Full article is attached below.
Introduction
An immense, subterranean aquatic realm encompassing 361,000,000 square kilometres and 71% of the planet Earth… (more accurately Ocean), is currently home to trillions of species, billions of us depend upon, without even realising and knowing it. Via the prism of the ocean-blue-marine economy, and other interrelated concepts it is receiving unprecedented prominence among politicians and policy makers, celebrities and CEOS, academics, NGOS, communities, innovators, financiers and individuals as evidenced at the 3rd United Nations Oceans Conference (UNOC3) and increasingly at COP events on climate change. Projected to reach over $3 trillion by 2030, as the next emergent investment frontier and potential saviour of our human species; it can no longer be ignored! Yet equally, it can no longer be taken for granted! A colossal barren desert as far as the senses can perceive; where formerly flourished entire universities of marine life. Suffocation. Lifelessness… Behold an all too real future that potentially threatens all this. Whilst there are many ascending risks that have previously received attention, from climate change and natural disasters, to population growth, to sound and more general forms of marine pollution, to extractive controversial activities such as fossil fuel extraction and seabed mining to illegal fisheries, invasive species and coastal development; this post’s core focus is that of the seldom examined, rising phenomena of Oxygen Dead Zones, that increasingly threaten our oceans, our ecosystems, communities and any true path to a climate resilient, sustainable, prosperous, inclusive and meaningful, blue economy future.
Over 700 “Oxygen Dead Zones” exist globally, threatening over 245,000 km² of marine habitats, fisheries, tourism, water purification, carbon and oxygen generating cycles and billions of lives and livelihoods (around 95,000 square miles, the size of the UK) globally and growing rapidly. Whilst plastic pollution has been calculated by sources such as the International Union for the Conservation of Nature in 2024 as over 460 million tonnes produced annually, and 19-23 million tonnes leaking into oceans yearly; no direct equivalent has yet to be calculated accurately for the true threat provided by oxygen depleted zones. The world’s largest or Baltic Sea, extends over 70,000 km(2). The Arabian Sea and Gulf of Oman has been estimated at 164,982 km2 at its last survey in 2018. The Gulf of Mexico/”Gulf of America was recorded by the US government National Oceanic and Atmospheric Administration or NOAA as -17, 365.9 km2. Recently, numerous stakeholders expressed professional concerns about this historically invisible and more marginalised threat. In 2025 the seasonal Gulf of Mexico/America dead zone arose from high algae blooms related to agricultural and industrial excess nutrient runoff, and other types of pollution. calculated the dead zone costs U.S. seafood and tourism industries a minimum of $82,000,000 a year or over 40% of national fisheries production. More and more fisherfolk, aquaculture and tourism facilities are vulnerable, initiating ever higher business and personal costs from algal blooms, red tides, hypoxia and anoxia (Greenpeace 2008).
In July 2025 NOAA estimated the Gulf of America dead zone reached over 4,402 square miles or 2,800,000 acres of habitat loss to fish and other marine species. The extent of the problem is illustrated in Figure 1.1 below. The Figure also illuminated variations over time. Whilst, 30% smaller than July 2024 and a historic peak of 6700 miles the overall historic trend is rapidly increasing across many rivers, oceans and waterways, still with significant financial, environmental, social health, carbon offset, water purification, cruise, dive, recreational tourism and other loss from algae blooms and infertile wastes. It has become so pervasive as a concern that since 1997, the US government via NOAA established the Mississippi River/Gulf of Mexico (now Gulf of America) Hypoxia Task Force. However, it remains an ongoing problem both in the region and globally, based on upstream and ocean related ongoing threats, to tourism and seafood species growth and health from excessive fertiliser and other pollution/resource pressures via the Mississippi-Atchafalaya River with ever increasing impact cost consequences as detailed in this article. This Task Force has tried but failed, each year, to reduce the 5 year average dead zone miles to less than 1,900 miles by 2035, not even a complete abolishment. The 5 year current average is 4,755 square miles or 12,890.37 km2
This paper focuses on exploring on Letting Our Oceans Breathe, What Does It Truly Mean for the Ocean/Blue Economy and marine ecosystems. Thus, what are the potential risks, impact cost consequences and to what extent should we be aware and concerned, given the globally significant research and wholly existing inadequate response to solutions so far… Global oxygen dead zones, have surfaced since around 2000 as an ascending concern, receiving only minor attention including recently. However, the causes, interest and solutions have not been commensurate, with those of many other global socioenvironmental and economic issues. It has received only minimal press, civic society, NGO, policymaker, funding, industry, community and individual attention, relying on a comparative fringe set of sources, monitoring attentions, and solution orientated entities to pursue effective solutions. It receives few dedicated task forces, financial, legal or policy incentives and guidelines. Politics jeopardises existing progress in the USA and other areas. My aim, = is to highlight the historic and current status quo, to raise more consciousness and consider possible solutions to project a future for our sustainable, blue economy.
