Increases in atmospheric carbon dioxide (CO2) accelerate ocean acidification (OA), which has been shown to alter olfactory behaviours in marine organisms. Coastal regions currently experience pCO2 greater than end-of-century open ocean predictions with daily and seasonal fluctuations. Therefore, we hypothesized that marine organisms inhabiting the coastal regions are tolerant to the effects of OA. The acute, static, and fluctuating effects of acidification on the olfactory system were investigated in the coastal yellow shore crab (Hemigrapsus oregonensis (Dana, 1851)). After exposures, the olfactory behaviour to a food cue, putrescine, was measured, and changes in olfactory sensory receptors and neurons (OSNs) were determined using immunohistochemistry. Crabs took 3 times longer to locate the odorant and preferred it less after acute (minutes) and long-term (14 days) static exposures to OA. This impairment was correlated with a 16 to 30% decrease in olfactory receptor protein (IR25a) immunoreactivity and a 20% decrease in OSN volume. Crabs exposed to daily fluctuating pCO2 (7 days) displayed behavioural responses intermediate to crabs in control or static acidification conditions, and showed no changes in IR25a. These results indicate that despite their variable natural environment, yellow shore crabs are affected by acidification, being particularly vulnerable during sustained upwelling events (long-term static high pCO2).
Continue reading ‘Acute, static, and fluctuating ocean acidification effects on the olfactory system of the yellow shore crab, Hemigrapsus oregonensis’Posts Tagged 'crustaceans'
Acute, static, and fluctuating ocean acidification effects on the olfactory system of the yellow shore crab, Hemigrapsus oregonensis
Published 8 October 2025 Science ClosedTags: biological response, crustaceans, laboratory, North Pacific, performance, physiology
Identifying and reducing climate uncertainty in fisheries management reference points
Published 15 September 2025 Science ClosedTags: biological response, communitymodeling, crustaceans, fisheries, modeling, socio-economy
Modelling has predicted that reductions in ocean pH and increases in temperature will reduce vital rates (survival and growth) of North Pacific crab stocks and hence the target levels of fishing mortality consistent with sustainable harvesting. However, these predictions have been based on the best estimates of the effects of changes in ocean pH and temperature on vital rates from laboratory experiments. We quantified the effects of several climate and market sources of variability in Alaskan red king and southern Tanner crab fisheries on predicted optimal fishing mortality rates, including changes in ocean chemistry and temperature on vital rates, non-linear relationships between prices, costs and catch, and the uncertainty in population dynamics models. The declines in survival consistently lead to predictions of a reduction in productivity and hence the optimal level of fishing intensity over time, but the extent of change is uncertain. Uncertainty related to the effects of ocean pH and temperature on vital rates and variability among Earth System Models and future emission scenarios are the dominant sources of uncertainty, although potential fluctuations in prices and costs are also consequential. Further, simulations are used to explore the relationship between changes in ocean pH or temperature and vital rates (additional experimental replicates and a wider range of levels of ocean pH in experiments) and hence identify approaches to reduce the uncertainty in estimates of future projections of target fishing mortality rates. Importantly, we demonstrate that optimal approaches to reducing uncertainty depend on life stage (juvenile growth for red king crab and larval survival for southern Tanner crab), and the optimal experiment depends on species (increasing the range of pH levels for red king crab vs increasing sample sizes for southern Tanner crab). The results of this study can inform priorities for future ocean acidification-related laboratory experiments and provide a basis for evaluating “investment in research” more broadly.
Continue reading ‘Identifying and reducing climate uncertainty in fisheries management reference points’A collaborative climate vulnerability assessment of California marine fishery species
Published 20 August 2025 Science ClosedTags: biological response, crustaceans, fish, fisheries, mollusks, North Pacific, policy, review
Climate change and the associated shifts in species distributions and ecosystem functioning pose a significant challenge to the sustainability of marine fisheries and the human communities dependent upon them. In the California Current, as recent, rapid, and widespread changes have been observed across regional marine ecosystems, there is an urgent need to develop and implement adaptive and climate-ready fisheries management strategies. Climate Vulnerability Assessments (CVA) have been proposed as a first-line approach towards allocating limited resources and identifying those species and stocks most in need of further research and/or management intervention. Here we perform a CVA for 34 California state-managed fish and invertebrate species, following a methodology previously developed for and applied to federally managed species. We found Pacific herring, warty sea cucumber, and California spiny lobster to be three of the species expected to be the most sensitive to climate impacts with California halibut, Pacific bonito, and Pacific hagfish expected to be the least sensitive. When considering climate sensitivity in combination with environmental exposure in both Near (2030–2060) and Far (2070–2100) Exposure climate futures, red abalone was classified as a species with Very High climate vulnerability in both periods. Dungeness and Pacific herring shifted from High to Very High climate vulnerability and Pismo clam and pink shrimp shifted from Moderate to Very High climate vulnerability as exposure conditions progressed. In providing a relative and holistic comparison of the degree to which state-managed marine fishery species are likely to be impacted as climate change progresses, our results can help inform strategic planning initiatives and identify where gaps in scientific knowledge and management capacity may pose the greatest risk to California’s marine resource dependent economies and coastal communities.
