Comparison of the alkalinity and calcium anomaly techniques to estimate rates of net calcification

Gazeau, Frédéric; Urbini, Lidia; Cox, Te; Alliouane, Samir; Gattuso, Jean‐Pierre

doi:10.3354/meps11287

Cited by 32 publications

(30 citation statements)

References 53 publications

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“…Measurements of both shell height and length are used routinely during the thinning process of scallops in commercial aquaculture operations (Hennen & Hart 2012). In addition, calcification and dissolution rates (see also Gazeau et al 2015) were estimated from changes in the buoyant weight of individual scallops and changes in empty shell weight recorded on Days 1 and 18 of the experiment using an analytical balance. Briefly, the buoyant weight is a non-destructive technique useful to estimate the shell weight in gastropods, where the whole animal is immersed in seawater (Palmer 1982).…”

Section: Biological Responsesmentioning

confidence: 99%

Effects of temperature and ocean acidification on shell characteristics of Argopecten purpuratus: implications for scallop aquaculture in an upwelling-influenced area

Lagos¹,

Benítez²,

Duarte³

et al. 2016

Aquacult. Environ. Interact.

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mate system, leading to increased global mean temperatures (i.e. global warming) of approximately 0.7°C, a trend that will continue and fluctuate over a broad range (1−4°C) towards the end of the century (IPCC 2014 ABSTRACT: Coastal upwelling regions already constitute hot spots of ocean acidification as naturally acidified waters are brought to the surface. This effect could be exacerbated by ocean acidification and warming, both caused by rising concentrations of atmospheric CO 2 . Along the Chilean coast, upwelling supports highly productive fisheries and aquaculture activities. However, during recent years, there has been a documented decline in the national production of the native scallop Argopecten purpuratus. We assessed the combined effects of temperature and pCO 2 -driven ocean acidification on the growth rates and shell characteristics of this species farmed under the natural influence of upwelling waters occurring in northern Chile (30°S, Tongoy Bay). The experimental scenario representing current conditions (14°C, pH ~8.0) were typical of natural values recorded in Tongoy Bay, whilst conditions representing the low pH scenario were typical of an adjacent upwelling area (pH ~7.6). Shell thickness, weight, and biomass were reduced under low pH (pH ~7.7) and increased temperature (18°C) conditions. At ambient temperature (14°C) and low pH, scallops showed increased shell dissolution and low growth rates. However, elevated temperatures ameliorated the impacts of low pH, as evidenced by growth rates in both pH treatments at the higher temperature treatment that were not significantly different from the control treatment. The impact of low pH at current temperature on scallop growth suggests that the upwelling could increase the time required for scallops to reach marketable size. Mortality of farmed scallops is discussed in relation to our observations of multiple environmental stressors in this upwelling-influenced area.

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Section: Biological Responsesmentioning

confidence: 99%

Effects of temperature and ocean acidification on shell characteristics of Argopecten purpuratus: implications for scallop aquaculture in an upwelling-influenced area

Lagos¹,

Benítez²,

Duarte³

et al. 2016

Aquacult. Environ. Interact.

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“…Total alkalinity was determined according to the method described above. Net calcification rates at light and in the dark (G l and G d , respectively; in µmol CaCO 3 g DW −1 h −1 ) were calculated according to the alkalinity anomaly technique (Smith and Key, 1975) and corrected for NH + 4 fluxes (Gazeau et al, 2015). This correction was applied to calcareous species and assemblage incubations following Eq.…”

Section: Metabolic Measurementsmentioning

confidence: 99%

“…For instance, urchins defecated carbonate pellets following consumption of maerl thalli. These feces are likely to dissolve during incubation, introducing a bias in the measurement of calcification (Gazeau et al, 2015). In the summer, temperature increase by 3 • C reduced P. miliaris respiration rates.…”

