Ocean acidification, a reduction in the pH of the oceans caused by increasing CO2, can have negative physiological effects on marine species. In this study, we examined how CO2-driven acidification affected the growth and survival of juvenile golden king crab (Lithodes aequispinus), an important fishery species in Alaska. Juveniles were reared from larvae in surface ambient pH seawater at the Kodiak Laboratory. Newly molted early benthic instar crabs were randomly assigned to one of three pH treatments: (1) surface ambient pH ~ 8.2, (2) likely in situ ambient pH 7.8, and (3) pH 7.5. Thirty crabs were held in individual cells in each treatment for 127 days and checked daily for molting or death. Molts and dead crabs were photographed under a microscope and measured using image analysis to assess growth and morphology. Mortality was primarily associated with molting in all treatments, differed among all treatments, and was highest at pH 7.5 and lowest at ambient pH. Crabs at pH 7.5 were smaller than crabs at ambient pH at the end of the experiment, both in terms of carapace length and wet mass; had a smaller growth increment after molting; had a longer intermolt period. Carapace morphology was not affected by pH treatment. Decreased growth and increased mortality in laboratory experiments suggest that lower pH could affect golden king crab stocks and fisheries. Future work should examine if larval rearing conditions affect the juvenile response to low pH.
Climate-enhanced stock assessment models represent potentially vital tools for managing living marine resources under climate change. We present a climate-enhanced stock assessment where environmental variables are integrated within a population dynamics model assessment of biomass, fishing mortality and recruitment that also accounts for process error in demographic parameters. Probability distributions for the impact of the associated environmental factors on recruitment and growth can either be obtained from Bayesian analyses that involve fitting the population dynamics model to the available data or from auxiliary analyses. The results of the assessment form the basis for the calculation of biological and economic target and limit reference points, and projections under alternative harvest strategies. The approach is applied to northern rock sole (Lepidopsetta polyxystra), an important component of the flatfish fisheries in the Eastern Bering Sea. The assessment involves fitting to data on catches, a survey index of abundance, fishery and survey age-compositions and survey weight-at-age, with the relationship between recruitment and cold pool extent and that between growth increment in weight and temperature integrated into the assessment. The projections also allow for an impact of ocean pH on expected recruitment based on auxiliary analyses. Several alternative models are explored to assess the consequences of different ways to model environmental impacts on population demography. The estimates of historical biomass, recruitment and fishing mortality for northern rock sole are not markedly impacted by including climate and environmental factors, but estimates of target and limit reference points are sensitive to whether and how environmental variables are included in stock assessments and projections.
Calcified coralline algae are ecologically important in rocky habitats in the marine photic zone worldwide and there is growing concern that ocean acidification will severely impact them. Laboratory studies of these algae in simulated ocean acidification conditions have revealed wide variability in growth, photosynthesis and calcification responses, making it difficult to assess their future biodiversity, abundance and contribution to ecosystem function. Here, we apply molecular systematic tools to assess the impact of natural gradients in seawater carbonate chemistry on the biodiversity of coralline algae in the Mediterranean and the NW Pacific, link this to their evolutionary history and evaluate their potential future biodiversity and abundance. We found a decrease in the taxonomic diversity of coralline algae with increasing acidification with more than half of the species lost in high pCO2 conditions. Sporolithales is the oldest order (Lower Cretaceous) and diversified when ocean chemistry favoured low Mg calcite deposition; it is less diverse today and was the most sensitive to ocean acidification. Corallinales were also reduced in cover and diversity but several species survived at high pCO2; it is the most recent order of coralline algae and originated when ocean chemistry favoured aragonite and high Mg calcite deposition. The sharp decline in cover and thickness of coralline algal carbonate deposits at high pCO2 highlighted their lower fitness in response to ocean acidification. Reductions in CO2 emissions are needed to limit the risk of losing coralline algal diversity.
