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Scaling up experimental ocean acidification and warming research: From individuals to the ecosystem
Abstract
Understanding long-term, ecosystem-level impacts of climate change is challenging because experimental research frequently focuses on short-term, individual-level impacts in isolation. We address this shortcoming first through an inter-disciplinary ensemble of novel experimental techniques to investigate the impacts of 14-month exposure to ocean acidification and warming (OAW) on the physiology, activity, predatory behaviour and susceptibility to predation of an important marine gastropod (Nucella lapillus). We simultaneously estimated the potential impacts of these global drivers on N. lapillus population dynamics and dispersal parameters. We then used these data to parameterise a dynamic bioclimatic envelope model, to investigate the consequences of OAW on the distribution of the species in the wider NE Atlantic region by 2100. The model accounts also for changes in the distribution of resources, suitable habitat and environment simulated by finely resolved biogeochemical models, under three IPCC global emissions scenarios. The experiments showed that temperature had the greatest impact on individual level responses, while acidification has a similarly important role in the mediation of predatory behaviour and susceptibility to predators. Changes in Nucella predatory behaviour appeared to serve as a strategy to mitigate individual level impacts of acidification, but the development of this response may be limited in the presence of predators. The model projected significant large-scale changes in the distribution of Nucella by the year 2100 that were exacerbated by rising greenhouse gas emissions. These changes were spatially heterogeneous, as the degree of impact of OAW on the combination of responses considered by the model varied depending on local environmental conditions and resource availability. Such changes in macro-scale distributions cannot be predicted by investigating individual level impacts in isolation, or by considering climate stressors separately. Scaling up the results of experimental climate change research requires approaches that account for long-term, multi-scale responses to multiple stressors, in an ecosystem context.
Supplementary resource (1)
... Therefore, it does not explicitly consider the specificities of the predator-prey interactions. SS-DBEM has been declined in several ecosystems: Northeast Atlantic (Fernandes et al., 2013;Queirós et al., 2015;Fernandes et al., 2020a,b) Bay of Bengal (Fernandes et al., 2016), Kenya and Tanzania EEZs (Wilson et al., 2021), UK fisheries waters (Fernandes et al., 2017) and North Sea (Queirós et al., 2018a,b), on a variety of fish and invertebrates (Table 2). Moreover, several climate scenarios were tested using this model, like the IPCC A1B (Queirós et al., 2015;Fernandes et al., 2016), the RCP2.6 (Queirós et al., 2015;Fernandes et al., 2017Fernandes et al., , 2020a and the RCP8.5 (Queirós et al., 2015(Queirós et al., , 2018aFernandes et al., 2017Fernandes et al., , 2020aWilson et al., 2021). ...
... SS-DBEM has been declined in several ecosystems: Northeast Atlantic (Fernandes et al., 2013;Queirós et al., 2015;Fernandes et al., 2020a,b) Bay of Bengal (Fernandes et al., 2016), Kenya and Tanzania EEZs (Wilson et al., 2021), UK fisheries waters (Fernandes et al., 2017) and North Sea (Queirós et al., 2018a,b), on a variety of fish and invertebrates (Table 2). Moreover, several climate scenarios were tested using this model, like the IPCC A1B (Queirós et al., 2015;Fernandes et al., 2016), the RCP2.6 (Queirós et al., 2015;Fernandes et al., 2017Fernandes et al., , 2020a and the RCP8.5 (Queirós et al., 2015(Queirós et al., , 2018aFernandes et al., 2017Fernandes et al., , 2020aWilson et al., 2021). ...
... SS-DBEM has been declined in several ecosystems: Northeast Atlantic (Fernandes et al., 2013;Queirós et al., 2015;Fernandes et al., 2020a,b) Bay of Bengal (Fernandes et al., 2016), Kenya and Tanzania EEZs (Wilson et al., 2021), UK fisheries waters (Fernandes et al., 2017) and North Sea (Queirós et al., 2018a,b), on a variety of fish and invertebrates (Table 2). Moreover, several climate scenarios were tested using this model, like the IPCC A1B (Queirós et al., 2015;Fernandes et al., 2016), the RCP2.6 (Queirós et al., 2015;Fernandes et al., 2017Fernandes et al., , 2020a and the RCP8.5 (Queirós et al., 2015(Queirós et al., , 2018aFernandes et al., 2017Fernandes et al., , 2020aWilson et al., 2021). ...
... Acidification may also impact invertebrates' ability to locate nearby food items, although this response appears to be species-specific, with only some species negatively affected. For instance, Quierós et al. (2015) identified acidification as a more influential factor in regulating predator-prey interactions compared to temperature for N. lapillus [28], and acidification impeded the foraging success of N. festivus as well [12]. However, a review conducted by Clemente and Hunt highlighted significant variability in the types of responses discovered by acidification studies on behavior and suggested that multiple mechanisms are likely involved in governing species' responses [29]. ...
... We examined mud snail foraging using Y-mazes, which is common in choice experiments utilizing a wide range of animals, from mice to fish to snails [28,[36][37][38]. The first set of experiments in 2017 used a block-shaped Y-maze, while the second and third sets of experiments in 2021 used a more streamlined Y-maze ( Figure 1), but both used the same general setup. ...
... Notably, in all three of the experiments we conducted, there was an increase in the number of snails that made "no decision" within the time limit of the experiment (Figure 2). This aligns with previous work suggesting that rapid acidification leads to higher levels of inactivity in both N. festivus and N. lapillus [12,28]. ...
Ocean acidification may diminish the response of many marine organisms to chemical cues that can be used to sense nearby food and predators, potentially altering community dynamics. We used a Y-maze choice experiment to investigate the impact of ocean acidification on the ability of mud snails (Ilyanassa obsoleta) to sense food cues in seawater. Mud snails have a well-adapted chemosensory system and play an important role in estuarine ecosystem functioning. Our results showed substantially diminished foraging success for the mud snail under acidified conditions, as snails typically moved towards the food cue in controls (pH 8.1) and away from it in acidified treatments (pH 7.6). These results, coupled with previous work, clearly demonstrate the magnitude at which ocean acidification may impair foraging efficiency, potentially resulting in severe alterations in future ecosystem dynamics.
... Shell calcification processes in marine organisms can be affected by ocean acidification as has been documented for a number of molluscan taxa (Gaylord et al., 2011;Coleman et al., 2014;Queirós et al., 2015;Marshall et al., 2019;Doney et al., 2020). The scientific literature on the effects of ocean acidification on molluscs has expanded rapidly indicating a general trend of shell growth reduction under low pH conditions. ...
... The shell degradation of gastropods as a result of ocean acidification (low pH) has been documented in previous studies for several species (Bibby et al., 2007;Gazeau et al., 2013;Melatunan et al., 2013;Queirós et al., 2015;Chatzinikolaou et al., 2017;Harvey et al., 2018;Barclay et al., 2020). The capacity of marine organisms to construct calcium carbonate (CaCO 3 ) shells and skeletons can be impaired by reduced pH (Doney et al., 2009). ...
... A previous study also indicated that the maximum reduction (8%) estimated in the shell density of this species was in the apex, which is the oldest shell part and might often be eroded (Chatzinikolaou et al., 2017). Similarly in Nucella lapillus low pH caused apex dissolution and a 20-30% reduction in shell lip density (Queirós et al., 2015). Mytilus edulis shells grown under ocean acidification conditions displayed significant reductions in shell aragonite thickness, shell thickness index and changes to shell shape, making them more vulnerable to fracture (Fitzer et al., 2015). ...
The increased absorption of atmospheric CO2 by the ocean reduces pH and affects the carbonate chemistry of seawater, thus interfering with the shell formation processes of marine calcifiers. The present study aims to examine the effects of ocean acidification and warming on the shell morphological properties of two intertidal gastropod species, Nassarius nitidus and Columbella rustica. The experimental treatments lasted for 3 months and combined a temperature increase of 3°C and a pH reduction of 0.3 units. The selected treatments reflected the high emissions (RCP 8.5) “business as usual” scenario of the Intergovernmental Panel on Climate Change models for eastern Mediterranean. The morphological and architectural properties of the shell, such as density, thickness and porosity were examined using 3D micro-computed tomography, which is a technique giving the advantage of calculating values for the total shell (not only at specific points) and at the same time leaving the shells intact. Nassarius nitidus had a lower shell density and thickness and a higher porosity when the pH was reduced at ambient temperature, but the combination of reduced pH and increased temperature did not have a noticeable effect in comparison to the control. The shell of Columbella rustica was less dense, thinner and more porous under acidic and warm conditions, but when the temperature was increased under ambient pH the shells were thicker and denser than the control. Under low pH and ambient temperature, shells showed no differences compared to the control. The vulnerability of calcareous shells to ocean acidification and warming appears to be variable among species. Plasticity of shell building organisms as an acclimation action toward a continuously changing marine environment needs to be further investigated focusing on species or shell region specific adaptation mechanisms.
... As ocean acidification primarily affects the saturation of carbonate ions in seawater (Morse et al., 2007;Ries et al., 2009), it is possible that decreases in carbonate saturation itself may not affect calcification in organisms that are biologically able to control the site of calcification (DeCarlo et al., 2018;Findlay et al., 2011;Leung et al., 2020Leung et al., , 2019Roleda et al., 2012), although hypercapnia would likely still be an added stress (Byrne and Fitzer, 2019). However, existing calcified structures are still susceptible to dissolution if seawater becomes undersaturated in carbonates (Chatzinikolaou et al., 2017;Harvey et al., 2018;Nienhuis et al., 2010;Queirós et al., 2015). Therefore the ability to maintain existing structures or respond plastically to changes in carbonate saturation may become critical for molluscs as carbonate saturation decreases (Duquette et al., 2017;Langer et al., 2014;Leung et al., 2017b;Ries, 2011a), particularly as shells provide protection against predators, parasites, and may also provide temperature regulation (Geller, 1982a;Vermeij, 1993). ...
... The results of the previous study match the prediction that shells with greater aragonite and organic content (e. g., Tegula) experience greater costs with respect to shell production and maintenance under decreased seawater pH than those with more calcite. Other studies of Nucella species have also found that calcification is maintained under decreased pH, and have found that the shells experienced dissolution (Nienhuis et al., 2010;Queirós et al., 2015;Rühl et al., 2017). However, without examining the shell structure of both species in more detail, it is unclear how these responses manifested in either of the species studied, or whether reductions in strength are due to dissolution. ...
... As dissolution was expected to occur on the external surface, for each selected slice, a band of the external shell surface was selected for analysis. Each image was edited in ImageJ, where a 15 pixel-wide band was created along the external edge of the shell to be used in analyses, following the methods of Queirós et al. (2015) (Fig. 1), except in the case of the lip area, where the shell was thin enough to include the entire section. The mean greyscale values of each section were then determined using the binary threshold module (1-255 greyscale histogram range) in the program CTAnalyser (Sky-Scan™), with higher greyscale values indicating greater density of the shell materials. ...
Organisms, such as molluscs, that produce their hard parts from calcium carbonate are expected to show increased difficulties growing and maintaining their skeletons under ocean acidification (OA). Any loss of shell integrity increases vulnerability, as shells provide protection against predation, desiccation, and disease. Not all species show the same responses to OA, which may be due to the composition and microstructural arrangement of their shells. We explore the role of shell composition and microstructure in resisting dissolution caused by decreases in seawater pH using a combination of microCT scans, XRD analysis, and SEM imaging. Two gastropods with different shell compositions and microstructure, Tegula funebralis and Nucella ostrina, were exposed to simulated ocean acidification conditions for six months. Both species showed signs of dissolution on the exterior of their shells, but changes in density were significantly more pronounced in T. funebralis. XRD analysis indicated that the exterior layer of both shell types was made of calcite. T. funebralis may be more prone to dissolution because their outer fibrous calcite layer has more crystal edges and faces exposed, potentially increasing the surface area on which dissolution can occur. These results support a previous study where T. funebralis showed significant decreases in both shell growth and strength, but N. ostrina only showed slight reductions in shell strength, and unaffected growth. We suggest that microstructural arrangement of shell layers in molluscs, more so than their composition alone, is critical for determining the vulnerability of mollusc shells to OA.
... The six-month duration of this study represents a relatively long-term mesocosm experiment compared to the majority of previous studies (Stewart et al., 2013;Guy-Haim et al., 2017), allowing us to observe more persistent ecological responses. The system was created to simulate a shallow temperate marine ecosystem under future climate change conditions (ocean acidification and warming) scaling up the understanding of abrupt climate change from individuals and organism to community-level responses with the incorporation of multiple drivers, acting alone or in combination (Gilman et al., 2010;Queirós et al., 2015;Riebesell and Gattuso, 2015;Nagelkerken and Munday, 2016). The ecological complexity provided to the mesocosms increase the likelihood of including buffering processes (Queirós et al., 2015), which contrasts experiments with fewer species that might not include strong interactions that can counter-balance the direct effects of climate change (for further information on the mesocosm set up see the methods section in the Supplementary information). ...
... The system was created to simulate a shallow temperate marine ecosystem under future climate change conditions (ocean acidification and warming) scaling up the understanding of abrupt climate change from individuals and organism to community-level responses with the incorporation of multiple drivers, acting alone or in combination (Gilman et al., 2010;Queirós et al., 2015;Riebesell and Gattuso, 2015;Nagelkerken and Munday, 2016). The ecological complexity provided to the mesocosms increase the likelihood of including buffering processes (Queirós et al., 2015), which contrasts experiments with fewer species that might not include strong interactions that can counter-balance the direct effects of climate change (for further information on the mesocosm set up see the methods section in the Supplementary information). Furthermore, in our experiment we used stable carbon (δ 13 C) and nitrogen (δ 15 N) isotopes, as proxies for trophic niches, given their established accuracy in reflecting long-term dietary patterns and trophic positions within ecosystems (Post, 2002;Peterson and Fry, 1987). ...
... Small-scale aquariums are well adapted for individual levels, while obviously less useful for populations and communities, for which mesocosms permit more insights. Mesocosms can include multiple trophic levels at the same place and time, but they often lack the ability to represent networks with sufficient interacting groups under various conditions (Queiroś et al., 2015). These ones are more challenging, costly, and finally lack predictive power (Forbes et al., 2008;Andersson et al., 2015;Queiroś et al., 2015). ...
... Mesocosms can include multiple trophic levels at the same place and time, but they often lack the ability to represent networks with sufficient interacting groups under various conditions (Queiroś et al., 2015). These ones are more challenging, costly, and finally lack predictive power (Forbes et al., 2008;Andersson et al., 2015;Queiroś et al., 2015). Moreover, when experimental results are used as inputs for upscaling, these must be carefully treated to provide realistic projections. ...
Numerous threats affect aquatic ecosystems at different biological organizational levels from individuals to ecosystems. Stresses occurring on the metabolism and physiological functions of individuals can have repercussions on the individual behavior, its ability to survive and reproduce, also known as the individual fitness, which may then influence the demography and spatial distribution of populations, and ultimately modify trophic flows and ecosystem functioning. In a context of a globally changing environment, predicting the life history traits and fitness of individuals can be relevantly performed with the association of laboratory experiments with Dynamic Energy Budget (DEB) theory, while modeling species interactions have proven to be an efficient tool to understand aquatic food webs using mass-balanced models such as linear inverse models (LIMs) or Chance and Necessity (CaN) models. However, while predictive results obtained on individuals can be provided with a thorough mechanistic interpretation, the propagation of the effects is most often limited to the closest biological hierarchical level, i.e., the population, and rarely to the food-web level. Furthermore, there is a need to understand how to avoid misleading approaches and interpretations due to the simplicity of experiments. For the moment, no clear methodology has stood out yet to do so. In this study, we provide a new methodology based on a combination of models (i.e., DEB, LIM, and CaN) aiming at upscaling information from laboratory experiments on individuals to ecosystems to address multiple ecological issues. This framework has a potential to enhance our understanding of higher-scale consequences of the effect of stressors measured at the sub-individual scale. This combination of models was chosen for the convergence of their framework but also their ability to consider a substantial portion of the projected uncertainty. The description of this methodology can help experimenters and modelers to jointly address a specific question involving upscaling from individual to ecosystem, proposes approaches, and gives tips on the pitfalls to avoid along the upscaling process.
