Ocean acidification may increase calcification, but at a cost. Proc Roy Soc Lond B

Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, UK.
Proceedings of the Royal Society B: Biological Sciences (Impact Factor: 5.05). 09/2008; 275(1644):1767-73. DOI: 10.1098/rspb.2008.0343
Source: PubMed


Ocean acidification is the lowering of pH in the oceans as a result of increasing uptake of atmospheric carbon dioxide. Carbon dioxide is entering the oceans at a greater rate than ever before, reducing the ocean's natural buffering capacity and lowering pH. Previous work on the biological consequences of ocean acidification has suggested that calcification and metabolic processes are compromised in acidified seawater. By contrast, here we show, using the ophiuroid brittlestar Amphiura filiformis as a model calcifying organism, that some organisms can increase the rates of many of their biological processes (in this case, metabolism and the ability to calcify to compensate for increased seawater acidity). However, this upregulation of metabolism and calcification, potentially ameliorating some of the effects of increased acidity comes at a substantial cost (muscle wastage) and is therefore unlikely to be sustainable in the long term.


Available from: Hannah Louise Wood
  • Source
    • "Contrary to studies on many calcifying invertebrates (e.g. Wood et al., 2008; Kroeker et al., 2010; Wittmann and Pörtner, 2013), juveniles of the common cuttlefish Sepia officinalis actually mineralize more CaCO 3 in their cuttlebones during exposure to elevated seawater pCO 2 , while maintaining growth and metabolism (Gutowska et al., 2008, 2010b; Dorey et al., 2013). Questions remain as to how S. officinalis responds to ocean acidification in terms of physiology, development, and growth. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Elevated pCO2 drives lower growth and yet increased calcification in the early life history of the cuttlefish Sepia officinalis Ocean acidification is an escalating environmental issue and associated changes in the ocean carbonate system have implications for many calcifying organisms. The present study followed the growth of Sepia officinalis from early-stage embryos, through hatching, to 7-week-old juveniles. Responses of cuttlefish to elevated pCO 2 (hypercapnia) were investigated to test the impacts of near-future and extreme ocean acidification conditions on growth, developmental time, oxygen consumption, and yolk utilization as proxies for individual fitness. We further examined gross morphological characteristics of the internal calcareous cuttlebone to determine whether embryonically secreted shell lamellae are impacted by environmental hypercapnia. Embryonic growth was reduced and hatching delayed under elevated pCO 2 , both at environmentally relevant levels (0.14 kPa pCO 2 similar to predicted ocean conditions in 2100) and extreme conditions (0.40 kPa pCO 2). Comparing various metrics from control and intermediate treatments generally showed no significant difference in experimental measurements. Yet, results from the high pCO 2 treatment showed significant changes compared with controls and revealed a consistent general trend across the three treatment levels. The proportion of animal mass contributed by the cuttlebone increased in both elevated pCO 2 treatments. Gross cuttlebone morphology was affected under such conditions and cuttlebones of hypercapnic individuals were proportionally shorter. Embryonic shell morphology was maintained consistently in all treatments, despite compounding hypercapnia in the perivitelline fluid; however, post-hatching, hypercapnic animals developed denser cuttlebone laminae in shorter cuttlebones. Juvenile cuttlefish in acidified environments thus experience lower growth and yet increased calcification of their internal shell. The results of this study support recent findings that early cuttlefish life stages are more vulnerable towards hypercapnia than juveniles and adults, which may have negative repercussions on the biological fitness of cuttlefish hatchlings in future oceans.
    ICES Journal of Marine Science 10/2015; DOI:10.1093/icesjms/fsv188 · 2.38 Impact Factor
  • Source
    • "damage to the gills or digestive epithelia, and impaired cardiac function) (Lawson et al., 1995; Giari et al., 2007; Lannig et al., 2008). Exposure to elevated CO 2 may exacerbate the negative effects of metals on energy balance by increasing the basal maintenance costs often observed during exposure to moderate hypercapnia (Wood et al., 2008; Munday et al., 2009; Lannig et al., 2010; Dissanayake and Ishimatsu, 2011; Stumpp et al., 2011; Catarino et al., 2012; Strobel et al., 2012; Dickinson et al., 2013; Matoo et al., 2013) and at least partially driven by elevated energy demand for protein synthesis and ion transport (Pan et al., 2015). In contrast, extremely elevated P CO2 or low pH typically causes the metabolic rate depression (Michaelidis et al., 2005; Melatunan et al., 2011; Hu et al., 2014). