scholarly journals Linear extension, skeletal density, and calcification rates of the blue coral Heliopora coerulea

Coral Reefs ◽  
2021 ◽  
Author(s):  
Travis A. Courtney ◽  
James R. Guest ◽  
Alasdair J. Edwards ◽  
Romeo M. Dizon
Keyword(s):  
Thermal Stress ◽  
Ocean Acidification ◽  
Linear Extension ◽  
Ocean Warming ◽  
Storm Damage ◽  
Relative Resistance ◽  
Skeletal Density ◽  
Building Capacity ◽  
West Pacific

AbstractThe brooding reef-building octocoral Heliopora is widespread on Indo-West Pacific reefs and appears to be relatively resistant to thermal stress, which may enable it to persist locally while scleractinians diminish under Anthropocene conditions. However, basic physiological measurements of “blue corals” are lacking and prevent their inclusion in trait-based studies. We address this by quantifying rates (mean ± SE) of linear extension (0.86 ± 0.05 cm yr−1) and skeletal density (2.01 ± 0.06 g cm−3) to estimate calcification rates (0.87 ± 0.08 g cm−2 yr−1) for the small branching/columnar morphology of Heliopora coerulea. We postulate that H. coerulea may become an increasingly important reef-builder under ocean warming due to its relative resistance to thermal stress and high skeletal density that make colonies less vulnerable to storm damage under ocean acidification. Moreover, Heliopora corals are likely dispersal limited suggesting they may be an underappreciated genus for restoration of stress-tolerant reef-building capacity on degraded reefs.

scholarly journals Thermal stress reduces pocilloporid coral resilience to ocean acidification by impairing control over calcifying fluid chemistry

2021 ◽  
Vol 7 (2) ◽  
pp. eaba9958
Author(s):  
Maxence Guillermic ◽  
Louise P. Cameron ◽  
Ilian De Corte ◽  
Sambuddha Misra ◽  
Jelle Bijma ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Ocean Acidification ◽  
Pocillopora Damicornis ◽  
Carbonate Chemistry ◽  
Negative Interaction ◽  
Saturation State ◽  
Stylophora Pistillata ◽  
Coral Calcification ◽  
Influence Of Temperature On ◽  
Different Time Scales

The combination of thermal stress and ocean acidification (OA) can more negatively affect coral calcification than an individual stressors, but the mechanism behind this interaction is unknown. We used two independent methods (microelectrode and boron geochemistry) to measure calcifying fluid pH (pHcf) and carbonate chemistry of the corals Pocillopora damicornis and Stylophora pistillata grown under various temperature and pCO2 conditions. Although these approaches demonstrate that they record pHcf over different time scales, they reveal that both species can cope with OA under optimal temperatures (28°C) by elevating pHcf and aragonite saturation state (Ωcf) in support of calcification. At 31°C, neither species elevated these parameters as they did at 28°C and, likewise, could not maintain substantially positive calcification rates under any pH treatment. These results reveal a previously uncharacterized influence of temperature on coral pHcf regulation—the apparent mechanism behind the negative interaction between thermal stress and OA on coral calcification.

scholarly journals Ocean acidification induces biochemical and morphological changes in the calcification process of large benthic foraminifera

2015 ◽  
Vol 282 (1803) ◽  
pp. 20142782 ◽  
Author(s):  
Martina Prazeres ◽  
Sven Uthicke ◽  
John M. Pandolfi
Keyword(s):  
Ocean Acidification ◽  
Benthic Foraminifera ◽  
Morphological Changes ◽  
Ambient Conditions ◽  
Skeletal Density ◽  
Buoyant Weight ◽  
Large Benthic Foraminifera ◽  
Sediment Formation ◽  
Ph Conditions ◽  
Main Factor

Large benthic foraminifera are significant contributors to sediment formation on coral reefs, yet they are vulnerable to ocean acidification. Here, we assessed the biochemical and morphological impacts of acidification on the calcification of Amphistegina lessonii and Marginopora vertebralis exposed to different pH conditions. We measured growth rates (surface area and buoyant weight) and Ca-ATPase and Mg-ATPase activities and calculated shell density using micro-computer tomography images. In A. lessonii , we detected a significant decrease in buoyant weight, a reduction in the density of inner skeletal chambers, and an increase of Ca-ATPase and Mg-ATPase activities at pH 7.6 when compared with ambient conditions of pH 8.1. By contrast, M. vertebralis showed an inhibition in Mg-ATPase activity under lowered pH, with growth rate and skeletal density remaining constant. While M. vertebralis is considered to be more sensitive than A. lessonii owing to its high-Mg-calcite skeleton, it appears to be less affected by changes in pH, based on the parameters assessed in this study. We suggest difference in biochemical pathways of calcification as the main factor influencing response to changes in pH levels, and that A. lessonii and M. vertebralis have the ability to regulate biochemical functions to cope with short-term increases in acidity.