Section: Net Production Gross Productionmentioning

confidence: 99%

Species interactions can shift the response of a maerl bed community to ocean acidification and warming

et al. 2017

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Abstract. Predicted ocean acidification and warming are likely to have major implications for marine organisms, especially marine calcifiers. However, little information is available on the response of marine benthic communities as a whole to predicted changes. Here, we experimentally examined the combined effects of temperature and partial pressure of carbon dioxide (pCO 2 ) increases on the response of maerl bed assemblages, composed of living and dead thalli of the free-living coralline alga Lithothamnion corallioides, epiphytic fleshy algae, and grazer species. Two 3-month experiments were performed in the winter and summer seasons in mesocosms with four different combinations of pCO 2 (ambient and high pCO 2 ) and temperature (ambient and +3 • C). The response of maerl assemblages was assessed using metabolic measurements at the species and assemblage scales. This study suggests that seasonal variability represents an important driver influencing the magnitude and the direction of species and community response to climate change. Gross primary production and respiration of assemblages was enhanced by high pCO 2 conditions in the summer. This positive effect was attributed to the increase in epiphyte biomass, which benefited from higher CO 2 concentrations for growth and primary production. Conversely, high pCO 2 drastically decreased the calcification rates in assemblages. This response can be attributed to the decline in calcification rates of living L. corallioides due to acidification and increased dissolution of dead L. corallioides. Future changes in pCO 2 and temperature are likely to promote the development of non-calcifying algae to the detriment of the engineer species L. corallioides. The development of fleshy algae may be modulated by the ability of grazers to regulate epiphyte growth. However, our results suggest that predicted changes will negatively affect the metabolism of grazers and potentially their ability to control epiphyte abundance. We show here that the effects of pCO 2 and temperature on maerl bed communities were weakened when these factors were combined. This underlines the importance of examining multifactorial approaches and community-level processes, which integrate species interactions, to better understand the impact of global change on marine ecosystems.

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“…For instance, coral communities have already proven to be particularly vulnerable to rapidly changing global environmental conditions (e.g., Albright et al, 2018). In order to help project the future of coral reefs, accurate estimates of calcification rates during realistic perturbation experiments are necessary in order to produce high-quality and intercomparable results (Cohen et al, 2017;Gazeau et al, 2015;Langdon et al, 2010;Riebesell et al, 2010;Schoepf et al, 2017).…”

mentioning

confidence: 99%

Intercomparison of four methods to estimate coral calcification under various environmental conditions

et al. 2020

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Abstract. Coral reefs are constructed by calcifiers that precipitate calcium carbonate to build their shells or skeletons through the process of calcification. Accurately assessing coral calcification rates is crucial to determine the health of these ecosystems and their response to major environmental changes such as ocean warming and acidification. Several approaches have been used to assess rates of coral calcification, but there is a real need to compare these approaches in order to ascertain that high-quality and intercomparable results can be produced. Here, we assessed four methods (total alkalinity anomaly, calcium anomaly, 45Ca incorporation, and 13C incorporation) to determine coral calcification of the reef-building coral Stylophora pistillata. Given the importance of environmental conditions for this process, the study was performed under two starting pH levels (ambient: 8.05 and low: 7.2) and two light (light and dark) conditions. Under all conditions, calcification rates estimated using the alkalinity and calcium anomaly techniques as well as 45Ca incorporation were highly correlated. Such a strong correlation between the alkalinity anomaly and 45Ca incorporation techniques has not been observed in previous studies and most probably results from improvements described in the present paper. The only method which provided calcification rates significantly different from the other three techniques was 13C incorporation. Calcification rates based on this method were consistently higher than those measured using the other techniques. Although reasons for these discrepancies remain unclear, the use of this technique for assessing calcification rates in corals is not recommended without further investigations.

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Comparison of the alkalinity and calcium anomaly techniques to estimate rates of net calcification

Abstract: Calcification rates in 4 benthic calcifiers with distinct metabolism were determined by both the alkalinity and calcium anomaly techniques: (A) coralline alga, (B) scleractinian coral, (C) sea urchin, (D) mussel.

Cited by 32 publications

References 53 publications

Effects of temperature and ocean acidification on shell characteristics of Argopecten purpuratus: implications for scallop aquaculture in an upwelling-influenced area

Effects of temperature and ocean acidification on shell characteristics of Argopecten purpuratus: implications for scallop aquaculture in an upwelling-influenced area

Species interactions can shift the response of a maerl bed community to ocean acidification and warming

Intercomparison of four methods to estimate coral calcification under various environmental conditions

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