... Elevated CO 2 impaired the predator-escape response in this jumping snail by potentially affecting decision-making, while the physical ability to jump, and therefore the capacity to escape, was retained . Furthermore, ocean acidification may lead to thinner and weaker shells in marine gastropods (Welladsen et al., 2010;Queirós et al., 2015), reducing this critical antipredator defense. Enhanced defenses could give some gastropod species a relative advantage under ocean acidification compared to those with weakened antipredator abilities. ...
... In some gastropod species such as the marine snail Littorina saxatilis, more prominent individuals assert dominance over smaller conspecifics in fights over resources such as food and mates (Johannesson et al., 2010). Ocean acidification has been shown to hinder growth and shell development in juvenile L. saxatilis, resulting in smaller adult sizes (Queirós et al., 2015). Smaller adult sizes may prevent individuals from attaining dominance, disrupting size-based hierarchies. ...
... Over the last decade, the OA research community has highlighted the vulnerability of calcification-dependent marine organisms to OA [2]. Queirós, et al. [3] reported that, CO 2 have increased from~280 ppm (pre-industrial) to~400 ppm today. According to the climate change model, Richard et al. [4] predicted that OA may last a few centuries, and the ocean water pH value will be 7. 4 in the year 2300. ...
... Urea/urease-aided CaCO 3 mineralization had been reported previously. The process takes advantage of the supply of CO 3 2ions derived from urea hydrolysis and an increase in the pH generated by the reaction, the presence of Ca 2+ ions leads to the precipitation of CaCO 3 [82]. The elevation of both Arg and urea implied that the mussel mantle may use urea to generate CO 3 2and NH 4 + ions, thereby promoting shell repair and increasing the local pH value. ...
Mytilus coruscus is an economically important marine bivalve mollusk found in the Yangtze River estuary, which experiences dramatic pH fluctuations due to seasonal freshwater input and suffer from shell fracture or injury in the natural environment. In this study, we used intact-shell and damaged-shell M. coruscus and performed metabolomic analysis, free amino acids analysis, calcium-positive staining, and intracellular calcium level tests in the mantle to investigate whether the mantle-specific metabolites can be induced by acute sea-water acidification and understand how the mantle responds to acute acidification during the shell repair process. We observed that both shell damage and acute acidification induced alterations in phospholipids, amino acids, nucleotides, organic acids, benzenoids, and their analogs and derivatives. Glycylproline, spicamycin, and 2-aminoheptanoic acid (2-AHA) are explicitly induced by shell damage. Betaine, aspartate, and oxidized glutathione are specifically induced by acute acidification. Our results show different metabolic patterns in the mussel mantle in response to different stressors, which can help elucidate the shell repair process under ocean acidification. furthermore, metabolic processes related to energy supply, cell function, signal transduction, and amino acid synthesis are disturbed by shell damage and/or acute acidification, indicating that both shell damage and acute acidification increased energy consumption, and disturb phospholipid synthesis, osmotic regulation, and redox balance. Free amino acid analysis and enzymatic activity assays partially confirmed our findings, highlighting the adaptation of M. coruscus to dramatic pH fluctuations in the Yangtze River estuary.
... The changing environmental conditions associated with elevated CO 2 and increased temperature can alter the risk-induced trait response in prey with potential interaction modifications (Lord et al., 2019;Kong et al., 2019;Jahnsen-Guzmán et al., 2022). For example, in the case of gastropod prey, OA and OW (or their interaction) have shown to impair feeding and sensory behavior Jellison et al., 2016), alter metabolic rate, reduce inducible defensive structures or chemical compounds (Bibby et al., 2007;Kong et al., 2019;Barclay et al., 2019), and to increase the prey vulnerability of being crushed and consumed by predators (e.g., Queirós et al., 2015;Barclay et al., 2019). In the case of crustaceans predators, high pCO 2 and increases in temperature (and their interaction) have been shown to alter the feeding and foraging behavior (e.g., Dodd et al., 2015;Wang et al., 2018), reduce claw strength (e.g., Landes and Zimmer, 2012), inhibit crab foraging (Wu et al., 2017) and alter growth and survival (e.g., Melzner et al., 2009;Walther et al., 2010;Long et al., 2017). ...
... In this study, slower self-righting behavior was observed in individuals maintained at OW conditions in the presence of predator cues. These results agree in part with studies carried out in other invertebrates where the increase of temperature and pCO 2 levels (or their combination) alter anti-predator behavior of marine snail species (Queirós et al., 2015;Jellison and Gaylord, 2019;Manríquez et al., 2022). In gastropods, effects of warming and ocean acidification varied within and across species. ...
... This increase in mean temperature is a likely candidate to explain the observed shell thickening. For N. lapillus, this is not only expected from the kinetics of shell production, as CaCO 3 saturation states in seawater change with temperature but also from a physiological standpoint since metabolic rates and foraging behaviour are temperature-dependent in this species [98][99][100] . In addition, higher temperatures are also expected to reduce the metabolic energy cost per unit shell due to a proportional reduction of shell organic matter 92,93,96 , making higher temperatures generally more favourable for shell formation. ...
... This gives hope that the intertidal rocky-shore community structure on the Southern North Sea may survive predicted future OA scenarios longer than expected, extending the point of no return into the future. Studies like ours demonstrate that museum collections can provide useful ground-truthing data that will serve an important function in future modelling exercises attempting to reconcile large-scale global environmental change impacts on ecosystems 100 . ...
Ocean acidification and global climate change are predicted to negatively impact marine calcifiers, with species inhabiting the intertidal zone being especially vulnerable. Current predictions of organism responses to projected changes are largely based on relatively short to medium term experiments over periods of a few days to a few years. Here we look at responses over a longer time span and present a 130-year shell shape and shell thickness record from archival museum collections of the marine intertidal predatory gastropod Nucella lapillus. We used multivariate ecological models to identify significant morphological trends through time and along environmental gradients and show that, contrary to global predictions, local N. lapillus populations built continuously thicker shells while maintaining a consistent shell shape throughout the last century. Marine gastropod shells have thickened over the past 130 years on the southern North Sea coast as local environmental conditions counteracted global ocean acidification, suggest analyses of a 130-year record of dog whelk morphology.
... to predation themselves under rising ocean acidification (Queirós et al., 2015). ...
... Expanding the scope from an individual to a community level is a highly complex undertaking. An generalization approach was made by Queirós et al. (2015), who modeled the distribution of the marine gastropod Nucella lapillus under three IPCC scenarios. Based on the results of a lab experiment, they concluded that spatial distribution cannot be accurately predicted from single-species experiments. ...
Most intertidal rocky systems are exposed to severe tidal, diurnal, and seasonal changes in environmental parameters. In addition, they show extreme vulnerability to anthropogenic impacts. Research on multiple drivers is therefore crucial to understand the complexity of their potential interactions. Here, we first give an overview of the natural environment and impacts of climate change on rocky shore intertidal systems, and then focus on the impacts of multiple drivers. We further provide a summary of existing multiple driver studies in the literature with the aim for a better understanding of multiple driver interactions. As multiple drivers can affect rocky shore intertidal systems at different spatial and temporal scales, and the outcome of their effects are still more of an “ecological surprise,” we recommend a more widespread assessment of the environmental and biological context. We propose a new, integrated approach based on existing literature: this complements previous frameworks but with an improved understanding of co-occurring multiple driver systems of the rocky intertidal, in order to find management solutions based on accurate and informed predictions in these times of global change.
... The response of organisms to changing environmental conditions is, therefore, governed by cumulative effects across multiple biological levels, from molecular pathways to whole-organism processes. Ultimately, changes in organism fitness will affect population composition, ecosystem structure, and evolutionary potential (Munday et al., 2013;Queirós et al., 2014). ...
... In contrast, an impact with weaker or less direct links across levels would be a reduction in metabolic efficiency, which represents a malleable response with largely indirect effects on individual fitness through energy reallocation (Cao et al., 2018). Connections across biological levels, therefore, require further consideration as, despite our limited understanding, they are recognized to play a key influence in the overall response of mollusks (Queirós et al., 2014) and other calcifying taxa to environmental change (Calosi et al., 2013;Palumbi et al., 2014). ...
Biological fitness relies on processes acting at various levels of organization, all of which can be modified by environmental change. Application of synthesis frameworks, such as the Adverse Outcome Pathway (AOP), can enhance our understanding of the responses to stressors identified in studies at each level, as well as the links among them. However, the use of such frameworks is often limited by a lack of data. In order to identify contexts with sufficient understanding to apply the AOP framework, we conducted a meta-analysis of studies considering ocean acidification effects on calcifying mollusks. Our meta-analysis identified that most studies considered the adult life history stage, bivalve taxonomic group, individual-level changes, and growth- and metabolism-related responses. Given the characteristics of the published literature, we constructed an AOP for the effects of ocean acidification on calcification in an adult bivalve, specifically the Pacific oyster (Magallana gigas). By structuring results within the AOP framework, we identify that, at present, the supported pathways by which ocean acidification affects oyster calcification are via the downregulation of cavortin and arginine kinase transcription. Such changes at the molecular level can prompt changes in cellular and organ responses, including altered enzyme activities, lipid peroxidation, and regulation of acid–base status, which have impacts on organism level metabolic rate and, therefore, calcification. Altered calcification may then impact organism mortality and population sizes. We propose that when developed and incorporated in future studies, the AOP framework could be used to investigate sources of complexity including varying susceptibility within and among species, feedback mechanisms, exposure duration and magnitude, and species interactions. Such applications of the AOP framework will allow more effective reflections of the consequences of environmental change, such as ocean acidification, on all levels of biological organization.
... At current CO 2 emission rates, by 2100 atmospheric CO 2 concentrations are predicted to exceed 1000 ppm in some instances (Stocker et al., 2013), leading to reductions in pH of between 0.3 and 0.4 units from today's conditions (Doney et al., 2009). For marine life, changes in pH can have significant, detrimental effects on their structure and functioning (Lemasson et al., 2017a including abnormal larval development (Kurihara et al., 2007;Kurihara, 2008), increased pressure on acid-base regulatory mechanisms (Lindinger et al., 1984;Thomsen and Melzner, 2010;Scanes et al., 2017) and changes to behavior (Queiros et al., 2015;Sadler et al., 2018). For calcifying species, OA can be especially problematic due to disruption of the biomineralization process that is so crucial to the development of shells, exoskeletons and tests. ...
... (e.g., Carcinus maenas, Nucella lapillus) typically use crushing or boring to penetrate the shell (Elner, 1978;Sadler et al., 2018). Furthermore, predators of bivalve mollusks may themselves become susceptible to OA through impacts on fitness (Whiteley, 2011;Landes and Zimmer, 2012;Sadler et al., 2018), feeding structures (Landes and Zimmer, 2012) and predatory behavior (Dixson et al., 2010;Queiros et al., 2015;Sadler et al., 2018). ...
Negative impacts of global climate change are predicted for a range of taxa. Projections predict marked increases in sea surface temperatures and ocean acidification (OA), arguably placing calcifying organisms at most risk. While detrimental impacts of environmental change on the growth and ultrastructure of bivalve mollusk shells have been shown, rapid and diel fluctuations in pH typical of coastal systems are often not considered. Mytilus edulis, an economically important marine calcifier vulnerable to climate change, were exposed to current and future OA (380 and 1000 ppm pCO2), warming (17 and 20°C), and ocean acidification and warming (OAW) scenarios in a seawater system incorporating natural fluctuations in pH. Both macroscopic morphometrics (length, width, height, volume) and microscopic changes in the crystalline structure of shells (ultrastructure) using electron backscatter diffraction (EBSD) were measured over time. Increases in seawater temperature and OAW scenarios led to increased and decreased shell growth respectively and on marginal changes in cavity volumes. Shell crystal matrices became disordered shifting toward preferred alignment under elevated temperatures indicating restricted growth, whereas Mytilus grown under OAW scenarios maintained single crystal fabrics suggesting OA may ameliorate some of the negative consequences of temperature increases. However, both elevated temperature and OAW led to significant increases in crystal size (grain area and diameter) and misorientation frequencies, suggesting a propensity toward increased shell brittleness. Results suggest adult Mytilus may become more susceptible to biological determinants of survival in the future, altering ecosystem structure and functioning.
... For example, ocean acidification has been reported to increase activity in multiple species of squid (Spady et al. 2018). In gastropods, ocean acidification effects on movement speed are highly variable, with studies reporting increased (Fields 2013;Watson et al. 2017), decreased (Queirós et al. 2015), and unaltered (Schram et al. 2014) speeds under ocean acidification conditions. Taxonomic differences appear to explain some of the effect size variability in ocean acidification studies on shellfish prey defence behaviours, with bivalves exhibiting responses to ocean acidification perceived to be detrimental, cephalopods exhibiting responses perceived to be beneficial, and gastropods, echinoderms, and malacostracan crustaceans appearing unaffected (Clements and Comeau 2019). ...
Human activities pose existential challenges to wildlife and ecosystems everywhere. In many species, behavioural adjustments are often the first responses when environments are altered. But how can an understanding of such responses—and knowledge of animal behaviour more generally—contribute to solving real-world problems? This book focuses on the many challenges facing wildlife and their habitats, and how a deeper understanding of animal behaviour can be used to predict and mitigate the anthropogenic impacts. The book is organised into two parts. Part 1 focusses on the myriad of environmental challenges that are affecting wildlife, the many ways in which behavioural responses to these challenges can be used to contribute to our understanding of the wildlife and environmental impacts, as well as potential solutions and interventions for addressing them. Part 2 extends upon these themes by examining how application of behavioural knowledge can contribute to better practical outcomes for wildlife conservation and management, animal welfare, the control of pests and diseases, and even improvements to the health, security and well-being of human society. It concludes with a synthesis of the key themes and lessons for shaping the discipline so that it is better equipped to address the many challenges that the world is facing, both now and into the future— and to elevate the application of behavioural knowledge to the next level of efficacy for real-world benefits.
... For instance, although OA was reported to suppress the antipredation behavior of marine bivalves by reducing their shell hardness and adhesion ability (Kroeker et al., 2010), the foraging behavior of their predators like crabs was also decreased under OA conditions (Sanford et al., 2014). In this regard, experiments exploring individua lbased responses of single species alone are unlikely to predict their consequences accurately in the complex ecological environments, where species also interact (Queirós et al., 2015). In the future the impacts of OA on a marine species under elevated pCO2 conditions should be studied in the context of different trophic levels. ...
In this book, researchers provide a comprehensive and systematic overview of the current state of the art research on the impacts of ocean acidification on marine mollusks from seven perspectives: overview, reproduction, growth and development, physiological metabolism, immunity and host-microbe interactions, behavior, and Omics technology application.
This chapter summarizes our current understanding of the impacts of OA on marine mollusks and aims to highlight knowledge gaps and potential future research directions.
... Last but not least, traditional research always focuses on short-term and individual-level influence in isolation. According to Emergent Property Principle, new properties would emerge if components are combined into a hierarchical organization such as ecosystem, so it should be emphasized that investigating the long-term influence of climate changes like OA on an ecosystem level is also essential (Queiros et al. 2015). Hence, future researches should closely combine the different physiological mechanisms of marine invertebrates and ecosystem evaluation such as relationship between food webs, abiotic factors, energy and matter flow etc. Future studies should also investigate the complex stress mechanism of OA and other environment factors (warming, pollution, hypoxia and salinity etc.) to relieve the negative influence of climate on marine invertebrates by multifactorial synergistic or antagonistic experiment. ...