Several solutions are increasingly being focused on, with varying levels of resources required and implications. Whilst some have focused on traditional policies, financial incentives, enforcement and monitoring linked to pollution reduction; others are focusing specifically on oxygenation solutions -natural, artificial and natural upwelling, geoengineering and others, to directly concentrate on ocean oxygen zones more specifically. This would aim to amplify oxygen, nutrients and associated blue carbon/carbon offset, capture and sequestration processes. As indicated later, several emerging startups and innovative research are seeking to explore if this is a viable, credible pathway forward for us to pursue, or if there are too many unknown risks. Whilst carbon markets and credits are emerging as one funding pathway, many of these other more experimental solutions, compete with other, more conventional initiatives. Yet internationally, questions remain about technical and financial feasibility, sustainability, viability, effectiveness, monitoring, reporting and verification by external credible entities, consistently. Environmental implications for local ecosystems and resource constraints remain ongoing voiced concerns. Questions of national and international law including relating to pollution or dumping of substances , sinking of biomass or conducting trial processes or upscaling to larger effects, after trials, still remain unknown for many policymakers. The Gulf of Mexico/America, Black Sea and Middle East, as oxygen depleted subterranean aquatic depths, have all received interest from various startups such as Alarivean, Carboniferous, Molear and Rewind.
The increasingly favoured, scientific perspective, is in the value of restoring biomass, whilst enhancing oxygen, upwelling and other processes remains more uncertain, as ongoing research and experiments are undertaken. Marine carbon dioxide removal, biodiversity and carbon markets have faced a number of recent financial, marketing reputational, technical, capacity and other implementation challenges, as demonstrated by Running Tide, and other existing or previously operating companies or startups. Oxygen dead zones with diminished marine species biomass, biodiversity, algae blooms and diminished or damaged reefs are becoming increasingly probable, from many sources generating pollution and threatening ecosystems, water quality, public health, sanitation, tourism, fisheries and aquaculture livelihoods, trade, food security, livelihoods, biotechnology, research, blue carbon, oxygen generation and other natural processes. More and more species are getting physically and psychologically harassed. In 2020 the Union of Concerned Scientists published a report indicating agricultural nitrogen runoff has caused up to $2.4 billion in damages to US fisheries and marine habitat every year since 1980. This requires solutions with greater urgency, despite current implementation issues. For example, after 28 years of continuous funding to NOAA, the United States 2026 Federal Budget allocates 0 funding to the Gulf of America/Mexico dead zones, in contrast to the $192,800,000 for states to reduce nutrient pollution. Early warning monitoring networks also received funding cuts. Heatwaves and other climate related effects are projected to amplify the issue. The US is one of the few nations globally that have actively focused on long term research, monitoring, funding and institutional capacity specifically for oxygen dead zones. Disruptions to the Environmental Protection Agency Hypoxia Task Force and other related initiatives, not only complicates local progress in resolving the dead zones but complicates global resolution of the issues.
