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’Posts Tagged 'socio-economy'
Functional saturation of Earth’s habitable domains: constraints on land systems and potential in marine environments
Published 16 October 2026 Science Leave a CommentTags: algae, Antarctic, North Atlantic, phanerogams, review, socio-economy
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.
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’Characterizing decision optimization strategies for managing climate change impacts on aquatic ecosystems and public health in Asia
Published 4 September 2026 Science ClosedTags: mitigation, North Pacific, review, socio-economy
Climate change is dramatically reshaping the delicate balance of Asia’s freshwater and marine ecosystems, intensifying threats to biodiversity, water quality, and public health. This review explores the profound interconnections between climate change and aquatic environments, highlighting the escalating risks posed by rising temperatures, shifting precipitation patterns, and extreme weather events. The paper delves into the alarming surge in harmful algal blooms, shifts in species distributions, and the increasing prevalence of waterborne diseases, all of which undermine both potable water sources and food security. In addition, the review examines the compounding impact of pollution, which further exacerbates the vulnerability of aquatic ecosystems. As global temperatures rise, the resulting decrease in dissolved oxygen and proliferation of pathogens create hostile environments for aquatic life, while extreme climatic events exacerbate water contamination and scarcity in many regions. Vulnerable communities, heavily reliant on aquatic resources for survival, face a dual challenge of environmental and socioeconomic instability. As Asia’s aquatic ecosystems continue to face unprecedented stress, proactive interventions are essential to safeguard food security, water resources, and public health for future generations.
Continue reading ‘Characterizing decision optimization strategies for managing climate change impacts on aquatic ecosystems and public health in Asia’Chapter 22 – Environmental ethics and the case of ocean acidification
Published 2 September 2026 Science ClosedTags: policy, socio-economy
Ocean acidification (OA) is a paradigm case of an encroaching long-term environmental problem that is mainly caused by CO2-emissions and will have diverse and often uncertain impacts on marine organisms and ecosystems. SDG 14 (‘Life below water’) demands to halt or slow down OA. Since occurrence of OA is remote to our daily terrestrial life, it has not been in the focus of moral attention so far. This chapter emerged from the BIOACID research programme at Kiel University. It examines five sources of normativity in environmental ethics, addresses problems of uncertainty and framing, and interprets the metaphor of ‘ocean health’ with recurrence to an updated version of Aldo Leopold’s principle. The chapter argues that basic non-anthropocentric approaches, such as biocentrism, ecocentrism, and holism, face severe problems with respect to marine environments and can’t serve as solid groundings for an ocean ethics. The chapter proposes that a deep anthropocentric environmental ethics can provide an appropriate grounding for ambitious marine stewardship policies, including ocean acidification. Finally, the chapter proposes to define a critical threshold for OA which should not be passed.
22.1 Introduction
This chapter addresses ocean acidification (OA) from an environmental ethics perspective. Ocean acidification is seen as a paradigm case for post-normal science. At its core, the chapter adopts and substantiates several ethical building blocks from a discourse-pragmatic approach, as (a) common heritage of humankind, (b) strong sustainability, (c) Aldo Leopold’s principle, and (d) ecosystem services, with a special eye on cultural services. The idea to attribute inherent moral value to marine organisms and ecological systems is seen critically.
This chapter emerged from the research programme BIOACID (Biological Impacts of Ocean Acidification) being conducted at Kiel University. Within the final period of the BIOACID research programme, a work package on environmental ethics was included to address the underlying normative issues. This project resulted in a monograph: Frederike Böhm and Konrad Ott, Impacts of Ocean Acidification: An Analysis from an Environmental Ethics Perspective (Böhm & Ott, 2019).1 The following chapter presents the essential lines of reasoning of this book and adds new thoughts. It is organized as follows: Section 22.2 gives a brief overview of the scientific dimension. Section 22.3 presents a post-normal-science framing of OA. Section 22.4 deals with interrelated sources of normativity which stem from environmental ethics. Section 22.5 addresses the problem of defining a planetary boundary for OA.