Continue reading ‘A collaborative climate vulnerability assessment of California marine fishery species’Complementary genetic and epigenetic changes facilitate rapid adaptation to multiple global change stressors
Published 1 August 2025 Science ClosedTags: adaptation, biological response, crustaceans, laboratory, molecular biology, multiple factors, otherprocess, temperature, zooplankton
Significance
Organisms must adapt or acclimate to survive global change, but how these processes interact and the role of epigenetic variation is unknown. We experimentally evolved the marine copepod Acartia tonsa for 25 generations in global change conditions and measured their genomic, epigenomic, and gene expression responses. We found that both genetic and epigenetic changes contributed to resilience and were inversely related, acting in different regions of the genome. Epigenetic changes were functionally linked to the regulation of stress and transposable elements and correlated with shifts in gene expression. These findings paint a surprising picture of the complementary contributions of both genetic and epigenetic mechanisms to population resilience in global change conditions.
Abstract
To persist under unprecedented rates of global change, populations can adapt or acclimate. However, how these resilience mechanisms interact, particularly the role of epigenetic variation in long-term adaptation, is unknown. To address this gap, we experimentally evolved the foundational marine copepod Acartia tonsa for 25 generations under ocean acidification, warming, and their combination and then measured epigenomic, genomic, and transcriptomic responses. We observed clear and consistent epigenomic and genomic divergence between treatments, with epigenomic divergence concentrated in genes related to stress response and the regulation of transposable elements. However, epigenetic and genetic changes were inversely related and occurred in different regions of the genome; levels of genetic differentiation (FST) were up to 2.5× higher in regions where methylation did not differ between treatments compared to regions with significant methylation changes. This negative relationship between epigenetic and genetic divergence could be driven by local inhibition of one another or distinct functional targets of selection. Finally, epigenetic divergence was positively, though weakly, associated with gene expression divergence, suggesting that epigenetic changes may facilitate phenotypic change. Taken together, these results suggest that unique, complementary genetic and epigenetic mechanisms promote resilience to global change.
Continue reading ‘Complementary genetic and epigenetic changes facilitate rapid adaptation to multiple global change stressors’Stage-dependent life-history, physiological, and behavioral responses to low pH in an estuarine crab
Published 18 July 2025 Science ClosedTags: adaptation, biological response, crustaceans, laboratory, mortality, otherprocess, performance, physiology, reproduction, South Atlantic
Highlights
- We assessed the effects of low pH on larval stages of the crab Neohelice granulata.
- Low pH affects intermolt period, mortality, and oxygen consumption.
- Low pH also impacts swimming velocity and distance traveled.
- Marine larval stages were more adversely affected than the exported (first) larval stage.
Abstract
Early stages of marine invertebrates are vulnerable to ocean acidification. We investigated low pH effects on larval stages of the crab Neohelice granulata. We hypothesized that Zoea I, adapted to fluctuating environments, would show greater resilience than Zoea II and III, which develop in stable nearshore areas. We assessed pH 8 -control-, pH 7.5, and pH 6.9 effects on intermolt duration, mortality, oxygen consumption, and swimming behavior. Zoea I tolerated low pH with no changes in development or mortality, though oxygen consumption decreased at pH 6.9. In contrast, Zoea II and III showed delayed development, higher mortality, and reduced oxygen consumption at pH 6.9. While Zoea I showed no changes in swimming, Zoea II and III exhibited reduced swimming velocity and distance traveled under acidified conditions. These findings show that Zoea II and III are more sensitive to low pH, while Zoea I is more resilient.