- High CO2 conditions profoundly affected biofilm community composition
- Species turnover explained differences in community composition
- Biofilm communities were more homogeneous under high CO2 conditions
- Toxin producing and turf-forming algae were enriched under high CO2 conditions
Biofilms harbour a wealth of microbial diversity and fulfil key functions in coastal marine ecosystems. Elevated carbon dioxide (CO2) conditions affect the structure and function of biofilm communities, yet the ecological patterns that underpin these effects remain unknown. We used high-throughput sequencing of the 16S and 18S rRNA genes to investigate the effect of elevated CO2 on the early successional stages of prokaryotic and eukaryotic biofilms at a CO2 seep system off Shikine Island, Japan. Elevated CO2 profoundly affected biofilm community composition throughout the early stages of succession, leading to greater compositional homogeneity between replicates and the proliferation of the potentially harmful algae Prymnesium sp. and Biddulphia biddulphiana. Species turnover was the main driver of differences between communities in reference and high CO2 conditions, rather than differences in richness or evenness. Our study indicates that species turnover is the primary ecological pattern that underpins the effect of elevated CO2 on both prokaryotic and eukaryotic components of biofilm communities, indicating that elevated CO2 conditions represent a distinct niche selecting for a distinct cohort of organisms without the loss of species richness.
Ocean acidification (OA) is negatively affecting calcification in a wide variety of marine organisms. These effects are acute for many tropical scleractinian corals under short-term experimental conditions, but it is unclear how these effects interact with ecological processes, such as competition for space, to impact coral communities over multiple years. This study sought to test the use of individual-based models (IBMs) as a tool to scale up the effects of OA recorded in short-term studies to community-scale impacts, combining data from field surveys and mesocosm experiments to parameterize an IBM of coral community recovery on the fore reef of Moorea, French Polynesia. Focusing on the dominant coral genera from the fore reef, Pocillopora, Acropora, Montipora and Porites, model efficacy first was evaluated through the comparison of simulated and empirical dynamics from 2010–2016, when the reef was recovering from sequential acute disturbances (a crown-of-thorns seastar outbreak followed by a cyclone) that reduced coral cover to ~0% by 2010. The model then was used to evaluate how the effects of OA (1,100–1,200 µatm pCO2) on coral growth and competition among corals affected recovery rates (as assessed by changes in % cover y−1) of each coral population between 2010–2016. The model indicated that recovery rates for the fore reef community was halved by OA over 7 years, with cover increasing at 11% y−1 under ambient conditions and 4.8% y−1 under OA conditions. However, when OA was implemented to affect coral growth and not competition among corals, coral community recovery increased to 7.2% y−1, highlighting mechanisms other than growth suppression (i.e., competition), through which OA can impact recovery. Our study reveals the potential for IBMs to assess the impacts of OA on coral communities at temporal and spatial scales beyond the capabilities of experimental studies, but this potential will not be realized unless empirical analyses address a wider variety of response variables representing ecological, physiological and functional domains.
Global change driven by anthropogenic carbon emissions is altering ecosystems at unprecedented rates, especially coral reefs, whose symbiosis with algal endosymbionts ise particularly vulnerable to increasing ocean temperatures and altered carbonate chemistry. Here, we assess the physiological responses of the coral holobiont (animal host + algal symbiont) of three Caribbean coral species from two reef environments after exposure to simulated ocean warming (28, 31 °C), acidification (300 – 3290 μatm), and the combination of stressors for 93 days. We used multidimensional analyses to assess how multiple coral holobiont physiological parameters respond to ocean acidification and warming. Our results demonstrate significantly diminishing holobiont physiology in S. siderea and P. astreoides in response to projected ocean acidification, while future warming elicited severe declines in P. strigosa. Offshore S. siderea fragments exhibited higher physiological plasticity than inshore counterparts, suggesting that this offshore population has the capacity to modulate their physiology in response to changing conditions, but at a cost to the holobiont. Plasticity of P. strigosa and P. astreoides was not clearly different between natal reef environments, however, temperature evoked a greater plastic response in both species. Interestingly, while these species exhibit unique physiological responses to ocean acidification and warming, when data from all three species are modeled together, convergent stress responses to these conditions are observed, highlighting the overall sensitivities of tropical corals to these stressors. Our results demonstrate that while ocean warming is a severe acute stressor that will have dire consequences for coral reefs globally, chronic exposure to acidification may also impact coral physiology to a greater extent than previously assumed. The variety of responses to global change we observe across species will likely manifest in altered Caribbean reef assemblages in the future.
