The regulation of gene expression by epigenetic markers is a growing area of focus for researchers who seek to explain rapid phenotypic acclimatization to environmental change. Yet even as empirical datasets accumulate exponentially, the mechanistic underpinnings of epigenetic changes and their role in connecting environmental variation with the regulation of gene function remain unclear. Here, we use a stochastic model of epigenetic change to generate three testable predictions: (1) that organisms require environmental feedback to track their environments through epigenetic responses, (2) that this tracking requires coordination between the addition and removal of epigenetic markers, and (3) that epigenetically driven tracking is only effective under specific subsets of environmental variability. Despite the intuitiveness of these postulates, few to no experimental studies directly test them. Using marine invertebrates as a case study, we review correlational evidence consistent with the model’s predictions, describe hypothetical mechanisms by which epigenetic strategies could evolve, and clearly identify knowledge gaps and urgent experimental needs in the field. Overall, the field of environmental epigenetics is poised for major advances, which can be enhanced through the continued synthesis of mathematical frameworks and empirical data.
Continue reading ‘Epigenetic intelligence: how organisms track their environment through molecular memory’Posts Tagged 'biological response'
Epigenetic intelligence: how organisms track their environment through molecular memory
Published 13 November 2026 Science Leave a CommentTags: adaptation, biological response, corals, individualmodeling, methods, modeling, molecular biology, mollusks, morphology, otherprocess, physiology, reproduction, review, zooplankton
Uncoupling the effects of pH and pCO2: how Phaeocystis globosa adapts its nitrogen assimilation to an acidifying ocean
Published 13 November 2026 Science Leave a CommentTags: adaptation, algae, biological response, growth, molecular biology, otherprocess, photosynthesis, physiology, phytoplankton
Ocean acidification (OA) fundamentally reshapes the chemical landscape of coastal waters, yet the mechanistic basis for the resilience and metabolic adaptation of the bloom-forming alga Phaeocystis globosa remains poorly understood. By disentangling the individual and interactive effects of elevated pCO2 and reduced pH, this study shows that P. globosa exhibits distinct physiological and metabolic responses to these stressors. Reduced pH emerged as the stronger physiological constraint, significantly inhibiting growth, whereas the reduction in relative maximum electron transport rate (rETRmax) was not statistically significant; these responses override the potential benefits of CO2 fertilization. Transcriptomic profiling revealed diver-specific reprogramming of carbon and nitrogen metabolism: reduced pH induced coordinated down-regulation, elevated pCO2 coordinated up-regulation, and combined stress opposing trends. Key nitrogen genes (NR, NiR, GS) shifted phase-dependently. The absence of detectable CPS and OTC transcripts, together with multiple pathways potentially contributing to endogenous ammonium supply, points to a potentially truncated urea cycle and flexible nitrogen utilization. As an exploratory transcriptomic analysis, these results suggest that P. globosa may possess ecological resilience under future acidification.
Continue reading ‘Uncoupling the effects of pH and pCO2: how Phaeocystis globosa adapts its nitrogen assimilation to an acidifying ocean’Surfgrass canopy cover drives non-linear changes in tidepool biodiversity and seawater chemistry
Published 13 November 2026 Science Leave a CommentTags: abundance, biological response, BRcommunity, chemistry, field, mesocosms, otherprocess, phanerogams
Ocean acidification (OA) and deoxygenation, driven by anthropogenic CO2 emissions, threaten marine biodiversity by altering seawater chemistry and disrupting ecosystems. Foundation species like marine macrophytes may locally mitigate these stressors through metabolic activity, potentially improving the average condition or providing daytime refugia and influencing community structure. Yet few studies have quantified the influence of plant structural traits, like canopy cover on the buffering potential of marine macrophytes. We investigated how the canopy cover of surfgrass Phyllospadix spp., dominant macrophytes in northern California tidepools, relates to local seawater chemistry (pH and dissolved oxygen) and biodiversity. Through instantaneous sampling of 29 tidepools and continuous sampling in focal pools, we found non-linear relationships between surfgrass cover, pH, dissolved oxygen, and community diversity. Pools with intermediate surfgrass cover (~40%) had maximum overall species diversity and macrophyte diversity, and largest diel fluctuations in pH and dissolved oxygen, while the highest surfgrass abundances were associated with decreased diversity and dampened chemical variation. A controlled mesocosm experiment corroborated the field pattern: surfgrass in mesocosms caused chemical fluctuations comparable to those in natural tidepools with similar surfgrass abundance. These results suggest that surfgrass can influence ecosystem function through direct metabolic effects and can facilitate or inhibit community diversity depending on its abundance. Our findings underscore the complexity of foundation species’ roles in coastal ecosystems and highlight the need to account for non-linear responses when predicting refugia potential of marine macrophytes.