Continue reading ‘Stage-dependent life-history, physiological, and behavioral responses to low pH in an estuarine crab’Ocean acidification decreases molting but not survival of Antarctic amphipods Djerboa furcipes, Gondogeneia antarctica, and Prostebbingia gracilis
Published 10 July 2025 Science ClosedTags: Antarctic, biological response, crustaceans, laboratory, morphology, mortality, physiology, zooplankton
Ocean acidification refers to a decrease in the pH of the world’s oceans from the oceanic uptake of human-derived atmospheric CO2. Low pH is known to decrease the calcification and survival of many calcifying invertebrates. Shallow, hard bottom communities along the Western Antarctic Peninsula often have incredibly large numbers of invertebrate mesograzers that shelter on and are mutualists with the dominant brown macroalgae. The common amphipod species Djerboa furcipes, Gondogeneia antarctica, and Prostebbingia gracilis were collected from the immediate vicinity of Palmer Station, Antarctica (64°46′S, 64°03′W) in January–February 2023 and maintained under three different pH treatments simulating ambient conditions (approximately pH 8.0), near-future conditions for 2100 (pH 7.7), and distant future conditions (pH 7.3) for 8 weeks. Molt number and mortality were monitored throughout the course of the experiment. After the 8 week exposure, amphipods were analyzed for their biochemical compositions including the Mg/Ca ratio of their exoskeletons. There was no significant difference in biochemical composition or survival among the pH treatments for any of the amphipod species. All three species, however, had significantly fewer total numbers of molts in the pH 7.3 treatment than in the ambient treatment. These results suggest that amphipods may be able to maintain their survival in decreased pH by reallocating energy into compensatory behaviors, such as acid–base regulation, and away from energy expensive processes like molting.
Continue reading ‘Ocean acidification decreases molting but not survival of Antarctic amphipods Djerboa furcipes, Gondogeneia antarctica, and Prostebbingia gracilis’Climate vulnerability assessment of fish and invertebrates in the U.S. South Atlantic large marine ecosystem
Published 9 July 2025 Science ClosedTags: biological response, crustaceans, fish, mollusks, North Atlantic, review
Trait-based climate vulnerability assessment (CVA) is a rapid and repeatable approach to simultaneously assess the vulnerability of a large number of species to projected regional changes in climate. We conducted the first CVA in the U.S. South Atlantic Large Marine Ecosystem for 71 ecologically, economically, and culturally important fish and invertebrate species. The CVA was conducted by a 16-member panel based on scoring 12 biological sensitivity attributes and seven climate exposure factors. About two-thirds of the species were considered highly vulnerability to future climate projected under the RCP 8.5 emissions scenario, with diadromous species, invertebrates, and deepwater reef fishes the most vulnerable functional groups. Ocean acidification, sea surface temperature, and salinity were the exposure factors with the greatest influence on climate vulnerability, while population growth rate, population status, and early life history traits were the most important biological sensitivity attributes. More than two-thirds of the species had high potential for shifts in geographic distribution, due mostly to the prevalence of broadcast spawning, extensive larval dispersal, and high adult mobility of many species, and the generalist habitat requirements of several estuary-dependent and hard-bottom reef species. Some shifts in distribution have already occurred though potential relationships to environmental conditions associated with climate are not well-understood. Uncertainty analyses confirmed the robustness of the climate vulnerability rankings, but comparison of alternative types of elicited informed judgement did not always agree, suggesting higher uncertainty in climate vulnerability for some species. In addition, several species may benefit under future climate conditions, and climate effects on some species considered to be highly vulnerable may be of relatively small magnitude. These results can be used to prioritize conservation, research, and management efforts, and identify key uncertainties related to the impacts of future climate on fishery resources in the U.S. South Atlantic region.
