Productivity gains do not compensate for reduced calcification under near-future ocean acidification in the photosynthetic benthic foraminifer speciesMarginopora vertebralis

2012 ◽  
Vol 18 (9) ◽  
pp. 2781-2791 ◽  
Author(s):  
Sven Uthicke ◽  
Katharina E. Fabricius
2016 ◽  
Author(s):  
Merinda C. Nash ◽  
Sophie Martin ◽  
Jean-Pierre Gattuso

Abstract. Red calcareous coralline algae are thought to be among organisms the most vulnerable to ocean acidification due to the high solubility of their magnesium calcite skeleton. Although, skeletal mineralogy is proposed to change as CO2 and temperature continues rising, there is currently very little information available on the response of coralline algal carbonate mineralogy to near-future changes in pCO2 and temperature. Here we present results from a one-year controlled laboratory experiment to test mineralogical responses to pCO2 and temperature in the Mediterranean crustose coralline alga (CCA) Lithophyllum cabiochae. Our results show that Mg incorporation is mainly constrained by temperature (+1 mol% MgCO3 for an increase of 3 °C) and there was no response to pCO2. This suggests that L. cabiochae thalli have the ability to buffer calcifying medium against ocean acidification, enabling them to continue to deposit Mg-calcite with a significant mol% MgCO3 under elevated pCO2. Analyses of CCA dissolution chips showed a decrease in Mg content after 1 year for all treatments but this was not affected by pCO2 nor by temperature. Our findings suggest that biological processes exert a strong control on calcification on Mg-calcite and that CCA may be more resilient under rising CO2 than previously thought. However, previously demonstrated increased skeletal dissolution with ocean acidification will still have major consequences for the stability and maintenance of Mediterranean coralligenous habitats.


2018 ◽  
Vol 14 (7) ◽  
pp. 20180371 ◽  
Author(s):  
Maggie D. Johnson ◽  
Robert C. Carpenter

Ocean acidification (OA) and nutrient enrichment threaten the persistence of near shore ecosystems, yet little is known about their combined effects on marine organisms. Here, we show that a threefold increase in nitrogen concentrations, simulating enrichment due to coastal eutrophication or consumer excretions, offset the direct negative effects of near-future OA on calcification and photophysiology of the reef-building crustose coralline alga, Porolithon onkodes . Projected near-future pCO 2 levels (approx. 850 µatm) decreased calcification by 30% relative to ambient conditions. Conversely, nitrogen enrichment (nitrate + nitrite and ammonium) increased calcification by 90–130% in ambient and high pCO 2 treatments, respectively. pCO 2 and nitrogen enrichment interactively affected instantaneous photophysiology, with highest relative electron transport rates under high pCO 2 and high nitrogen. Nitrogen enrichment alone increased concentrations of the photosynthetic pigments chlorophyll a , phycocyanin and phycoerythrin by approximately 80–450%, regardless of pCO 2 . These results demonstrate that nutrient enrichment can mediate direct organismal responses to OA. In natural systems, however, such direct benefits may be counteracted by simultaneous increases in negative indirect effects, such as heightened competition. Experiments exploring the effects of multiple stressors are increasingly becoming important for improving our ability to understand the ramifications of local and global change stressors in near shore ecosystems.


2009 ◽  
Vol 6 (12) ◽  
pp. 3009-3015 ◽  
Author(s):  
J. N. Havenhand ◽  
P. Schlegel

Abstract. An increasing number of studies are now reporting the effects of ocean acidification on a broad range of marine species, processes and systems. Many of these are investigating the sensitive early life-history stages that several major reviews have highlighted as being potentially most susceptible to ocean acidification. Nonetheless there remain few investigations of the effects of ocean acidification on the very earliest, and critical, process of fertilization, and still fewer that have investigated levels of ocean acidification relevant for the coming century. Here we report the effects of near-future levels of ocean acidification (≈−0.35 pH unit change) on sperm swimming speed, sperm motility, and fertilization kinetics in a population of the Pacific oyster Crassostrea gigas from western Sweden. We found no significant effect of ocean acidification – a result that was well-supported by power analysis. Similar findings from Japan suggest that this may be a globally robust result, and we emphasise the need for experiments on multiple populations from throughout a species' range. We also discuss the importance of sound experimental design and power analysis in meaningful interpretation of non-significant results.


