Having evolved in the chronically cold and thermally stable waters of the Southern Ocean (SO) for millions of years, Antarctic fish possess a suite of physiological specializations that enable them to survive at temperatures near the freezing point of seawater. Adaptations include the evolution of antifreeze proteins, modifications of membrane composition, altered metabolic processes, unique mechanisms of oxygen transport and utilization, and distinctive cellular stress responses. This review synthesizes current knowledge of the physiological adaptations of Antarctic fish, focusing on the mechanisms that support survival in extreme cold environments. We examine adaptations related to cold tolerance, osmoregulation, metabolism, reproduction, sensory biology and oxygen transport and discuss the evolutionary processes that have shaped these traits. We further evaluate how ongoing climate-driven changes, including ocean warming, acidification and biological invasions, may affect Antarctic fish populations and ecosystems. Understanding the physiological foundations underlying Antarctic fish adaptation provides important insights into evolutionary responses to environmental extremes and provides a framework for predicting potential vulnerabilities of polar marine organisms in a rapidly changing world.
Continue reading ‘Adaptation to extreme environments: a review of Antarctic fish physiology’Posts Tagged 'review'
Adaptation to extreme environments: a review of Antarctic fish physiology
Published 2 November 2026 Science Leave a CommentTags: Antarctic, biological response, fish, performance, physiology, reproduction, review
Current knowledge of marine crustaceans in Mauritius and their global importance in a changing climate
Published 30 October 2026 Science Leave a CommentTags: abundance, biological response, community composition, crustaceans, fisheries, otherprocess, performance, physiology, reproduction, review
Marine crustaceans are ecologically and socio-economically important components of coastal and marine ecosystems; however, in Mauritius, knowledge of their biodiversity, functional roles, and responses to climate change remains limited and fragmented. This narrative review synthesizes available information on Mauritian marine crustaceans, with particular emphasis on the class Malacostraca, while identifying key knowledge gaps and research priorities relevant to their ecological importance and climate-change vulnerability at both local and global scales. Although existing records document 61 crustacean families in Mauritius, these data are sparse, outdated, and largely based on historical surveys, highlighting the urgent need for updated inventories and long-term monitoring. Globally, marine crustaceans act as trophic intermediaries, ecosystem engineers, and scavengers, contributing to nutrient cycling, sediment dynamics, and habitat stability. They support fisheries, aquaculture, tourism, and cultural practices, and provide valuable bioresources such as chitin, chitosan, and other bioactive compounds with applications in regeneratiom engineering, medicine, agriculture, environmental remediation, and biotechnology. Trade patterns further emphasize their economic importance, revealing export-oriented dynamics in Mauritius, instead of local consumption, that result in a net reliance on imports. Climate change poses an escalating threat through ocean warming, acidification, and increasing environmental variability, affecting DNA repair, protein synthesis, haemolymph, metabolic performance, calcification, reproduction, immunity, behavior, and species interactions. These stressors are further compounded by habitat degradation, altered symbiotic interactions and food-web disruption. The scarcity of empirical studies from Mauritius underscores the need for integrative, multi-stressor, and long-term research to support effective conservation, fisheries management, and climate resilience.
Continue reading ‘Current knowledge of marine crustaceans in Mauritius and their global importance in a changing climate’Connecting international ocean, climate and biodiversity governance to protect deep-sea life
Published 29 October 2026 Science ClosedTags: mitigation, policy, review
Deep-ocean biodiversity plays a fundamental role in the global carbon cycle and Earth’s climate system. Despite this critical function, international biodiversity and climate change governance frameworks have rarely considered deep-sea life to any considerable extent historically. Recent developments create opportunities to close this gap, including through the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement), the Paris Agreement under the UN Framework Convention on Climate Change (UNFCCC), and the Kunming-Montreal Global Biodiversity Framework under the Convention on Biological Diversity (CBD). We review the history and developments of these conventions to date regarding how they address the interface between climate, biodiversity, and the deep ocean, and use this historical overview to identify specific opportunities and mechanisms that can be used to sustain and protect life in the deep ocean more effectively and coherently going forward. Practical suggestions include incorporating climate and carbon considerations in the creation of marine protected areas and other area-based management tools under the BBNJ Agreement, establishing cross-cutting mechanisms that can align efforts under the UNFCCC, CBD, and the BBNJ Agreement, and, under the Paris Agreement, incorporating deep-ocean actions in nationally determined contributions, reconsidering what counts as mitigation or adaptation to encourage consideration of carbon conservation actions, and ensuring that climate change mitigation efforts do not harm deep-ocean biodiversity.