Continue reading ‘Surfgrass canopy cover drives non-linear changes in tidepool biodiversity and seawater chemistry’An experimental approach to assessing climate sensitivity in juvenile Yellowbelly Flounder (Rhombosolea leporina): methodological insights and applications
Published 13 November 2026 Science Leave a CommentTags: biological response, fish, laboratory, mortality, multiple factors, performance, physiology, reproduction, South Pacific, temperature
As anthropogenic CO₂ emissions continue to rise, marine ecosystems face the dual threats of ocean acidification and ocean warming. A number of studies have examined the effects of ocean acidification and warming on coastal marine fin fish species, but little attention has been paid to estuarine species, the assumption being that they are likely to be tolerant to fluctuations in seawater parameters given freshwater and large tidal dynamics. This thesis investigates the impacts of these stressors on the early life history of the estuarine yellowbelly flounder (Rhombosolea leporina), an ecologically and culturally significant taonga species in New Zealand.
Research was conducted in two phases; a larval pilot study focusing on the transition to exogenous feeding, and a behavioural study on juveniles assessing olfactory mediated responses to food and predator cues.
The larval pilot study, carried out in aquaria, revealed an extreme developmental bottleneck at approximately 14 days post-hatch (dph). Mass mortality occurred across all treatments, coinciding with the onset of metamorphosis and the “critical period” of first feeding. The extent of the mortality event masked any possible treatment effects imposed in terms of pH and temperature combinations. These results highlight the high physiological sensitivity of R. leporina during early ontogeny, independent of climate stressors.
In the second phase, juvenile flounder were exposed to a fully-crossed factorial design of pH (~7.3 & ~8.0) and temperature (20°C & 25°C). Behavioural trials using a two channel choice chamber measured the proportion of time spent in stimulus streams (Perna canaliculus food cues & Notolabrus celidotus predator cues). A three-way ANOVA revealed a significant main effect of stimulus type (p = 0.017) and temperature (p=0.040), but no significant effect of pH and no interactive effects. Interestingly, 66.7% of individuals remained in the neutral mixing zone, particularly during predator trials and under elevated temperatures.
These findings suggest that while R. leporina larvae remain highly vulnerable to intrinsic developmental bottlenecks, juveniles exhibit a degree of behavioural resilience to reduced pH, potentially due to their evolved tolerance of fluctuating estuarine environments. The preference for remaining stationary (crypsis) in the neutral zone is interpreted as a natural, risk-averse strategy for this benthic species. This research underscores the importance of considering species-specific ecology and life stage transitions when predicting the impacts of climate change on New Zealand fisheries.
Overall, this research apparently represents the first study to experimentally examine the effects of ocean acidification and warming on estuarine flatfish species across critical early life stages. Although no clear pH-driven effects were detected in the juvenile behavioural trials, the study remains valuable in testing hypotheses around the resilience of marine species that naturally experience highly variable environmental conditions. In particular, species with significant estuarine habitat phases may possess inherent tolerance to fluctuations in seawater chemistry, yet may still face vulnerability during key developmental transitions. Investigations such as this are therefore important for improving our understanding of how climate change stressors interact with species-specific ecology and life history bottlenecks, and for informing future research on the adaptive capacity of estuarine-associated marine fishes.
Continue reading ‘An experimental approach to assessing climate sensitivity in juvenile Yellowbelly Flounder (Rhombosolea leporina): methodological insights and applications’Morphometric and morphological response of Eprolithus floralis to Oceanic Anoxic Event 2 (Cenomanian/Turonian, Late Cretaceous)
Published 13 November 2026 Science Leave a CommentTags: abundance, biological response, dissolution, morphology, otherprocess, paleo, phytoplankton
Understanding the response of calcareous nannoplankton to past environmental perturbations is critical for assessing the impact of paleoenvironmental changes on marine calcifiers. Here, we analyze the size, morphotype distribution, and abundance of Eprolithus floralis across Oceanic Anoxic Event (OAE) 2 at Clot Chevalier (SE France), Novara di Sicilia (S Italy), and Tarfaya (Morocco), and compare them with Eastbourne (UK) to distinguish supra-regional from local environmental controls.
Mean total diameter differs by ∼1 μm between northern and southern sections and decreases from pre-OAE 2 to OAE 2, with minimum mean values generally reached around peak B of the carbon-isotope excursion. The magnitude of this decrease varies among sections, reflecting different regional baseline conditions. Rounded specimens are on average ∼0.58 μm smaller than spiky specimens, and their increased relative abundance during OAE 2 contributes to the observed size decrease. Specimens with lowest size (3.2–3.5 μm) are extremely rare, suggesting a possible minimum size for the species. The magnitude of the morphometric response differs among sections, with the largest size reductions during OAE 2 at Clot Chevalier (16%) and Tarfaya (10%) and most complete post-OAE 2 recovery recorded at the northern localities, which also display the largest pre-OAE 2 average size. Neither temperature nor nutrient availability explains the common morphometric evolution observed across the four localities. Instead, the temporal correspondence between volcanism, atmospheric CO2 increase and the onset, maximum size decrease and recovery, suggests that perturbations of the marine carbonate system exerted a control on coccolithophore calcification.