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Continue reading ‘Chapter 22 – Environmental ethics and the case of ocean acidification’Chapter 21 – How can we curb ocean acidification in a time of multiple competing crises?
Published 2 September 2026 Science ClosedTags: policy, socio-economy
Since the 1972 Stockholm Conference, many global environmental agreements have been struck for climate, biodiversity, and sustainable development goals. Still, the planets environment has continued to decline, including on the ocean. One result has been ocean acidification, caused by the uptake of 30–40 per cent of all carbon dioxide from the atmosphere. On its face, this ocean CO2 uptake sounds positive. However, with a continuous increase of CO2 in the atmosphere, this also means an increase in the ocean, which alters its chemistry in ways that may disrupt oceanic biodiversity through making waters more acidic. When coupling this with other major global crisis, we see that we have only adopted global environmental agreements that protect humans from our own nature-induced change – and not ensured that we take our ethical obligation to nature itself by protecting it from human use. This chapter looks at the risk perception literature and considers how the science–policy interface can be exploited to convey the importance of ocean acidification, and whether the anthropogenic lens is what will always be necessary to ensure action to protect something from ourselves.
21.1 Introduction
Around the end of the eighteenth century, with the design of the steam engine by James Watt, the geological age of the Anthropocene started (Crutzen 2006). This has led to unprecedented changes in the natural environment, the most serious of which is climate change. We have tried to change our paths since then though. In fact, more than 50 years have now passed since the 1972 Stockholm Conference (Rockström et al. 2021) – the United Nations Conference on the Human Environment. This was when global leaders for the first time made the environment and the triple planetary crisis of climate, nature, and pollution a focus issue. At that time, in 1972, they warned – and this still holds true today – that ‘Through ignorance or indifference we can do massive and irreversible harm to the earthly environment on which our life and well-being depend’ (United Nations 1973).
Since then, state leaders have created the United Nations Environment Programme (UNEP) entered into force both a climate and biodiversity agreement (United Nations Framework Convention on Climate Change (UNFCCC) and the Convention on Biological Diversity (CBD)) with many iterations; signed the UN 17 Sustainable Development Goals (SDGs) in 2015 with corresponding targets, as part of the realization of Agenda 2030; and in 2022 and 2023, state leaders also signed the Kunming-Montreal Global Biodiversity Framework (GBF) and the Agreement under the United Nations Convention on the Law of the Sea on the conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction (BBNJ). Still, we have continued to saturate Earth’s capacity to support future generations (Intergovernmental Panel on Climate Change 2018). The planet is more polluted than earlier, there are fewer fish in the ocean, the temperature is increasing, methane levels are at their highest in 800,000 years, polar regions are melting, plastics are ubiquitous, and the ocean is more acidic than ever (Barnes & Kaiser 2009; Hönisch et al. 2012; Worm & Branch 2012; MacLeod et al. 2021; Intergovernmental Panel on Climate Change 2022).
In fact, six of nine planetary boundaries that are needed for humans to be able to develop and thrive for generations to come have been breached already (Richardson et al. 2023). Then, in 2025, the ocean acidification boundary was crossed (Findlay et al. 2025). This is a boundary that is also specifically mentioned in the SDGs, with target 3 of SDG14 Life below water specifying the need to ‘Minimize and address the impacts of ocean acidification, including through enhanced scientific cooperation at all levels’. It was in fact the only by-product of climate change and greenhouse gas emission that was singled out to be included under this goal (United Nations Department of Economic and Social Affairs 2022). Still, there is a lack of concrete knowledge of how breaching this boundary will impact either non-human populations or the corresponding human population that depends on these (Buckley et al. 2017).
In light of this, the current chapter considers ocean acidification within the planetary boundaries framework and assesses the lack of responses that led to, and may further exacerbate, the breaching of this boundary. We argue that this in part can be explained by the human-centric perspective of global environmental governance, where effective governance is linked to risk perception within a human context. In terms of ocean acidification, we argue that humans still have a low personal risk perception, coupled with a lack of knowledge (or interest) about it, which directly hinders its agenda setting and implementation of effective governance. We conclude with considering whether the increased saliency of biodiversity challenges, as brought to the surface with the signing of the GBF in 2022, can bring more attention to the role of stressors such as ocean acidification on sustainability and the consequences the breach of this planetary boundary can have on not only humans but also non-human populations.