Continue reading ‘Connecting international ocean, climate and biodiversity governance to protect deep-sea life’How ocean acidification makes marine fish reproduction vulnerable: physiological mechanisms and ecosystem consequences
Published 29 October 2026 Science ClosedTags: biological response, fish, fisheries, mortality, multiple factors, physiology, reproduction, review, temperature
Highlights
What are the main findings?
- Ocean Acidification (OA) disrupts the HPG axis, reducing sex steroids and vitellogenesis.
- OA impairs gamete quality, sperm motility, egg integrity, and Ca²⁺ signaling.
- pH decline may weaken Dax1 repression of P450arom, but this remains unvalidated.
- OA plus warming often worsens reproductive dysfunction; multigenerational recruitment effects are still unknown.
What is the implication of the main finding?
- OA threatens fish recruitment, community structure, and fishery productivity/food security.
- Long-term, multigenerational, multi-stressor field studies are needed for effective management.
Abstract
Ocean acidification, driven by the absorption of anthropogenic carbon dioxide into seawater, poses a significant threat to marine environments and biodiversity. This comprehensive review examines the specific impacts of acidification on the reproductive physiology of fish, integrating recent advances in our understanding of gonadal development, gametogenesis, and early embryonic development. We synthesize current findings on how altered carbonate chemistry disturbs the reproductive system from gametogenesis and fertilization to larval development and beyond. Our analysis reveals that ocean acidification affects multiple physiological pathways, including disruption of the hypothalamic–pituitary–gonadal (HPG) axis, impairment of calcium signaling, and alterations in sex hormone synthesis. We propose a mechanistic model in which pH reduction may weaken Dax1-mediated repression of P450arom transcription, thereby dysregulating aromatase activity and leading to sex hormone imbalance that impairs gonadal development; however, this proposed mechanism requires direct experimental validation under ocean acidification, as the net outcome may be modulated by additional regulatory layers such as epigenetic modifications and other transcription factors. Furthermore, we discuss the synergistic effects of ocean acidification with temperature elevation and other stressors, which often exacerbate reproductive dysfunction. This review concludes that no multi-generational study has yet evaluated HPG axis disruption to population-level recruitment failure, a critical gap for fishery resource assessment. We emphasize the critical importance of multi-generational and field-based studies to fully understand these impacts, which is essential for forecasting consequences for global marine biodiversity and the long-term sustainability of fisheries.
Coastal benthic ecosystems in a changing ocean: a mini review
Published 29 October 2026 Science ClosedTags: biogeochemistry, biological response, BRcommunity, community composition, corals, otherprocess, review
Coastal benthic ecosystems are shaped by the combined effects of climate change and anthropogenic pressures. Ocean warming, acidification, and deoxygenation interact with eutrophication, pollution, bottom trawling, and coastal development, altering biodiversity, habitat structure, and functioning from shallow coasts to continental margins. Benthic communities, comprising infaunal and epifaunal taxa, regulate key processes including nutrient cycling, sediment dynamics, and carbon burial, thereby underpinning benthic-pelagic coupling and biogeochemical dynamics. Rising temperatures and marine heatwaves drive widespread losses of habitat-forming species, while ocean acidification constrains calcification. Warming, acidification, hypoxia, eutrophication, and pollution increasingly simplify assemblages, and alter trophic pathways and performance. Interactions among stressors can amplify organismal sensitivity and push ecosystems towards ecological thresholds. However, many knowledge gaps remain. Recent methodological advances, including environmental DNA metabarcoding, automated imaging, trait-based analyses, and multi-stressor experiments, are improving the detection of ecosystem changes at large and our mechanistic understanding of ecosystem responses to ongoing change. By summarizing the various stressors that benthic habitats and taxa face, their interactions and potential outlooks, this review provides a concise synthesis of current understanding and identifies key knowledge gaps for future research and management under accelerating climate change.