Continue reading ‘Morphometric and morphological response of Eprolithus floralis to Oceanic Anoxic Event 2 (Cenomanian/Turonian, Late Cretaceous)’Ocean acidification impairs embryonic development and disrupts ink sac gene expression in the pharaoh cuttlefish (Sepia pharaonis)
Published 12 November 2026 Science Leave a CommentTags: biological response, laboratory, molecular biology, mollusks, morphology, mortality, North Pacific, physiology, reproduction
Background: Ocean acidification (OA) represents a growing threat to marine biodiversity, particularly affecting the sensitive early life stages of invertebrates. While the physiological impacts of OA are widely recognized, its specific effects on organogenesis and the molecular regulation of defensive traits in cephalopods remain poorly understood. This study investigated the influence of acidified seawater on the embryonic development and ink sac formation in the Pharaoh cuttlefish (Sepia pharaonis).
Methods: Embryos were reared under four pH conditions (8.0, 7.7, 7.3, and 6.5). Embryonic growth, survival, hatching success, and ink sac morphogenesis were monitored throughout development. The expression of melanin synthesis–related genes, including tyr, per, and spNOS, was quantified using qRT-PCR.
Results: Ocean acidification impaired embryonic development in a pH-dependent manner. Severe acidification (pH 6.5) resulted in complete mortality and no surviving embryos by Day 9, while moderate acidification (pH 7.3) led to delayed development and failure to hatch by Day 11, compared to the hatching observed in the control group. Ink sac development was markedly inhibited under acidified conditions, resulting in reduced size and pigmentation. Consistent with these morphological abnormalities, the expression of melanin synthesis markers, including tyrosinase (tyr) and peroxidase (per), exhibited a biphasic response, with early transient induction followed by consistent downregulation across all acidified treatments, while, the expression of the regulatory gene Sepia pharaonis nitric oxide synthase (spNOS) was significantly suppressed under severe acidification.
Conclusions: These findings provide evidence that OA is associated with disrupted embryogenesis and impaired ink sac formation in S. pharaonis, accompanied by altered expression of melanin synthesis-related genes. The resulting reduction in defensive capacity may increase the vulnerability of hatchlings and potentially affect population recruitment under future ocean acidification scenarios.
Continue reading ‘Ocean acidification impairs embryonic development and disrupts ink sac gene expression in the pharaoh cuttlefish (Sepia pharaonis)’Potential governing mechanisms of iodine radioisotopes behavior in marine and freshwater fish: transfer, accumulation, biotransformation, and uncertainties under climate change
Published 12 November 2026 Science Leave a CommentTags: biological response, fish, physiology, review
Highlights
- Waterborne iodine isotopes uptake shifts from the gills to the GIT in seawater.
- Exposure pathway and chemical form shape biodistribution and kinetics.
- Accumulation in the gills and liver is determined more by species-specific factors.
- Climate stressors nonlinearly alter iodine isotopes metabolism.
Abstract
The anthropogenic, long-lived radioisotope 129I is a growing long-term concern for aquatic ecosystems due to its predominantly chronic release from nuclear industry facilities, high environmental mobility, and strong biological affinity. Unlike well-studied radionuclides, the mechanisms governing the transfer, accumulation, and biotransformation of iodine radioisotopes in marine and freshwater biota remain insufficiently understood, particularly in fish, which represent a critical link in human exposure pathways. This knowledge gap limits the accuracy of radiological risk assessments and the development of effective mitigation strategies for a contaminant that persists on geological time scales. These uncertainties are further amplified under climate change, as rising temperatures, acidification, and increased co-occurring pollutant loads alter fish physiology and affect iodine metabolism. In aquatic systems, 129I occurs mainly as iodide and iodate, both biologically relevant and involved in enzymatically mediated pathways leading to the synthesis of iodine-containing compounds, including thyroid hormones. Despite the ecological and physiological importance of these processes, existing reviews largely address iodine in fish in a general or thyroid-centered context. This review synthesizes and critically evaluates current knowledge on the mechanisms of iodine radioisotope transfer, accumulation, and biotransformation in marine and freshwater fish, with particular emphasis on membrane transport systems, tissue-specific metabolism, and climate change effects.