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Continue reading ‘Chapter 21 – How can we curb ocean acidification in a time of multiple competing crises?’Chapter 20 – Introduction to the ocean acidification boundary
Published 2 September 2026 Science ClosedTags: policy, socio-economy
The oceans mirror many of the environmental problems described in the planetary boundaries framework and reported widely in the media, such as overfishing and deep-sea mining (biosphere integrity), plastic islands or microplastics (novel entities), shipping (atmospheric aerosol loading), or dead zones lacking oxygen (biogeochemical flows). Less present in the media is the problem of ocean acidification addressed by the planetary boundary. Like the atmosphere, the oceans are sinks for CO2 produced by the burning of fossil fuels.
CO2 absorption changes the chemistry of the oceans, lowering their pH. The resulting acidification also leads to fewer of the calcium carbonate shells produced by numerous creatures sinking carbon to the ocean floor before they dissolve back into the water. The boundary’s control variable relates to this by describing the ‘carbonate ion concentration in surface seawater’ and, more specifically, the ‘average global surface ocean saturation state with respect to aragonite’ (Richardson et al. 2023). Aragonite is one of the most abundant forms of calcium carbonate. The boundary is at more than 80 per cent of the pre-industrial aragonite concentration, defined as 3.44. In 2023, the level was 81 per cent, meaning the ocean boundary was, at that time, still one of the few that had not been crossed. Thus, Pelejero et al. (2010: 332) describe ocean acidification as the ‘“evil twin” of global warming’ – it is a moot question, though, as to which is of the two is more evil. This also means that reducing greenhouse gas emissions will reduce the pressure on ocean acidification.
Acidification of the oceans and declining concentrations of calcium carbonate are becoming a problem for marine life. Many creatures depend on the presence of these calcium compounds in the water to build their shells or skeletons. Lower pH not only erodes the existing structures of these creatures, but they also find less calcium to rebuild them. These include plankton, corals, crustaceans, and molluscs, which are vital to marine biodiversity, marine food chains, and, ultimately, human food security (Rockström et al. 2009). So, the control variable of the ocean boundary is the global average saturation state of calcium carbonate in surface water. The framework sets the preindustrial Holocene base value at 3.44 and the boundary value at 2.75. Since 2009, the actual values have fluctuated between 2.8 and 2.9 (Richardson et al. 2023). In 2025, the ocean acidification boundary was first recognized as having been crossed (Findlay et al. 2025).
Both chapters on ocean acidification take the problem structure of the ocean acidification boundary as the starting point of their ethical reflections. Konrad Ott describes it as post-normal, that is, a situation when problem-solving has to cope with uncertain facts, disputed values, high-stakes, and urgent decisions (Funtowicz & Ravetz 1993). Ott explores the issue of ocean acidification from an environmental ethics perspective. He discusses different ways of justifying why ocean acidification is an ethical problem and what follows from this. In doing so, he aims to show how well the most common environmental ethical approaches can address the issue. They mostly differ in their scope of the moral community, that is, to whom we have direct moral obligations: to humans only, or also to individual animals, species, or ecosystems? Depending on the answer one gives, the reasons for protecting oceans will change. Ultimately, Ott intends to specify the normative building blocks of deep anthropocentrism as his preferred approach to the issue.
Rachel Haug Fossbakk, too, addresses the issue of decision-making relating to uncertainty and risk perception. She argues that the human response to ocean acidification is inadequate. This is despite the fact that there is already enough knowledge to act. Her hypothesis is that action requires an adequate perception of risk, which many people do not have when it comes to ocean acidification. She concludes by asking who has a responsibility to act, and on what ethical basis. Rachel Haug Fossbakk then advocates an ecocentric perspective by which she understands a situation ‘where humans are part of nature and need to live sustainably as part of it on the same term as other species’.
