Stopping the flow of waste and pollution into the ocean is essential. Preventing extraction by keeping products and materials in use at their highest value is vital. Doing all of this alongside practices which actively restore degraded ecosystems and regenerate nature offers real hope for the ocean and all that it supports. But what does that look like in practice?
By Emma Elobeid and Tansy Robertson-Fall
The ocean is a big place – 139.5 million square miles, to be precise. It would be easy to feel overwhelmed at the scale of the regeneration challenge. We already know what regenerative systems can look like on land. Whether woodland, cropland, grassland, or rainforest, practices with regenerative outcomes – like agroforestry, conservation agriculture, and agroecology – each help to rebuild the health and harmony of discrete and damaged ecosystems by improving soil health and stability, encouraging biodiversity, and improving air and water quality, providing benefits for nature and people alike.
At sea, underwater ecosystems are as, if not more, interconnected as land-based ecosystems, increasing the complexity for those looking to restore them.
But the ocean itself can show us the way.
In the marine world examples of regeneration abound.
Crabs that regrow lost limbs.
Broken starfish made whole again.
Sea cucumbers with special healing cells.
Unicellular algae capable of life after death.
By eliminating waste and pollution (reducing threats to nature) and circulating products and materials and keeping them in use (leaving room for nature), we can help ocean species retain these regeneration abilities.
But an enabling approach alone is not enough.
It is time to redesign our economic system so that it actively contributes to ocean regeneration, both in localised spaces and at scale.
From extractive sea use to regenerative sea use
As we look to ease pressure on land ecosystems, attention is increasingly on ocean spaces to produce more food and materials, and provide us with the things we need.
In 2019, the EAT-Lancet Commission report called for a shift away from high-impact animal proteins towards lower impact seafood products, both protein and plant based. This transition to aquatic food sources offers significant opportunities for economic growth and job creation alongside a reduction in emissions.
But, while there are quantifiable benefits in direct comparison to the polluting and wasteful terrestrial food system, a straight switch from land to sea production should not be seen as a quick fix. Rather, we must actively pursue complexity. On land, a circular economycircular economyA systems solution framework that tackles global challenges like climate change, biodiversity loss, waste, and pollution. It is based on three principles, driven by design: eliminate waste and pollution, circulate products and materials (at their highest value), and regenerate nature. for food means prioritising lower impact ingredients, diverse ingredients which promote biodiversity and build resilience, and upcycled ingredients which make use of byproducts. Each approach contributes to a regenerative food system that supports biodiversity and ecosystem health.
It is vital that these same principles are applied at sea.
Steps towards regenerative fishing
With fish stocks already depleted, an increased focus on seafood could signal further damage to ecosystems if their health isn’t considered. It is estimated that some 4 million fishing vessels of all sizes now ply the oceans. As pressure from fishing grows, the likelihood of damage to the structure and function of the ocean ecosystem increases.
Yet the ocean is overfished not only from the perspective of ecosystem stability; today’s worldwide fishing fleet is large enough to catch up to two-and-a-half times the amount of fish we actually need. The scale of ocean overexploitation from fishing has led to vast volumes of non-target species being unnecessarily extracted from the ocean; such bycatch is thought to account for around 40% of global marine catches.
Fish and other sea life must be allowed to replenish at a rate that secures them for the future – both as species and resources. Beyond that, we need to find a way to farm the sea using methods which not only avoid damaging biodiversity but actively secure ecosystem health.
Fishing using practices that avoid disturbing or disrupting the wider ecosystem is a good place to start. Traditional – more targeted – fishing methods such as purse-seine nets which have no contact with the seabed, and pole and line, which picks out single species, are preferable to methods such as bottom trawling that decimate seabed habitats and gillnets that result in high levels of bycatch.
Some regions are beginning to move this way. In Florida, for example, regulations are in place to permit the harvesting of scallops off the coast from Mexico Beach down to the southernmost border of Pasco County only if done by hand or using a landing or dip net. The seasons for scalloping are also limited to allow the population to regenerate.
Diversifying the species targeted by fishing – by diversifying the seafood people eat – is another important action. In the UK, 80% of the seafood consumed is made up of just five species: cod, haddock, salmon, tuna, and prawns. Designing diets to include many other types of seafood can reduce demand for those under pressure and enable populations of species to recover.