Continue reading ‘Climate vulnerability assessment of fish and invertebrates in the U.S. South Atlantic large marine ecosystem’Increased temperature and acidification elevate the risk of starvation in American lobster larvae
Published 4 July 2025 Science ClosedTags: biological response, crustaceans, laboratory, morphology, multiple factors, North Atlantic, physiology, reproduction, temperature
The geographic range of the American lobster, Homarus americanus, spans a steep thermal gradient along the coastal Northwest Atlantic. As CO2 emissions increase globally, this range is rapidly warming and acidifying. Larval H. americanus hatch with a finite amount of maternally sourced lipid stores in their yolk sac, which provide an energetic buffer during the intermediate period between hatch and first feed. This study examines the response of newly-hatched, unfed H. americanus larvae to the combined effects of elevated pCO2 and temperature. Using a space-for-time approach, we compared larvae of two distinct sub-populations from thermally contrasting regions: Rhode Island, at the warmer, southern limit of the species range, and Midcoast, Maine, a cooler northern region. Average larval initial post-hatch weight was similar across regions and variability therein could be explained by maternal effects. Under 6 days of starvation, larvae from the two regions lost ∼14% of their initial dry weight and 25% of their Carbon weight. Still, end-century elevated temperature or acidification did not substantially alter those rates for larvae from either region. However, under an identical range of conditions over the 6-day experiment, larvae from the warmer regime maintained relatively stable oxygen consumption rates, while those from the cooler regime started 50% higher, then dropped by 80% within 2 days. If depressed metabolic functioning translates to reduced feeding efficiency for cool regime larvae, our findings suggest that subpopulations in the southern edge of the species range have a relative advantage in food-scarce environments under these conditions, adding to previous evidence for countergradient variation in this species. Further analysis of total fatty acid losses conducted on Midcoast larvae suggested starved larvae exposed to elevated temperature (19°C) experienced considerably greater losses of key lipid groups than larvae under ambient conditions (16°C, 400 ppm), particularly within the first 2 days of exposure. Our results highlight the short time frames over which ocean warming can accelerate the depletion of energy stores and make larvae more vulnerable to starvation.
Continue reading ‘Increased temperature and acidification elevate the risk of starvation in American lobster larvae ‘Non-additive phospholipidomic responses to ocean warming and acidification drive intraspecific variation in cell membrane vulnerability in a marine ectotherm
Published 1 July 2025 Science ClosedTags: adaptation, biological response, crustaceans, laboratory, multiple factors, North Atlantic, otherprocess, physiology, temperature
Highlights
- Shrimp show non-additive phospholipidome responses to combined OW and OA.
- Synergistic and antagonistic responses are origin- and scenario-dependent.
- Physiological shifts emerge when OA occurs near shrimp’s thermal limits.
- Shrimp show potential local adaptation/acclimatisation of cell membrane phenotypes.
- Shrimp cell membrane vulnerability to combined OW and OA is origin-dependent.
Abstract
The lipidome is fundamental to the good functioning of cells and organisms. However, its role in species acclimatisation and adaptation to global changes remains overlooked. Investigating intraspecific variation in lipidome responses to combined global change drivers is therefore paramount to predict species’ vulnerability in future oceans. Here, we profiled the phospholipidome of the Northern shrimp, Pandalus borealis, from four different origins in the Northwest Atlantic, within an orthogonal design of ocean warming (OW) and acidification (OA) scenarios. We report complex origin-dependent non-additive responses under combined global changes. Shrimp display a high degree of intraspecific variation with distinct profiles of synergism, antagonism or temperature-driven phospholipidome responses when OA is superimposed on OW. Shrimp from the southernmost origin are only sensitive to OW, whilst those from the other three origins respond to combined OW and OA. These patterns involve changes in cellular membranes’ unsaturation, fluidity, curvature and thickness, underlying differential intraspecific cellular vulnerability to global changes. The isolated effects of OA are subtler, visible only in shrimp from the St. Lawrence Estuary (SLE). Shrimp from SLE also show the most pronounced phospholipidome remodelling, allowing them to acclimate to combined OW and OA. Whilst SLE shrimp seem most sensitive to global changes, those from the northernmost origins (Newfoundland and Esquiman Channel) display the greatest cellular vulnerability under combined OW and OA. Our findings evidence the highly complex interplay of OW and OA in remodelling marine ectotherms’ phospholipidomes, with direct implications for prioritising conservation efforts on populations most vulnerable to global changes.
Continue reading ‘Non-additive phospholipidomic responses to ocean warming and acidification drive intraspecific variation in cell membrane vulnerability in a marine ectotherm’Commentary: synthesis of thresholds of ocean acidification impacts on decapods
Published 30 June 2025 Science ClosedTags: biological response, crustaceans, review
Biologically-relevant ocean acidification (OA) thresholds and syntheses are critical for interpreting the growing body of OA monitoring data and guiding ocean conservation actions. Bednaršek et al. (2021a) conducted such a synthesis and developed OA-specific thresholds for decapods, compiling literature data and analyzing 27,000 data points from 55 studies, making it one of the most robust OA decapod meta-analyses. Bednaršek et al. (2021a) related biological responses to OA stress and then convened a working group of experts to develop consensus thresholds based on that evidence, using similar approaches and data analyses as published previously for pteropods and echinoderms (Bednaršek et al., 2019, 2021b).