Continue reading ‘Chapter 20 – Introduction to the ocean acidification boundary’SDG14 assessment of progress against sustaining life below water: a case study from Torres Strait
Published 31 August 2026 Science ClosedTags: crustaceans, fisheries, socio-economy, South Pacific
The United Nations Sustainable Development Goals (SDGs) represent a global call for action to sustain humans, the planet and prosperity. SDG14 (Sustaining Life below water) focuses on oceans, their conservation and sustainable use. Since committing to the 2030 Agenda for Sustainable Development, there have been several calls to take stock of progress and encourage decisive action to build a sustainable future. Here we evaluate progress against achieving each of the SDG14 goals using as an example Australia’s Torres Strait tropical rock lobster (TRL) Panulirus ornatus fishery because of the very strong dependence of Indigenous fishers and local communities on this resource. Our evaluation draws on 40 years of research, highlighting how changes have improved alignment or are on-track to meet the 2030 targets. We assessed that all targets were achieved to 2025 due to the small fishery ecological footprint, sound sustainable fishery and ecosystem management, science-based management plans, economic benefits derived though sustainable management, growth in research capacity as well as access for small-scale artisanal fishers to marine resources and markets. Our case-study therefore complements best practices examples in achieving SDG14 for a regionally important fishery. To meet 2030 aspirational goals, progress was assessed as on-track to address impacts of ocean acidification, enhanced transfer of marine technology and need to work with global partners to encourage market access for sustainable fisheries that are vital in supporting Indigenous and regional livelihoods. Overall, we calculated a conservative score of 3.5 reflecting very high achievement (~ 88%) towards future aspirational SDG targets.
Continue reading ‘SDG14 assessment of progress against sustaining life below water: a case study from Torres Strait’Pressures on coastal biodiversity in South Africa: a cross-realm review
Published 13 August 2026 Science ClosedTags: review, socio-economy
South Africa’s coastal zone comprises diverse ecosystems and species, and provides important benefits to people. It is also under significant pressure from numerous activities that take place on land, in estuaries, and in the sea, and that are rarely considered together. Here, we review the pressures on coastal biodiversity in South Africa, taking a cross-realm perspective. The pressures are reviewed under 10 themes: biological resource use; energy production and mining; pollution; coastal development; transportation and service corridors; natural systems modifications (sand-flow disruptions, estuarine hydrological regime change, livestock grazing and browsing); human intrusions and disturbance; aquaculture, agriculture and plantation forestry; invasive and other problematic species and diseases; and climate change, severe weather and ocean acidification. Many of these are intense or pervasive cross-realm pressures, often with cumulative, synergistic impacts that are collectively causing habitat fragmentation and loss, declines in species richness and abundance, altered animal behaviour, reduced ecosystem resilience, and declines in capacity to provide ecosystem services. However, the inter-connected nature of these pressures also means that integrated coastal management provides opportunities to address multiple pressures and impacts cross-realm. Sustainable development that is mindful of long-term climate projections is imperative in the coastal zone to safeguard this national asset into the future.