Continue reading ‘Coastal benthic ecosystems in a changing ocean: a mini review’Climate change and fish reproduction: a meta-analysis of global laboratory-based experimental evidence across species and ecosystems
Published 22 October 2026 Science ClosedTags: biological response, fish, laboratory, multiple factors, oxygen, performance, physiology, reproduction, review, temperature
Climate change is altering fish reproduction by disrupting spawning cycles, reducing egg viability, and altering reproductive behaviours essential for population sustainability, to our knowledge, this is the first synthesis to integrate laboratory-based evidence for temperature, hypoxia, ocean acidification, and their combined exposure across reproductive performance, physiological, developmental, and molecular endpoints, and across freshwater, brackish, and marine habitats. Following PICOS and PRISMA criteria, we synthesised 779 effect sizes (740 retained after outlier exclusion) from 80 controlled laboratory studies (38,500 observations; 54 species; 28 countries). A three-level multilevel model accounting for non-independence among effect sizes drawn from the same study showed a significant overall negative effect of climate stressors on fish reproduction (Hedges’ g = −0.421, 95% CI: −0.631 to −0.210, p < 0.001; I² = 94.9%, decomposed into 36.3% between-study and 58.6% within-study heterogeneity). Hypoxia was the dominant and statistically distinct driver (g = −1.145, 95% CI: −1.648 to −0.643, p < 0.0001), most severely impairing gonadal development and sperm quality. The overall warming effect did not reach significance once non-independence was accounted for (g = −0.221, 95% CI: −0.448–0.006, p = 0.057), an uncertain negative trend rather than confirmed impairment, although tropical freshwater species showed significant subgroup-specific declines in reproductive physiology and genetic parameters. Ocean acidification showed a small positive effect (g = 0.199, 95% CI: 0.056–0.343, p = 0.006) that was not robust under robust variance estimation (p = 0.133) and is interpreted with caution. Combined multi-stressor exposure showed a negative trend (g = −0.901, 95% CI: −1.992–0.190, p = 0.106) that did not reach significance, based on only three studies. A formal omnibus test confirmed that stressor categories differ significantly in their effects (QM = 18.61,df = 3, p = 0.0003), with hypoxia statistically distinct from both temperature and ocean acidification. Leave-one-out and cumulative meta-analyses confirmed the robustness of the overall finding.
Inside the Extinction Envelope: a systemic review and meta-analysis of paleoclimate extinction markers with comments on the necessary array of last-threshold interventions
Published 21 October 2026 Science ClosedTags: mitigation, paleo, policy, review
Every element of the causal chain that produced the five largest mass extinctions of the last half-billion years is presently active in the Earth system. The rate of the modern perturbation exceeds every peer-reviewed paleoclimate reference case. A six-intervention portfolio, deployed together at wartime industrial scale beginning now, is the physically necessary and sufficient response. The window in which that portfolio remains fully effective closes between 2028 and 2040. The anthropogenic-versus-feedback tipping point is expected between 2035 and 2040; corrected for the at-least-order-of-magnitude higher rate of contemporary carbon release, loss of agency — the point at which coordinated intervention can no longer arrest the cascade — arrives 200 to 400 years after feedback engagement under sustained portfolio deployment, and collapses onto the tipping point itself under any scenario in which the portfolio is not deployed within the 2028–2040 window.