Ocean acidification (OA) will decrease shellfish growth and survival, with ecological and economic consequences for fisheries and aquaculture. However, the high variability of results among experiments, and the lack of long-term studies, make it difficult to predict the effect that OA will have on bivalve species. We tested the long-term effect of high CO2 on growth, calcification rates, and survival of juveniles of the commercial bivalve species Chamelea gallina from Southern Portugal. The local high alkalinity of seawater probably buffered the negative effect of the pH drop, and after 75 days juveniles increased their growth and calcification rates with CO2. However, after 217 days, the situation reversed, bivalves under control conditions had the highest growth and calcification rates, while individuals under high CO2 presented negative calcification rates. The biometric variable that responded first was the width of the individuals, followed by the height and length of the shells. Survival was unaffected except for a mortality peak of juveniles under control and intermediate conditions as a consequence of a temperature drop. In the short term, C. gallina will increase their calcification rates to compensate for OA. However, in the long term, the additional energy expended will be translated into growth losses with negative repercussions for the fisheries and aquaculture. The cultivation of shellfish on high alkaline seawater should be further explored as a bioremediation measure to mitigate the negative effect of OA on shellfish aquaculture.
Responses of marine populations to climate conditions reflect the integration of a suite of complex and interrelated physiological and behavioral responses at the individual level. Many of these responses are not immediately reflected in changes to survival, but may impact growth or survival at later life stages. Understanding the broad range of impacts of rising CO2 concentrations on marine fishes is critical to predicting the consequences of ongoing ocean acidification. Walleye pollock (Gadus chalcogrammus) support the largest single-species fishery in the world and provide a critical forage base throughout north Pacific ecosystems. Previous studies of high CO2 effects on early life stages of walleye pollock have suggested a general resiliency in this species, but those studies focused primarily on growth and survival rates. Here, we expand on earlier studies with an independent experiment focused on walleye pollock larval development, swimming behavior, and lipid composition from fertilization to 4 weeks post-hatch at ambient (~ 425 µatm) and elevated (~ 1230 µatm) CO2 levels. Consistent with previous observations, size metrics of walleye pollock were generally insensitive to CO2 treatment. However, 4-week post-hatch larvae had significantly reduced rates of swim bladder inflation. A modest change in the swimming behavior of post-feeding larvae was observed at four, but not at 2 weeks post-hatch. Although there were no differences in overall lipid levels between CO2 treatments, the ratio of energy storage lipids (triacylglycerols) to structural membrane lipids (sterols) was lower among larvae reared at high CO2 levels. Although we observed higher survival to 4 weeks post-hatch among fish reared at high CO2 levels, the observations of reduced swim bladder inflation rates and changes in lipid cycling suggest the presence of sub-lethal effects of acidification that may carry over and manifest in later life stages. These observations support the continued need to evaluate the impacts of ocean acidification on marine fishes across a wide range of traits and life stages with replicated, independent experiments.