Continue reading ‘Pressures on coastal biodiversity in South Africa: a cross-realm review’Multi-stressor responses in marine bivalves: integrating climate change, pollutants, and microbiome shifts for aquaculture resilience
Published 27 July 2026 Science ClosedTags: biological response, fisheries, mollusks, review, socio-economy
Marine bivalves play pivotal ecological and economic roles but are increasingly challenged by multiple environmental stressors. Although there is extensive research on the effects of individual stressors, a comprehensive review is needed to synthesize current evidence and clarify how multiple interacting stressors collectively affect the physiology and resilience of marine bivalves. This review integrates evidence from 2010 to 2025, encompassing 178 peer-reviewed studies emphasizing the combined and interactive impacts of climate change drivers (warming, hypoxia, salinity, and ocean acidification), pollutants (heavy metals, persistent organic pollutants, endocrine-disrupting chemicals, antibiotics, nanoparticles, microplastics), and microbiome shifts on future aquaculture resilience. Literature was systematically retrieved from Web of Science, Scopus, PubMed, and Google Scholar in accordance with PRISMA 2020 guidelines. Bibliometric mapping (VOSviewer 1.6.20) revealed a rapid growth in research after 2018, characterized by studies on Mytilus, Crassostrea, and Ruditapes. A systematic evaluation of recent evidence was conducted, combining data from physiological, molecular, and microbial studies, with particular attention to implications for aquaculture. The analysis reveals that stressors rarely act alone. Instead, their cumulative and interactive effects cause oxidative stress, disrupted energy allocation, destabilized host-microbe relationships, lowered tolerance thresholds, and other eco-physiological consequences. These results highlight the vulnerability of bivalve populations to rapid coastal urbanization, declining water quality, and sediment contamination. The review concludes that resilience can be enhanced through selective breeding for stress-tolerant genotypes, integrated monitoring of pollutants and microbial indicators, and multi-omics approaches to guide adaptive aquaculture management.
Continue reading ‘Multi-stressor responses in marine bivalves: integrating climate change, pollutants, and microbiome shifts for aquaculture resilience’The Third World Ocean Assessment
Published 20 July 2026 Newsletters and reports , Science ClosedTags: policy, resource, socio-economy
Share the knowledge on the ocean
The ocean is the foundation of life on Earth. But its health is at grave risk as ecosystems and habitats approach or surpass critical tipping points. In the search for solutions, ocean science is indispensable. The third World Ocean Assessment offers the most comprehensive evaluation to date, providing Governments, institutions and the public with the evidence needed to shape coordinated, effective action.
Five years ago, the previous Assessment found persistent degradation of marine ecosystems. This third Assessment documents a deepening crisis, as climate change, pollution, overfishing and biodiversity loss put ocean systems under severe strain. Its findings demand urgent action, through stronger multilateral cooperation, greater ambition and decisions grounded in the best available science.
This Assessment comes midway through the United Nations Decade of Ocean Science for Sustainable Development and the United Nations Decade on Ecosystem Restoration. It takes stock of what we have learned, how far we have come and what more is needed to secure a healthy, resilient ocean for current and future generations.
The entry into force of 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 in January 2026 marks a historic milestone for ocean stewardship and multilateral cooperation. Now we must translate that momentum, and the latest science, into decisive action for a healthy and resilient ocean.
May this Assessment strengthen our resolve to protect the ocean and, in doing so, help safeguard our climate, our food systems, our prosperity and our future.
António Guterres, Secretary-General of the United Nations
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Continue reading ‘The Third World Ocean Assessment’Reassessing the climate mitigation benefits and environmental risks of coastal seaweed farming
Published 6 July 2026 Science ClosedTags: algae, mitigation, socio-economy
Seaweed farming is increasingly promoted as a nature-based solution for marine carbon dioxide removal (mCDR), offering the dual promise of climate mitigation and ecosystem enhancement. However, here we highlight a fundamental paradox: while macroalgae cultivation can significantly boost carbon sequestration and support biodiversity, it also introduces site-specific ecological risks—most notably eutrophication, hypoxia, and acidification—particularly in semi-enclosed coastal systems with limited water exchange. We synthesize current understanding of both the positive and negative impacts of large-scale macroalgae farming, examining pathways of carbon uptake, storage, and export alongside biogeochemical and food web disruptions. Critically, we identify the overlooked roles of hydrodynamic conditions and benthic-pelagic coupling in mediating ecological outcomes. To ensure that macroalgae aquaculture contributes effectively to climate goals while safeguarding coastal ecosystem resilience, we call for the development of a targeted and comprehensive evaluation framework capable of accurately assessing its impacts on adjacent waters. Such a framework should incorporate site-specific water-exchange characteristics and biogeochemical vulnerability, thereby enabling more informed and adaptive management strategies—including hydrodynamically guided site zoning—to support sustainable, long-term ecosystem benefits.