Assessment of ocean acidification and warming on the growth, calcification, and biophotonics of a California grass shrimp

2017 ◽  
Vol 74 (4) ◽  
pp. 1150-1158 ◽  
Author(s):  
Kaitlyn B. Lowder ◽  
Michael C. Allen ◽  
James M. D. Day ◽  
Dimitri D. Deheyn ◽  
Jennifer R. A. Taylor
Keyword(s):  
Ocean Acidification ◽  
Environmental Conditions ◽  
Spectral Reflectance ◽  
Visual Communication ◽  
Carapace Length ◽  
Grass Shrimp ◽  
Ocean Warming ◽  
Increased Temperature

Cryptic colouration in crustaceans, important for both camouflage and visual communication, is achieved through physiological and morphological mechanisms that are sensitive to changes in environmental conditions. Consequently, ocean warming and ocean acidification can affect crustaceans’ biophotonic appearance and exoskeleton composition in ways that might disrupt colouration and transparency. In the present study, we measured growth, mineralization, transparency, and spectral reflectance (colouration) of the caridean grass shrimp Hippolyte californiensis in response to pH and temperature stressors. Shrimp were exposed to ambient pH and temperature (pH 8.0, 17 °C), decreased pH (pH 7.5, 17 °C), and decreased pH/increased temperature (pH 7.5, 19 °C) conditions for 7 weeks. There were no differences in either Mg or Ca content in the exoskeleton across treatments nor in the transparency and spectral reflectance. There was a small but significant increase in percent growth in the carapace length of shrimp exposed to decreased pH/increased temperature. Overall, these findings suggest that growth, calcification, and colour of H. californiensis are unaffected by decreases of 0.5 pH units. This tolerance might stem from adaptation to the highly variable pH environment that these grass shrimp inhabit, highlighting the multifarious responses to ocean acidification, within the Crustacea.

scholarly journals Losing a winner: thermal stress and local pressures outweigh the positive effects of ocean acidification for tropical seagrasses

2018 ◽  
Vol 219 (3) ◽  
pp. 1005-1017 ◽  
Author(s):  
Catherine J. Collier ◽  
Lucas Langlois ◽  
Yan Ow ◽  
Charlotte Johansson ◽  
Manuela Giammusso ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Ocean Acidification ◽  
Positive Effects ◽  
Local Pressures

scholarly journals Warming up, turning sour, losing breath: ocean biogeochemistry under global change

2011 ◽  
Vol 369 (1943) ◽  
pp. 1980-1996 ◽  
Author(s):  
Nicolas Gruber
Keyword(s):  
Ocean Acidification ◽  
Synergistic Effects ◽  
Biogeochemical Cycles ◽  
Ocean Warming ◽  
Low Oxygen ◽  
Primary Driver ◽  
Stratified Ocean ◽  
Biological Environment ◽  
Induced Changes ◽  
Ocean Deoxygenation

In the coming decades and centuries, the ocean’s biogeochemical cycles and ecosystems will become increasingly stressed by at least three independent factors. Rising temperatures, ocean acidification and ocean deoxygenation will cause substantial changes in the physical, chemical and biological environment, which will then affect the ocean’s biogeochemical cycles and ecosystems in ways that we are only beginning to fathom. Ocean warming will not only affect organisms and biogeochemical cycles directly, but will also increase upper ocean stratification. The changes in the ocean’s carbonate chemistry induced by the uptake of anthropogenic carbon dioxide (CO 2 ) (i.e. ocean acidification) will probably affect many organisms and processes, although in ways that are currently not well understood. Ocean deoxygenation, i.e. the loss of dissolved oxygen (O 2 ) from the ocean, is bound to occur in a warming and more stratified ocean, causing stress to macro-organisms that critically depend on sufficient levels of oxygen. These three stressors—warming, acidification and deoxygenation—will tend to operate globally, although with distinct regional differences. The impacts of ocean acidification tend to be strongest in the high latitudes, whereas the low-oxygen regions of the low latitudes are most vulnerable to ocean deoxygenation. Specific regions, such as the eastern boundary upwelling systems, will be strongly affected by all three stressors, making them potential hotspots for change. Of additional concern are synergistic effects, such as ocean acidification-induced changes in the type and magnitude of the organic matter exported to the ocean’s interior, which then might cause substantial changes in the oxygen concentration there. Ocean warming, acidification and deoxygenation are essentially irreversible on centennial time scales, i.e. once these changes have occurred, it will take centuries for the ocean to recover. With the emission of CO 2 being the primary driver behind all three stressors, the primary mitigation strategy is to reduce these emissions.

scholarly journals PRACTICAL GUIDELINES FOR ASSESSING CORAL CALCIFICATION VIA COMPUTED TOMOGRAPHY

2018 ◽  
Vol 43 (2) ◽  
pp. 95-99
Author(s):  
Intan Suci Nurhati
Keyword(s):  
Computed Tomography ◽  
Ocean Acidification ◽  
Environmental Changes ◽  
Interdisciplinary Approach ◽  
Standard Operating Procedure ◽  
Ecological Impacts ◽  
Extension Rate ◽  
Skeletal Density ◽  
Coral Calcification ◽  
Practical Guidelines