Symbiosis establishment is a milestone in the life cycles of most broadcast-spawning corals; however, it remains largely unknown how initial symbiont infection is affected by ocean warming and acidification, particularly for massive corals. This study investigated the combined effects of elevated temperature (29 vs. 31 °C) and pCO2 (~ 450 vs. ~ 1000 μatm) on the recruits of a widespread massive coral, Platygyra daedalea. Results showed that geometric diameter and symbiosis establishment were unaffected by high pCO2, while elevated temperature significantly reduced successful symbiont infection by 50% and retarded the geometric diameter by 6%. Although neither increased temperature, pCO2, nor their interaction affected survival or algal pigmentation of recruits, there was an inverse relationship between symbiont infection rates and survivorship, especially at high temperatures, possibly as a result of oxidative stress caused by algal symbionts under increased temperature. Intriguingly, the proportion of Durusdinium did not increase in recruits at 31 °C, while recruits reared under high pCO2 hosted less Breviolum and more Durusdinium, indicating a high degree of plasticity of early symbiosis and contrasting to the previous finding that heat stress usually leads to the prevalence of thermally tolerant Durusdinium in coral recruits. These results suggest that ocean warming is likely to be more deleterious for the early success of P. daedalea than ocean acidification and provide insights into our understanding of coral-algal symbiotic partnerships under future climatic conditions.
The sponge-associated microbial community contributes to the overall health and adaptive capacity of the sponge holobiont. This community is regulated by the environment and the immune system of the host. However, little is known about the effect of environmental stress on the regulation of host immune functions and how this may, in turn, affect sponge–microbe interactions. In this study, we compared the bacterial diversity and immune repertoire of the demosponge, Neopetrosia compacta, and the calcareous sponge, Leucetta chagosensis, under varying levels of acidification and warming stress based on climate scenarios predicted for 2100. Neopetrosia compacta harbors a diverse microbial community and possesses a rich repertoire of scavenger receptors while L. chagosensis has a less diverse microbiome and an expanded range of pattern recognition receptors and immune response-related genes. Upon exposure to RCP 8.5 conditions, the microbiome composition and host transcriptome of N. compacta remained stable, which correlated with high survival (75%). In contrast, tissue necrosis and low survival (25%) of L. chagosensis was accompanied by microbial community shifts and downregulation of host immune-related pathways. Meta-analysis of microbiome diversity and immunological repertoire across poriferan classes further highlights the importance of host–microbe interactions in predicting the fate of sponges under future ocean conditions.
With coral reefs declining globally, resilience of these ecosystems hinges on successful coral recruitment. However, knowledge of the acclimatory and/or adaptive potential in response to environmental challenges such as ocean acidification (OA) in earliest life stages is limited. Our combination of physiological measurements, microscopy, computed tomography techniques and gene expression analysis allowed us to thoroughly elucidate the mechanisms underlying the response of early-life stages of corals, together with their algal partners, to the projected decline in oceanic pH. We observed extensive physiological, morphological and transcriptional changes in surviving recruits, and the transition to a less-skeleton/more-tissue phenotype. We found that decreased pH conditions stimulate photosynthesis and endosymbiont growth, and gene expression potentially linked to photosynthates translocation. Our unique holistic study discloses the previously unseen intricate net of interacting mechanisms that regulate the performance of these organisms in response to OA.
Rapid evolution may provide a buffer against extinction risk for some species threatened by climate change; however, the capacity to evolve rapidly enough to keep pace with changing environments is unknown for most taxa. The ecosystem-level consequences of climate adaptation are likely to be the largest in marine ecosystems, where short-lived phytoplankton with large effective population sizes make up the bulk of primary production. However, there are substantial challenges to predicting climate-driven evolution in marine systems, including multiple simultaneous axes of change and considerable heterogeneity in rates of change, as well as the biphasic life cycles of many marine metazoans, which expose different life stages to disparate sources of selection. A critical tool for addressing these challenges is experimental evolution, where populations of organisms are directly exposed to controlled sources of selection to test evolutionary responses. We review the use of experimental evolution to test the capacity to adapt to climate change stressors in marine species. The application of experimental evolution in this context has grown dramatically in the past decade, shedding light on the capacity for evolution, associated trade-offs, and the genetic architecture of stress-tolerance traits. Our goal is to highlight the utility of this approach for investigating potential responses to climate change and point a way forward for future studies.