Continue reading ‘Reassessing the climate mitigation benefits and environmental risks of coastal seaweed farming’Ocean acidification effects on larval development and survival in commercially important shellfish
Published 10 June 2026 Science ClosedTags: biological response, fisheries, growth, mitigation, molecular biology, mollusks, mortality, physiology, reproduction, socio-economy
This paper studies the consequences of ocean acidification (OA) on the growth and survival of the larvae of commercially significant shellfish species such as oysters, mussels, and scallops. The authors of the study are particularly concerned with the negative processes of OA with respect to the growth of larvae, shell development, and behavior, which result in decreased survival rates, particularly the consequences of the reduced availability of calcium carbonate on the weakening of shells and larvae, which are preyed upon. The paper also studies the interference with the behavior of larvae, particularly with respect to the adequate detection of sites to settle, which is harmful to recruitment success. Additionally, the study looks at the OA-induced metabolic stress, where the larvae are expected to expend higher energy to maintain homeostasis at the expense of growth and immunity. By focusing on this issue, the paper outlines the OA’s impacts on the shellfish populations and industries. The paper also looks at the available soft measures, such as the implementation of buffering solutions to limit the acidification in hatcheries, the use of genetic selection to incorporate acidification-resistant traits, and coastal management measures to limit local sources of acidification. The paper also suggests some potential new ways to increase the resilience of shellfish stock, including more flexible adaptive aquaculture practices. With commercial shellfish interests emerging, this paper fills some of the more critical gaps in the existing literature and offers insight into the impact of OA on the sustainability of the shellfish industry. It also provides OA mitigation strategies to preserve shellfish stocks in a changing climate.
Continue reading ‘Ocean acidification effects on larval development and survival in commercially important shellfish’Climate change impact on the socioeconomic conditions and well-being of the South Asian small-scale fishermen: a review
Published 5 June 2026 Science ClosedTags: policy, review, socio-economy
Climate change is a major threat to the small-scale fishing communities, particularly in South Asia, a region characterized by widespread coastlines, extreme population density, and high dependence on marine resources for food, income, and employment. This review synthesizes findings from peer-reviewed articles published between 2000 and 2025 to analyse the climate change impact on socioeconomic conditions and well-being of the small-scale fishermen. The review identifies a range of climatic stressors, such as rising sea surface temperatures, ocean acidification, sea level rise, and extreme weather events, that are severely disrupting marine ecosystems and fish availability. These ecological shifts directly affect the livelihoods, income stability, and food security of fishing communities, escalating existing vulnerabilities like poverty, indebtedness, and limited occupational mobility. The study categorizes the impacts into physical, economic, and social dimensions, highlighting issues such as declining catch volumes, increased operational costs, infrastructure destruction, and disruptions in food supply and nutrition. It also examines local and regional adaptation responses, ranging from ecosystem-based solutions, such as mangrove restoration and cage aquaculture, to institutional and behavioural shifts, including migration, livelihood diversification, and early warning systems. While some adaptations enhance resilience, others pose sustainability challenges. This review highlights the pressing need for targeted policy interventions that support sustainable adaptation, enhance institutional frameworks, and prioritize vulnerable fishing communities in climate resilience planning.
Continue reading ‘Climate change impact on the socioeconomic conditions and well-being of the South Asian small-scale fishermen: a review’Demonstration of an automated bioreactor for controlled acid dosing to enhance marine algae productivity
Published 26 May 2026 Science ClosedTags: algae, biological response, fisheries, laboratory, socio-economy
Microalgae are an important feedstock in aquaculture with significant economic potential in generating a diversity of bioproducts. To facilitate expansion of microalgal cultivation, a continuous automated bioreactor that uses waste acid to increase carbon bioavailability in seawater for enhanced biomass production was designed and tested with Tetraselmis suecica UTEX2286. Carbon bioavailability was inferred from culture pH and bioreactor headspace CO2 concentration measurements and controlled via acidification and seawater dilution. Operating over a period of several days, the culture exhibited greater biomass productivity at a pH setpoint of 7-7.5. Outside of this range, algal activity slowed, accompanied by greater CO2 released to the headspace and lower pH during incubation. Increasing the carbon introduced to the bioreactor by increasing the dilution factor did not significantly increase the algal productivity. Importantly, acidification led to statistically significant gains in biomass productivity. Preliminary cost analysis showed while seawater is inexpensive, the acid cost drives the overall cost of the designed bioreactor system. Thus, the designed bioreactor and control scheme supports algal cultivation but requires low-cost acid to be economical, which may be achieved by strategically integrating microalgae cultivation with other coastal industries.