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Changes in the global environment such as ocean acidification (OA) may interact with anthropogenic pollutants including trace metals threatening the integrity of marine ecosystems. We analyze recent studies on the interactive effects of OA and trace metals on marine organisms with a focus on the physiological basis of these interactions. Our analysis shows that the responses to elevated CO2 and metals are strongly dependent on the species, developmental stage, metal biochemistry and the degree of environmental hypercapnia, and cannot be directly predicted from the CO2-induced changes in metal solubility and speciation. The key physiological functions affected by both the OA and trace metal exposures involve acid-base regulation, protein turnover and mitochondrial bioenergetics, reflecting the sensitivity of the underlying molecular and cellular pathways to CO2 and metals. Physiological interactions between elevated CO2 and metals may impact the organisms’ capacity to maintain acid-base homeostasis and reduce the amount of energy available for fitness-related functions such as growth, development and reproduction thereby affecting survival and performance of estuarine populations. Environmental hypercapnia may also affect the marine food webs by altering predator-prey interactions and the trophic transfer of metals in the food chain. However, our understanding of the degree to which these effects can impact the function and integrity of marine ecosystems is limited due the scarcity of the published research and its bias towards certain taxonomic groups. Future research priorities should include studies of metal x PCO2 interactions focusing on critical physiological functions (including acid-base, protein and energy homeostasis) in a greater range of ecologically and economically important marine species, as well as including the field populations naturally exposed (and potentially adapted) to different levels of metals and CO2 in their environments.
    Current Zoology 08/2015; 61(4):653-668. · 1.59 Impact Factor
    • "Ideally, this added realism would not be sacrificed in an attempt to increase the numbers of experimental units, which further highlights the complexities faced by future ocean acidification research. A large number of studies have found that ocean acidification will likely negatively impact the calcification or growth of calcifying invertebrates, coccolithophores, calcifying macroalgae, and corals (Riebesell et al., 2000; Gazeau et al., 2007; Anthony et al., 2008; Wood et al., 2008; Byrne et al., 2010), and influence the behavioural traits of invertebrates and fish (Munday et al., 2009; Appelhans et al., 2012; Nilsson et al., 2012). Subsequent shifts in ecosystem structure and function are likely to occur due to the direct biological effects on many ecologically important species (Hall-Spencer et al., 2008; Fabricius et al., 2011; Kroeker et al., 2013a). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Ocean acidification has been identified as a risk to marine ecosystems, and substantial scientific effort has been expended on investigating its effects, mostly in laboratory manipulation experiments. However, performing these manipulations correctly can be logistically difficult, and correctly designing experiments is complex, in part because of the rigorous requirements for manipulating and monitoring seawater carbonate chemistry. To assess the use of appropriate experimental design in ocean acidification research, 465 studies published between 1993 and 2014 were surveyed, focusing on the methods used to replicate experimental units. The proportion of studies that had interdependent or non-randomly interspersed treatment replicates, or did not report sufficient methodological details was 95%. Furthermore, 21% of studies did not provide any details of experimental design, 17% of studies otherwise segregated all the replicates for one treatment in one space, 15% of studies replicatedCO2 treatments in away that made replicates more interdependent within treatments than between treatments, and 13% of studies did not report if replicates of all treatments were randomly interspersed. As a consequence, the number of experimental units used per treatment in studies was low (mean ~ 2.0). In a comparable analysis, there was a significant decrease in the number of published studies that employed inappropriate chemical methods of manipulating seawater (i.e. acid–base only additions) from 21 to 3%, following the release of the “Guide to best practices for ocean acidification research and data reporting” in 2010; however, no such increase in the use of appropriate replication and experimental design was observed after 2010. We provide guidelines on how to design ocean acidification laboratory experiments that incorporate the rigorous requirements for monitoring and measuring carbonate chemistry with a level of replication that increases the chances of accurate detection of biological responses to ocean acidification.
    ICES Journal of Marine Science 07/2015; DOI:10.1093/icesjms/fsv118. · 2.38 Impact Factor
Show more