There is a need to understand the responses of marine molluscs in this era of rapid climate change. Transgenerational plasticity that results in resilient offspring provides a mechanism for rapid acclimation of marine organisms to climate change. This study tested the hypothesis that adult parental exposure to elevated pCO2 and warming will have transgenerational benefits for offspring in the oysters Saccostrea glomerata and Crassostrea gigas. Adult S. glomerata and C. gigas were exposed to orthogonal treatments of ambient and elevated pCO2, and ambient and elevated temperature for 8 weeks. Gametes were collected and fertilized, larvae were then reared for 9 days under ambient and elevated pCO2. Egg lipidome and larval morphology and lipidome were measured. Parental exposure to warming and elevated pCO2 led to limited beneficial transgenerational responses for eggs and larvae of S. glomerata and C. gigas. Overall, larvae of S. glomerata were more sensitive than C. gigas, and both species had some capacity for transgenerational plasticity. This study supports the idea that transgenerational plasticity acts as an acclimatory mechanism for marine organisms to cope with the stress of climate change, but there are limitations, and it may not be a panacea or act equally in different species.
The Atlantic surfclam (Spisula solidissima) supports a $29.2-million fishery on the northeastern coast of the United States. Increasing global carbon dioxide (CO2) in the atmosphere has resulted in a decrease in ocean pH, known as ocean acidification (OA), in Atlantic surfclam habitat. The effects of OA on larval Atlantic surfclam were investigated for 28 d by using 3 different levels of partial pressure of CO2 (ρCO2): low (344 μatm), medium (821 μatm), and high (1243 μatm). Samples were taken to examine growth, shell height, time to metamorphosis, survival, and lipid concentration. Larvae exposed to a medium ρCO2 level had a hormetic response with significantly greater shell height and growth rates and a higher percentage that metamorphosed by day 28 than larvae exposed to the high- and low-level treatments. No significant difference in survival was observed between treatments. Although no significant difference was found in lipid concentration, Atlantic surfclam did have a similar hormetic response for concentrations of phospholipids, sterols, and triacylglycerols and for the ratio of sterols to phospholipids, indicating that larvae may have a homeoviscous adaptation to OA at medium ρCO2 levels. Our results indicate that larval Atlantic surfclam have some tolerance to slightly elevated ρCO2 concentrations but that, at high ρCO2 levels, they may be susceptible to OA.
The walrus (Odobenus rosmarus) is classified as a focal ecosystem component of the Arctic, defined as a biological element that is considered central to the functioning of an ecosystem, is of major importance to Arctic residents and/or is likely to be a good proxy for short- and long-term changes in the environment. The Arctic is undergoing large-scale environmental changes due to rapid global warming, including a marked reduction of sea ice in several areas inhabited by walruses. This chapter reviews how walruses already have been affected by global warming, or likely will be in the future. Specifically, we review the effects on walruses of projected changes in sea ice cover, marine productivity, ocean acidification, predation, pathogens and ultraviolet radiation, whereas changes in human activity patterns are discussed elsewhere in this volume. We find that, while the Pacific walrus seems to experience negative effects of warming and decrease in sea ice, the Atlantic walruses may be less affected; also in comparison to other ice-associated pinnipeds. Hence, we concur with previous assessments that the walrus is likely to survive into the future; at least in areas where human disturbance is minimal, and suitable terrestrial haul-outs are close enough to their feeding grounds.
- Ocean acidification (OA) under delta (∆) pH = – 0.3 (pH ~7.7), but not ∆pH = – 0.1 (pH ~ 7.9) relative to the present (~8.0 pH), reduced the survival, respiration and moulting of phyllosomas of T. australiensis.