Ocean acidification (OA) arises as a consequence of excessive carbon dioxide (CO2) inputs into the ocean, a situation further exacerbated by anthropogenic gas emissions. Predictions indicate that seawater surface pH will decrease by 0.4 by the end of the twenty-first century. Notably, studies have observed significant alterations in molluscan assemblages due to OA, leading to a substantial decline of 43% in species richness and 61% in overall mollusc abundance. Moreover, OA has been associated with a 13 ± 3% reduction in the skeletal density of massive Porites corals on the Great Barrier Reef since 1950, particularly affecting marine invertebrates. Given these impacts, this review aims to comprehensively assess the research status and main effects of OA on the physiology and ecology of marine invertebrates over the past two decades, employing bibliometric analysis. Additionally, this review aims to offer valuable insights into potential future research directions. The analysis reveals that research on OA and its influence on marine invertebrates is predominantly conducted in Europe, America, and Australia, reflecting the local extent of acidification and the characteristics of species in these regions. OA significantly affects various physiological aspects of marine invertebrates, encompassing the calcification process, oxidative stress, immunity, energy budget, metabolism, growth, development, and genetics, consequently impacting their behaviour and causing disruptions in the population structure and marine ecosystem. As a result, future research should aim to intimately connect the different physiological mechanisms of marine invertebrates with comprehensive ecosystem evaluation, such as investigating the relationships between food webs, abiotic factors, energy, and matter flow. Furthermore, it is crucial to explore the interactive effects of OA with other stressors, assess the potential for adaptation and acclimation in marine invertebrates, and evaluate the broader ecological implications of OA on entire marine ecosystems. Emphasizing these aspects in future studies will contribute significantly to our understanding of OA's impact on marine invertebrates and facilitate effective conservation and management strategies for these vital biological communities within marine ecosystems.
... Southern stations were characterized by high expression of modalities biodiffuser and deposit feeders, on the account of S. scutata and the echinoderm Amphiura chiajei. Biodiffusers are dominant in muddy sediments since they can constantly and randomly biomix (both horizontally and vertically) the local sediments over a short distance, which results in particle transport (Queirós et al., 2015). Among them, gallery biodiffusers often occur in finer sediments in which they are promoters of diffusive local biomixing primarily due to burrowing activities within the upper 10-30 cm of sediments (Kristensen et al., 2012). ...
Sewage discharges represent a very common source of anthropogenic impact in coastal areas, contributing to generate a high intake of organic matter with consequent reduction of oxygen in the water column and sediments. Among the coastal benthic communities, macrofaunal community is widely involved in the main ecological processes, therefore environmental alterations that threaten these communities, affect their stability over time, and consequently their resistance and resilience.
The main objective of this Ph.D. project was to evaluate both on a spatial and temporal scale, structural, functional, and trophic variations of the coastal macrofaunal community, influenced by the sewage discharge of urban and domestic wastewater in the Gulf of Trieste (North Adriatic Sea). The sampled macrofauna was investigated through new analytical approaches that can best highlight the community response with all its characteristics as well as its change towards a functioning evaluation of the target ecosystem. In general, the community was characterized by high biodiversity values in conjunction with the presence of stress-tolerant species which suggested that the communities are subject to a moderate level of stress. Through the functional traits analysis, the expression of traits related to semi-continuous reproduction, sediment transporters, and sub-surface depositories were increased by moving from the most distant stations to those closest to the main discharge pipeline, suggesting the presence of a continuous wastewater supply. On the contrary, in the more distant stations, a greater expression of the suspension feeder was observed, indicating the presence of lower inputs of organic matter. However, from the analysis of functional richness and β-diversity emerged that following improvement of the plant, which took place over the years studied, the community responded with an increase in the number of species, particularly in the stations near the sewage discharge loading. Furthermore, the bioturbation and bio-irrigation potential were not directly connected with the variation of allochthonous substance but rather with the granulometric characteristics of the area. On the contrary, macrofaunal secondary production also seems to have been influenced by the presence of sewage discharge. High values of the P/B̅ ratio were calculated at the stations furthest from the sewage pipelines and a negative relationship was observed between biomass and trophic efficiency (TE) values. Therefore, it appears that sewage discharge induces an increase in TE at stations close to the pipelines. In our case, the sewage discharge has determined the presence of tolerant species with small size, low biomass, high reproduction, and growth rate, which seem to have allowed a greater transfer efficiency of energy at higher trophic levels.
Overall, community analyses both on a spatial and temporal scale have shown a good degree of resilience to environmental variations induced by the pronounced contribution of organic matter, as well as different patterns of organic matter use in terms of secondary production, productivity, and TE. These aspects (P, P/B̅ and TE) were also treated for the first time in the context of macrozoobenthic communities subject to the influence of sewage and organic enrichment.
The variety of methods applied suggest how the use of integrated approaches that consider macrofaunal communities, analyzing them both from a structural and functional-trophic point of view, can provide useful tools to better understand, monitor and evaluate the functioning of coastal ecosystems, including to multiple disturbing factors.
... In addition to predation pressure potentially being a significant driver for shell ornamentation, the chemistry of marine waters could also influence shell ornamentation (e.g., ocean acidification, Khanna et al., 2013;Queirós et al., 2015), which can add more com- ...
As a potential anti-predatory defensive structure, the shell ornamentation of marine calcifiers is usually used to understand the macro coevolution of the interactions between predators and preys. Marine calcifiers' shell ornamentation complexity is generally believed to vary negatively with latitude and water depth. In this paper, we explored the association between shell ornamentation and latitude/bathymetry using the latest global database of living brachiopods. We found that (1) ~59% of living brachiopods species are characterized by smooth shells and that (2) there is no statistically significant linear trend, either positive or negative, between the ornamentation index and latitudes nor with water depths. Both findings are puzzling for living brachiopods as they are sharply contrasted to the patterns of fossil brachiopods whereby the latter, especially Paleozoic brachiopods, are known to exhibit (1) a much greater ornamentation diversity and (2) (at least for the geological periods that have been studied) a linear latitudinal gradient of ornamentation complexity existed. The reasons why living brachiopods have such a high proportion of smooth or weakly ornamented shells and fail to demonstrate an unequivocal linear latitudinal ornamentation gradient were explored and are linked to a multitude of potential factors rather than uniquely only to the predation pressure. Among these, the most plausible factor seems to be the cryptic (refuge-type) habitats (e.g., deep waters, cold polar regions, and submarine rock caves) that living brachiopods have been adapted to due to their low metabolism, where predation pressure is low, allowing brachiopods to enact the predator avoidance strategy rather than having to manufacture robust shell ornamentation to survive in an otherwise highly engaged predator-prey global marine ecosystem.
... Southern stations were characterized by high expression of biodiffuser and deposit feeders, on the account of S. scutata and the echinoderm Amphiura chiajei. Biodiffusers are dominant in muddy sediments since they can constantly and randomly biomix (both horizontally and vertically) the local sediments over a short distance, which results in particle transport [84]. Among them, gallery biodiffusers often occur in finer sediments in which they are promoters of diffusive local biomixing primarily due to burrowing activities within the upper 10-30 cm of sediments [47]. ...
We assessed the influence of different organic matter (OM) inputs associated with ter-rigenous/freshwater allochthonous and sewage derive on bioturbation and irrigation potential community indices (BP c and IP c) of the soft-bottom macrofauna community. The macrofauna was sampled from two different sedimentary impacted areas, in front of the Po River Delta (northern Adriatic Sea) and sewage discharge diffusion zone (Gulf of Trieste). The highest values of BP c and IP c were observed at the northward sampling stations of the prodelta and the stations 25 m distance in front of the main sewage outfall. Species richness showed high values in the prodelta likely due to the OM positive effect from the delta, and it increased with increasing distance from the pipeline due to the effect of OM from the sewage discharge. The bioturbation indices differed due to the presence of surface deposit feeders and the injection depth (from 2 to 5 cm) with limited movement at the station located northwards in the prodelta and 25 m distance in the diffusion zone. We infer that the difference in bioturbation indices was likely due to the effects of grain-size composition and the degree of organic enrichment in both study areas.
... Poor people will be particularly affected by hazard management and soil and water control at low-elevation coastal zones and dryland margins as a result of the ecosystem-related effects of climate change (Hallegatte et al. 2016 ). Multi-species studies have demonstrated parallel changes in feeding and predation susceptibility, species diversity, and abundance (Queirós et al. 2015 ). Warming can impact the growth and recruitment of plants that are subject to herbivory, but it can also mitigate its effects by accelerating plant growth rates (Holmgren et al. 2006 ). ...
The biodiversity of a region is determined by the species composition, morphology, reproduction, and development influenced by geographic and climatic conditions. The sustainability of the environment is threatened and challenged substantially by climate change, which impacts the health of ecosystems, food security, natural resources, productivity, and economic stability. The damage causes to biodiversity, ecological services, and sustainable development by climate change is worse than habitat loss in many aspects. Climate change is the primary factor impacting the terrestrial ecosystem, which alters species distributions and composition and imposes significant abiotic stresses on biotic interactions, growth, and development. It has directly influenced biodiversity and various ecosystem services by changing climatic components, shifting latitudes, altitudes, and phenology, and reducing species resilience and fitness. Adaptations and mitigation measures are essential to promote long-term sustainability and sustainable development that offers new possibilities, paths, and action capacities for reducing the impacts of climate change. In addition, conservation and finding solutions are crucial for lowering carbon emissions, switching to renewable energy sources, enhancing nutrient efficiency, lowering GHG emissions, increasing the production of organic foods and perennial crops, and making the best use of water resources. Ecosystem-based adaptations are practical and affordable nature-based solutions that can be applied globally to improve resilience, reduce damage, and adapt to climate change. The implications of climate change on biodiversity were highlighted in this chapter, along with potential adaptation and mitigation measures that may be taken to promote ecosystem services and sustainable development.KeywordsClimate changeChallengesMitigationAdaptationSustainable development
... Mechanisms included in each model and the climatic and fishing scenarios are described. Based onQueirós et al. (2015),Fernandes et al. (2013) andCheung et al. (2011). ...
Tunas and billfishes are the main large pelagic commercial fish species. Tunas comprised around 5.5 million t and USD 40 billion in 2018. Climate change studies and projections estimate that overall, global fisheries productivity will decrease due to climate change. However, there are seldom projections of the climate-driven productivity of the higher trophic levels where tunas and billfishes belong. In this work, we use a mechanistic model to evaluate the effects of climate change and fishing for globally distributed and commercially exploited
seven tuna species and swordfish which are divided into 30 stocks for management purposes, under a range of climate change (RCP 2.6 and 8.5) and fishing scenarios (from no fishing to 1.5 times the fishing mortality (F) at the Maximum Sustainable Yield, FMSY) from two Earth System Models (IPSL and MEDUSA). The results suggest that high trophic level species will be more impacted by climate change than by fishing pressure under the assumption that they remain nearby their MSY levels. However, no-fishing scenarios project much higher biomass. The overall productivity of the target species will decrease by 36% and only the Pacific bluefin showing a slight increase in the future. Five species; Atlantic and Southern bluefins, swordfish, bigeye, and albacore are estimated to decrease in biomass and size at different rates. These species represent almost a third of the landings in the Atlantic Ocean and 10% in the Pacific Ocean being the bluefins, the highest-valued tuna species. On average, the body size is expected to decrease up to 15% by 2050. Fish price and demand are partially driven by body size and therefore, revenues can be reduced even in stocks with an increase in productivity. The fishing industry can adapt to the changing climate by increasing the value of fish through sustainability certifications and reducing fuel consumption and time at sea with higher digitalization. Reducing fuel consumption would also be an additional mitigation measure to climate change since it would reduce CO2 emissions.
... Bath water was chilled to 16 C using an aquarium chiller and agitated via aquaria pumps. This baseline temperature was chosen as it reflected the mean temperature experienced by seabed organisms in Plymouth Sound at this time of year (Queir os, Fernandes et al., 2015). LED blocks (Biolumen, UK) were fitted to a frame positioned at the top of the seawater bath, and the whole setup was covered by PVC sheets to reduce evaporation. ...
Harnessing natural solutions to mitigate climate change requires an understanding of carbon fixation, flux, and sequestration across ocean habitats. Recent studies have suggested that exported seaweed particulate organic carbon is stored within soft‐sediment systems. However, very little is known about how seaweed detritus disperses from coastlines, or where it may enter seabed carbon stores, where it could become the target of conservation efforts. Here, focusing on regionally dominant seaweed species, we surveyed environmental DNA (eDNA) from natural coastal sediments, and studied their connectivity to seaweed habitats using a particle tracking model parameterized to reproduce seaweed detritus dispersal behavior based on laboratory observations of seaweed fragment degradation and sinking. Experiments showed that seaweed detritus density changed over time, differently across species. This, in turn, modified distances traveled by released fragments until they reached the seabed for the first time, during model simulations. Dispersal pathways connected detritus from the shore to the open ocean but, importantly, also to coastal sediments, and this was reflected by field eDNA evidence. Dispersion pathways were also affected by hydrodynamic conditions, varying in space and time. Both the properties and timing of released detritus, individual to each macroalgal population, and short‐term near‐seabed and medium‐term water‐column transport pathways, are thus seemingly important in determining the connectivity between seaweed habitats and potential sedimentary sinks. Studies such as this one, supported by further field verification of sedimentary carbon sequestration rates and source partitioning, are still needed to help quantify the role of seaweed in the ocean carbon cycle. Such studies will provide vital evidence to inform on the potential need to develop blue carbon conservation mechanisms, beyond wetlands.
... Measuring the effects of multiple environmental drivers on biodiversity is imperative during this time of rapid climate change (Boyd et al., 2016;Giménez et al., 2021). Approaches to tackle such a complex task are emerging but the task itself remains formidable, particularly when considering the multi-faceted responses of organisms, let alone ecosystems (Queirós et al., 2015;Orr et al., 2020;Tekin et al., 2020). Responses can be trait specific and effects of drivers can be highly variable between species and life-stages (Pandori and Sorte, 2019). ...
Phenomics offers technological advances for high-dimensional phenotyping, facilitating rapid, high-throughput assessment of physiological performance and has proven invaluable in global research challenges including drug discovery and food security. However, this rapidly growing discipline has remained largely inaccessible to the increasingly urgent challenge of assessing organismal functional sensitivity to global change drivers. Here, we investigate the response of an ecologically important marine invertebrate to multiple environmental drivers using Energy Proxy Traits (EPTs), a new approach for measuring complex phenotypes captured on video as a spectrum of energy levels across different temporal frequencies in fluctuating pixel values. We imaged three developmental stages of the common prawn Palaemon serratus at different salinities and temperatures, and measured EPTs and heart rate, a major proxy of physiological performance in ectotherms present across stages. Significant interactions were detected between temperature, developmental stage and salinity in frequency-specific energy levels. Despite cardiac activity being a significant contributor to the EPT spectra, treatment interactions were different from those observed on EPTs, highlighting additional phenotypic drivers of EPTs. Elevated temperature resulted in a shift of the EPT spectra towards higher frequency signals, indicating a reallocation of resources within the phenome. Using a non-linear dimensionality reduction, we interrogated the responses of EPT spectra in high-dimensional space. We discovered complex developmental-stage specific sensitivities, highlighting both the complexity of phenotypic responses, and the limits of using univariate approaches with pre-selected traits to assess responses to multiple global environmental drivers. EPTs are a high-dimensional, transferrable method of phenotyping, and are therefore highly relevant to addressing the current limitations of traditional methods of phenotyping applied to assessing biological sensitivity to drivers of global change. We predict that EPTs will become an important tool for indiscriminate phenotyping, transferrable between species, developmental stages and experimental designs.