Artificial Upwelling, Nanobubbles, Oxygenation, and Geoengineering or Other Innovative, Emerging Solutions
A number of emerging startups are exploring potential solutions to oxygen dead zones. For example, artificial upwelling, downwelling and associated geoengineering has received increasing interest in artificially recirculating water currents, via pumps, pipes or equivalent mechanisms to facilitate oxygen towards depleted areas to promote phytoplankton, seagrass and fisheries biomass growth (Aquavetic Labs 2025; CDMARE 2025; Jürchott, Oschlies, and Koeve 2023). It offers intended objectives of addressing red tides, HABS and blue carbon sequestration rate growth. These artificial processes also respond to the changing depth and intensity of the stratification of the oceanic water column and resultant effects on marine species growth/heath. Improving ocean alkalinity may also aid preservation, survival and resilience of coral reefs to increasing ocean acidification and marine pollution. The effectiveness of such solutions, depends considerably on the availability of essential micronutrients. However, there are no global and few local standard guidelines, methods and best practise case studies to emulate, aside from financial investor markets and legal uncertainty at present. This leads us, to inquire of policymakers and others, as to which enabling solutions and conditions to potentially follow, replicate and upscale? What are the true risks, costs and benefits of deploying artificial upwelling/downwelling and other innovative solutions? Currently, international regulations are conditional upon MARPOL, the 1982 United Nations Convention on Law of the Sea and upcoming BBNJ Treaty from January 2026, which allows for marine scientific research and other solutions within nation’s Exclusive Economic Zones up to 200 nautical miles from shore, provided efforts are taken to minimise/avoid marine pollution. Others include the Antarctic Treaty, Convention on Biological Diversity (“CBD”), the Convention on the Prevention of Marine Pollution by Dumping of Waste and Other Matter (“London Convention).However, this does not allow for commercialisation and other unvalidated pilot experiments to be upscaled at present, unless legal risks are examined and legislation revised.
One simulated example that has adapted this technology towards vertical oceans is Canada’s Marinova startup, with seawater circulating tower tanks that claim to individually sequester up to 20 tons of CO₂ per year, while generating edible protein, bioplastic raw material for fuel, and clean water vapor, along with oxygen. During 2023-2024, 3 other European focused ocean/marine reoxygenation research pilot projects were also announced. quavetic Labs are also exploring artificial upwelling technology solutions. What could be the potential of Artificial Ocean Reoxygenation? Any geoengineering experiment faces legal, economic, political and environmental uncertainty, especially when seeking to validate, replicate and transfer the results on a far more significant or industrial scale, where it could address any artificially induced Oxygen Minimum Zone worldwide. Such processes highly recommended to follow the Precautionary Principle, conduct long term scientific advice, professional economic, environmental and social impact assessments, with adequate stakeholder consultation. Questions remain as to if this would be considered commercialisable -i.e. can a market be derived to sustainably support it, or should it be regarded as a more essential, public good or service? The Global Oxygen Observation Network under the Intergovernmental UNESCO and Scripps Institution of Oceanography have already indicated projected global declines in atmospheric and oceanic oxygen levels (An average of 2% since the 1960’s). The area of low oxygen water in the open ocean has increased by about 4,500,000 km2 and volume of water entirely devoid of oxygen has more than quadrupled over the last 50 years. Over 700 coastal sites reported new or worsening low-oxygen conditions, up from only 45 in the 1960s. Relatively few global dead zone sites have been exposed to oxygenation restoring activities. The challenge remains ensuring it is cost-effective and practical in upscaling and ensuring permanent rather than temporary effects as benefits.