Continue reading ‘Inside the Extinction Envelope: a systemic review and meta-analysis of paleoclimate extinction markers with comments on the necessary array of last-threshold interventions’Present but overlooked: biogenic acidification in aquaculture waters and its implication for mollusc mariculture
Published 21 October 2026 Science ClosedTags: biological response, calcification, chemistry, fisheries, mitigation, mollusks, morphology, physiology, review
Mollusc mariculture, a critical global source of high-quality protein, is increasingly threatened by seawater acidification. While climate-driven ocean acidification (OA) has been widely studied, intensive aquaculture systems face an additional, locally exacerbated phenomenon: biogenic acidification. In this review, we comprehensively compare biogenic acidification with OA and other seawater acidification types, highlighting its occurrence across various aquaculture systems and its capacity to induce conditions more corrosive than end-of-century OA projections under densely stocked settings. Driven by the respiration and calcification of high-density mollusc populations, biogenic acidification leads to distinct alterations in the carbonate chemistry of mollusc farming systems—notably a reduction in total alkalinity (TA)—that are mechanistically different from OA. We further discuss how biogenic acidification imposes stronger physiological stresses on molluscs, impairing calcification, growth, and energy allocation, and how it synergistically interacts with climate change. Finally, we propose practical mitigation strategies, including TA supplementation and integrated multi-trophic aquaculture, to enhance the resilience and sustainability of mollusc farming. This review underscores the necessity to address biogenic acidification as a distinct and ongoing challenge in global mariculture.
Continue reading ‘Present but overlooked: biogenic acidification in aquaculture waters and its implication for mollusc mariculture’The impact of the CO2 fertilization effect in seagrasses: a comparative perspective with terrestrial plants
Published 20 October 2026 Science ClosedTags: biological response, communityMF, morphology, multiple factors, nutrients, phanerogams, photosynthesis, physiology, reproduction, review, temperature
This article comments on:
Pazzaglia J, Marín-Guirao L, Ambrosino L, Pes K, Costa M, Barrote I, Silva J, Procaccini G. 2025. Handling the heat: ocean acidification mitigates the effects of marine heatwaves on Posidonia oceanica seedlings. Journal of Experimental Botany 76, 6958–6973. https://doi.org/10.1093/jxb/eraf276.
Seagrass meadows are among the world’s most ecologically and economically important marine ecosystems. Although they cover only 0.1% of the seafloor, they sequester carbon at rates rivalling tropical rainforests, protect coastlines, and support marine biodiversity (do Amaral Camara Lima et al., 2023). Yet they are declining globally due to anthropogenic pressures including coastal development, pollution, and climate change (Waycott et al., 2009; Dunic et al., 2021). While ocean acidification and ocean warming are pervasive stressors under accelerating global change, Pazzaglia et al. (2025) have demonstrated that elevated dissolved CO2 may enhance seagrass resilience by increasing thermal tolerance in Posidonia oceanica seedlings through the CO2 fertilization effect.
Continue reading ‘The impact of the CO2 fertilization effect in seagrasses: a comparative perspective with terrestrial plants’Functional saturation of Earth’s habitable domains: constraints on land systems and potential in marine environments
Published 16 October 2026 Science ClosedTags: algae, Antarctic, North Atlantic, phanerogams, review, socio-economy
In this context, functional saturation is defined as the state in which a system’s capacity to sustain additional productive or regulatory functions becomes constrained due to cumulative anthropogenic pressures, even if some physical space remains available. This review examines whether the progressive contraction of terrestrial plant communities under intensifying anthropogenic pressure can be functionally compensated by the expansion of marine macroalgal systems in a high-CO2 world. Integrating perspectives from Earth system ecology, biogeochemistry, and spatial analysis, the study evaluates three interdependent dimensions: the saturation of habitable terrestrial space, the relative openness yet ecological constraint of marine environments, and the dynamic coupling between atmospheric CO2 and ocean chemistry. The synthesis reveals a fundamental asymmetry between land and ocean systems. Terrestrial ecosystems are undergoing direct structural transformation through land-use change, resulting in a measurable contraction of ecologically functional space and increasing transgression of planetary boundaries. In contrast, marine systems retain substantial geometric space but are subject to diffuse, cumulative stressors, particularly in productive coastal zones where macroalgal communities are most viable. Elevated CO2 exerts dual effects on marine primary producers, simultaneously enhancing photosynthetic potential while intensifying ocean acidification, with temporally lagged responses mediated by air–sea exchange dynamics. Although macroalgae may exhibit localized increases in productivity, their capacity to provide long-term carbon sequestration and ecosystem stability remains inherently limited due to rapid biomass turnover, susceptibility to regime shifts, and the interaction of multiple stressors. The available evidence suggests that marine macroalgal expansion is unlikely to fully compensate for terrestrial vegetation loss at global ecological and biogeochemical scales. Instead, the Earth system is undergoing a net reduction in biospheric resilience, characterized by declining terrestrial complexity and increasingly unstable marine productivity. These findings challenge assumptions of compensatory redistribution of primary production and underscore the necessity of preserving terrestrial ecosystems alongside mitigating pressures on marine environments.