... There are few studies that combine biological responses with modelled data and which help to map and assess potential future trends. In two examples relevant to the UK waters, the effects of acidification and warming on the dogwhelk (Nucella lapillus) (Queiros et al., 2015), blue mussel, common cockle, and scallop (Fernandes et al., 2017) were assessed using inferences from experimental data and a suite of coupled hydrodynamic-biogeochemistry models, like the one shown here, and dynamic bioclimatic envelope models. Similar attempts have been explored in Canada, to assess ocean acidification effects on the life-stages and spatio-temporal patterns of catch and revenues of American lobster (Homarus americanus) using bioclimate envelope models (Tai et al., 2021). ...
Ocean acidification has become one of the most intensively studied climate change topics and it is expected to have both direct and indirect impacts on species, ecosystems, and economies. Experiments have been performed on different taxa, life stages, and at different pH levels. Despite this wealth of information, several key challenges remain, including (1) uncertainty about how to incorporate current pH ranges and variability experienced by organisms into experiments, and (2) how to bring this information together to support analysis and assessments at the broader ecosystem level. Sophisticated modelling tools are needed to ‘scale-up’ from experimental results to regional-scale insights. This paper highlights the challenges of combining information to determine how commercially exploited species may be affected under future pH levels, and how modelling and experimental results might be better aligned, using northwest Europe and the waters around the British Isles as an example. We argue that in most cases the current evidence does not offer sufficient information into impacts at projected pH levels, and that future experiments should be designed to consider the pH levels actually experienced by organisms, as well as variability in pH. These types of study are key in safeguarding commercially exploited shellfish stocks.
... As slow-moving, hypometabolic species with low ion-exchange and acid-base-regulation abilities ( Pörtner & Farrell, 2008 ), whelks are particularly vulnerable to changes in environmental conditions ( Kroeker et al. , 2013 ). Moreover, as important predators, whelks play a crucial role in benthic community structure and dynamics Queirós et al. , 2015 ;Donohue et al. , 2017 ). Whelks feed on mussels and other habitat-forming species ( Wickens & Griffiths, 1985 ), and can therefore influence habitat complexity, shelter availability, algal growth and recruitment of associated fauna ( Menge & Branch, 2001 ). ...
Despite the existing body of research that considers altered ocean temperature and acidification as co-occurring stressors, our understanding of the consequences of such shifts remains limited. This is particularly problematic in relation to predators such as whelks, as they can exert strong top-down control of communities yet, as calcifying ectotherms, they are likely to be vulnerable to climate change. This study assessed the effects of simultaneous changes in water temperature and pH on the South African girdled dogwhelk Trochia cingulata. For 12 weeks, whelks were exposed to three temperatures, 9 °C (cooling), 13 °C (current) and 17 °C (warming), each at three target pH levels, 8.0 (current), 7.7 (intermediate) and 7.5 (extreme). For each treatment shell thickness, strength and shape were measured after 6 and 12 weeks, while mortality was recorded daily. Survival was not affected by pH and was highest at 9 °C. Almost all whelks exposed to warming died within 2 weeks. After 6 weeks, shell strength declined significantly as acidity increased, regardless of temperature, and shells of whelks held at 9 °C were thinner. By 12 weeks, whelks exposed to cooling and extreme pH had the weakest shells. Notably, temperature no longer influenced shell thickness, but whelks held at 9 °C became globular in shape. These changes in shell morphology likely resulted from the increased cost of shell maintenance in cool, acidic conditions. The differences observed at 6 and 12 weeks demonstrate how responses can change over time, a point that should be kept in mind when assessing species sensitivities to changing environments. The dominant effect of temperature highlights that T. cingulata is particularly vulnerable to warming, while regional cooling may pose a challenge with respect to shell morphology.
... As restoring this acid-base balance requires energy, many organisms alter their physiological processes such as their food intake and different metabolic processes, affecting energy allocation to, among others, activity, growth and reproduction. This energy allocation potentially affects overall fitness of the organisms (Queirós et al., 2015;Sokolova et al., 2012;Wood et al., 2009). This is well documented for various epifaunal and pelagic marine calcifying organisms (Mostofa et al., 2016), but empirical evidence for infaunal species remains scant, despite the fact that their activity can contribute importantly to marine soft-sediment ecosystem functioning (Clements and Hunt, 2017). ...
The presence and behaviour of bivalves can affect the functioning of seafloor sediments through the irrigation of deeper strata by feeding and respiring through siphonal channels. Here, we investigated the physiological response and consecutive impact on functioning and body condition of the white furrow shell Abra alba in three pH treatments (pH = 8.2, pH = 7.9 and pH = 7.7). Although no pH effect on survival was found, lowered respiration and calcification rates, decreased energy intake (lower absorption rate) and increased metabolic losses (increased excretion rates) occurred at pH ∼ 7.7. These physiological responses resulted in a negative Scope for Growth and a decreased condition index at this pH. This suggests that the physiological changes may not be sufficient to sustain survival in the long term, which would undoubtedly translate into consequences for ecosystem functioning.
... Mechanisms included in each model and the climatic and fishing scenarios are described. Based onQueirós et al. (2015),Fernandes et al. (2013) andCheung et al. (2011). ...
... However, reduced preference for algae with lower nutritional content results in contrastingly decreased consumption in multiple choice feeding assays (Borell et al., 2013;Duarte et al., 2016), highlighting the role that foraging behavior plays in mediating rates of herbivory. Foraging behavior may also be negatively impacted by ocean acidification through the impaired ability of grazers to orient to the chemical cues produced by their food, which has been documented in urchins , molluscs (Queirós et al., 2015;Horwitz et al., 2020), and crustaceans . Therefore, predicting the effects of ocean acidification on urchin herbivory is complicated by the interaction of complex urchin and macroalgae physiology and the resulting impacts to multiple facets of their trophic interaction. ...
When predicting the response of marine ecosystems to climate change, it is increasingly recognized that understanding the indirect effects of ocean acidification on trophic interactions is as important as studying direct effects on organism physiology. Furthermore, comprehensive studies that examine these effects simultaneously are needed to identify and link the underlying mechanisms driving changes in species interactions. Using an onshore ocean acidification simulator system, we investigated the direct and indirect effects of elevated seawater pCO2 on the physiology and trophic interaction of fleshy macroalgae and the grazing sea urchin Lytechinus variegatus. Macroalgal (Dictyota spp.) biomass increased despite decreased photosynthetic rates after two-week exposure to elevated pCO2. Algal tissue carbon content remained constant, suggesting the use of alternative carbon acquisition pathways beneficial to growth under acidification. Higher C:N ratios driven by a slight reduction in N content in algae exposed to elevated pCO2 suggest a decrease in nutritional content under acidification. Urchin (L. variegatus) respiration, biomass, and righting time did not change significantly after six-week exposure to elevated pCO2, indicating that physiological stress and changes in metabolism are not mechanisms through which the trophic interaction was impacted. Correspondingly, urchin consumption rates of untreated macroalgae (Caulerpa racemosa) were not significantly affected by pCO2. In contrast, exposure of urchins to elevated pCO2 significantly reduced the number of correct foraging choices for ambient macroalgae (Dictyota spp.), indicating impairment of urchin chemical sensing under acidification. However, exposure of algae to elevated pCO2 returned the number of correct foraging choices in similarly exposed urchins to ambient levels, suggesting alongside higher C:N ratios that algal nutritional content was altered in a way detectable by the urchins under acidification. These results highlight the importance of studying the indirect effects of acidification on trophic interactions simultaneously with direct effects on physiology. Together, these results suggest that changes to urchin chemical sensing and algal nutritional quality are the driving mechanisms behind surprisingly unaltered urchin foraging behavior for fleshy macroalgae under joint exposure to ocean acidification. Consistent foraging behavior and consumption rates suggest that the trophic interaction between L. variegatus and fleshy macroalgae may be sustained under future acidification. However, increases in fleshy macroalgal biomass driven by opportunistic carbon acquisition strategies have the potential to cause ecological change, depending on how grazer populations respond. Additional field research is needed to determine the outcome of these results over time and under a wider range of environmental conditions.
... Those that have, have focussed on gastropod shells, the outer surfaces of which undergo passive dissolution in ways that often correlate with reductions in seawater pH and aragonite saturation (Ω ara ) (Bednaršek et al., 2012a, b, 2014, Marshall et al., 2008. Many studies have used gastropod shells to understand ecological impacts of ocean acidification Garilli et al., 2015;Hall-Spencer et al., 2008), but these have largely concerned shell calcification and energetics (Chen et al., 2015;Connell et al., 2017;Harvey et al., 2016Harvey et al., , 2018Spalding et al., 2017), to appreciate the constraints on building shells under carbonate-undersaturated conditions Duquette et al., 2017;Queirós et al., 2015;Rodolfo-Metalpa et al., 2011). Gastropod biomonitoring studies have specifically considered pelagic, oceanic pteropods (Bednaršek et al., 2012a(Bednaršek et al., , b, 2014, and estuarine and rocky shore animals (Marshall et al., 2008(Marshall et al., , 2019. ...
The rapidly changing marine environmental chemistry associated with growing industrialisation, urban population expansion, and the unabated rise in atmospheric CO2 necessitates monitoring. Traditional approaches using metres, dataloggers, and buoys to monitor marine acidification have limited application in coastal oceans and intertidal zones subjected to direct wave action. The present study trialled a system to biomonitor coastal acidification (carbonate ion and pH) based on the dissolution of living gastropod shells. We extended on an approach that ranked shell erosion (SER) in Nerita chamaeleon (Nc) in environments where such erosion was found to correlate with exposure to acidified water. We assessed the spatial scale at which the Nc-SER marker could detect change in acidification along rocky shores, and whether snail body size affected this marker. We found that proportional and unique Nc-SERs not only varied between acidified and non-acidified reference shores at a coarse spatial scale (10 km), but also in predictable ways at fine scales (metres), vertically and horizontally within a shore. Differences between acidified and reference shores in the relationship for snail size and Nc-SER were accentuated by less weathered shells at reference localities, highlighting the value of including small, juvenile snails in monitoring protocols. Gastropod shells are shown to be useful for assessing point sources of acidification and the spatial area of affected coastal zones. This cost-effective and easy-to-use approach (potentially even by citizen-scientists) offers an early warning system of acidification of rocky shore ecosystems, where the deployment of instruments is precluded.
... In parallel, many seabed species have limited ability to track climatedriven changes in habitat distributions due to limited movement and dispersal ability (Hiddink et al., 2015). This is exacerbated by individual-level trade-offs between energetically costly stress response pathways triggered by environmental change and processes supporting dispersal potential (Calosi et al., 2013;Queirós et al., 2015). Such impacts likely further affect important benthic-pelagic coupling processes mediated by benthic communities, indicating that CC may in this way indirectly affect broader ocean functioning in the region (Snelgrove et al., 2018). ...
Marine spatial planning that addresses ocean climate-driven change (‘climate-smart MSP’) is a global aspiration to support economic growth, food security and ecosystem sustainability. Ocean climate change (‘CC’) modelling may become a key decision-support tool for MSP, but traditional modelling analysis and communication challenges prevent their broad uptake. We employed MSP-specific ocean climate modelling analyses to inform a real-life MSP process; addressing how nature conservation and fisheries could be adapted to CC. We found that the currently planned distribution of these activities may become unsustainable during the policy's implementation due to CC, leading to a shortfall in its sustainability and blue growth targets. Significant, climate-driven ecosystem-level shifts in ocean components underpinning designated sites and fishing activity were estimated, reflecting different magnitudes of shifts in benthic versus pelagic, and inshore versus offshore habitats. Supporting adaptation, we then identified: CC refugia (areas where the ecosystem remains within the boundaries of its present state); CC hotspots (where climate drives the ecosystem towards a new state, inconsistent with each sectors’ present use distribution); and for the first time, identified bright spots (areas where oceanographic processes drive range expansion opportunities that may support sustainable growth in the medium term). We thus create the means to: identify where sector-relevant ecosystem change is attributable to CC; incorporate resilient delivery of conservation and sustainable ecosystem management aims into MSP; and to harness opportunities for blue growth where they exist. Capturing CC bright spots alongside refugia within protected areas may present important opportunities to meet sustainability targets while helping support the fishing sector in a changing climate. By capitalizing on the natural distribution of climate resilience within ocean ecosystems, such climate-adaptive spatial management strategies could be seen as nature-based solutions to limit the impact of CC on ocean ecosystems and dependent blue economy sectors, paving the way for climate-smart MSP.
... Multiple shallow-water bivalve species exhibit reduced growth and/or survival under either low oxygen or low pH conditions; together, these stressors often induce additive or synergistic negative effects (Figure 4), although high tolerance may exist in some species or life stages (Gobler and Baumann, 2016). Elevated CO 2 typically raises energetic requirements of invertebrates, inducing greater OC consumption (Thomsen et al., 2013;Queirós et al., 2015); the addition of hypoxia causes metabolic depression, potentially impairing how sediment fauna cope with acidification (Ravaglioli et al., 2019). Studies of the combined effects of reduced oxygen and elevated CO 2 suggest slower microbial degradation and enhanced carbon burial, although additional studies of coupled abiotic stressors involving oxygen are needed (Sampaio et al., 2021). ...
Benthic animals profoundly influence the cycling and storage of carbon and other elements in marine systems, particularly in coastal sediments. Recent climate change has altered the distribution and abundance of many seafloor taxa and modified the vertical exchange of materials between ocean and sediment layers. Here, we examine how climate change could alter animal-mediated biogeochemical cycling in ocean sediments.The fossil record shows repeated major responses from the benthos during mass extinctions and global carbon perturbations, including reduced diversity, dominance of simple trace fossils, decreased burrow size and bioturbation intensity, and nonrandom extinction of trophic groups. The broad dispersal capacity of many extant benthic species facilitates poleward shifts corresponding to their environmental niche as overlying water warms. Evidence suggests that locally persistent populations will likely respond to environmental shifts through either failure to respond or genetic adaptation rather than via phenotypic plasticity. Regional and global ocean models insufficiently integrate changes in benthic biological activity and their feedbacks on sedimentary biogeochemical processes. The emergence of bioturbation, ventilation, and seafloor-habitat maps and progress in our mechanistic understanding of organism-sediment interactions enable incorporation of potential effects of climate change on benthic macrofaunal mediation of elemental cycles into regional and global ocean biogeochemical models.
... • Weakly acidic environments impaired the ability of juvenile salmon to detect and respond to alarm cues [100]. • Littorinid snails on rocky shores switched from thickening shells in the presence of predators to avoidance behavior when exposed to OA [101], while the predatory snail, Nucella, showed decreased chemosensory abilities, taking longer to locate food [102]. • Impacts on chemosensory function when exposed to acidification have also been observed in some crabs [103] and fish (e.g., Refs. ...
Oceans have the capacity to absorb large amounts of carbon dioxide (CO2) because CO2 dissolves and reacts in seawater to form bicarbonate (HCO3⁻) and protons (H⁺). About a quarter to a third of the CO2 emitted into the atmosphere from the burning of fossil fuels, cement manufacturing, and land use changes has been absorbed by the oceans. Over thousands of years, the changes in pH have been buffered by bases, such as carbonate ions (CO3²⁻). However, the rate at which CO2 is currently being absorbed into the oceans is too rapid to be buffered sufficiently to prevent substantial changes in ocean pH and CO3²⁻. As a consequence, the relative seawater concentrations of CO2, HCO3–, CO3²⁻, and pH have been altered. Since preindustrial times, the ocean pH has decreased by a global average of 0.1. It is estimated that unmitigated CO2 emissions will cause ocean pH to decrease by as much as 0.4 by 2100 and 0.77 by 2300. These will be the most rapid and greatest changes in ocean carbonate chemistry experienced by marine organisms over the past tens of millions of years. Laboratory experiments, field observations of natural CO2-rich seawater “hot spots,” and studies of previous ocean acidification in Earth's history indicate that these changes are a threat to the survival of many marine organisms but particularly organisms that use CaCO3 to produce shells, tests, and skeletons. The only way of reducing the impacts of ocean acidification on a global scale is through urgent and substantial reductions in anthropogenic CO2 emissions. Ocean acidification is a key argument for united global societal action in ongoing climate change negotiations.