Continue reading ‘Demonstration of an automated bioreactor for controlled acid dosing to enhance marine algae productivity’Ocean acidification and blue food security: mapping two overlapping regime complexes
Published 27 March 2026 Science ClosedTags: fisheries, policy, socio-economy
The dual challenges of blue food security and ocean acidification (OA) have become increasingly urgent concerns for global sustainability. Blue foods, which provide key nutrients, are threatened by OA, posing risks to biodiversity, fisheries, and the livelihoods of communities that depend on them. The pressure of OA highlights the urgency of addressing blue food security through the lens of OA. Understanding the governance landscape that shapes responses is crucial, yet existing literature has largely considered the OA and blue food security regimes separately. This paper analyzes whether and how the international governance of OA and blue food security intersect by mapping their regime complexes. The central research question investigates how international regimes interact in governing this nexus. The analysis finds that the two regime complexes overlap in many areas, including fisheries/marine resources and climate change. Although many actors and instruments mention both topics, significant governance fragmentation persists. Case studies on the Food and Agriculture Organization (FAO) and the United Nations Framework Convention on Climate Change (UNFCCC) reveal that neither institution provides a comprehensive framework for governing the nexus of OA and blue food security resilience. The FAO lacks an explicit mandate for OA governance. If mentioned, OA is relegated to a list of stressors. The UNFCCC addresses OA only indirectly through CO2 mitigation efforts, and its instruments, while referencing food production, generally do not link it explicitly to OA. This results in fragmented authority, unclear responsibility, and limited integration across policy domains. Furthermore, a discrepancy exists where blue food security is recognized as a topic of legal and political urgency, while OA often only gains scientific attention. We conclude that further joint integration of OA and blue food security in legal and policy frameworks is necessary to enhance coherence and coordination across these regimes.
Continue reading ‘Ocean acidification and blue food security: mapping two overlapping regime complexes’The economic impact of climate change on coral reef in the Main Hawaiian Islands
Published 18 March 2026 Science ClosedTags: biological response, communitymodeling, corals, modeling, multiple factors, North Pacific, socio-economy, temperature
Coral reefs are highly diverse and productive ecosystems that provide a wide range of ecosystem services, including recreation, coastal protection, and marine biodiversity. Climate change impacts, including ocean warming and acidification, pose a significant threat to coral reefs and the ecosystem services they provide. The variability of these impacts underlines the need to develop more spatially explicit tools in coastal ecosystem management that integrate and assess potential ecological and socio-economic outcomes. To address this, a spatially explicit predictive ecological model is applied to project changes in coral reef cover, using downscaled data from Shared Socioeconomic Pathway (SSP) climate scenarios. Based on these projections, welfare impacts of changes in recreational value are estimated across different populations and landscapes. Cumulative welfare losses for Hawaiʻi residents range from $1.5 to $3.3 billion in 2024$ by 2100. Counterintuitively, cumulative welfare losses are higher under optimistic emissions scenarios, where coral reef degradation is less severe than higher emission scenarios, because more people will experience smaller ecological losses. The approach incorporates site-specific characteristics, income distribution, and projected regional population growth to connect ecological change with welfare outcomes. EJScreen is used to assess variation in welfare impacts, identifying disadvantaged communities based on demographic and environmental indicators such as poverty, minority status, and exposure to environmental risks. These findings can inform policy and resource allocation by supporting ecosystem management strategies that account for both ecological dynamics and community-level socio-economic conditions.