Continue reading ‘Functional saturation of Earth’s habitable domains: constraints on land systems and potential in marine environments’Environmental regulation of interspecific interactions among macrobenthic seaweeds and its implications for community phase transition
Published 15 October 2026 Science ClosedTags: algae, community composition, otherprocess, review
Macrobenthic seaweeds are key species in temperate and boreal nearshore rocky ecosystems, and their interspecific interactions profoundly affect the species composition, spatial distribution and dynamic succession of the community. This paper systematically reviews the mechanisms of interspecific competition and facilitative effects among macrobenthic seaweeds. We also examine their environmental regulation and impacts on community phase transitions. Competition mainly centers on three major resources: light, space and nutrients. It manifests as an asymmetric hierarchical structure, in which canopy-forming species exert a disproportionate repressive effect on lower algal layers through light competition. Facilitative effects are realized through several mechanisms. These include canopy shading to mitigate heat stress and water loss, physical structure building to create complex habitats, and nutrient retention with chemical microenvironment regulation. Moreover, the relative strengths of facilitation and competition shift systematically across environmental stress gradients. Multi-trophic level regulation further shapes community diversity maintenance mechanisms through the suppression of dominant species by vegetative predators and the cascading effect of top predators on vegetative predators. In the context of global change, physiological asymmetries driven by oceanic heat waves are tilting the competitive balance in favor of opportunistic turf algae. These algae form a lock-in state through the triple positive feedbacks: physical barriers, biogeochemical deterioration, and chemosensory exclusion. This significantly decreases the resilience of algal field recovery. Tropical coral-macroalgae phase transition is highly consistent with the degradation of temperate algal fields in terms of driving logic. They follow the law of coupling resource competition imbalance, downward regulatory relaxation, and positive feedback lock-up. This paper suggests several priorities for future research. Studies should focus on the nonlinear response of multifactor interaction, the quantitative correlation between key functional traits and community resilience, and the establishment of a cross-ecosystem comparison framework. These efforts will provide theoretical support for predicting and adaptively managing offshore ecosystems under global change.
Continue reading ‘Environmental regulation of interspecific interactions among macrobenthic seaweeds and its implications for community phase transition’Microplastics in a warming ocean with coupled climate change interactions and implications for marine ecosystem functioning
Published 9 October 2026 Science ClosedTags: mitigation, multiple factors, plastics, policy, review
Highlights
- Climate driven processes intensify microplastic fragmentation and redistribution.
- Microplastics disrupt carbon cycling and climate sensitive ocean processes.
- Warming acidification and ice melt amplify microplastic impacts on marine biota.
- Polar ice acts as a major reservoir and emerging source of legacy microplastics.
- Integrating microplastics into climate policy is critical for ocean resilience.