- OA under pH ~7.7 adversely affected the attraction of T. australiensis phyllosomas to jellyfish cues.
- The majority of individual metabolites of phyllosomas were suppressed even in mild pH ~ 7.9.
- The interaction between phyllosoma and jellyfish may be impaired under pH ~7.7.
Ocean acidification (OA) can alter the behaviour and physiology of marine fauna and impair their ability to interact with other species, including those in symbiotic and predatory relationships. Phyllosoma larvae of lobsters are symbionts to many invertebrates and often ride and feed on jellyfish, however OA may threaten interactions between phyllosomas and jellyfish. Here, we tested whether OA predicted for surface mid-shelf waters of Great Barrier Reef, Australia, under ∆ pH = −0.1 (pH ~7.9) and ∆pH = −0.3 (pH ~7.7) relative to the present pH (~8.0) (P) impaired the survival, moulting, respiration, and metabolite profiles of phyllosoma larvae of the slipper lobster Thenus australiensis, and the ability of phyllosomas to detect chemical cues of fresh jellyfish tissue. We discovered that OA was detrimental to survival of phyllosomas with only 20% survival under ∆pH = −0.3 compared to 49.2 and 45.3% in the P and ∆pH = −0.1 treatments, respectively. The numbers of phyllosomas that moulted in the P and ∆pH = −0.1 treatments were 40% and 34% higher, respectively, than those in the ∆pH = −0.3 treatment. Respiration rates varied between pH treatments, but were not consistent through time. Respiration rates in the ∆pH = −0.3 and ∆pH = −0.1 treatments were initially 40% and 22% higher, respectively, than in the P treatment on Day 2 and then rates varied to become 26% lower (∆pH = −0.3) and 17% (∆pH = −0.1) higher towards the end of the experiment. Larvae were attracted to jellyfish tissue in treatments P and ∆pH = −0.1 but avoided jellyfish at ∆pH = −0.3. Moreover, OA conditions under ∆pH = −0.1 and ∆pH = −0.3 levels reduced the relative abundances of 22 of the 34 metabolites detected in phyllosomas via Nuclear Magnetic Resonance (NMR) spectroscopy. Our study demonstrates that the physiology and ability to detect jellyfish tissue by phyllosomas of the lobster T. australiensis may be impaired under ∆pH = −0.3 relative to the present conditions, with potential negative consequences for adult populations of this commercially important species.
- More simplified and modularized bacterial networks of rearing seawater under elevated pCO2.
- Changed abundances of CNPS cycling genes of seawater microbiome under elevated pCO2.
- Changed C, N, and P chemistry of rearing seawater under elevated pCO2.
- Seawater C, N, and P chemistry may be affected by future elevated pCO2 via seawater microbiome.
Mean oceanic CO2 values have already risen and are expected to rise further on a global scale. Elevated pCO2 (eCO2) changes the bacterial community in seawater. However, the ecological association of seawater microbiota and related geochemical functions are largely unknown. We provide the first evidence that eCO2 alters the interaction patterns and functional potentials of microbiota in rearing seawater of the swimming crab, Portunus trituberculatus. Network analysis showed that eCO2 induced a simpler and more modular bacterial network in rearing seawater, with increased negative associations and distinct keystone taxa. Using the quantitative microbial element cycling method, nitrogen (N) and phosphorus (P) cycling genes exhibited the highest increase after one week of eCO2 stress and were significantly associated with keystone taxa. However, the functional potential of seawater bacteria was decoupled from their taxonomic composition and strongly coupled with eCO2 levels. The changed functional potential of seawater bacteria contributed to seawater N and P chemistry, which was highlighted by markedly decreased NH3, NH4+-N, and PO43--P levels and increased NO2−-N and NO3−-N levels. This study suggests that eCO2 alters the interaction patterns and functional potentials of seawater microbiota, which lead to the changes of seawater chemical parameters. Our findings provide new insights into the mechanisms underlying the effects of eCO2 on marine animals from the microbial ecological perspective.