... Finally, artificial reefs, like natural reefs, are being subjected to a warmer and acidified marine environment. The combination of acidification and warming leads to substantial, non-additive and complex changes in community dynamics (Queirós et al., 2015), affects pelagic and benthic nutrient cycling (Braeckman et al., 2014), and alters the mechanism behind predator-prey interactions (Draper and Weissburg, 2019). Thus, current understanding of the artificial reef effect in OWFs must be considered within a modern changing environment. ...
Offshore wind farms (OWFs) are proliferating globally. The submerged parts of their structures act as artificial reefs, providing new habitats and likely affecting fisheries resources. While acknowledging that the footprints of these structures may result in loss of habitat, usually soft sediment, we focus on how the artificial reefs established by OWFs affect ecosystem structure and functioning. Structurally, the ecological response begins with high diversity and biomass in the flora and fauna that gradually colonize the complex hard substrate habitat. The species may include nonindigenous ones that are extending their spatial distributions and/or strengthening populations, locally rare species (e.g., hard substrate-associated fish), and habitat-forming species that further increase habitat complexity. Functionally, the response begins with dominant suspension feeders that filter organic matter from the water column. Their fecal deposits alter the surrounding seafloor communities by locally increasing food availability, and higher trophic levels (fish, birds, marine mammals) also profit from locally increased food availability and/or shelter. The structural and functional effects extend in space and time, impacting species differently throughout their life cycles. Effects must be assessed at those larger spatiotemporal scales.
... The flumes were then left to settle for 7 days in darkened and aerated conditions at L4 bottom water temperatures. The mesocosm laboratory is an environment controlled room where, in addition to other controls, air, and thereby also water, temperature is regulated on a monthly basis to follow the seasonal cycle of bottom water temperature at L4 (Queirós et al., 2015a). ...
In coastal temperate environments, many processes known to affect the exchange of particulate and dissolved matter between the seafloor and the water column follow cyclical patterns of intra-annual variation. This study assesses the extent to which these individual short term temporal variations affect specific direct drivers of seafloor-water exchanges, how they interact with one another throughout the year, and what the resulting seasonal variation in the direction and magnitude of benthic-pelagic exchange. Existing data from a multidisciplinary long-term time-series from the Western Channel Observatory, UK, were combined with new experimental and in-situ data collected throughout a full seasonal cycle. These data were used to define an average year, split into five ‘periods’ (winter, pre-bloom, bloom, post-bloom and autumn) based around the known importance of pelagic primary production and hydrodynamically active phases of the year. Multivariate analyses were used to identify specific sub-sets of parameters that described the various direct drivers of seafloor-water exchanges. Both dissolved and particulate exchange showed three distinct periods of significant flux during the year, although the specific timings of these periods and the cause-effect relationships to the direct and indirect drivers differed between the two types of flux. Dissolved matter exchange was dominated by an upward flux in the pre-bloom period driven by diffusion, then a biologically induced upward flux during the bloom and an autumn downward flux. The latter was attributable to the interactions of hydrodynamic and biological activity on the seafloor. Particulate matter exchanges exhibited a strongly hydrologically influenced upward flux during the winter, followed by a biologically induced downward flux during the bloom and a second period of downward flux throughout post-bloom and autumn periods. This was driven primarily through interactions between biological activity, and physical and meteorological drivers. The integrated, holistic and quantitative data-based analysis of intra-annual variability in benthic/pelagic fluxes presented in this study in a representative temperate coastal environment, demonstrates not only the various process’ inter-connectivity, but also their relative importance to each other. Future investigations or modelling efforts of similar systems will benefit greatly from the relationships and baseline rules established in this study.
... Using a simple size-spectrum approach based on temperature and primary production (Jennings et al. 2008), an increase of 2°C in temperature (and at the same primary production level) can trigger a 20% decrease in total biomass, but an increase of smaller size fish abundance and biomass . This is consistent with higher trophic and benthic species projected to decrease as a result of warming and ocean acidification in southern areas of the NEA (Queirós et al. 2015;Fernandes et al. 2017;Lotze et al. 2019). The two biogeochemical models show agreement on the main trends and areas of impacts. ...
Small- and intermediate-size pelagic fisheries are highly impacted by environmental variability and climate change. Their wide geographical distribution and high mobility makes them more likely to shift their distribution under climate change. Here, we explore the potential impact of different climate change scenarios on the four main commercial pelagic species in the North-East Atlantic (NEA): Atlantic mackerel (Scomber scombrus), European sprat (Sprattus sprattus), Atlantic herring (Clupea harengus) and blue whiting (Micromesistius poutassou). We used a process-based fisheries model (SS-DBEM), where all the target species were exploited at their maximum sustainable yield (MSY), to project future potential catches under a high- and low-future-greenhouse-gas scenario (RCP 2.6 and 8.5, respectively). Two ocean biogeochemical models (GDFL and MEDUSA) were used to force the environmental conditions. Mackerel and sprat are projected to have increases in a potential catch under both scenarios. Herring and blue whiting are projected to increase under the RCP2.6, but future projections under RCP8.5 show mixed responses with decreases or no changes forecasted. Overall, the potential catch is projected to increase in the northern area of the NEA but is projected to decrease in the southern area. These projected changes are mainly driven by changes in temperature and primary production. Shifts in the distribution of pelagic resources may destabilize existing international agreements on sharing of straddling resources as exemplified by the dispute in sharing of quota for Atlantic mackerel. Novel climate-ready policy approaches considering full species distribution are needed to complement current stock-based approaches.
... It was demonstrated that short-term exposures to low pH values could lead to hypercapnic conditions in sea urchin coelomic fluid (Miles et al. 2007;Spicer et al. 2011;Dupont and Thorndyke 2012;Spicer and Widdicombe 2012;Stumpp et al. 2012;Holtmann et al. 2013;Kurihara et al. 2013). This effect could represent a "shock" response (Byrne 2012;Queirós et al. 2015) possibly related to both the absence of respiratory pigments and low capability of sea urchins to regulate ions. Generally, in most species, with few exceptions (Kurihara et al. 2013), the acid-base balance is recovered in some days or weeks (Calosi et al. 2013;Dupont and Thorndyke 2012;Stumpp et al. 2012;Holtman et al. 2013;Moulin et al. 2014). ...
Seawater pH lowering, known as ocean acidification, is considered among the major threats to marine environment. In this study, post-spawning adults of the sea urchin Paracentrotus lividus were maintained at three pH values (8.0, 7.7, 7.4) for 60 days. Physiological, biochemical, cellular, behavioural and reproductive responses were evaluated in males and females. Significant differences between sexes were observed, with higher ammonia excretion and lower catalase activity in males. Respiration rate (after 21 days), catalase activity in gonads and total coelomocyte count showed the same increasing trend in males and females under low pH. Ammonia excretion, gonadosomatic index and lysozyme activity exhibited opposite responses to low pH, with an increasing trend in males and decreasing in females. Results demonstrated that exposure to low pH could result in different response strategies of male and female sea urchins at a physiological, biochemical and immunological level. Reduced female gonadosomatic index under low pH suggested decreased energy investment in reproduction.
The effect of ocean warming and acidification on predator-prey interactions in the intertidal zone is a topic of growing concern for the scientific community. In this review, we aim to describe how scientists have explored the topic via research weaving, a combination of a systematic review, and a bibliometric approach. We assess articles published in the last decade exploring the impact of both stressors on predation in the intertidal zone, via experimental or observational techniques. Several methods were used to delve into how climate change-induced stress affected intertidal predation, as the study design leaned toward single-based driver trials to the detriment of a multi-driver approach. Mollusks, echinoderms, and crustaceans have been extensively used as model organisms , with little published data on other invertebrates, vertebrates, and algae taxa. Moreover, there is a strong web of co-authoring across institutions and countries from the Northern Hemisphere, that can skew our understanding towards temperate environments. Therefore, institutions and countries should increase participation in the southern hemisphere networking, assessing the problems under a global outlook. Our review also addresses the various impacts of ocean acidification, warming, or their interaction with predation-related variables, affecting organisms from the genetic to a broader ecological scope, such as animal behaviour or interspecific interactions. Finally, we argue that the numerous synonyms used in keywording articles in the field, possibly hurting future reviews in the area, as we provide different keyword standardizations. Our findings can help guide upcoming approaches to the topic by assessing what has been already done and revealing gaps in emerging themes, like a strong skew towards single-driver (specially acidification) lab experiments of northern hemisphere organisms and a lack of field multi-stressor experiments.
Independently, ocean warming (OW) and acidification (OA) from increased anthropogenic atmospheric carbon dioxide are argued to be two of the greatest threats to marine organisms. Increasingly, their interaction (ocean acidification and warming, OAW) is shown to have wide-ranging consequences to biological functioning, population and community structure, species interactions and ecosystem service provision. Here, using a multi-trophic experiment, we tested the effects of future OAW scenarios on two widespread intertidal species, the blue mussel Mytilus edulis and its predator Nucella lapillus. Results indicate negative consequences of OAW on the growth, feeding and metabolic rate of M. edulis and heightened predation risk. In contrast, Nucella growth and metabolism was unaffected and feeding increased under OAW but declined under OW suggesting OA may offset warming consequences. Should this differential response between the two species to OAW, and specifically greater physiological costs to the prey than its predator come to fruition in the nature, fundamental change in ecosystem structure and functioning could be expected as trophic interactions become disrupted.
Harnessing natural solutions to mitigate climate change requires an understanding of carbon fixation, flux and sequestration across ocean habitats. Recent studies suggest that exported seaweed particulate organic carbon is stored within soft sediment systems. However, very little is known about how seaweed detritus disperses from coastlines, or where it may enter seabed carbon stores, where it could become the target of conservation efforts. Here, focusing on regionally dominant seaweed species, we surveyed environmental DNA (eDNA) of natural coastal sediments, and studied their connectivity to seaweed habitats using a particle tracking model parameterized to reproduce seaweed detritus dispersal behavior based on laboratory observation of seaweed fragment degradation and sinking. Experiments showed seaweed detritus density changing over time, differently across species. This, in turn, modified distances travelled by released fragments until they reached the seabed for the first time, during model simulations. Dispersal pathways connected detritus from the shore to the open ocean but, importantly, also to coastal sediments, and this was reflected by field eDNA evidence. Dispersion pathways were also affected by hydrodynamic conditions, varying in space and time. Both the properties and timing of released detritus, individual to each macroalgal population, and short-term near-seabed and medium-term water-column transport pathways, are thus seemingly important in determining the connectivity between seaweed habitats and potential sedimentary sinks. Studies such as this one, supported by further field verification of sedimentary carbon sequestration rates and source partitioning, are still needed to help quantify the role of seaweed in the ocean carbon cycle. Such studies will provide vital evidence to inform on the potential need to develop blue carbon conservation mechanisms, beyond wetlands.
The authors investigated left–right turning preferences of n = 260 juvenile European sea bass (Dicentrarchus labrax) reared in ambient conditions and ocean acidification (OA) conditions or in ambient conditions but tested in OA water. Groups of 10 individuals were observed alone in a circular tank, and individuals' left and right turning during free‐swimming was quantified using trajectory data from the video. The authors showed that near‐future OA levels do not affect the number of turns made, or behavioural lateralization (turning preference), in juvenile D. labrax tested in groups.
The driving factors of climate change, especially ocean acidification (OA), have many detrimental impacts on marine bivalves. Hybridization is one of the important methods to improve environmental tolerance of animals and plants. In this study, we explored the feasibility of intraspecific hybridization as an OA mitigation strategy in noble scallop Chlamys nobilis (ecologically and economically important bivalve species). The results of this study revealed that exposure of C. nobilis to OA condition significantly reduced the hatching rate, survival rate, growth rate (shell height, shell length, shell width and shell weight), and total carotenoid content (TCC), as well as increased the deformity rate of C. nobilis larvae. Interestingly, under both ambient water and OA condition, the intraspecific hybridization of C. nobilis exhibited heterosis in terms of hatching rate, survival rate and growth rate (excepted for growth in shell length under OA). Transcriptome sequencing of C. nobilis (inbreed and hybrid under ambient and OA conditions) identified four main differentially expressed genes involved in signal transduction, biological process maintenances, nucleic acid binding and post-translational modification. In addition, the expression of these four genes in hybrid C. nobilis was significantly higher than that in inbreed C. nobilis. In conclusion, hybrid C. nobilis showed heterosis in growth rate and survival rate under both ambient water and acidified seawater condition, which may be the result of enhanced expression of genes related to signal transduction, DNA replication and post-translational modification.
Scaling experimentally derived effects of CO 2 on marine fauna to population responses is critical for informing management about potential ecological ramifications of ocean acidification. We used an individual-based model of winter flounder to extrapolate laboratory-derived effects of elevated CO 2 assumed for early life stages of fish to long-term population dynamics. An offspring module with detailed hourly to daily representations of spawning, growth, and mortality that incorporates potential elevated CO 2 effects was linked to an annual time-step parent module. We calibrated the model using a 40 yr Reference simulation (1977-2016) that included gradual warming and then performed ‘Retrospective’ simulations that assumed a suite of elevated CO 2 effects by changing fertilization rate, mortality rate of embryos due to developmental malformations, larval growth rate, and size-at-settlement. ‘Recovery’ simulations that started at low population size were then used to further explore possible interactions between the effects of CO 2 and warming on population productivity. Warming had a major negative effect on the simulated winter flounder population abundance, and reduced larval growth had the largest single impact among the CO 2 effects tested. When a combination of the assumed CO 2 effects was imposed together, average annual recruitment and spawning stock biomass were reduced by half. In the Recovery simulations, inclusion of CO 2 effects amplified the progressive decrease in population productivity with warming. Our analysis is speculative and a first step towards addressing the need for extrapolating from laboratory effects of ocean acidification to broader, ecologically relevant scales.
Ocean acidification is predicted to have significant implications for marine calcifying organisms. However, little is known about the physiological responses of Pacific oyster, Crassostrea gigas, to elevated partial pressure of atmospheric carbon dioxide (pCO2) under natural fluctuations associated with a farm environment. The present study evaluated the effect of two pCO2 levels (i.e. ambient ∼625 μatm and elevated ∼1432 μatm) on the physiological processes and growth of C. gigas in in situ mesocosms that simulated the farm environment. Oysters were exposed for 30 days over a sensitive period during their production cycle when they are first exposed to natural coastal conditions. Despite this being a well-known “bottleneck” in production, it remains understudied with respect to climate change. Results showed that elevated pCO2 levels decreased clearance rate, ingestion rate, absorption efficiency, and oxygen to nitrogen ratio, while increasing oxygen consumption and ammonia-N excretion rates. These physiological responses of oysters resulted in a reduction in energy available for growth (scope for growth). No mortality was observed in the control or elevated pCO2 treatments, indicating that although oyster may survive future coastal acidification, the allocation of energy towards production within aquaculture systems will decrease in the future, affecting the culture of these economically important marine bivalves.
In the past decades, the impacts of ocean acidification (OA) on marine animals have gained much attention. To date, numerous works in the literature have shown that OA can affect a variety of biological processes of marine animals, and our knowledge about its effects on marine organisms is mainly focused on the following aspects: (1) fertilization and early development; (2) biomineralization, metabolism, and growth; and (3) immunity and behaviors. However, there are still some limitations that currently exist in research on OA, which include (1) performing experiments with “constant acidification” rather than natural pH fluctuations that may not fully reflect their future true living conditions; (2) using pCO2 levels that were predicted to be reached in a hundred years in the future for experiments with relatively short exposure times, thus overlooking marine organisms’ potential for genetic adaptation or acclimation to the acidified seawater; (3) large amounts of experiments examining OA’s physiological impacts while leaving the potential affecting mechanisms largely unstudied; and (4) a lack of experiments investigating indirect effects of OA on marine organisms and the whole ecosystem. After providing a summary of the current knowledge of OA’s impacts on marine animals, this review aims to highlight potential directions for future studies.