2013 ◽  
Vol 19 (7) ◽  
pp. 2264-2275 ◽  
Author(s):  
Maria Byrne ◽  
Melanie A. Ho ◽  
Lucas Koleits ◽  
Casandra Price ◽  
Catherine K. King ◽  
...  

2013 ◽  
Vol 368 (1627) ◽  
pp. 20120442 ◽  
Author(s):  
Sean D. Connell ◽  
Kristy J. Kroeker ◽  
Katharina E. Fabricius ◽  
David I. Kline ◽  
Bayden D. Russell

Predictions concerning the consequences of the oceanic uptake of increasing atmospheric carbon dioxide (CO 2 ) have been primarily occupied with the effects of ocean acidification on calcifying organisms, particularly those critical to the formation of habitats (e.g. coral reefs) or their maintenance (e.g. grazing echinoderms). This focus overlooks direct and indirect effects of CO 2 on non-calcareous taxa that play critical roles in ecosystem shifts (e.g. competitors). We present the model that future atmospheric [CO 2 ] may act as a resource for mat-forming algae, a diverse and widespread group known to reduce the resilience of kelp forests and coral reefs. We test this hypothesis by combining laboratory and field CO 2 experiments and data from ‘natural’ volcanic CO 2 vents. We show that mats have enhanced productivity in experiments and more expansive covers in situ under projected near-future CO 2 conditions both in temperate and tropical conditions. The benefits of CO 2 are likely to vary among species of producers, potentially leading to shifts in species dominance in a high CO 2 world. We explore how ocean acidification combines with other environmental changes across a number of scales, and raise awareness of CO 2 as a resource whose change in availability could have wide-ranging community consequences beyond its direct effects.


2017 ◽  
Vol 13 (2) ◽  
pp. 20160797 ◽  
Author(s):  
Sue-Ann Watson ◽  
Jennifer B. Fields ◽  
Philip L. Munday

Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (CO 2 ) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus . Projected near-future seawater CO 2 levels (975 µatm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm min −1 ) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 µatm). Despite increasing activity, elevated CO 2 reduced predation rate during predator–prey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus ; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated CO 2 predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predator–prey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predator–prey relationship are altered by elevated CO 2 suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades.


2011 ◽  
Vol 69 (3) ◽  
pp. 460-464 ◽  
Author(s):  
Steve S. Doo ◽  
Symon A. Dworjanyn ◽  
Shawna A. Foo ◽  
Natalie A. Soars ◽  
Maria Byrne

Abstract Doo, S. S., Dworjanyn, S. A., Foo, S. A., Soars, N. A., and Byrne, M. 2012. Impacts of ocean acidification on development of the meroplanktonic larval stage of the sea urchin Centrostephanus rodgersii. – ICES Journal of Marine Science, 69: 460–464. The effects of near-future ocean acidification/hypercapnia on larval development were investigated in the sea urchin Centrostephanus rodgersii, a habitat-modifying species from eastern Australia. Decreased pH (−0.3 to −0.5 pH units) or increased pCO2 significantly reduced the percentage of normal larvae. Larval growth was negatively impacted with smaller larvae in the pH 7.6/1800 ppm treatments. The impact of acidification on development was similar on days 3 and 5, indicating deleterious effects early in development. On day 3, increased abnormalities in the pH 7.6/1600 ppm treatment were seen in aberrant prism stage larvae and arrested/dead embryos. By day 5, echinoplutei in this treatment had smaller arm rods. Observations of smaller larvae in C. rodgersii have significant implications for this species because larval success may be a potential bottleneck for persistence in a changing ocean.


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