McElhany and Bush (2024) critiqued the decapod synthesis and suggested a need for re-evaluation. Their primary concerns were with the statistical methods, particularly the use of Least Squares Regression (LSR) and Piecewise Regression (PR). They argued that LSR-derived thresholds are dependent on experimental pH ranges, while PR is criticized because all data points were treated equally, rather than weighing them so each study has an equal influence on the outcome.
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While we disagree with the McElhany and Bush (2024) critiques and assert the thresholds developed by Bednaršek et al. (2021a) through expert consensus are suitable for OA risk assessments, we do want to highlight that these important numbers should be subject to continual refinement. We suggest that the greatest improvements in the threshold estimates in the future will come from more targeted experimental design focusing specifically on deriving biological thresholds. Specifically, increasing the number of exposure levels and the number of species across different habitats will allow for greater species-specific data resolution robustness of their thresholds. Moreover, conducting studies that account for, or better yet quantify, multifactorial stressors, biological variability and adaptations will provide greater value. Reducing the differences in experimental parameters will improve future statistical modelling and help the scientific community advance towards more robust thresholds that can effectively guide conservation efforts.
Continue reading ‘Commentary: synthesis of thresholds of ocean acidification impacts on decapods’Developmental and transgenerational effects of climate change on inorganic mercury toxicity in a marine copepod
Published 25 June 2025 Science ClosedTags: biological response, crustaceans, laboratory, molecular biology, multiple factors, North Pacific, oxygen, physiology, reproduction, zooplankton
Highlights
- Offspring/persistent OA plus OW aggravated IHg toxicity in T. japonicus.
- Persistent OA had stronger mitigating effect on IHg toxicity than offspring OA.
- OA plus OW intensified IHg toxicity in copepods mainly via lysosome dysfunction.
- Persistent OA enhanced energy metabolism and Hg efflux, decreasing IHg toxicity.
- Different scenarios of climate change can variably affect IHg toxicity in copepods.
Abstract
Dynamic shifts in multiple stressors are frequent in the marine environment. Here, we conducted a multigenerational experiment (F1-F4) to explore how different temporal scenarios of climate change, i.e., offspring/persistent ocean acidification (OA), warming (OW), and their combination (AW), could affect inorganic mercury (IHg) toxicity in the marine copepod Tigriopus japonicus. We found that persistent OA exhibited stronger mitigating effect on IHg toxicity in copepods than offspring OA, while offspring/persistent OW and AW aggravated its toxicity effects. We specifically performed transcriptomic analysis for the copepods of F4. Our transcriptomic result showed energy metabolism and detoxification were activated by persistent OA, enabling the copepods to resist IHg exposure. Instead, detoxification- and reproduction-related processes were inhibited in IHg-treated copepods under offspring/persistent OW and AW scenarios. Although apoptosis was suppressed to probably protect IHg-treated copepods under persistent AW, oxidative stress and lysosomal dysfunction ultimately caused reproductive impairment. Our study highlights that offspring/persistent (i.e., developmental/transgenerational) OA and OW could differentially modulate Hg toxicity in marine copepods, and more studies should focus on the temporal variation and complex interaction of multiple stressors, helping accurately project marine biota’s response in the future ocean.
Continue reading ‘Developmental and transgenerational effects of climate change on inorganic mercury toxicity in a marine copepod’Antarctic macroalgal-associated amphipod assemblages exhibit long-term resistance to ocean acidification
Published 19 June 2025 Science ClosedTags: abundance, algae, Antarctic, biological response, BRcommunity, community composition, crustaceans, laboratory, mortality, otherprocess
The pH of the world’s oceans has decreased since the Industrial Revolution due to the oceanic uptake of increased atmospheric CO2 in a process called ocean acidification. Low pH has been linked to negative impacts on the calcification, growth, and survival of calcifying invertebrates. Along the Western Antarctic Peninsula, dominant brown macroalgae often shelter large numbers of diverse invertebrate mesograzers, many of which are calcified. Mesograzer assemblages in this region are often composed of large numbers of amphipods which have key roles in Antarctic macroalgal communities. Understanding the impacts of acidification on amphipods is vital for understanding how these communities will be impacted by climate change. To assess how long-term acidification may influence the survival of different members in these assemblages, mesograzers, particularly amphipods, associated with the brown alga Desmarestia menziesii were collected from the immediate vicinity of Palmer Station, Antarctica (S64°46′, W64°03′) in January 2020 and maintained under three different pH treatments simulating ambient conditions (approximately pH 8.1), near-future conditions for 2100 (pH 7.7), and distant future conditions (pH 7.3) for 52 days then enumerated. Total assemblage number and the relative proportion of each species in the assemblage were found to be similar across the pH treatments. These results suggest that amphipod assemblages associated with D. menziesii may be resistant to long-term exposure to decreased pH.