Projected future carbon dioxide (CO2) levels in the ocean can alter marine animal behaviours. Disrupted functioning of γ-aminobutyric acid type A (GABAA) receptors (ligand-gated chloride channels) is suggested to underlie CO2-induced behavioural changes in fish. However, the mechanisms underlying behavioural changes in marine invertebrates are poorly understood. We pharmacologically tested the role of GABA-, glutamate-, acetylcholine- and dopamine-gated chloride channels in CO2-induced behavioural changes in a cephalopod, the two-toned pygmy squid (Idiosepius pygmaeus). We exposed squid to ambient (∼450 µatm) or elevated (∼1,000 µatm) CO2 for seven days. Squid were treated with sham, the GABAA receptor antagonist gabazine, or the non-specific GABAA receptor antagonist picrotoxin, before measurement of conspecific-directed behaviours and activity levels upon mirror exposure. Elevated CO2 increased conspecific-directed attraction and aggression, as well as activity levels. For some CO2-affected behaviours, both gabazine and picrotoxin had a different effect at elevated compared to ambient CO2, providing robust support for the GABA hypothesis within cephalopods. In another behavioural trait, picrotoxin but not gabazine had a different effect in elevated compared to ambient CO2, providing the first pharmacological evidence, in fish and marine invertebrates, for altered functioning of ligand-gated chloride channels, other than the GABAA R, underlying CO2-induced behavioural changes. For some other behaviours, both gabazine and picrotoxin had a similar effect in elevated and ambient CO2, suggesting altered function of ligand-gated chloride channels was not responsible for these CO2-induced changes. Multiple mechanisms may be involved, which could explain the variability in the CO2 and drug treatment effects across behaviours.
Most future projections forecast significant and ongoing climate change during the 21st century, but with the severity of impacts dependent on efforts to restrain or reorganise human activity to limit carbon dioxide (CO2) emissions. A major sink for atmospheric CO2, and a key source of biological resources, the World Ocean is widely anticipated to undergo profound physical and – via ocean acidification – chemical changes as direct and indirect results of these emissions. Given strong biophysical coupling, the marine biota is also expected to experience strong changes in response to this anthropogenic forcing. Here we examine the large-scale response of ocean biogeochemistry to climate and acidification impacts during the 21st century for Representative Concentration Pathways (RCPs) 2.6 and 8.5 using an intermediate complexity global ecosystem model, MEDUSA-2.0. The primary impact of future change lies in stratification-led declines in the availability of key nutrients in surface waters, which in turn leads to a global decrease (1990s vs. 2090s) in ocean productivity (−6.3%). This impact has knock-on consequences for the abundance of the low trophic level biogeochemical actors modelled by MEDUSA-2.0 (−5.8%), and these would be expected to similarly impact higher trophic level elements such as fisheries. Related impacts are found in the flux of organic material to seafloor communities (−40.7% at 1000 m), and in the volume of ocean suboxic zones (+12.5%). A sensitivity analysis removing an acidification feedback on calcification finds that change in this process significantly impacts benthic communities, suggesting that a~better understanding of the OA-sensitivity of calcifying organisms, and their role in ballasting sinking organic carbon, may significantly improve forecasting of these ecosystems. For all processes, there is geographical variability in change – for instance, productivity declines −21% in the Atlantic and increases +59% in the Arctic – and changes are much more pronounced under RCP 8.5 than the RCP 2.6 scenario.
Species distribution models (SDMs) use spatial environmental data to make inferences on speciesÕ range limits and habitat suitability. Conceptually, these models aim to determine and map components of a speciesÕ ecological niche through space and time, and they have become important tools in pure and applied ecology and evolutionary biology. Most approaches are correlative in that they statistically link spatial data to species distribution records. An alternative strategy is to explicitly incorporate the mechanistic links between the functional traits of organisms and their environments into SDMs. Here, we review how the principles of biophysical ecology can be used to link spatial data to the physiological responses and constraints of organisms. This provides a mechanistic view of the fundamental niche which can then be mapped to the landscape to infer range constraints. We show how physiologically based SDMs can be developed for different organisms in different environmental contexts. Mechanistic SDMs have different strengths and weaknesses to correlative approaches, and there are many exciting and unexplored prospects for integrating the two approaches. As physiological knowledge becomes better integrated into SDMs, we will make more robust predictions of range shifts in novel or non-equilibrium contexts such as invasions, translocations, climate change and evolutionary shifts.
Cheung, W. W. L., Dunne, J., Sarmiento, J. L., and Pauly, D. 2011. Integrating ecophysiology and plankton dynamics into projected
maximum fisheries catch potential under climate change in the Northeast Atlantic. – ICES Journal of Marine Science, 68: 1008–1018.
Previous global analyses projected shifts in species distributions and maximum fisheries catch potential across ocean basins
by 2050 under the Special Report on Emission Scenarios (SRES) A1B. However, these studies did not account for the effects
of changes in ocean biogeochemistry and phytoplankton community structure that affect fish and invertebrate distribution and
productivity. This paper uses a dynamic bioclimatic envelope model that incorporates these factors to project distribution
and maximum catch potential of 120 species of exploited demersal fish and invertebrates in the Northeast Atlantic. Using projections
from the US National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory Earth System Model
(ESM2.1) under the SRES A1B, we project an average rate of distribution-centroid shift of 52 km decade−1 northwards and 5.1 m decade−1 deeper from 2005 to 2050. Ocean acidification and reduction in oxygen content reduce growth performance, increase the rate
of range shift, and lower the estimated catch potentials (10-year average of 2050 relative to 2005) by 20–30% relative to
simulations without considering these factors. Consideration of phytoplankton community structure may further reduce projected
catch potentials by ∼10%. These results highlight the sensitivity of marine ecosystems to biogeochemical changes and the need
to incorporate likely hypotheses of their biological and ecological effects in assessing climate change impacts.
Marine biodiversity currently faces unprecedented threats from multiple pressures arising from human activities. Global drivers such as climate change and ocean acidification interact with regional eutrophication, exploitation of commercial fish stocks and localized pressures including pollution, coastal development and the extraction of aggregates and fuel, causing alteration and degradation of habitats and communities. Segregating natural from anthropogenically induced change in marine ecosystems requires long-term, sustained observations of marine biota. In this review, we outline the history of biological recording in the coastal and shelf seas of the UK and Ireland and highlight where sustained observations have contributed new understanding of how anthropogenic activities have impacted on marine biodiversity. The contributions of sustained observations, from those collected at observatories, single station platforms and multiple-site programmes to the emergent field of multiple stressor impacts research, are discussed, along with implications for management and sustainable governance of marine resources in an era of unprecedented use of the marine environment.
Elevations in atmospheric carbon dioxide (CO2) are anticipated to acidify oceans because of fundamental changes in ocean chemistry created by CO2 absorption from the atmosphere. Over the next century, these elevated concentrations of atmospheric CO2 are expected to result in a reduction of the surface ocean waters from 8.1 to 7.7 units as well as a reduction in carbonate ion (CO3²⁻) concentration. The potential impact that this change in ocean chemistry will have on marine and estuarine organisms and ecosystems is a growing concern for scientists worldwide. While species-specific responses to ocean acidification are widespread across a number of marine taxa, molluscs are one animal phylum with many species which are particularly vulnerable across a number of life-history stages. Molluscs make up the second largest animal phylum on earth with 30,000 species and are a major producer of CaCO3. Molluscs also provide essential ecosystem services including habitat structure and food for benthic organisms (i.e., mussel and oyster beds), purification of water through filtration and are economically valuable. Even sub lethal impacts on molluscs due to climate changed oceans will have serious consequences for global protein sources and marine ecosystems.
Climate change is postulated to influence marine resources worldwide with consequent ramifications for the management of commercially important fisheries. There is a need to understand the likely impacts of climate change affecting the biology of fisheries at each of the different levels: (a) individual (reproductive potential, larval settlement, spatial distribution); (b) population (carrying capacity, productivity, spatial distribution); (c) multi-species (replacement of one fishery by another) and (d) ecosystem (dependent predator species, shifts in community composition). When addressing these problems it is important to integrate information across a range of dimensions pertaining to the resource and stakeholders, using a combination of biological, economic and social research elements. This is necessary for a better understanding of the likely changes to catches and in turn the possible socio-economic implications. We assessed the impact and likelihood of a range of plausible climate impacts on a number of lobster life history parameters, using the Torres Strait tropical rock lobster Panulirus ornatus as a case study. The hypothesised high risk effects of climate change were implemented through modifications to the lobster stock assessment model. Projected catches and an input–output model of the Australian economy were used to determine the flow-on effects of climate-change impacts affecting this lobster fishery. We highlight the potential of this combination of quantitative and qualitative approaches as a pragmatic first step to exploring climate-change impacts on a fishery and summarise implications for management. Our results suggest that there may be positive as well as negative consequences. Our integrated methodology is a step towards linking the interrelation between different variables and fishery productivity, and quantifying the resultant socio-economic effects to fishers, their communities and national economies.
The increase in atmospheric CO2 is a dual threat to the
marine environment: from one side it drives climate change leading to
changes in water temperature, circulation patterns and stratification
intensity; on the other side it causes a decrease in pH (Ocean
Acidification or OA) due to the increase in dissolved CO2.
Assessing the combined impact of climate change and OA on marine
ecosystems is a challenging task: the response of the ecosystem to a
single driver is highly variable and still uncertain, as well as the
interaction between these that could be either synergistic or
antagonistic. In this work we use the coupled oceanographic-ecosystem
model POLCOMS-ERSEM driven by climate forcing to study the interaction
between climate change and OA. We focus in particular on primary
production and nitrogen speciation. The model has been run in three
different configurations in order to separate the impacts of ocean
acidification from those due to climate change. The model shows
significant interaction among the drivers and high variability in the
spatial response of the ecosystem. Impacts of climate change and of OA
on primary production have similar magnitude, compensating in some area
and exacerbating in others. On the contrary, the direct impact of OA on
nitrification is much lower than the one imposed by climate change.
Most future projections forecast significant and ongoing climate change
during the 21st century, but with the severity of impacts dependent on
efforts to restrain or reorganise human activity to limit carbon dioxide
(CO2) emissions. A major sink for atmospheric CO2,
and a key source of biological resources, the World Ocean is widely
anticipated to undergo profound physical and - via ocean acidification -
chemical changes as direct and indirect results of these emissions.
Given strong biophysical coupling, the marine biota is also expected to
experience strong changes in response to this anthropogenic forcing.
Here we examine the large-scale response of ocean biogeochemistry to
climate and acidification impacts during the 21st century for
Representative Concentration Pathways (RCPs) 2.6 and 8.5 using an
intermediate complexity global ecosystem model, Medusa-2.0. The primary
impact of future change lies in stratification-led declines in the
availability of key nutrients in surface waters, which in turn leads to
a global decrease (1990s vs. 2090s) in ocean productivity (-6.3%). This
impact has knock-on consequences for the abundances of the low trophic
level biogeochemical actors modelled by Medusa-2.0 (-5.8%), and these
would be expected to similarly impact higher trophic level elements such
as fisheries. Related impacts are found in the flux of organic material
to seafloor communities (-40.7% at 1000 m), and in the volume of ocean
suboxic zones (+12.5%). A sensitivity analysis removing an acidification
feedback on calcification finds that change in this process
significantly impacts benthic communities, suggesting that a better
understanding of the OA-sensitivity of calcifying organisms, and their
role in ballasting sinking organic carbon, may significantly improve
forecasting of these ecosystems. For all processes, there is
geographical variability in change, and changes are much more pronounced
under RCP 8.5 than the RCP 2.6 scenario.
Ocean acidification poses a range of threats to marine invertebrates; however, the potential effects of rising carbon dioxide (CO2) on marine invertebrate behaviour are largely unknown. Marine gastropod conch snails have a modified foot and operculum allowing them to leap backwards rapidly when faced with a predator, such as a venomous cone shell. Here, we show that projected near-future seawater CO2 levels (961 µatm) impair this escape behaviour during a predator-prey interaction. Elevated-CO2 halved the number of snails that jumped from the predator, increased their latency to jump and altered their escape trajectory. Physical ability to jump was not affected by elevated-CO2 indicating instead that decision-making was impaired. Antipredator behaviour was fully restored by treatment with gabazine, a GABA antagonist of some invertebrate nervous systems, indicating potential interference of neurotransmitter receptor function by elevated-CO2, as previously observed in marine fishes. Altered behaviour of marine invertebrates at projected future CO2 levels could have potentially far-reaching implications for marine ecosystems.
The harbour ragworm, Nereis (Hediste) diversicolor is a common intertidal marine polychaete that lives in burrows from which it has to partially emerge in order to forage. In doing so, it is exposed to a variety of predators. One way in which predation risk can be minimised is through chemical detection from within the relative safety of the burrows. Using CCTV and motion capture software, we show that H. diversicolor is able to detect chemical cues associated with the presence of juvenile flounder (Platichthys flesus). Number of emergences, emergence duration and distance from burrow entrance are all significantly reduced during exposure to flounder conditioned seawater and flounder mucous spiked seawater above a threshold with no evidence of behavioural habituation. Mucous from bottom-dwelling juvenile plaice (Pleuronectes platessa) and pelagic adult herring (Clupea harengus) elicit similar responses, suggesting that the behavioural reactions are species independent. The data implies that H. diversicolor must have well developed chemosensory mechanisms for predator detection and is consequently able to effectively minimize risk.
Metabolic rate determines the physiological and life-history performances of ectotherms. Thus, the extent to which such rates are sensitive and plastic to environmental perturbation is central to an organism's ability to function in a changing environment. Little is known of long-term metabolic plasticity and potential for metabolic adaptation in marine ectotherms exposed to elevated pCO2. Consequently, we carried out a series of in situ transplant experiments using a number of tolerant and sensitive polychaete species living around a natural CO2 vent system. Here, we show that a marine metazoan (i.e. Platynereis dumerilii) was able to adapt to chronic and elevated levels of pCO2. The vent population of P. dumerilii was physiologically and genetically different from nearby populations that experience low pCO2, as well as smaller in body size. By contrast, different populations of Amphiglena mediterranea showed marked physiological plasticity indicating that adaptation or acclimatization are both viable strategies for the successful colonization of elevated pCO2 environments. In addition, sensitive species showed either a reduced or increased metabolism when exposed acutely to elevated pCO2. Our findings may help explain, from a metabolic perspective, the occurrence of past mass extinction, as well as shed light on alternative pathways of resilience in species facing ongoing ocean acidification.
Most research on Ocean Acidification (OA) has largely focused on the process of calcification and the physiological trade-offs employed by calcifying organisms to support the building of calcium carbonate structures. However, there is growing evidence that OA can also impact upon other key biological processes such as survival, growth and behaviour. On wave-swept rocky shores the ability of gastropods to self-right after dislodgement, and rapidly return to normal orientation, reduces the risk of predation.
The impacts of OA on this self-righting behaviour and other important parameters such as growth, survival, shell dissolution and shell deposition in Concholepas concholepas (loco) were investigated under contrasting pCO2 levels. Although no impacts of OA on either growth or net shell calcification were found, the results did show that OA can significantly affect self-righting behaviour during the early ontogeny of this species with significantly faster righting times recorded for individuals of C. concholepas reared under increased average pCO2 concentrations (± SE) (716±12 and 1036±14 µatm CO2) compared to those reared at concentrations equivalent to those presently found in the surface ocean (388±8 µatm CO2). When loco were also exposed to the predatory crab Acanthocyclus hassleri, righting times were again increased by exposure to elevated CO2, although self-righting times were generally twice as fast as those observed in the absence of the crab.
These results suggest that self-righting in the early ontogeny of C. concholepas will be positively affected by pCO2 levels expected by the end of the 21st century and beginning of the next one. However, as the rate of self-righting is an adaptive trait evolved to reduce lethal predatory attacks, our result also suggest that OA may disrupt prey responses to predators in nature.