Graphical Abstract
Physio–biochemical and transcriptomic responses of the marine green microalga Chlorella sp. to elevated pH and total alkalinity
Published 12 November 2026 Science Leave a CommentTags: algae, biogeochemistry, biological response, growth, laboratory, molecular biology, North Atlantic, photosynthesis, physiology, phytoplankton
The effects of elevated pH and total alkalinity (TA ≈ HCO3– + 2CO32–) on marine primary productivity–the cornerstone of marine food webs and trophic dynamics–remains poorly understood. In this study, we investigated the physiological, biochemical and transcriptomic responses of the green microalga Chlorella sp. to elevated pH (pH = 8.30, TA = 2353 μmol kg–1) and elevated TA under high pH conditions (pH = 8.30, TA = 3854 μmol kg–1). Elevated pH reduced the growth rate and cellular carbohydrate contents, and down–regulated transcripts encoding key enzymes involved in photosynthetic carbon fixation (including ribulose–1,5–bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase), as well as ion transport components (V–type H+ ATPase and Na+ (K+, urea)–H+ transporter). Conversely, elevated TA significantly enhanced the growth rate and increased cellular particulate organic carbon and carbohydrate contents. Furthermore, elevated TA mitigated the inhibitory effect of high pH by up–regulating or stabilizing gene expressions involved in carbon fixation, fatty acid biosynthesis and degradation pathways, V–type H+ ATPase and H+ exporter. Overall, these findings demonstrate that elevated TA effectively relieves high–pH stress and stimulates photosynthetic carbon uptake in Chlorella sp., providing valuable scientific insights in phytoplankton–mediated carbon dioxide removal (CDR) strategies.
Tissue-specific expression responses of antioxidant, immune, and metabolic genes in juvenile yellowfin tuna (Thunnus albacares) under acute low-pH stress
Published 12 November 2026 Science Leave a CommentTags: biological response, fish, laboratory, molecular biology, North Pacific, physiology
Acute reductions in seawater pH may disrupt acid–base regulation and physiological homeostasis in marine fish, but tissue-specific molecular responses in juvenile yellowfin tuna remain poorly understood. Juveniles of yellowfin tuna were exposed for 48 h to four seawater pH levels (8.1, 7.6, 7.1, and 6.6), with three replicate tanks per treatment. The expression of selected antioxidant-, immune-, inflammatory-, and metabolism-related genes in the liver and gill was quantified using qRT-PCR. In the gill, most examined genes were upregulated under low-pH exposure, although the magnitude and pH dependence of the responses varied among genes. In the liver, antioxidant genes and most immune-related genes were downregulated, whereas tnf-α was upregulated at pH 7.1. Hepatic metabolic genes also exhibited treatment-dependent responses: mdh2 was significantly downregulated across all low-pH treatments, whereas pck2 was significantly upregulated only at pH 7.1 and 6.6. In contrast, dgat1b was significantly downregulated exclusively at pH 7.1 and 6.6. These contrasting expression patterns demonstrate marked tissue specificity in the acute low-pH response of juvenile yellowfin tuna, with broader transcriptional activation in the gill and selective suppression and metabolic adjustment in the liver. The findings provide an initial molecular basis for further evaluating the physiological consequences of acute and chronic low-pH exposure in this high-metabolic-rate pelagic species.
Continue reading ‘Tissue-specific expression responses of antioxidant, immune, and metabolic genes in juvenile yellowfin tuna (Thunnus albacares) under acute low-pH stress’Microhabitat-driven variation in predator–prey interactions between the crab Acanthocyclus hassleri and the mussel Perumytilus purpuratus
Published 12 November 2026 Science Leave a CommentTags: biological response, BRcommunity, crustaceans, field, mollusks, morphology, multiple factors, performance, predation, salinity, South Pacific, temperature
Highlights
- Microhabitat variability modulates predator–prey interactions in rocky intertidal systems.
- Tide pool mussels experience recurrent hyposalinity and low pH conditions.
- Reduced shell resistance increases predation vulnerability in tide pool mussels.
- Fine-scale coastal heterogeneity drives trait-mediated trophic interactions.
Abstract
This study evaluates how the microhabitat of origin of the mussel Perumytilus purpuratus is associated with its vulnerability to predation by the crab Acanthocyclus hassleri. A comparison was made of individuals of P. purpuratus from three intertidal microhabitats: higher limit, lower limit, and tide pool (HL, LL, TP, respectively). The latter receives freshwater inputs associated with an adjacent stream and rainfall. Three environmental variables (salinity, temperature, and pH) and prey shell-breaking strength were measured, and predation experiments using single-prey and mixed-prey diets were also conducted. These experiments evaluated attack rate, handling time, attack zone, size of prey consumed, and crushing claw force. The results indicate that TP experience more extreme conditions, with lower salinity and pH during low tide compared with the other microhabitats (HL and LL). These conditions were associated with lower shell-breaking strength, which may reduce prey resistance to predator attacks. While attack rate remained similar across different diets, under a mixed diet, the predator A. hassleri showed greater consumption of mussels from TP. Tide pool prey also tended to require less handling time than prey from the other microhabitats. The anterior region of the prey shell (umbo area) was the most frequently attacked, regardless of the microhabitat. Smaller individuals from LL were more frequently consumed, whereas larger prey sizes were targeted in HL and TP. A. hassleri possesses the strength necessary to attack prey from all three microhabitats. Overall, these findings suggest that microhabitat-associated differences in shell characteristics may influence prey vulnerability to predation and shape prey selection by A. hassleri.