Antarctic krill habitat suitability changes: historical trends and future projections under climate scenarios
Published 17 June 2025 Science ClosedTags: Antarctic, biological response, crustaceans, field, modeling, multiple factors, regionalmodeling, review, temperature, zooplankton
Highlights
- Sea temperature and pH are key environmental factors affecting krill habitats.
- Krill habitat suitability shows spatiotemporal heterogeneity across regions.
- Under low emission scenario, krill habitat suitability will recover by 2100.
- Under high emission scenario, highly suitable habitat may be lost by 2100.
Abstract
Antarctic krill plays a crucial role in the Southern Ocean ecosystem. However, data limitations leave a significant gap in understanding the changes in krill habitat suitability. This study integrated data from Chinese Antarctic research expeditions and KRILLBASE database, using Maxent model to assess spatiotemporal shifts in krill suitable habitat from 1991 to 2100 across the eastern and western Antarctic under SSP-RCP scenarios. The results reveal regional differences in climate and environmental impacts on krill habitats. Sea temperature and pH are dominant environmental factors affecting habitat suitability. With climate changes, the suitable habitats are shifting toward higher latitudes, and the latitudinal shift of habitats in CCAMLR Areas 48 and 58 is in the opposite direction. Under high-emission scenarios, krill habitats face severe contraction and loss, whereas low-emission scenarios suggest partial recovery by 2100. Coordinated global action to protect krill habitats is essential to address the biodiversity crisis in the Southern Ocean.
Continue reading ‘Antarctic krill habitat suitability changes: historical trends and future projections under climate scenarios’Population and maternal variation in the sensitivity of Dungeness crab Metacarcinus magister zoeae to elevated CO2
Published 10 June 2025 Science ClosedTags: adaptation, biological response, crustaceans, laboratory, morphology, mortality, North Pacific, otherprocess, reproduction
The response of marine organisms to ocean acidification depends on their adaptive capacity, which can be partially understood by evaluating the amount of existing variability in CO2 sensitivity within a species. The process of local adaptation is a mechanism that can drive variability in CO2 sensitivity. In this study, we measured the survival and molt rate of Dungeness crab Metacarcinus magister zoeae that were produced by gravid crabs collected from 3 locations in waters off of Washington State, USA, and reared in a common laboratory in ambient, medium, and high CO2 treatments. The 3 locations from which crabs were collected have different carbonate chemistry dynamics, and Dungeness crabs in these locations are to some extent genetically distinct. We hypothesized that these conditions may favor local adaptation. We did not find evidence of local adaptation, but did see different levels of CO2 sensitivity associated with the mother. This variation in CO2 sensitivity suggests an adaptive capacity that is likely to influence Dungeness crab response to future acidification.
Continue reading ‘Population and maternal variation in the sensitivity of Dungeness crab Metacarcinus magister zoeae to elevated CO2’Evaluating the impact of ocean acidification on seafood – a global approach
Published 23 April 2025 Science ClosedTags: biological response, crustaceans, echinoderms, fish, fisheries, growth, mitigation, mollusks, mortality, review
The quality of human life and food security are closely linked to the health of the ocean and the many goods and services it provides. However, the ocean is under cumulative stress from various human-driven pressures, leading to eutrophication, deoxygenation, loss of genetic biodiversity, contamination with emerging pollutants (e.g., microplastics and pesticides), and climate change (warming and ocean acidification). The effects of multiple ocean stressors and their interplay on marine life and ecosystems remain poorly understood. This underscores the urgent need for innovative science to resolve the complexity of the interplay of stressors and the resulting impacts. This paper reports findings from the Coordinated Research Project CRP K41018, a five-year program framed by the IAEA. The project was explicitly designed to advance Member States’ understanding of both quantitative and qualitative impacts of ocean acidification on key economically relevant seafood species across different world regions. Furthermore, based on different sensitivity baselines across species, it aimed at exploring adaptation pathways for aquaculture and food industries. As a result, Member States would have improved their comprehension of resilience building in specific local contexts (e.g., types of environments, geographical parameters, human dimension). In this context, it is essential to look for ocean solutions to mitigate adverse impacts on seafood and support adaptation strategies based on nature that can counteract stressors. It is concluded that there is great synergy in planning integrated mitigation and adaptation strategies to multiple stressors in marine ecosystems.