Nanobubble technology is another rece innovative form of artificial reoxygenation into dead zones Harmful Algal Blooms, Red Tides, eutrophication and similar oxygen depleted zone phenomena. It artificially inserts minuscule oxygen bubbles that stay suspended up to months at a time, delivering oxygen deep into sediments and water to revive ecosystems, control nutrient releases and curb pollution simultaneously for marine environments. Ultra-fine bubbles (UFBs) are tiny (<100 nm diameter), negatively charged, highly pressurized bubbles of gas. It remains experimental but seeks to provide a more cost-effective mechanism for dispersing pollutants, restricting HABS and restoring the nutrient balance, as oxygen is more slowly dispersed as a filter for microbial control. This can subsequently improve water quality and divert nutrients towards sustaining phytoplankton and other life forms rather than algae, eutrophication or dead zones. It can oxidise and reduce toxic pollutants. One potentially promising nanobubble startup concept is Alarivean, which ambitiously aims to deploy vessels with variant solutions to address sectors such as more fresh water desalination initiatives/Swimmable Rivers, coral restoration for fisheries, ecosystems and tourism; to support blue carbon and biodiversity offsets/ecosystem restoration and address harmful algae blooms or HABS. For coral reefs it focuses on heat reduction as an alternative mechanism to reduce pressures. The solution claims it would deploy powerful oxidation systems aboard its novel-class SeaBreather as aquatic remediation vessels to fix problems like coastal pollution, nutrient loading, algae blooms, harmful emissions, dead zones, and more. These would potentially inject up to 4,000 water gallons per minute with life-giving oxygen and adaptive AOP (advanced oxidation process) systems focusing on a non-ceramic, full-flow-through gas generator that meets NOAA-determined ocean application. Whilst the emphasis of this report focuses on ocean/marine zones, oxygenation technology is also applicable to lakes, rivers, canals and other waterways or locations.
A second nanobubble solution based startup is Molear which focuses on patented mobile generators and applying bubbles to accelerate various natural processes. It claims to deliver >85% oxygen transfer efficiency in just 2 feet of water. It can help disperse fats, oils and grease from congealing, reduce chemical contamination and facilitate aerobic processes, with similar benefits for pollution reduction and water quality. Nanobubble technology is also being adapted to areas in agriculture, aquaculture, environmental remediation and pollution control for lakes, ponds and waterways, mining, offshore oil and gas along with water and wastewater treatment processes. This solution aims to be more thorough in aerating dissolved oxygen, being more cost effective and avoid chemicals, then traditional pollution treatment measures. Initial experiments worked for ponds in Florida and golf courses in Palm Springs California. Other nanobubble linked startups undertaking pilot projects include Ireland’s NanobOx (which uses low-voltage electric fields to create pure nanobubbles, cutting energy use and fouling issues in aquaculture) and South Korea’s Honour Farm (nanobubble technology for water treatment, agriculture, and fisheries). The Ireland-UK AquaB company targets electrostriction-based nanobubble technology to offshore oil and gas sectors. Chile’s Kran and the US’s Pure Nanotech similarly applies cavitation with flow through processes and pipes; and electric field based, nanobubble technology on low power and no membranes.
Oxygen dead zone impact costs to marine ecosystems and fisheries across the Gulf of Mexico/America were projected at between US $552,000,000 and $2.4 billion annually in damage, as calculated in 2024 by the Union of Concerned Scientists. US agriculture and industry have continuously failed to invest in ecologically sustainable, technologically advanced systems, despite receiving subsidies. This report supports major revisions to incentivise major changes. The USA’s Environmental Protection Agency developed the Gulf Hypoxia Program to support the work of nutrient-reduction programs. The Bipartisan Infrastructure Law committed $60,000,000 to support state-driven strategies to reduce nutrient runoff within the Mississippi River Basin. This funding will be spread across 12 states over the next 5 years. This programme was subsequently denied funding under the current US administration’s Federal budget for 2026. This can be complemented by adequate drainage, protecting flood plans, enforcement and monitoring with smart technology, smart monitoring sensors, drones, cameras, satellites, LIDAR, radar, physical inspections and increasingly used as AI, aiming to pre-empt, respond and adapt to oxygen dead zones being formed and connected incidents. Also, it is no longer adequate to merely ignore or dismiss oxygen dead zones as simply a local or even a regional problem but increasingly a transboundary and international problem, that may require mutual cooperation and engagement with partners, structures, processes, budgets and resources. Examples include the Benguela Current Commission for Angola, Namibia and South Africa, PROCAIRIBE for the Caribbean and HELCOM -or Baltic Marine Environment Protection Commission. Since discovery in 2024, growing scientific interest has focused on the role of oxygenation via dark oxygen" produced by metallic nodules in the deep sea. This offers possible implications for potential deep-sea mining startups in pressurising politically for actions to pause seabed mineral exploration and exploitation until the role of nodules in supporting oxygen zones and processes is more clearly understood.