Continue reading ‘Microhabitat-driven variation in predator–prey interactions between the crab Acanthocyclus hassleri and the mussel Perumytilus purpuratus’Red list of ecosystems assessment of Pacific coral reefs
Published 12 November 2026 Science Leave a CommentTags: biological response, calcification, community composition, corals, fisheries, mortality, North Pacific, policy, review, South Pacific
Coral reefs of the Pacific region extend across approximately 30°N to 30°S, covering roughly 35 500 km2. They range from tropical waters of Papua New Guinea in the West to subtropical latitudes, such as Southeastern Pitcairn or Northern Hawaii borders. This encompasses 21 coral reef ecoregions as defined by the Marine Ecoregions Of the World (MEOW) and Marine and Coastal Biodiversity Management in Pacific Island Countries (MACBIO) classifications. The region hosts exceptionally diverse coral and reef fish communities, the latter featuring high levels of endemism in various locations, and is characterised by extensive tropical archipelagos and atolls spanning wide gradients in ocean productivity, human influence, remoteness, geomorphology and climatic conditions. These ecosystems face increasing pressure from ocean warming and marine heatwaves, acidification, extreme weather events, invasive and harmful species outbreaks, overfishing, coastal development and pollution. The IUCN Red List of Ecosystems assessment, based on the benthic and fish datasets from the Global Coral Reef Monitoring Network (1993-2024) and the NOAA Degree Heating Weeks (DHW) dataset (1985-2025), found that coral reefs within all 21 Pacific ecoregions were at a high risk of collapse (i.e. featuring declining attributes to levels where the ecosystem transforms into a different type or is completely lost). This result was, however, largely driven by future climate change projections. Indeed, several criteria assessed in this work are still showing optimistic trends at the regional scale, especially when looking at the actual distribution of Pacific coral reefs or when comparing past and recent estimates of coral cover decline. Under Criterion A (decline in hard coral cover distribution), about 72% of the Pacific reef surface area (14 ecoregions) was classified as Least Concern, while 14% (3 ecoregions) was Vulnerable and 13% (4 ecoregions) was Endangered. Under Criterion B (restricted distribution), about 95% of the Pacific reef area (17 ecoregions) was Least Concern, while 3% (encompassing 3 ecoregions) was Vulnerable. Under Criterion C1 (observed thermal stress), the trend is reversed, with 49% of the reef area (9 ecoregions) classified as Vulnerable, 19% (6 ecoregions) as Endangered and the remaining 32% as either Near Threatened (5 ecoregions) or Least Concern (New Caledonia only). Criterion C2 (projected thermal stress) drives the entire Pacific reef area and all 21 ecoregions to Critically Endangered. Under Criterion D (alteration of biotic interactions), about 52% of the reef area (7 ecoregions) was either Least Concern or Near Threatened, 16% (7 ecoregions) was Vulnerable and 32% (7 ecoregions) was either Endangered or Critically Endangered. These results highlight the need to consolidate reef resilience towards future climate change and to reinforce the conservation of coral reef habitats through strengthened area-based management, sustainable fisheries operation, climate adaptation measures and accelerated global efforts to reduce greenhouse gas emissions.
Continue reading ‘Red list of ecosystems assessment of Pacific coral reefs’Analysis of the effects of seawater acidification on the biochemical composition and digestive enzyme activities of Oratosquilla oratoria (in Chinese)
Published 11 November 2026 Science Leave a CommentTags: biological response, crustaceans, fisheries, laboratory, North Pacific, physiology
Objective
This study aimed to investigate the effects of CO2-induced seawater acidification on the biochemical composition and digestive enzyme activities of mantis shrimp (Oratosquilla oratoria).
Method
A 49-day aquaculture experiment was conducted. Three acidified treatment groups (pH 7.90, pH 7.70, pH 7.50) were established by introducing CO2 gas into seawater, using natural seawater (pH 8.10) serving as the control.
Result
(1) Under acidified conditions, the muscle moisture content of O. oratoria increased with decreasing pH levels. From day 21 onward, the moisture content in the pH 7.70 and pH 7.50 groups exhibited significantly higher than that in the control group (P < 0.05). Conversely, the contents of ash, crude protein, and crude lipid contents decreased with pH reduction. All acidified groups displayed significantly lower ash content than the control from day 7 onward (P < 0.05). The crude protein levels in respective acidified groups became significantly lower than those in the control starting on days 28 (pH 7.90 group), 14 (pH 7.70 group), and 7 (pH 7.50 group), respectively (P < 0.05). All acidified groups showed significantly reduced crude lipid content compared to the control from day 7 onward (P < 0.05). (2) Pepsin and trypsin activities showed an initial increase followed by a decrease, while lipase activity exhibited a gradual increasing trend. Although acidified groups exhibited marginally higher pepsin and trypsin activities than the control at day 7, these enzymes showed declining trends subsequently, with significant inhibition observed in pepsin by day 21 and trypsin by day 35, respectively (P < 0.05). Lipase activities in the acidified groups became significantly elevated compared to the control starting on day 28 (pH 7.90 group), day 7 (pH 7.70 group), and day 7 (pH 7.50 group), respectively (P < 0.05).