Continue reading ‘Evaluating the impact of ocean acidification on seafood – a global approach’Physiological effects of acute exposure to acidification conditions in embryos of the American lobster (Homarus americanus)
Published 12 March 2025 Science ClosedTags: biological response, crustaceans, laboratory, North Atlantic, physiology, reproduction
Highlights
- Protein carbonyl concentration increased, and Na+/K+-ATPase activity decreased with decreasing acute pH in American lobster embryos.
- Oxygen consumption rate and antioxidant content of embryos increased significantly over development.
- American lobster embryos were sensitive to acute pH reductions representative of future ocean and coastal acidification.
Abstract
Ocean and coastal acidification are altering carbonate chemistry conditions and inducing physiological stress in marine organisms. Early life history stages of marine invertebrates, including commercially important species like the American lobster (Homarus americanus) may have limited physiological capacity to tolerate changes in carbonate chemistry. Using American lobster embryos, we quantified physiological disturbances caused by acute changes in carbonate chemistry. We exposed freshly isolated lobster embryos to conditions ranging from 6.94 to 8.07 pH for 24 h at three points during embryo development. With more extreme conditions of acidification, protein carbonyl concentration (indicative of cellular damage from oxidative stress) increased, and Na+/K+-ATPase activity (associated with acid-base regulation) decreased at all stages of development examined. Although oxygen consumption rate and ferric-reducing antioxidant potential both increased over the course of embryogenesis, we found no evidence that the relationship between pH and these physiological metrics varied during ontogeny. Our results indicate that acid-base regulation and oxidative stress in American lobster embryos may be sensitive to acidification-induced hypercapnia within a 24-h period across a large portion of embryo development.
Continue reading ‘Physiological effects of acute exposure to acidification conditions in embryos of the American lobster (Homarus americanus)’Biomarkers responses in the amphipod Tiburonella viscana exposed to the biocide DCOIT and CO2-induced ocean acidification
Published 10 March 2025 Science ClosedTags: biological response, crustaceans, laboratory, multiple factors, physiology, South Atlantic, toxicants, zooplankton
Highlights
- Biomarkers responses in amphipods assessed in sediment testing with the biocide DCOIT;
- Environmentally relevant concentrations of DCOIT produced biomarker responses;
- Enzymatic activities of GST and AChe were reported, including LPO and DNA damage;
- Biomarkers responses were observed in CO2-induced acidification conditions.
Abstract
Anthropogenic carbon dioxide emissions (CO2) have led to climate change and marine acidification, with an estimated decrease in ocean surface pH of 0.3-0.4 units by the end of the current century. Chemical pollution also contributes to biodiversity loss in marine environments. This issue is particularly critical in areas under pressure from shipping activities, where the introduction of new antifouling system formulations poses a major threat to non-target species. The biocide DCOIT is the most widely used alternative to organotin compounds due to its rapid degradation in seawater. The toxicity of waterborne DCOIT to marine organisms has been documented, but sediment-bound effects are limited to apical responses and pH scenarios corresponding to current levels. In this study, we determine in a combined way, the toxicity of DCOIT under marine acidification scenarios assessing biomarker responses in the burrowing amphipod Tiburonella viscana as a parameter of sublethal effects in solid phase exposures. Environmental relevant concentrations of DCOIT caused inhibition of the enzyme glutathione S-transferases (GST), changed acetylcholinesterase-like activity (AChE), and increased DNA damage at pHs of 7.7 and 7.4. For lipid peroxidation (LPO), increased levels caused by DCOIT were found for both control (8.1) and intermediate (7.7) conditions of pH. Our data provides evidence of oxidative and genotoxic effects induced by DCOIT, with activation of detoxification and defense mechanisms in T. viscana. These results are important for ecological risk assessment and managing of antifouling paint biocides in multiple stressors scenarios.
Continue reading ‘Biomarkers responses in the amphipod Tiburonella viscana exposed to the biocide DCOIT and CO2-induced ocean acidification’The effects of ocean warming and elevated CO2 on the feeding behavior and physiology of two sympatric mesograzers
Published 4 March 2025 Science ClosedTags: biological response, crustaceans, laboratory, multiple factors, performance, physiology, respiration, temperature, zooplankton
Highlights
- Combining climate stressors gives better insights into climate change effects.
- Sympatric species respond differently to the same environmental stressors.
- Temperature and pH did not influence the physiology and feeding of H. niger.
- Combined effects of temperature and pH reduced feeding rate in C. filosa.
- Rates of ammonia excretion and protein catabolism increase with warming.