Abstract
Microplastics (MPs) pollution and climate change are now recognized as two pervasive and interacting stressors reshaping marine ecosystems, yet their combined effects remain insufficiently integrated within marine pollution research. This review synthesizes current global evidence on how climate-driven processes modulate the sources, transport, fate, and ecological impacts of MPs, and how MPs in turn influence climate-linked ocean processes. A systematic literature review was conducted following PRISMA principles, drawing on peer-reviewed studies retrieved from major scientific databases without temporal restriction. A total of 205 publications included for qualitative synthesis. The results demonstrate that ocean warming, acidification, sea-ice melt, extreme weather events, and altered circulation patterns intensify MP fragmentation, redistribution, and bioavailability across marine environments. Warming accelerates polymer degradation and enhances biological interactions, acidification alters surface chemistry and toxicity, and polar ice melt releases large reservoirs of legacy MPs into vulnerable ecosystems. Evidence further shows that MPs disrupt key climate-related processes, including primary productivity, nutrient cycling, and the biological carbon pump, thereby creating feedbacks that may weaken oceanic climate regulation. Combined exposure to MPs and climate stressors amplifies physiological stress, reduces growth and reproductive performance, and compromises resilience across multiple trophic levels. These findings highlight that MPs are not passive contaminants but active modifiers of climate-sensitive marine systems. Integrating MP dynamics into climate research, monitoring frameworks, and policy instruments is therefore essential. Addressing plastic pollution alongside climate mitigation and adaptation strategies will be critical to safeguarding marine ecosystem functioning under future global change.
Continue reading ‘Microplastics in a warming ocean with coupled climate change interactions and implications for marine ecosystem functioning’Behavioural responses of fishes to abiotic stressors: a comparative synthesis of shared physiological mechanisms and ecological consequences
Published 8 October 2026 Science ClosedTags: biological response, fish, performance, physiology, reproduction, review
Highlights
- Comparative review of behavioural responses to major abiotic stressors
- Conserved physiological mechanisms underlie diverse behavioural responses
- Cross-stressor synthesis identifies common and stressor-specific effects
- Ecological consequences extend from individuals to populations
- Research priorities for predicting fish responses to global environmental change
Abstract
Anthropogenic activities, including global warming, deforestation, urbanization, intensive agriculture, and aquaculture, are accelerating environmental change with consequences for aquatic ecosystems. As ectothermic vertebrates, fishes are sensitive to alterations in abiotic conditions, responding through behavioural changes that influence survival, reproduction, and species interactions. Although several studies have investigated the effects of abiotic stressors, comparative syntheses across stressors remain limited, constraining our understanding of how environmental drivers influence fish behaviour. In this review, we synthesize evidence on the impacts of six abiotic stressors, including temperature, hypoxia, acidification, turbidity, salinity, and ammonia, and examine the processes underlying responses. Across these stressors, behavioural alterations affect swimming performance, feeding, predator avoidance, social interactions, habitat selection, exploration, courtship, and anxiety-like behaviours. Despite differences in their primary modes of action, these stressors frequently converge on physiological disturbances involving oxidative stress, neurotransmitter regulation, sensory impairment, ion homeostasis, and energy metabolism, ultimately producing behavioural outcomes with ecological consequences. Most studies have been conducted under controlled laboratory settings, limiting ecological relevance. Furthermore, the combined effects of multiple abiotic stressors, together with long-term, multigenerational, and transgenerational responses, remain poorly understood despite their potential consequences for fish growth, reproduction, recruitment, and community structure. This review highlights the urgent need for integrative, multi-stressor, and multigenerational studies spanning diverse species, developmental stages, and ecosystems to improve predictions of fish responses under environmental change. By identifying shared and stressor-specific responses, this synthesis provides a conceptual framework for understanding how abiotic stressors affect fish through physiological pathways that ultimately converge on common behavioural outcomes with important ecological implications.
Graphical abstract
Carbon in the ocean
Published 5 October 2026 Science ClosedTags: biogeochemistry, chemistry, review
This chapter examines the role of the oceans as the largest active surface reservoir of carbon in the Earth system and the chemical and physical processes that regulate the storage and redistribution of carbon in seawater. The oceans contain roughly 38,700 Gt of carbon, about fifty times more than the atmosphere, mostly in the form of dissolved inorganic carbon distributed among carbonic acid, bicarbonate, and carbonate species, whose proportions are largely controlled by seawater pH and alkalinity. The chapter introduces the fundamental equilibria of the marine carbonate system, including gas exchange with the atmosphere governed by Henry’s law, and explains how dissolved inorganic carbon and alkalinity determine the ocean’s capacity to absorb atmospheric CO2. It also reviews the origin and composition of seawater and the geochemical processes responsible for ocean salinity. Finally, the chapter describes the major mechanisms transferring carbon from the surface ocean to deeper waters, by the solubility, biological, and carbonate pumps, and examines how the depth of the saturation state of calcium carbonate, the lysocline, and the carbonate compensation depth regulate carbonate sedimentation and provide long-term negative feedback on atmospheric CO2.