Continue reading ‘The economic impact of climate change on coral reef in the Main Hawaiian Islands’A holistic approach to evaluating climate vulnerability of French Polynesia pearl oyster farming: bridging communities and scientific knowledge
Published 13 March 2026 Science ClosedTags: fisheries, socio-economy, South Pacific
Highlights
- A holistic assessment of climate vulnerability of black pearl aquaculture social-ecological system.
- Co-definition of adaptation strategies by scientific/institutional actors and local communities of French Polynesia.
- A list of scientifically robust and locally relevant vulnerability criteria potentially transferable to other Pacific pearl-producing countries.
- Interviewees consistently identify climate change as a factor that amplifies existing weaknesses in the pearl farming sector.
- COVID-19 exposed the sector’s dependence on global markets.
Abstract
While there is wide consensus about the reliance of climate projections at global scale, there is still uncertainty about changes at finer scale and even less on the effects of such fluctuations for local economies and societies. The vulnerability of social-ecological systems (SES) to climate change is a framework that takes into account the strong link between environment and local communities that depend on ecosystem services to ensure their livelihoods. This study explores the vulnerability of pearl farming SES to climate change, combining scientific insights with local knowledge from French Polynesian communities. A preliminary list of eighty-two criteria of exposure, sensitivity and adaptive capacity, identified through a targeted scoping review, was used to develop the interview guide that informed fifty-six face-to-face interviews and workshops conducted in 2020 and 2025. Using a combination of ranking questions and open-ended responses, the results highlight differences in the perceived exposure between scientific/institutional actors and local communities, which is reflected in the degree of sensitivity of the SES to climate drivers. Expectedly, the priorities given to adaptation measures were also different. The thematic analysis of the responses, however, shows that the two parties are aware of their own limitations in understanding the effects of climate change and recognise the need to fill mutual gaps through a collaborative production of knowledge. By integrating complementary forms of knowledge, this approach may help overcome the limitations of vulnerability assessments based exclusively on scientific expertise, and support the development of climate policies that are scientifically sound and socially accepted.
Continue reading ‘A holistic approach to evaluating climate vulnerability of French Polynesia pearl oyster farming: bridging communities and scientific knowledge’Pathways to adaptation for shellfish aquaculture on the U.S. West Coast
Published 2 March 2026 Science ClosedTags: fisheries, mitigation, North Pacific, socio-economy
Understanding how shellfish growers adapt to environmental and socioeconomic stressors is critical for food security, especially with growing impacts from climate change. However, we know relatively little about the supporting factors that lead shellfish growers who experience stressors to make adaptive choices. Through interviews conducted with US West Coast (California and Oregon) shellfish farm owners and managers (growers), we document environmental and socioeconomic stressors that growers experience and investigate whether they can adapt, react, or cope (ARC response) to these stressors. We further identify growers’ strategies for adaptation and link these strategies to theoretical adaptive capacity domains (ie, assets, flexibility, social organization, learning, agency, and governance) using qualitative comparative analysis (QCA). We found regulatory stressors were the most impactful to growers overall. These stressors caused financial burdens and time delays to operations for growers in both states. Ocean acidification and/or hypoxia (OAH) was the most frequently reported environmental stressor. Ocean acidification and/or hypoxia impacts include increased mortality and shellfish die-off events. Out of 125 responses to stressors, growers were able to adapt in just over half of stressor responses (54.4%). Agency, flexibility, learning, and social organization supported adaptation most frequently, while governance was employed the least. Growers responded with cope responses (35.2%) more frequently than react responses (10.4%). Growers combined adaptive capacity domains in various ways to adapt. For example, the adaptive capacity domain of agency was frequently employed, but almost always in combination with other adaptive capacity domains (eg, assets, governance, flexibility, and learning). This study demonstrates that US West Coast shellfish growers combine adaptive capacity domains in creative ways to form adaptive pathways and illuminates pathways to better support adaptive capacity in shellfish aquaculture.
Continue reading ‘Pathways to adaptation for shellfish aquaculture on the U.S. West Coast’