These and other methods would benefit from drones, manned and autonomous vessels for ongoing deployment of solutions, research and monitoring. Another solution is to explore Microbial Enhancement or using technology to boost beneficial microbes that consume nutrients using large scale electrodes, accelerating microbial sulphide oxidation, diminishing ammonium and phosphate. Examples include the use of sediment microbial fuel cells and oxygen micro-nanobubbles (OMNBs). Microbial fuel cells are more commonly restricted to various scientific laboratory experiments, whereas startups such as Hydrosome Labs and Ultrafine H20 have focused on machine and other engineering solutions relying upon nanobubbles. However, this remains experimental and as above solutions, focuses on impact cost consequence reduction rather than pre-emptive mitigation. Consensus has yet to be fully ascertained for these, artificial upwelling/downwelling and other proposed engineering solutions. Progress on solutions globally to reduce global climate change emissions, restoring ecosystems and others remains more developed but slow. Stakeholders are increasingly focusing on the value of exploring monitoring and technology solutions but such measures have yet to be recognised and supported in both mainstream political and popular consciousness. Nor is the extent and urgency of this recurring crisis, as traditionally understood and acted upon as a priority. However, more and more stakeholders are increasingly advised to consider what oxygen dead zones might mean for them. This extends to potentially rethinking how us, the species we depend upon, the climate, environment and ecosystem-ocean services will alter as a potential consequence as species adapt to fluctuating "oxicapes" (oxygen landscapes). It includes supporting investment in monitoring and measuring oxygen variations , addressing ocean acidification and any other threats to coral reefs, mangroves, seagrass and marine organisms
Under President Bill Clinton the United States allocated $5 billion including $322,000,000 for clean-up activities in the Gulf of Mexico up to 2000 (Joyce 2020). It also strengthened legislation e.g. the Clean Water + Clean Air Acts and the Harmful Algal Bloom and Hypoxia Research Control Act of 1998, followed by the 2008 Gulf Hypoxia Action Plan. Alternatively, governments such as the USA mostly focused on a centralised coordinating mechanism, regular cruise and scientific monitoring program, along with proactive enforcement and measures to contain upstream pollution and runoff via the Gulf of Mexico/Gulf of America Hypoxia Task Force (United States Environmental Protection Agency 2017). This included annual briefings and reports to US Congress and President for increased accountability and action under the Harmful Algal Bloom and Hypoxia Research and Control Amendments Act 2014. The Task Force identified for other nations and similarly affected stakeholders global best practises e.g. : the importance of:planning and targeting at a watershed scale; identifying the critical pollutants, their sources, and means of transport; using appropriate models to plan and evaluate implementation. Recommendations extend to using appropriate monitoring designs to evaluate conservation outcomes; understanding farmers’ attitudes toward conservation practices and working with them through appropriate messengers to offer financial and technical assistance. They include support to prevent a resurgence of the problem including sustaining engagement with the agricultural, industrial and public community following adoption of conservation systems and other solutions.
Further time would also be advised to understand the need for artificial downwelling, or oxygen-rich surface water into the depths of lakes, estuaries, and coastal ocean waters, to reduce potential incidents of hypoxia. In 2020 a Carnegie Institution for Science experiment led by David Koweek at the Searsville Reservoir in Woodside, California tested various models for oxygen downwelling (pumping down oxygen to dead zones). It identified downwelling would be 3 to 100 times more efficient than bubbling from the bottom and 10,000 to 1000,00 times more efficient than spraying fountain water across the surface. Initial results concluded downwelling could increase oxygen saturation in the immediate area surrounding the pumps by between 10 and 30% enough to alleviate hypoxic stress for many marine organism. Yet initially, cost remained a concern as operating downwelling pumps year-round in the Chesapeake could cost between $4 and $47,000,000; In the Gulf of Mexico/America the equivalent could cost between $26 and $263,000,000. MOxygenation solutions and startups such as Alarivean and Molear offer potential options for developing more thermal resilient coral reefs, through oxygen saturation according to recent research (Parry et al. 2025). Oxygen along with temperature can influence coral reef health, as another potential market.