Continue reading ‘Carbon in the ocean’The future of aquatic food systems: climate change adaptation and resilience strategies – a narrative review
Published 30 September 2026 Science ClosedTags: biological response, fish, fisheries, mitigation, multiple factors, oxygen, physiology, policy, review, socio-economy, temperature
Across the world’s oceans, lakes, and rivers, climate change is reshaping fisheries and aquaculture systems on which billions of people depend for food and millions rely for their livelihoods. This narrative review summarizes peer-reviewed and selected literature published between 2008 and 2026 on climate impacts, adaptation options, and critical knowledge gaps in marine and freshwater fisheries, with a particular focus on tropical and African inland fisheries. This review shows that warming, acidification, deoxygenation, and altered hydrology are disrupting fish physiology; shifting the distribution of marine species poleward by over 70 km per decade, at rates that vary greatly by taxon, depth, and area; and destroying critical habitats. Although this rapid poleward shift is well documented in open marine environments, it contrasts sharply with landlocked or fragmented freshwater systems, where horizontal migration is physically constrained, a contrast central to the concept of climate entrapment developed in this review. In scenarios characterized by high emissions, tropical fisheries may see a reduction of up to 40% in their maximum catch potential, a statistic relevant to specific tropical Exclusive Economic Zones based on bioclimate-envelope forecasts, which should not be interpreted as a global or universal result. This figure is a model-derived projection under a bioclimate-envelope framework rather than an observed trend, and the realized outcome will depend on future emission pathways. These biophysical changes compound already serious pressures, overfishing, habitat loss, and pollution, and the burden falls heaviest on those least responsible: small-scale fishers, women, and indigenous communities. We introduce the concept of climate entrapment to describe the distinct vulnerability of freshwater fisheries: trapped by fragmented habitats and hydrological barriers, fish stocks cannot migrate to more secure waters as conditions deteriorate. While there are promising adaptation strategies, major gaps remain in understanding what works, for whom, and under what conditions. We conclude with priority recommendations for research, policy, and practice.
The effects of ocean warming and acidification on fatty acid contents of marine organisms: a global meta-analysis
Published 23 September 2026 Science ClosedTags: algae, biological response, fish, multiple factors, physiology, phytoplankton, review, temperature
Ocean warming and acidification pose significant threats to marine biodiversity and human nutrition by fundamentally altering the biochemical composition of marine organisms. A primary concern is the potential decline in omega-3 fatty acids (FAs) that are essential to human health and primarily obtained through seafood consumption. The influence of these climate stressors on FA content across marine food webs remains poorly understood. To address this critical knowledge gap, we conducted a global meta-analysis of 489 experiments across 143 publications and 132 marine species, quantifying the effects of warming and acidification on nutritionally important FAs in marine primary producers, invertebrates and fishes. Under warmer conditions, we detected reductions of up to 34% and 50% in omega-3 FA proportions and concentrations, respectively, and up to 53% in omega-3: omega-6 ratios, together with increases of up to 22% and 17% in saturated FA proportions and concentrations, respectively across taxa groups. Critically, these effects were intensified as warming increased. The most severe reductions in omega-3 FAs were observed in primary producers, suggesting that climate-driven changes at the base of the food web could impair trophic transfer of these micronutrients, limiting nutrient availability for higher trophic levels and ultimately humans. Ocean acidification, conversely, demonstrated a minor overall effect on FA levels, although this result was based on substantially fewer studies. Furthermore, we identified species from environments with broader temperature ranges, diatoms, herbivorous invertebrates and low-resilience fish to display larger reductions in omega-3 FA proportions under warming. Our meta-analysis further highlighted the need for long-term studies under ecologically realistic conditions to improve predictions of nutritional responses to climate change. These findings are essential for understanding how the nutritional value of species change under climate change, and can inform fisheries management, aquaculture and public health policy aimed at securing the future availability of these vital micronutrients.