The sponge-associated microbial community contributes to the overall health and adaptive capacity of the sponge holobiont. This community is regulated by the environment, as well as the immune system of the host. However, little is known about the effect of environmental stress on the regulation of host immune functions and how this may, in turn, affect sponge-microbe interactions. In this study, we compared the microbiomes and immune repertoire of two sponge species, the demosponge, Neopetrosia compacta and the calcareous sponge, Leucetta chagosensis, under varying levels of acidification and warming stress. Neopetrosia compacta harbors a diverse bacterial assemblage and possesses a rich repertoire of scavenger receptors while L. chagosensis has a less diverse microbiome and an expanded range of pattern recognition receptors and proteins with immunological domains. Upon exposure to warming and acidification, the microbiome and host transcriptome of N. compacta remained stable, which correlated with high survival. In contrast, the bacterial community of L. chagosensis exhibited drastic restructuring and widespread downregulation of host immune-related pathways, which accompanied tissue necrosis and mortality. Differences in microbiome diversity and immunological repertoire of diverse sponge groups highlight the central role of host-microbe interactions in predicting the fate of sponges under future ocean conditions.
- Global climate change and local stressors are the main threats to reef-building organisms and habitats they build, such as rhodolith beds.
- Through an experimental essay and ecological niche modelling, we were able to determine the environmental factors that determine the distribution and affect the physiology of an important rhodolith-forming species in the southwestern Atlantic.
- Our results raise the possibility of some rhodolith-forming species being resilient to future environmental change based on our current understanding of their distributions, a perspective that will need to be further explored by future studies.
- This information is helpful in informing policies for the conservation of priority areas, aiding the preservation of marine biodiversity in the South Atlantic.
Given the ecological and biogeochemical importance of rhodolith beds, it is necessary to investigate how future environmental conditions will affect these organisms. We investigated the impacts of increased nutrient concentrations, acidification, and marine heatwaves on the performance of the rhodolith-forming species Lithothamnion crispatum in a short-term experiment, including the recovery of individuals after stressor removal. Furthermore, we developed an ecological niche model to establish which environmental conditions determine its current distribution along the Brazilian coast and to project responses to future climate scenarios. Although L. crispatum suffered a reduction in photosynthetic performance when exposed to stressors, they returned to pre-experiment values following the return of individuals to control conditions. The model showed that the most important variables in explaining the current distribution of L. crispatum on the Brazilian coast were maximum nitrate and temperature. In future ocean conditions, the model predicted a range expansion of habitat suitability for this species of approximately 58.5% under RCP 8.5. Physiological responses to experimental future environmental conditions corroborated model predictions of the expansion of this species’ habitat suitability in the future. This study, therefore, demonstrates the benefits of applying combined approaches to examine potential species responses to climate-change drivers from multiple angles.
It is widely projected that under future climate scenarios the economic importance of Arctic Ocean fish stocks will increase. The Arctic Ocean is especially vulnerable to ocean acidification and already experiences low pH levels not projected to occur on a global scale until 2100. This paper outlines how ocean acidification must be considered with other potential stressors to accurately predict movement of fish stocks toward, and within, the Arctic and to inform future fish stock management strategies. First, we review the literature on ocean acidification impacts on fish, next we identify the main obstacles that currently preclude ocean acidification from Arctic fish stock projections. Finally, we provide a roadmap to describe how satellite observations can be used to address these gaps: improve knowledge, inform experimental studies, provide regional assessments of vulnerabilities, and implement appropriate management strategies. This roadmap sets out three inter-linked research priorities: (1) Establish organisms and ecosystem physiochemical baselines by increasing the coverage of Arctic physicochemical observations in both space and time; (2) Understand the variability of all stressors in space and time; (3) Map life histories and fish stocks against satellite-derived observations of stressors.