Conclusion
When seawater acidification reached pH levels of 7.50–7.30, it induced a stress response in the mantis shrimp (Oratosquilla oratoria). After 7–14 days of exposure, energy reserves such as crude fat and crude protein were mobilized to cope with the acidic conditions. Although the activities of digestive enzymes including pepsin, trypsin, and lipase were temporarily enhanced, this response failed to alleviate the stress caused by seawater acidification.
Continue reading ‘Analysis of the effects of seawater acidification on the biochemical composition and digestive enzyme activities of Oratosquilla oratoria (in Chinese)’Warming, thresholds and extinctions: lessons from past hyperthermals on land and at sea
Published 11 November 2026 Science Leave a CommentTags: biological response, community composition, mortality, otherprocess, paleo, policy, protists, review
The current biodiversity crisis is driven primarily by human activities, including global warming resulting from human greenhouse-gas emissions, which act as multifaceted environmental stressors. Rising temperatures compromise organismal performance through thermal stress, creating demographic erosion and triggering ecological cascades that propagate across populations and ecosystems. The fossil record offers a unique archive for evaluating these dynamics, documenting biological responses to a wide spectrum of past climate regimes, including warming events far exceeding those experienced in human history and the conditions projected to take place during the coming century. Drawing on events across the Phanerozoic, we emphasize mechanisms that link climate change to extinction in both marine and terrestrial realms. Extreme ancient warming episodes reveal a recurring “deadly trio” of global warming, ocean acidification and deoxygenation, processes that mirror the emerging drivers of the contemporary crisis. Focusing on the Cenozoic and the Pleistocene Ice Ages, we review mammalian responses to rapid climatic fluctuations and highlight the synergistic contribution of Homo to Late Quaternary megafaunal collapse. Our synthesis shows that past crises provide key insights into extinction thresholds, rates of environmental change, and the vulnerability of ecological functions under warming. Critically, comparison with ancient analogs suggests that future extinction risk on land may exceed anything observed during past warming episodes, due to the unprecedented velocity of modern warming combined with direct anthropogenic pressures such as habitat loss and fragmentation. In the oceans, projected warming and deoxygenation point toward extinction intensities comparable to those of the most extreme hyperthermal events. Collectively, the evidence indicates that Earth is approaching temperature conditions historically associated with major extinction episodes.
Exploring biomineralization in echinoderms: a review of gene regulatory networks through bibliometrics and comparative genomics
Published 11 November 2026 Science Leave a CommentTags: biological response, echinoderms, molecular biology, morphology, physiology, review
Simple Summary
Echinoderms, including sea urchins, sea cucumbers, starfish, brittle stars, and crinoids, produce mineralized skeletons that vary greatly in form among different groups and developmental stages. Understanding how these skeletons form is important for revealing the biological mechanisms underlying skeletal development and diversity. This review summarizes the development and major research themes of echinoderm biomineralization studies and examines the genes involved in skeletal formation across different echinoderm groups. We show that many genes controlling skeletal development are broadly shared among echinoderms, whereas some genes directly involved in mineral formation vary considerably among groups. By integrating previous biological studies with literature-based and genomic comparisons, this review provides a broader understanding of the molecular basis of echinoderm biomineralization and highlights important questions for future research beyond the extensively studied sea urchins.
Abstract
Biomineralization is a defining feature of echinoderms and underlies the formation of their calcitic endoskeletons. Considerable progress has been made in understanding the molecular basis of echinoderm biomineralization, particularly in sea urchins. However, studies of other echinoderm classes remain limited, and a comprehensive comparison of biomineralization genes and gene regulatory networks across the phylum is still lacking. Here, we combine bibliometric analysis with comparative genomic evidence to summarize current advances in echinoderm biomineralization research. Bibliometric analyses reveal the development of the field, major research themes, and emerging directions, whereas comparative genomic analyses provide an overview of biomineralization genes and gene regulatory networks across different echinoderm classes. Comparative evidence indicates that many transcription factors associated with skeletogenesis are widely distributed across echinoderms. In contrast, biomineralization genes exhibit substantial variation among echinoderm classes. These similarities and differences suggest that broadly shared developmental regulators have been integrated with lineage-specific biomineralization genes to generate the diversity of echinoderm skeletal structures. This review provides a comprehensive overview of biomineralization genes and gene regulatory networks in echinoderms and establishes a comparative framework for future studies of skeletal development, gene regulation, and the evolution of biomineralization across the phylum.