Coral calcification as the product of extension rate and skeletal density, is projected to change under marine environmental changes of local (e.g., sedimentation, eutrophication) and global (e.g., warming, ocean acidification) scales. For the regional effort to monitor the ecological impacts of ocean acidification on coral reef ecosystems, the Intergovernmental Oceanographic Commission Sub-Commission for the Western Pacific (IOC-WESTPAC) has incorporated an interdisciplinary approach that includes monitoring of seawater carbonate parameters, coral calcification, net calcification minus bioerosion, and reef community structure. Currently, there is a need to formulate a standard operating procedure (SOP) for assessing coral calcification over the recent years via coral cores. The SOP needs to yield accurate data in a cost-effective way that can be applied by researchers in the region. High variation of coral calcification parameters between coral colonies warrants a sufficiently large number of samples thus a rapid method for analyzing coral extension rate, skeletal density, and calcification. This paper outlines practical guidelines for assessing coral calcification from the field to laboratory using the three-dimensional computed tomography (CT) method.

scholarly journals Thermal stress jeopardizes carbonate production of coral reefs across the western and central Pacific Ocean

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249008
Author(s):  
Robert van Woesik ◽  
Christopher William Cacciapaglia
Keyword(s):  
Thermal Stress ◽  
Pacific Ocean ◽  
Coral Reefs ◽  
Stress Gradient ◽  
Tropical Pacific ◽  
Tropical Pacific Ocean ◽  
Central Pacific ◽  
Carbonate Production ◽  
Building Capacity ◽  
Habitat Differences

Coral reefs protect islands, coastal areas, and their inhabitants from storm waves and provide essential goods and services to millions of people worldwide. Yet contemporary rates of ocean warming and local disturbances are jeopardizing the reef-building capacity of coral reefs to keep up with rapid rates of sea-level rise. This study compared the reef-building capacity of shallow-water habitats at 142 sites across a potential thermal-stress gradient in the tropical Pacific Ocean. We sought to determine the extent to which habitat differences and environmental variables potentially affect rates of net carbonate production. In general, outer-exposed reefs and lagoonal-patch reefs had higher rates of net carbonate production than nearshore reefs. The study found that thermal anomalies, particularly the intensity of thermal-stress events, play a significant role in reducing net carbonate production—evident as a diminishing trend of net carbonate production from the western to the central tropical Pacific Ocean. The results also showed a latent spatial effect along the same gradient, not explained by thermal stress, suggesting that reefs in the western tropical Pacific Ocean are potentially enhanced by the proximity of reefs in the Coral Triangle—an effect that diminishes with increasing distance and isolation.

scholarly journals Food availability and <i>p</i>CO<sub>2</sub> impacts on planulation, juvenile survival, and calcification of the azooxanthellate scleractinian coral, <i>Balanophyllia elegans</i>

2013 ◽  
Vol 10 (5) ◽  
pp. 7761-7783 ◽  
Author(s):  
E. D. Crook ◽  
H. Cooper ◽  
D. C. Potts ◽  
T. Lambert ◽  
A. Paytan
Keyword(s):  
Ocean Acidification ◽  
Coastal Upwelling ◽  
Food Level ◽  
Juvenile Survival ◽  
High Food ◽  
Saturation State ◽  
Skeletal Density ◽  
Algal Symbionts ◽  
Aragonite Crystal ◽  
Food Conditions

Abstract. Ocean acidification, the assimilation of atmospheric CO2 by the oceans that decreases the pH and CaCO3 saturation state (Ω) of seawater, is projected to have severe consequences for calcifying organisms. Strong evidence suggests that tropical reef-building corals containing algal symbionts (zooxanthellae) will experience dramatic declines in calcification over the next century. The responses of azooxanthellate corals to ocean acidification are less well understood, and because they cannot obtain extra photosynthetic energy from symbionts, they provide a system for studying the direct effects of acidification on the energy available for calcification. The orange cup coral Balanophyllia elegans is a solitary, azooxanthellate scleractinian species common on the California coast where it thrives in the low pH waters of an upwelling regime. During an 8 month study, we addressed the effects of three pCO2 treatments (410, 770, and 1230 μatm) and two feeding frequencies (High Food and Low Food) on adult Balanophyllia elegans planulation (larval release) rates, and on the survival, growth, and calcification of their juvenile offspring. Planulation rates were affected by food level but not pCO2, while juvenile survival was highest under 410 μatm and High Food conditions. Our results suggest that feeding rate has a greater impact on calcification of B. elegans than pCO2. Net calcification was positive even at 1230 μatm (~ 3 times current atmospheric pCO2), although the increase from 410 to 1230 μatm reduced overall calcification by ~ 25–45%, and reduced skeletal density by ~ 35–45%. Higher pCO2 also altered aragonite crystal morphology significantly. We discuss how feeding frequency affects azooxanthellate coral calcification, and how B. elegans may respond to ocean acidification in coastal upwelling waters.

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