Abstract
Atmospheric CO2 concentrations have increased significantly since pre-industrial times, leading to ocean warming and acidification. These environmental changes affect the physiology of marine organisms as they modify metabolic processes. Despite the critical role of temperature and pH in marine biology, studies of their combined effects are limited. This study investigated the interactive effects of ocean warming and acidification on the feeding behavior and physiology of two sympatric amphipods, Hyale niger and Cymadusa filosa. Using an orthogonal experimental design with two temperatures (27 °C and 30 °C) and two pH levels (7.8 and 7.5), we assessed feeding rates, respiration rates, ammonia excretion, and O/N ratios. Results indicated that C. filosa was less tolerant to these stressors than H. niger. While H. niger showed no significant changes between treatments, C. filosa showed reduced feeding rates and altered physiological responses to elevated temperature and decreased pH. Reducing the feeding rate of C. filosa may favor macroalgal biomass and strengthen bottom-up control in phytal communities. In addition, increased ammonia excretion in C. filosa suggests increased protein catabolism to meet energy demands at higher temperatures, despite reduced oxygen consumption. This indicates a compromised metabolism and a reduction in circulating oxygen capacity for C. filosa. The study shows heterogeneous responses to climate change, highlighting the need to assess combined environmental stressors in different species to accurately understand the impacts of climate change.
Continue reading ‘The effects of ocean warming and elevated CO2 on the feeding behavior and physiology of two sympatric mesograzers’New study shows impact of ocean acidification on Bering Sea red king crab
Published 3 March 2025 Press releases ClosedTags: biological response, crustaceans, fisheries
A fishing tender with 65,000 pounds of Bristol Bay red king crab arrives at Peter Pan in King Cove for processing in 2011. Photo by Margaret Bauman for The Cordova Times.
Ocean acidification appears to be a driver in the decline of Bristol Bay red king crab, a highly value wild Alaska seafood that has for years been threatened by climate change.
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A new report published on Feb. 7 in the Canadian Journal of Fisheries and Aquatic Science said that negative effects of acidification explained 21% of recruitment variability of Bristol Bay red king crab between 1980 and 2023, and 45% since 2000.
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“Anthropogenic emissions of carbon dioxide into the atmosphere have generated a substantial increase in ocean carbon uptake and a shift in the marine carbonate system to a state of higher acidity and lower carbonate saturation states in a process referred to as ocean acidification,” the report said. “Carbon dioxide is more soluble in cold water, and high-latitude waters that are naturally cold and carbon-rich, such as the Bering Sea, are particularly vulnerable to acidification.”
According to Darcy Dugan, director of the Alaska Ocean Acidification Network, these findings mark a shift in messaging from the research community.
“Prior to the study researchers believed species in Alaska were likely being impacted but we didn’t have the data or analysis to back it up,” she said. “Red king crab is the first species where we can see a correlation between acidity and the decline of a wild stock.”
Continue reading ‘New study shows impact of ocean acidification on Bering Sea red king crab ‘Impacts of ocean acidification on the palatability of two Antarctic macroalgae and the consumption of a grazer
Published 27 February 2025 Science ClosedTags: algae, Antarctic, biological response, BRcommunity, crustaceans, laboratory, performance
Increases in atmospheric CO2 have led to more CO2 entering the world’s oceans, decreasing the pH in a process called ’ocean acidification’. Low pH has been linked to impacts on macroalgal growth and stress, which can alter palatability to herbivores. Two common and ecologically important macroalgal species from the western Antarctic Peninsula, the unpalatable Desmarestia menziesii and the palatable Palmaria decipiens, were maintained under three pH treatments: ambient (pH 8.1), near future (7.7) and distant future (7.3) for 52 days and 18 days, respectively. Discs of P. decipiens or artificial foods containing extracts of D. menziesii from each treatment were presented to the amphipod Gondogeneia antarctica in feeding choice experiments. Additionally, G. antarctica exposed to the different treatments for 55 days were used in a feeding assay with untreated P. decipiens. For D. menziesii, extracts from the ambient treatment were eaten significantly more by weight than the other treatments. Similarly, P. decipiens discs from the ambient and pH 7.7 treatments were eaten more than those from the pH 7.3 treatment. There was no significant difference in the consumption by treated G. antarctica. These results suggest that ocean acidification may decrease the palatability of these macroalgae to consumers but not alter consumption by G. antarctica.
Continue reading ‘Impacts of ocean acidification on the palatability of two Antarctic macroalgae and the consumption of a grazer’