Recommendations include
1: Create, finance and improve a coordinating centralised Task Force locally, across regions and globally for improved resource and information sharing, communication, cooperation, understanding and enforcement. Recognition of ocean deoxygenation as one of multiple climate-induced stressors.
2: Develop, support and extend a local, regional and global Oxygen Dead Zone Monitoring and Surveillance Network, the United Nations General Assembly and other multilateral organisations to highlight, identify and proactively act upon unnatural ocean dead zones, areas of anoxia and hypoxia.
3: Identify and quantify initial ocean oxygen potential hotspots, causes and issues.
4: More research into the risks, impact costs and solutions of oxygen minimal and dead zones. Prioritise reduction in causes i.e. pollution, climate change, ocean acidification, alien and invasive species, population growth, coastal development and IUU fisheries pressures.
5: Conduct more stakeholder outreach, education and engagement including events, media, social media, education, workshops, webinars and activities.
6: Support Training, Capacity Building and Awareness related to oceanographic, climatic conditions, dead zones and responses including clear guidelines and best practise examples.
7: Develop effective finance, governance, policies and monitoring mechanisms, and incentives towards addressing causes, impact costs and risks, via innovative solutions, research and modelling.
8: Explore the feasibility of various solutions and prioritise based on available/projected resources including emerging solutions such as geoengineering, artificial oxygenation and nanobubble technology.
9: Identify, support and fund various innovative solutions and approaches, where resources permit. Link to marine spatial planning, ocean-blue economy, ecosystem restoration, blue carbon and ocean accounting developments
10: Enhance capacity and willingness to pre-empt dead zone outbreaks and recurrences, along with speeding up and preparing efficient responses, scenario planning and experiments as solutions.
In conclusion, this research was about highlighting the mostly silent and overlooked threat of ocean oxygen minimal or dead zones. It is about the implications of not letting our oceans breathe versus letting our oceans breathe, for our ecosystems, our communities, our trade, our blue economies and our lives. Our species suffer as living organisms struggle to breathe, leading to slower growth, weaker immune systems, and reduced reproduction. Each species -individual and school, rapidly runs out of oxygen, nutrients and spaces -squeezed into ever smaller areas, becoming even more vulnerable to human overfishing, fossil fuel, sound pollution and other threats as a result. Harmful Agal Blooms perpetuate ongoing zones barren of life, devoid of profit, destitute of hope and wonder. Shifts in species distribution and abundance, and changes in nutrient cycles disrupt ecosystems, accelerating collapse of deep-sea fish populations locally and thousands of kilometres away. Allowing HABS, oxygen minimal and dead zones, eviscerates our ocean’s capacity to filter and process marine pollution, from suppressing the very bivalves and other marine species that gives us the chance. It deprives more and more areas of the oceans, from an ever necessary biodiversity of species need to keep the oceans fecund and prospering -including potentially many of the species that may be needed not only to retain our trades and economies, but our survival… Most of all, it is severing us from our historic relationship with the oceans. The more and more dead zones our current and future generations see. The less inspired, motivated and passionate we feel, and greater reluctance, less pressure and urgency we feel as the need to save them and understand them. The less drive we feel to question and act upon many, many threats from fossil fuel and gas extraction, to destructive bottom trawling, gill netting, drift netting, explosives and other forms of legal and illegal fishing or to reduce our efforts at marine pollution, alien and invasive species or acting against climate change… Seabed mining is the latest form of uncertainty to potentially assess the implications, especially as more and more species are being only recently discovered in the abyssal plains, seamounts, hydrothermal vents and seabed. Planet Tracker claim up to $500 billion of marine ecosystem values and economic activity may be potentially affected by seabed mining extraction. Yet a true impact cost assessment as not yet adequately monitored and quantified this direct and indirect consequences of oxygen minimal and dead zones for the blue economy. Emerging solutions may aid us such as education, awareness, policy and financial incentives, tackling behavioural, socioeconomic and ecosystem restoration mechanisms, using technology, monitoring and more experimental, controversial mechanisms such as artificial upwelling/downwelling, geoengineering and nanobubble technology. We inherited an Ocean capable of supporting us -But can we retain it?