Increased levels of atmospheric CO2 are anticipated to cause decreased seawater pH. Despite the fact that calcified marine invertebrates are particularly susceptible to acidification, bar- nacles have received little attention. We examined larval condition, cyprid size, cyprid attachment and metamorphosis, juvenile to adult growth, shell calcium carbonate content, and shell resistance to dislodgement and penetration in the barnacle Amphibalanus amphitrite reared from nauplii in either ambient pH 8.2 seawater or under CO2-driven acidification of seawater down to a pH of 7.4. There were no effects of reduced pH on larval condition, cyprid size, cyprid attachment and metamorpho- sis, juvenile to adult growth, or egg production. Nonetheless, barnacles exposed to pH 7.4 seawater displayed a trend of larger basal shell diameters during growth, suggestive of compensatory calcifi- cation. Furthermore, greater force was required to cause shell breakage of adults raised at pH 7.4, indicating that the lower, active growth regions of the wall shells had become more heavily calcified. Ash contents (predominately calcium carbonate) of basal shell plates confirmed that increased calci- fication had occurred in shells of individuals reared at pH 7.4. Despite enhanced calcification, pen- etrometry revealed that the central shell wall plates required significantly less force to penetrate than those of individuals raised at pH 8.2. Thus, dissolution rapidly weakens wall shells as they grow. The ramifications of our observations at the population level are important, as barnacles with weakened wall shells are more vulnerable to predators.
In addition to the predicted rise in temperature, a recognised consequence of increased atmospheric CO2 is ocean acidification. The response of marine organisms to the stresses associated with acidification is still not understood, and a number of recent experiments have addressed this problem. The starting point for many of these studies has been the development of a system by which seawater pH can be altered and then maintained. The current paper presents details of a tempera- ture- and pH-controlled microcosm system, which enables the establishment of a tidal regime, for the experimental investigation of intertidal organisms. Two climate scenarios were simulated to evaluate the system's precision and accuracy; Year 2008 ('low' (CO2): 380 ppm and 14°C) conditions and Year 2100 ('high' (CO2)) conditions (based on the IPCC—Intergovernmental Panel on Climate Change— 2007 A2 scenario, 'high' (CO2): 1250 ppm and 2.0 to 5.4°C warming). The temperature and seawater carbonate chemistry were reliably maintained for 30 d during which time newly settled barnacle cyprids were allowed to metamorphose into juveniles, then grow and develop. The pH and (CO2) had 95% confidence intervals of ±0.03 units and ±17 ppm, respectively, under low (CO2) conditions, and of ±0.02 units and ±43 ppm, respectively, under high (CO2) conditions. The tidal regime is fully adjust- able, and on this occasion was set to a 6 h cycle. These microcosms have proved ideal for studying ben- thic organisms from a variety of near-surface environments and at different stages of their life-cycle.
Climate change has already altered the distribution of marine fishes. Future predictions of fish distributions and catches based on bioclimate envelope models are available, but to date they have not considered inter-specific interactions. We address this by combining the species-based Dynamic Bioclimate Envelope Model (DBEM) with a size-based trophic model. The new approach provides spatially and temporally resolved predictions of changes in species' size, abundance and catch potential that account for the effects of ecological interactions. Predicted latitudinal shifts are, on average, reduced by 20% when species interactions are incorporated, compared to DBEM predictions, with pelagic species showing the greatest reductions. Goodness-of-fit to biomass data from fish stock assessments in the North Atlantic between 1991 and 2003 is improved slightly by including species interactions. The differences between predictions from the two models may be relatively modest because, at the North Atlantic basin scale, (1) predators and competitors may respond to climate change together; (2) existing parameterization of the DBEM might implicitly incorporate trophic interactions; and/or (3) trophic interactions might not be the main driver of responses to climate. Future analyses using ecologically-explicit models and data will improve understanding of the effects of inter-specific interactions on responses to climate change, and better inform managers about plausible ecological and fishery consequences of a changing environment. This article is protected by copyright. All rights reserved.
Ocean acidification represents a threat to marine species worldwide, and forecasting the ecological impacts of acidification is a high priority for science, management, and policy. As research on the topic expands at an exponential rate, a comprehensive understanding of the variability in organisms' responses and corresponding levels of certainty is necessary to forecast the ecological effects. Here, we perform the most comprehensive meta-analysis to date by synthesizing the results of 228 studies examining biological responses to ocean acidification. The results reveal decreased survival, calcification, growth, development and abundance in response to acidification when the broad range of marine organisms is pooled together. However, the magnitude of these responses varies among taxonomic groups, suggesting there is some predictable trait-based variation in sensitivity despite the investigation of approximately 100 new species in recent research. The results also reveal an enhanced sensitivity of mollusc larvae, but suggest that an enhanced sensitivity of early life history stages is not universal across all taxonomic groups. In addition, the variability in species' responses is enhanced when they are exposed to acidification in multi-species assemblages, suggesting it is important to consider indirect effects and exercise caution when forecasting abundance patterns from single species laboratory experiments. Furthermore, the results suggest that other factors, such as nutritional status or source population, could cause substantial variation in organisms' responses. Last, the results highlight a trend towards enhanced sensitivity to acidification when taxa are concurrently exposed to elevated seawater temperature. © 2013 Blackwell Publishing Ltd.
Ocean acidification is expected to decrease calcification rates of bivalves. Nevertheless, in many coastal areas high pCO2 variability is encountered already today. Kiel Fjord (Western Baltic Sea) is a brackish (12-20 g kg(-1) ) and CO2 enriched habitat, but the blue mussel Mytilus edulis dominates the benthic community. In a coupled field and laboratory study we examined the annual pCO2 variability in this habitat and the combined effects of elevated pCO2 and food availability on juvenile M. edulis growth and calcification. In the laboratory experiment, mussel growth and calcification were found to chiefly depend on food supply, with only minor impacts of pCO2 up to 3350 μatm. Kiel Fjord was characterized by strong seasonal pCO2 variability. During summer, maximal pCO2 values of 2500 μatm were observed at the surface and >3000 μatm at the bottom. However, the field growth experiment revealed seven times higher growth and calcification rates of M. edulis at a high pCO2 inner fjord field station (mean pCO2 ca. 1000 μatm) in comparison to a low pCO2 outer fjord station (ca. 600 μatm). In addition, mussels were able to out-compete the barnacle Amphibalanus improvisus at the high pCO2 site. High mussel productivity at the inner fjord site was enabled by higher particulate organic carbon concentrations. Kiel Fjord is highly impacted by eutrophication, which causes bottom water hypoxia and consequently high seawater pCO2 . At the same time, elevated nutrient concentrations increase the energy availability for filter feeding organisms such as mussels. Thus, M. edulis can dominate over a seemingly more acidification resistant species such as A. improvisus. We conclude that benthic stages of M. edulis tolerate high ambient pCO2 when food supply is abundant and that important habitat characteristics such as species interactions and energy availability need to be considered to predict species vulnerability to ocean acidification.
The first decade of the new millennium saw a flurry of experiments to establish a mechanistic understanding of how climate change might transform the global biota, including marine organisms. However, the biophysical properties of the marine environment impose challenges to experiments, which can weaken their inference space. To facilitate strengthening the experimental evidence for possible ecological consequences of climate change, we reviewed the physical, biological and procedural scope of 110 marine climate change experiments published between 2000 and 2009. We found that 65% of these experiments only tested a single climate change factor (warming or acidification), 54% targeted temperate organisms, 58% were restricted to a single species and 73% to benthic invertebrates. In addition, 49% of the reviewed experiments had issues with the experimental design, principally related to replication of the main test‐factors (temperature or pH), and only 11% included field assessments of processes or associated patterns. Guiding future research by this inventory of current strengths and weaknesses will expand the overall inference space of marine climate change experiments. Specifically, increased effort is required in five areas: (i) the combined effects of concurrent climate and non‐climate stressors; (ii) responses of a broader range of species, particularly from tropical and polar regions as well as primary producers, pelagic invertebrates, and fish; (iii) species interactions and responses of species assemblages, (iv) reducing pseudo‐replication in controlled experiments; and (v) increasing realism in experiments through broad‐scale observations and field experiments. Attention in these areas will improve the generality and accuracy of our understanding of climate change as a driver of biological change in marine ecosystems.
Ocean acidification and warming are considered two of the greatest threats to marine biodiversity, yet the combined effect of these stressors on marine organisms remains largely unclear. Using a meta-analytical approach, we assessed the biological responses of marine organisms to the effects of ocean acidification and warming in isolation and combination. As expected biological responses varied across taxonomic groups, life-history stages, and trophic levels, but importantly, combining stressors generally exhibited a stronger biological (either positive or negative) effect. Using a subset of orthogonal studies, we show that four of five of the biological responses measured (calcification, photosynthesis, reproduction, and survival, but not growth) interacted synergistically when warming and acidification were combined. The observed synergisms between interacting stressors suggest that care must be made in making inferences from single-stressor studies. Our findings clearly have implications for the development of adaptive management strategies particularly given that the frequency of stressors interacting in marine systems will be likely to intensify in the future. There is now an urgent need to move toward more robust, holistic, and ecologically realistic climate change experiments that incorporate interactions. Without them accurate predictions about the likely deleterious impacts to marine biodiversity and ecosystem functioning over the next century will not be possible.
Coastal seas are critical components of the global carbon cycle, yet little research has been conducted on the impact of ocean acidification on coastal benthic organisms. Calcifying marine organisms are predicted to be most vulnerable to a decline in oceanic pH (ocean acidification) based on the assumption that calcification will decrease as a result of changes in seawater carbonate chemistry, particularly reduced carbonate ion concentration (and associated saturation states). Net calcium carbonate production is dependent on an organism's ability to increase calcification sufficiently to counteract an increase in dissolution. Here, a critical appraisal of calcification in five benthic species showed, contrary to popular predictions, the deposition of calcium carbonate can be maintained or even increased in acidified seawater. This study measured changes in the concentration of calcium ions seen in shells taken from living animals exposed to acidified seawater. These data were compared with data from isolated shells that were not associated with living material to determine a species' ability to maintain the physiological process of calcification under high carbon dioxide (CO2) conditions and characterize the importance of dissolution and abiotic influences associated with decreasing pH. Comparison with palaeoecological studies of past high CO2 events presents a similar picture. This conclusion implies that calcification may not be the physiological process that suffers most from ocean acidification; particularly as all species investigated displayed physiological trade-offs including increased metabolism, reduced health, and changes in behavioural responses in association with this calcification upregulation, which poses as great a threat to survival as an inability to calcify.
At the end of May, 17 scientists involved in an EU COST Action on Conservation Physiology of Marine Fishes met in Oristano, Sardinia, to discuss how physiology can be better used in modelling tools to aid in management of marine ecosystems. Current modelling approaches incorporate physiology to different extents, ranging from no explicit consideration to detailed physiological mechanisms, and across scales from a single fish to global fishery resources. Biologists from different sub-disciplines are collaborating to rise to the challenge of projecting future changes in distribution and productivity, assessing risks for local populations, or predicting and mitigating the spread of invasive species.
The effects of diet history, hunger and predation risk on short-term behavioral decisions of dogwhelks were tested in a specially designed test apparatus, termed a linear feeding array (LFA). The LFA consists of a sequential series of prey items mounted in a flume with unidirectional current directed towards a test (predatory) animal, and into which potential olfactory cues regarding predation risk are introduced. For dogwhelks the array was constructed vertically to accomodate intertidal foraging movements and is termed a vertical linear array (VLA). The behaviors exhibited by the dogwhelks were interpreted from distribution patterns in the VLA. Recent experimental studies and advances in optimal foraging theory provided the basis for the hypotheses tested in the VLA, which included: foraging and other behaviors are affected by predation, animals will avoid risk in the presence of predation threat, responses to predation threat will be proportional to the number and kinds of predator cues present, and starved animals will take greater risks than fed animals. We also test the proposition that foraging decisions are further modified by age. Three groups of juvenile and adult animals were maintained on diets of barnacles, mussels or no food (starved). The scent of crabs and damaged conspecifics served as olfactory cues to predation risk. Dogwhelks exhibited a range of behaviors in the VLA including: sheltering, searching, feeding, and aerial climbing. Distribution of animals in the tank assumed a relatively stable pattern after 2–3 h. These patterns were interpreted as the consequence of heirarchial decision making including: (i) a decision to become active, leaving the resting place or water refuge adopted during initial placement, followed by (ii) a decision to move vertically upwards or downwards, and (iii) a decision to attack prey when encountered. Analysis of movement patterns revealed that the initial decision, analogous to leaving a crevice as the tide comes in, was influenced in adults by predator cues and in juveniles by both predator cues and diet history. Perceived risk, as crab and damaged-conspecific odors, made individuals more likely to remain inactive, a risk-avoiding strategy for animals already in a refuge. Starved animals were more likely to descend into the tank and attack prey than fed animals. Our results support the hypotheses that higher-order predators affect the foraging decisions of dogwhelks and that juveniles and satiated animals are more sensitive to predation risk than starved ones. Together, these and earlier studies suggest that dogwhelks assess their environment before foraging, and that they are attuned to reducing the risks of mortality.
Physiological studies focus on the responses of cells, tissues and individuals to stressors, usually in laboratory situations. Conservation and management, on the other hand, focus on populations. The field of conservation physiology addresses the question of how abiotic drivers of physiological responses at the level of the individual alter requirements for successful conservation and management of populations. To achieve this, impacts of physiological effects at the individual level need to be scaled to impacts on population dynamics, which requires consideration of ecology. Successfully realizing the potential of conservation physiology requires interdisciplinary studies incorporating physiology and ecology, and requires that a constructive dialogue develops between these traditionally disparate fields. To encourage this dialogue, we consider the increasingly explicit incorporation of physiology into ecological models applied to marine fish conservation and management. Conservation physiology is further challenged as the physiology of an individual revealed under laboratory conditions is unlikely to reflect realized responses to the complex variable stressors to which it is exposed in the wild. Telemetry technology offers the capability to record an animal's behaviour while simultaneously recording environmental variables to which it is exposed. We consider how the emerging insights from telemetry can strengthen the incorporation of physiology into ecology.
Focuses on features of dog-whelk biology that are amenable to field study - feeding, predation, breeding, response to environmental stimuli and variation in shell characters. -from Author
Ocean acidity has increased by 30% since preindustrial times due to the uptake of anthropogenic CO2 and is projected to rise by another 120% before 2100 if CO2 emissions continue at current rates. Ocean acidification is expected to have wide-ranging impacts on marine life, including reduced growth and net erosion of coral reefs. Our present understanding of the impacts of ocean acidification on marine life, however, relies heavily on results from short-term CO2 perturbation studies. Here, we present results from the first long-term CO2 perturbation study on the dominant reef-building cold-water coral Lophelia pertusa and relate them to results from a short-term study to compare the effect of exposure time on the coral's responses. Short-term (1 week) high CO2 exposure resulted in a decline of calcification by 26–29% for a pH decrease of 0.1 units and net dissolution of calcium carbonate. In contrast, L. pertusa was capable to acclimate to acidified conditions in long-term (6 months) incubations, leading to even slightly enhanced rates of calcification. Net growth is sustained even in waters sub-saturated with respect to aragonite. Acclimation to seawater acidification did not cause a measurable increase in metabolic rates. This is the first evidence of successful acclimation in a coral species to ocean acidification, emphasizing the general need for long-term incubations in ocean acidification research. To conclude on the sensitivity of cold-water coral reefs to future ocean acidification further ecophysiological studies are necessary which should also encompass the role of food availability and rising temperatures.
