Decreasing algal skeletal density may offset the benefits of continued growth and calcification due to a weakening in structural integrity, which could have detrimental consequences for the diverse reef-like communities associated with algal structures in mid-to-high latitudes.

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 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 Changes in coral reef communities across a natural gradient in seawater pH

2015 ◽  
Vol 1 (5) ◽  
pp. e1500328 ◽  
Author(s):  
Hannah C. Barkley ◽  
Anne L. Cohen ◽  
Yimnang Golbuu ◽  
Victoria R. Starczak ◽  
Thomas M. DeCarlo ◽  
...  
Keyword(s):  
Coral Reef ◽  
Ocean Acidification ◽  
Benthic Communities ◽  
Coral Community ◽  
Low Ph ◽  
Coralline Algae ◽  
Negative Effects ◽  
Skeletal Density ◽  
Coral Communities ◽  
Coral Reef Ecosystems

Ocean acidification threatens the survival of coral reef ecosystems worldwide. The negative effects of ocean acidification observed in many laboratory experiments have been seen in studies of naturally low-pH reefs, with little evidence to date for adaptation. Recently, we reported initial data suggesting that low-pH coral communities of the Palau Rock Islands appear healthy despite the extreme conditions in which they live. Here, we build on that observation with a comprehensive statistical analysis of benthic communities across Palau’s natural acidification gradient. Our analysis revealed a shift in coral community composition but no impact of acidification on coral richness, coralline algae abundance, macroalgae cover, coral calcification, or skeletal density. However, coral bioerosion increased 11-fold as pH decreased from the barrier reefs to the Rock Island bays. Indeed, a comparison of the naturally low-pH coral reef systems studied so far revealed increased bioerosion to be the only consistent feature among them, as responses varied across other indices of ecosystem health. Our results imply that whereas community responses may vary, escalation of coral reef bioerosion and acceleration of a shift from net accreting to net eroding reef structures will likely be a global signature of ocean acidification.

scholarly journals Ocean acidification induces carry-over effects on the larval settlement of the New Zealand abalone, Haliotis iris

2020 ◽  
Author(s):  
Nadjejda Espinel-Velasco ◽  
Miles Lamare ◽  
Anna Kluibenschedl ◽  
Graeme Moss ◽  
Vonda Cummings
Keyword(s):  
New Zealand ◽  
Ocean Acidification ◽  
Larval Settlement ◽  
Marine Organisms ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Important Species ◽  
Seawater Ph ◽  
Settlement Success ◽  
Carry Over

Abstract Larval settlement is a key process in the lifecycle of benthic marine organisms; however, little is known on how it could change in reduced seawater pH and carbonate saturation states under future ocean acidification (OA). This is important, as settlement ensures species occur in optimal environments and, for commercially important species such as abalone, reduced settlement could decrease future population success. We investigated how OA could affect settlement success in the New Zealand abalone Haliotis iris by examining: (1) direct effects of seawater at ambient (pHT 8.05) and reduced pHT (7.65) at the time of settlement, (2) indirect effects of settlement substrates (crustose coralline algae, CCA) preconditioned at ambient and reduced pHT for 171 days, and (3) carry-over effects, by examining settlement in larvae reared to competency at ambient and reduced pHT (7.80). We found no effects of seawater pH or CCA incubation on larval settlement success. OA-induced carry-over effects were evident, with lower settlement in larvae reared at reduced pH. Understanding the mechanisms behind these responses is key to fully comprehend the extent to which OA will affect marine organisms and the industries that rely on them.

scholarly journals Ocean acidification reduces induction of coral settlement by crustose coralline algae

2012 ◽  
Vol 19 (1) ◽  
pp. 303-315 ◽  
Author(s):  
Nicole S. Webster ◽  
Sven Uthicke ◽  
Emanuelle S. Botté ◽  
Florita Flores ◽  
Andrew P. Negri
Keyword(s):  
Ocean Acidification ◽  
Coralline Algae ◽  
Crustose Coralline Algae ◽  
Coral Settlement
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