Continue reading ‘Exploring biomineralization in echinoderms: a review of gene regulatory networks through bibliometrics and comparative genomics’Pathways to calcification in coccolithophores
Published 11 November 2026 Science Leave a CommentTags: adaptation, biogeochemistry, biological response, calcification, morphology, otherprocess, photosynthesis, physiology, phytoplankton, protists, review
Calcification by coccolithophores represents a major biogeochemical process in the oceans. Calcification involves the formation of calcite coccoliths within a Golgi-derived compartment inside the cell. These are secreted to the cell surface where they form the coccosphere. Coccolithophore calcification is underpinned by membrane transport processes that deliver the inorganic carbon and calcium substrates from the external seawater to the site of calcification and by the removal of products, namely protons produced in the calcification reactions. Understanding these critical aspects of calcification will provide clearer insights into the responses of coccolithophores to chemical and physical conditions, both in terms of short-term acclimation and long-term adaptation to a changing ocean. In this review we consider these processes, their localization and the specific transporters likely to be involved. We also consider how transport processes are linked to structural aspects of the cell, providing specialized pathways for the substantial ion fluxes involved.
Continue reading ‘Pathways to calcification in coccolithophores’Coastal jellyfish blooms: causes, consequences, and policy frameworks for sustainable management
Published 11 November 2026 Science Leave a CommentTags: abundance, biological response, cnidaria, fisheries, mitigation, otherprocess, policy, review, socio-economy
Highlights
- Jellyfish blooms creates significant challenges for sustainable coastal management.
- Blooms are caused by combined influence of environmental and anthropogenic factors.
- Management approaches can significantly reduce the coastal pollution.
- Multidisciplinary approach is necessary for long−term success in mitigating jellyfish blooms.
Abstract
The growing occurrence of coastal jellyfish blooms worldwide creates significant challenges for sustainable coastal management. In recent years, occurrence of the jellyfish bloom has also been reported in the coastal area of Cox’s Bazar, Bangladesh, which tend to disrupt the ecosystem balance as well as decreases the appeal of the beach. These blooms are shaped by combined influence of environmental and anthropogenic factors including ocean warming, nutrient enrichment, overfishing, destruction of lobster, sea turtle, and other natural predators, and habitat modification, particularly the expansion of coastal infrastructure that facilitate polyp persistence. Therefore, this review synthesizes worldwide patterns of coastal jellyfish blooms, identifies the key drivers of bloom development and recurrence, and analyzes their ecological and socio−economic impacts. Special attention is given to the consequences for fisheries, aquaculture operations, and tourism, as well as to the role of human mediated environments in reinforcing bloom formation. Moreover, management strategies applied across regions are critically reviewed, revealing uneven implementation and limited long−term effectiveness. By bridging scientific evidence with management needs, this review underscores the need for integrated adaptive frameworks to manage jellyfish blooms under ongoing environmental change.
Continue reading ‘Coastal jellyfish blooms: causes, consequences, and policy frameworks for sustainable management’Ocean acidification pushes Mediterranean marine calcifiers toward a tipping point
Published 10 November 2026 Science Leave a CommentTags: biological response, community composition, dissolution, field, Mediterranean, modeling, molecular biology, morphology, otherprocess, protists, regionalmodeling, vents
The increasing emission of carbon dioxide (CO2) is altering seawater chemistry, lowering ocean pH and threatening marine biodiversity. Predicting how marine biota will be adversely affected by ocean acidification (OA) remains a key challenge. Here, we document that functional morphological traits offer a more robust metric of calcifier sensitivity to OA than taxonomic diversity alone. Using benthic foraminifera from a Mediterranean CO2 vent system, we identify an empirically derived pH threshold beyond which community structure and function shift markedly. Applying this threshold to end-of-century projections under Shared Socioeconomic Pathway SSP5-8.5 reveals that most western Mediterranean coastal zones will exceed critical acidification levels by 2090–2100. These results highlight the susceptibility of the Mediterranean coastal ecosystems to OA under high-emission scenarios, underscoring the risk of widespread biodiversity loss and impaired ecosystem functioning. Our approach provides a trait-based framework for forecasting ecosystem responses to OA and informing adaptation strategies in climate-sensitive marine regions.