Little is known about the effects of potential synergies between concurrent ocean warming and acidification on marine benthos. We investigated the effects of warming and acidification on development to the non-calcifying larval stage in the sea star Patiriella regularis, in embryos reared from fertilization in present and future (2100+) conditions. Fertilization using gametes from multiple parents, to represent populations of spawners, was resilient to both stressors, as were cleavage stage embryos. Warming increased developmental rate across all pH levels. For blastulae, there was a complex interaction between stressors, with +4 degrees C/pH 7.6 lethal to many embryos. A 4 degrees C warming increased mortality by the gastrulation stage by 13 to 25% across all pH levels. In conjunction with warming, pH 7.6 increased mortality by 25 to 27% across all temperatures. For embryos that reached the 3 d bipinnaria stage, warming reduced the percentage of normal larvae and larval size, with no effect of acidification. These results highlight the importance of considering both warming and acidification, and effects on early embryos, in assessing life history responses to ocean change. Bipinnaria reared to Day 28 to determine the effects of acidification on non-calcifying feeding larvae provided a comparison with results for calcifying echinoplutei. pH 7.6 resulted in smaller larvae and increased mortality by 30%. After 24 d, near-future ocean acidification levels (pH 7.8) also resulted in smaller larvae. The effects of acidification in reducing growth in larvae that do not calcify indicates that the stunting response of echinoderm feeding larvae to pH/pCO(2) is strongly influenced by hypercapnic changes in meta bolism and teratogenic effects. The results have implications for P. regularis in its invasive range in Australia, where this species is likely to be deleteriously affected by ocean warming.
The Arctic Ocean and its associated ecosystems face numerous challenges over the coming century. Increasing atmospheric CO2 is causing increasing warming and ice melting as well as a concomitant change in ocean chemistry (“ocean acidification”). As temperature increases it is expected that many temperate species will expand their geographic distribution northwards to follow this thermal shift; however with the addition of ocean acidification this transition may not be so straightforward. Here we investigate the potential impacts of ocean acidification and climate change on populations of an intertidal species, in this case the barnacle Semibalanus balanoides, at the northern edge of its range. Growth and development of metamorphosing post-larvae were negatively impacted at lower pH (pH 7.7) compared to the control (pH 8.1) but were not affected by elevated temperature (+4 °C). The mineral composition of the shells did not alter under any of the treatments. The combination of reduced growth and maintained mineral content suggests that there may have been a change in the energetic balance of the exposed animals. In undersaturated conditions more mineral is expected to dissolve from the shell and hence more energy would be required to maintain the mineral integrity. Any energy that would normally be invested into growth could be reallocated and hence organisms growing in lowered pH grow slower and end up smaller than individuals grown in higher pH conditions. The idea of reallocation of resources under different conditions of pH requires further investigation. However, there could be long-term implications on the fitness of these barnacles, which in turn may prevent them from successfully colonising new areas.
The influence of predation on rocky intertidal community structure has long emphasized the importance of indirect interactions. Most efforts in this area have focused on the density-mediated, or lethal effects, of predators on prey density. Recently, there has been growing interest in trait-mediated indirect interactions (TMIIs): the presence of a predator in the environment influences the interaction between two other species (prey and their resource) by altering a trait of the prey species. For example, waterborne cues released by predators can cause changes in prey species behavior, such as feeding rates, thereby altering the impact of the prey species on their resources. Thus, TMIIs represent the non- lethal effects of predators that contrast with the more traditional emphasis on lethal indirect effects. Marine ecologists are just beginning to explore the role of TMIIs in their systems. We examined whether risk cues released by a ubiquitous crab predator (Carcinus maen- as) influence the abundance of two dominant species in the rocky intertidal zone (barnacles (Semibalanus balanoides) and fucoid algae (Ascophyllum nodosum )) by altering the be- havior of two of its snail prey (Nucella lapillus and Littorina littorea). We found that the presence of green crab risk cues can have strong cascading indirect effects on the abundance of barnacles and fucoid algae. N. lapillus exposed to risk cues consumed up to 29% fewer barnacles compared to conspecifics feeding in the absence of risk cues, whereasL. littorea exposed to risk cues consumed 459% fewer fucoids compared to conspecifics feeding in the absence of risk cues. These cascading interactions appear to reflect suppression of snail feeding by predator risk cues. In both food chains, snails exhibited more refuge-seeking behavior and grew less in the presence of risk cues. Our experiments suggest that TMIIs may have an important and underappreciated influence on species interactions that shape community dynamics on rocky intertidal shores.
Although the purpose of models is to simplify complex reality to allow the investigation of patterns, processes and relationships, many ecosystem models retain high levels of complexity. The outputs from such models are highly multivariate. Taking the view that a perfect model simulation of a spatial domain over a determinate time period will reproduce observed variables from the same place over the same period perfectly, we demonstrate how appropriate multivariate methods may be used to elucidate patterns within observations and model outputs, to compare patterns between them, and to explore the nature and spatio-temporal distribution of model errors. Analyses based on observations collected from the southern North Sea in 1988–89 are compared to analyses based on an equivalent dataset extracted from the output of the POLCOMS-ERSEM model. A combination of PCA and nonparametric multivariate approaches is used to demonstrate that in broad terms the model performs well, simulating patterns in, and interrelationships between, a range of variables. Errors are greatest in late winter and early spring, and are associated with inaccurate estimation of the magnitude of primary production in coastal waters and the amount of suspended particulate matter in the water column.
Biogeochemical cycling in marine systems is intimately linked to the activity of specific plankton functional types (PFTs) such as diatoms, coccolithophores and nitrogen fixers, thereby providing a focus for contemporary modelling studies. Incorporating extra complexity beyond simple nutrient-phytoplankton-zooplankton-detritus (NPZD) models is, however, fraught with difficulties: poorly understood ecology; lack of data; aggregating diversity within functional groups into meaningful state variables and constants; sensitivity of output to the parameterizations in question and their physical and chemical environment. Although regional models addressing the seasonal succession of plankton types have achieved some degree of success, predicted distributions of PFTs in global biogeochemical models have thus far been less than convincing. While the continued articulation of detail in ecosystem models is surely the way forward, I argue that this can only be so with due care and attention to the formulations employed and a healthy dose of scepticism regarding model outcomes. Future directions should emphasize building up complexity gradually, objective assessment of the resulting parameterizations, and variety in approach such as the use of empirical alternatives to the fully dynamic representation of PFTs in models.
(1) Shore crabs attack dogwhelks by attempting to crush the shell. Because of differences in shell morphology, sheltered shore dogwhelks tend to be opened by removal of the apex and exposed shore dogwhelks by breaking the columella. (2) The proportion of successful attacks is unity for small dogwhelks but decreases rapidly as the shells grow and become more robust. The attack success rate curve begins to fall at a smaller shell height in sheltered than in exposed shore dogwhelks. Large adult sheltered shore dogwhelks are immune to attack. (3) For large male shore crabs preying on sheltered shore dogwhelks, prey value (energy yielded per unit handling time) forms a steep normal curve when plotted against shell height, peaking at about 14 mm. Because of the rapidly decreasing attack success rate, the prey value of individuals between the optimum and about 27 mm height is very unpredictable. (4) When presented with an abundance of prey in each size category in the laboratory, shore crabs did not specialize on the optimal size as predicted by optimal foraging theory. All encountered prey were attacked but rejected if unbroken after 0.25 to 2.75 minutes. Very small dogwhelks were sometimes dropped accidentally. As a result of these mechanical processes, optimally sized dogwhelks were the most frequently eaten. (5) The foraging tactics seem to be the most appropriate for prey types which have unpredictable prey values and are sparsely distributed so that encounter rates are always low. Most intertidal gastropods are of this type. The foraging tactics applied to dogwhelks contrast with those applied to mussels where prey value is predictable and encounter rates are high. (6) Exposed shore dogwhelks living in the virtual absence of shore crabs are much more vulnerable to attack than sheltered shore dogwhelks suffering high crab predation. Sheltered shore dogwhelks are better protected because of a narrower mouth which excludes the chelae of attacking crabs and a thicker, more robust shell. These attributes were even more pronounced in a sublittoral-fringe population of dogwhelks exposed to the more powerful edible crab. (7) The narrower mouth of sheltered shore dogwhelks is produced by a more elongated spiral growth form. This does not reduce the relative size of the visceral mass but it does reduce the relative area of the foot. (8) The thicker, more robust shell of sheltered shore dogwhelks results in a heavier load per g flesh and may represent a metabolic cost of the anti-predator adaptation. Such a cost is possibly unimportant because sublittoral-fringe dogwhelks frequently carry an extra load of encrusting barnacles, without any reduction in relative size of the visceral mass or total flesh weight. (9) Selective deaths caused by crab predation must occur below a shell height of about 27 mm. The most vulnerable stages, below about 14 mm height, tend to be inaccessible to crabs because of their propensity to remain under stones or within crevices. The habit of foraging on the outer surfaces of stones is acquired only by large dogwhelks and since many of these will be over 27 mm in height, only a few will likely fall prey to shore crabs.
As our reliance upon numerical models for forecasting environmental conditions increases, so does our need to quantitatively analyse their performance. Often, a single metric approach is adopted, the choice of which is dependent upon the application for which the model output are to be used. Here we present a multi-metric verification approach to analyse the spatial and temporal performance of a hydrodynamic ecosystem model. The metrics allow us to investigate the model's ability to predict the inter- and intra-annual spatial variations and are used to evaluate surface chlorophyll-a estimates from the POLCOMS-ERSEM model, using satellite Earth observation data from NASA's MODIS-Aqua sensor. The study focuses on a region of the north east Atlantic which encompasses both open ocean and shelf seas, presenting a sizeable challenge for any model. The metrics reveal that the model is able to capture the mean annual chlorophyll-a signal (as exhibited in the Earth observational data) and has the capability to describe medium scale spatial variations. The seasonal signal exhibited in the Earth observation data is not apparent in the model fields. Possible reasons for the mis-match between the Earth observation and model data are discussed. Notwithstanding these issues, the model exhibits predictive skill during the northern hemisphere summer months for a range of chlorophyll-a concentrations. This multi-metric evaluation approach provides a method for the rigorous evaluation of the spatial and temporal accuracy of the hydrodynamic ecosystem model.
Marine mussels are widely distributed and have been used extensively as environmental biomonitors. Communities associated with mussel patches have a high species richness but are typically dominated by a few very abundant species. These communities exhibit significant temporal and small-scale spatial variations in abundance and diversity which should be recognized when considering global patterns of marine biodiversity. Many of the species associated with tropical mussel beds are also represented by taxonomically and functionally equivalent species in mussel communities from temperate waters. The phenomenon of ‘parallel communities’ on rocky shores is thus apparently replicated on a finer spatial scale within mussel patches.
Foraging, when senses are limited to olfaction, is composed of two distinct stages: the detection of prey and the location of prey. While specialist olfactory foragers are able to locate prey using olfactory cues alone, this may not be the case for foragers that rely primarily on vision. Visual predators in aquatic systems may be faced with poor visual conditions such as natural or human-induced turbidity. The ability of visual predators to compensate for poor visual conditions by using other senses is not well understood, although it is widely accepted that primarily visual fish, such as three-spined sticklebacks, Gasterosteus aculeatus, can detect and use olfactory cues for a range of purposes. We investigated the ability of sticklebacks to detect the presence of prey and to locate prey precisely, using olfaction, in clear and turbid (two levels) water. When provided with only a visual cue, or only an olfactory cue, stickle-backs showed a similar ability to detect prey, but a combination of these cues improved their performance. In open-arena foraging trials, a dispersed olfactory cue added to the water (masking cues from the prey) improved foraging success, contrary to our expectations, whereas activity levels and swimming speed did not change as a result of olfactory cue availability. We suggest that olfaction functions to allow visual predators to detect rather than locate prey and that olfactory cues have an appetitive effect, enhancing motivation to forage.
Climate change can impact the pattern of marine biodiversity through changes in species’ distributions. However, global studies on climate change impacts on ocean biodiversity have not been performed so far. Our paper aims to investigate the global patterns of such impacts by projecting the distributional ranges of a sample of 1066 exploited marine fish and invertebrates for 2050 using a newly developed dynamic bioclimate envelope model. Our projections show that climate change may lead to numerous local extinction in the sub-polar regions, the tropics and semi-enclosed seas. Simultaneously, species invasion is projected to be most intense in the Arctic and the Southern Ocean. Together, they result in dramatic species turnovers of over 60% of the present biodiversity, implying ecological disturbances that potentially disrupt ecosystem services. Our projections can be viewed as a set of hypothesis for future analytical and empirical studies.
In many large-scale conservation or ecological problems where experiments are intractable or unethical, regression methods are used to attempt to gauge the impact of a set of nominally independent variables (X) upon a dependent variable (Y). Workers often want to assert that a given X has a major influence on Y, and so, by using this indirection to infer a probable causal relationship. There are two difficulties apart from the demonstrability issue itself: (1) multiple regression is plagued by collinear relationships in X; and (2) any regression is designed to produce a function that in some way minimizes the overall difference between the observed and predicted Ys, which does not necessarily equate to determining probable influence in a multivariate setting. Problem (1) may be explored by comparing two avenues, one in which a single best regression model is sought and the other where all possible regression models are considered contemporaneously. It is suggested that if the two approaches do not agree upon which of the independent variables are likely to be significant, then the deductions must be subject to doubt.
In the summer of 2008, the abundance, local aggregation structure, growth rate, and life span of the gastropod Nucella freycineti inhabiting the littoral zone of Yankicha Island (Kuriles), which is affected by the postvolcanic activity of the Ushishir
Volcano were studied. The parameters varied within a wide range and appreciably depended on the distance mollusk populations
were from underwater and land gas-hydrothermal vents, which caused strong heating (up to 48°C) of cold sea waters and the
formation of an unusually acidic environment (pH approximately 3.5) in the Kraternaya Bay. The mollusks occurred at a water
temperature below 24°C and a pH above 4, but formed multiage populations at a temperature of 2–14°C and a pH of approximately
6.4–8.2.
Key wordsgas-hydrothermal vent-Gastropoda-
Nucella freycineti
-distribution-size composition-shell morphology-growth-life span
Increasing atmospheric carbon dioxide (CO(2)) concentrations are expected to decrease surface ocean pH by 0.3-0.5 units by 2100 (refs 1,2), lowering the carbonate ion concentration of surface waters. This rapid acidification is predicted to dramatically decrease calcification in many marine organisms(3,4). Reduced skeletal growth under increased CO(2) levels has already been shown for corals, molluscs and many other marine organisms(4-9). The impact of acidification on the ability of individual species to calcify has remained elusive, however, as measuring net calcification fails to disentangle the relative contributions of gross calcification and dissolution rates on growth. Here, we show that corals and molluscs transplanted along gradients of carbonate saturation state at Mediterranean CO(2) vents are able to calcify and grow at even faster than normal rates when exposed to the high CO(2) levels projected for the next 300 years. Calcifiers remain at risk, however, owing to the dissolution of exposed shells and skeletons that occurs as pH levels fall. Our results show that tissues and external organic layers play a major role in protecting shells and skeletons from corrosive sea water, limiting dissolution and allowing organisms to calcify(10,11). Our combined field and laboratory results demonstrate that the adverse effects of global warming are exacerbated when high temperatures coincide with acidification.
The MarQUEST (Marine Biogeochemistry and Ecosystem Modelling Initiative in QUEST) project was established to develop improved descriptions of marine biogeochemistry, suited for the next generation of Earth system models. We review progress in these areas providing insight on the advances that have been made as well as identifying remaining key outstanding gaps for the development of the marine component of next generation Earth system models. The following issues are discussed and where appropriate results are presented; the choice of model structure, scaling processes from physiology to functional types, the ecosystem model sensitivity to changes in the physical environment, the role of the coastal ocean and new methods for the evaluation and comparison of ecosystem and biogeochemistry models. We make recommendations as to where future investment in marine ecosystem modelling should be focused, highlighting a generic software framework for model development, improved hydrodynamic models, and better parameterisation of new and existing models, reanalysis tools and ensemble simulations. The final challenge is to ensure that experimental/observational scientists are stakeholders in the models and vice versa.