Continue reading ‘The effects of ocean warming and acidification on fatty acid contents of marine organisms: a global meta-analysis’Coastal and marine ecosystems under climate change ecological and socio-environmental impacts
Published 15 September 2026 Science ClosedTags: corals, paleo, phanerogams, policy, review, socio-economy
Coastal and marine systems are some of the most biologically productive and economically important systems on Earth, yet they are being compromised at an accelerating pace by climate change. Ocean warming, marine heatwaves, sea-level rise, ocean acidification and deoxygenation along with increasing extreme events are interacting to change the structure, function and resilience of ecosystems among coral reefs, mangroves seagrass meadows and salt marshes. Although effort has been devoted to understanding individual ecosystem effects of climatic change, we know less about comparative mechanistic synthesis and cross-ecosystem vulnerability trajectories. This synthesis explores recent understanding of the biophysical determinants of ecosystem decline, with particular reference to thresholds, regime shifts and feedbacks that limit capacity to adapt. We explore different sensitivities among these biogenic coastal systems, and explain why coral reefs are confronted with sharp thermal and carbonate chemistry thresholds, while mangroves and tidal wetlands have threshold-based resilience contingent on sediment supply and geomorphologic setting. Beyond ecological effects, we compile social–environmental responses including fishery reduction, coastal defense loss and blue carbon release, and rising human vulnerability especially in small island and developing coastal regions. The review also examines ecosystem-based adaptation and nature-based solutions, considering their co-benefits and implementation challenges in a high-emission world. By synthesizing climate drivers, ecosystem thresholds, and social–ecological tipping points within a unified conceptual framework, this review integrates mechanisms of change and alternative stable-state transitions to improve understanding of coastal ecosystem resilience under accelerating climate change.
Continue reading ‘Coastal and marine ecosystems under climate change ecological and socio-environmental impacts’Natural environmental drivers of seagrass degradation: a global systematic review with implications for Indonesia
Published 15 September 2026 Science ClosedTags: phanerogams, review
Highlights
- Thermal stress was the most studied natural driver of seagrass decline.
- Study frequency reflects research effort, not ecological importance.
- Most multi-stressor studies assessed only two interacting drivers.
- Warming–acidification effects varied among species and exposure contexts.
- Indonesia remains underrepresented in long-term seagrass research.
Abstract
Seagrass ecosystems are exposed to natural environmental variability and climate-modulated extremes that can interact with anthropogenic pressures and accelerate ecological decline. This systematic review synthesized 60 peer-reviewed publications published between 2010 and 2025 to examine how temperature and marine heatwaves, ocean acidification and pH, salinity, drought and flooding, hydrodynamics, sea-level change, turbidity and light limitation, sediment conditions, and oxygen availability affect seagrass ecosystems. Thermal variables were the most frequently investigated category; however, publication frequency was treated as an indicator of research effort rather than a ranking of ecological importance. Experimental and field evidence showed that warming and marine heatwaves often reduce growth, photosynthetic performance, biomass, and recovery, although outcomes depend on species, exposure duration, light, nutrients, and prior stress history. Evidence for warming–acidification interactions was contrasting: acidification impaired plant performance during thermal stress in some studies, whereas enhanced inorganic carbon availability supported biomass or carbon metabolism in others. Most multi-stressor experiments evaluated only two drivers, and relatively few examined three or more simultaneous or successive stressors. The most commonly reported ecosystem consequences included habitat contraction, canopy and biomass loss, physiological impairment, altered carbon and nutrient cycling, sediment destabilization, community reorganization, and reduced resilience. Geographic evidence remained concentrated in Europe, the Mediterranean, Australia, China, and North America. Indonesia and much of Southeast Asia were comparatively underrepresented despite high seagrass diversity and documented declines associated with interacting environmental change. Future research should prioritize standardized long-term monitoring and multifactorial experiments that distinguish research frequency from ecological effect and support regionally calibrated risk assessment.