Continue reading ‘Ocean acidification pushes Mediterranean marine calcifiers toward a tipping point’Global change reshapes marine microbial communities, functions and One Health outcomes
Published 10 November 2026 Science Leave a CommentTags: biogeochemistry, biological response, community composition, corals, nitrogen fixation, otherprocess, photosynthesis, physiology, phytoplankton, policy, porifera, primary production, prokaryotes, respiration, review, socio-economy
Marine microorganisms underpin primary production, biogeochemical cycling and host-associated symbioses, supporting climate regulation, coastal protection, fisheries and other ecosystem services. Rapid global change, including ocean warming and marine heatwaves, acidification, deoxygenation, eutrophication, pollution and overuse reshape microbial communities and their functions across marine habitats. These changes can alter carbon, nitrogen and sulfur cycles, promote microbialization and harmful algal blooms, disrupt host–microbiome associations and modify pathogen and antimicrobial resistance dynamics, collectively amplifying the ecological and societal impacts of global change. This Review frames marine microbiomes as cross-scale mediators that translate external pressures, including climate change, pollution, eutrophication and habitat degradation, into altered microbial metabolism, biogeochemical fluxes, host-associated health outcomes, ecosystem service consequences and broader One Health risks. We synthesize shared mechanisms and cross-habitat patterns, highlight cases in which microbiome interventions and stewardship could mitigate impacts and/or accelerate recovery, and outline management options ranging from the reduction of local stressors to emerging microbiome stewardship approaches in ecosystem restoration. Building upon this, we outline pathways for embedding marine microbiome science into globally coordinated One Health strategies, operational management protocols and financing frameworks that align economic incentives with long-term ecosystem and public health outcomes.
Continue reading ‘Global change reshapes marine microbial communities, functions and One Health outcomes’Ocean acidification reshapes phytoplankton phosphorus metabolism under phosphate-limited conditions
Published 9 November 2026 Science Leave a CommentTags: adaptation, biogeochemistry, biological response, field, globalmodeling, growth, laboratory, mesocosms, modeling, molecular biology, multiple factors, North Pacific, nutrients, otherprocess, photosynthesis, physiology, phytoplankton, protists
Phosphorus (P) availability constrains marine productivity, yet how ocean acidification interacts with intensifying phosphate limitation remains unresolved. Here we present multi-omics analyses of >1,000 generations of experimental diatom evolution to disentangle evolutionary and acclimation-driven responses to ocean acidification under different phosphate regimes. Long-term selection under elevated CO2 produced heritable increases in growth and carbon fixation that persisted irrespective of phosphate availability. In contrast, ocean acidification-driven reductions in particulate organic phosphorus were reversed after reciprocal transfers between selection treatments under phosphate limitation, indicating acclimation and environment-dependent P allocation. Multi-omics analyses indicate that the particulate organic phosphorus decline could be attributed to depletion of cellular P reserves and enrichment of non-P cell membrane lipids under combined ocean acidification and phosphate stress. Coastal mesocosm experiments revealed similarly reduced particulate organic phosphorus in natural phytoplankton at low-phosphate stations under ocean acidification. Global meta-transcriptomes further indicate widespread upregulation of gene expression in non-P cell membrane lipid pathways in high-pCO2 and low-phosphate regions. Earth system models predict a 211% to 2,185% decline in particulate organic phosphorus by 2100 under the under the Shared Socioeconomic Pathway (SSP)2–4.5 or SSP5–8.5 scenarios, respectively. These results show that ocean acidification could intensify nutrient imbalance and reshape global phosphorus cycling in marine ecosystems.
Continue reading ‘Ocean acidification reshapes phytoplankton phosphorus metabolism under phosphate-limited conditions’Ocean acidification impairs the chiton shadow defensive response via degradation of aragonitic lenses
Published 9 November 2026 Science Leave a CommentTags: biological response, dissolution, laboratory, mollusks, morphology, North Pacific, performance, physiology
Ocean acidification (OA) has the potential to disrupt the behavior of marine organisms by altering the function of γ-aminobutyric acid type A (GABAA) receptors. In addition, OA can impair sensory performance by reducing the calcification of mineralized sensory structures. Some species of polyplacophoran mollusks (chitons) possess calcified visual organs (aragonitic lenses) that contribute to shadow defense responses triggered by sudden decreases in overhead illumination. Therefore, we hypothesized that OA affects this response by impairing GABAA-mediated signaling or lens calcification. To test this hypothesis, we exposed chitons to “control” or acidified seawater and examined their shadow defensive behavior with and without gabazine, a GABAA antagonist known to restore OA-induced GABAergic dysfunction. Although gabazine did not eliminate behavioral differences between the control and acidified groups, acidification reduced the response strength, suggesting that factors other than GABAA-mediated signaling may contribute to the observed behavioral impairment. Microscopic observations revealed clouding of aragonitic lenses under acidic conditions, suggesting reduced optical performance. Overall, our results indicate that OA-induced degradation of calcified lens structures is associated with impaired shadow defense responses and may contribute to behavioral dysfunction. To the best of our knowledge, this study provides the first evidence that acidification-induced physical and optical changes in the visual anatomy can alter behavioral performance in animals.
Continue reading ‘Ocean acidification impairs the chiton shadow defensive response via degradation of aragonitic lenses’