Protection through policy
For fisheries to diversify and adopt practices that have regenerative outcomes, the economics need to work. That means making changes to subsidies, taxes, and duties, internationally, to prevent overfishing and damaging fishing practices, and instead reward practices that support ecosystems and seafood stocks. In June 2022, the World Trade Organization (WTO) adopted the Agreement on Fisheries Subsidies, which prohibits fisheries subsidies that enable harmful practices such as overfishing. At the same time, a voluntary funding mechanism was established, helping WTO members to access support to integrate “fisheries sustainability elements into their fisheries subsidies policies and practices”, as well as strengthening management systems and improving transparency. Policies that empower individual countries to set vital boundaries for the protection of the species in surrounding waters mark an important step forwards. Changes to policy and regulation in this area also need to work for the people and businesses involved in fishing. A primary challenge associated with rectifying overfishing is illegal, unreported and unregulated (IUU) fishing, with the chief driver of this identified as money and avoidance of duties and taxes. But what if it was more lucrative to fish legally and regeneratively? Global policy has a central role to play in creating the right conditions in which practices that support the regeneration of ocean ecosystems are not only viable but valuable.
Habitats also need to be maintained and, where needed, improved to enable fish and sea life to reproduce and thrive. On land, cover crops can provide habitat for many different species above ground, and improve the activity of microbes in the soil. Similarly, in the ocean, plantlife can be maintained or restored to promote biodiversity and natural resources like fish.
In Ghana, climate change is predicted to reduce potential fish catches by 25% by 2050, threatening a vital food source. In response, Ghana plans to plant mangroves which will simultaneously revive fish habitats – providing nutrients and shelter – while storing carbon and protecting shorelines. Through the Mangrove Blue Carbon Pilot Program, USD 13.5 million will be spent to plant and maintainmaintainKeep a product in its existing state of quality, functionally and/or cosmetically, to guard against failure or decline. It is a practice that retains the highest value of a product by extending its use period. 3,000 hectares of mangrove trees over the next 20 years.
For climate-vulnerable coastal communities and for the world at large, protecting complex and multipurpose ecosystems such as mangroves is an essential part of local and global climate mitigation and adaptation. But, in the enthusiasm to fund and forest, we also need to be mindful of our methods. Just as some conservationists and scientists are warning that poorly planned mass ‘net zero’ tree planting schemes risk releasing more carbon dioxide than they sequester, recent research indicates that the benefits of mangroves are felt far more powerfully when re-established in places where forests once existed (reforestation) than when planted from scratch in areas where they never existed (afforestation).
On land, at sea, and across its intersecting coastal habitats, the regeneration of ecosystems needs to be carefully considered in terms of proportion and place.
Aquaculture has potential – but needs to be carried out regeneratively
Alongside fishing, the rapid expansion of aquaculture operations – breeding, raising, and harvesting fish, shellfish, and aquatic plants – has seen the farming industry at sea grow its worth to over USD 200 billion. However, many such enterprises are still operating within the current linear system as underwater monocultures which mirror the negative externalities of above water agricultural monocultures.
Though they may be thousands of miles apart, the rapid expansion of aquaculture industries has been powered by intensively grown and highly emitting land-based crops. Just as cows are sometimes fed fishmeal, fish are fattened from the field: soy, rapeseed, and corn form the main commercial feeds used in aquaculture. In the coming years, billions of bushels of US-grown soy are expected to drive the progress of global industrial aquaculture.
Failure to recognise the relationship between intensive industrial farming systems on land and intensive farming systems at sea is increasingly seen as a business risk, too. In 2019, FAIRR (Farm Animal Investment Risk and Return) urged its investor members to move aquaculture production to more diverse feed sources which neither deplete wild fish stocks nor contribute to the negative environmental impacts of conventional agriculture, suggesting instead fish processing byproducts, algal oil, or seaweed from polyculture production. On land, some studies have shown that, when added as a supplement to feed, a particular type of tropical red seaweed has the potential to significantly cut animal methane emissions.
Getting underneath the seaweed story
Apart from its potential applications in animal feed, seaweed is already being widely farmed and harvested to fuel and fulfil many circular economy innovation solutions on land.
Switching to seaweed-based compostable biomaterials, for example, as a replacement to single-use packaging – from takeaway boxes to flexible films – helps to eliminate problematic plastic packaging that impacts above and underwater ecosystems alike. Similarly, using ocean-sourced fibres instead of plastic-based textiles – whether a cardigan knitted from kelp or seaweed sneakers – helps to alleviate the indirect burdens placed on the ocean by the linear fashion system.
Seaweed as a material alternative to plastic: Sway
As a renewable material, seaweed has the potential to have a hugely positive impact – but it needs to be regeneratively produced.
Often referred to in shorthand, ‘seaweed’ is actually a collective noun for a macroalgae several thousand species strong.
On the Isle of Wight, overnight swell from the Solent brings morning drifts of chunky channelled wrack and common carrageen laced with wisps of bright green gutweed. In Northern Ireland, where the storms from the Irish sea are even more ferocious, sugar kelp is washed from rock pools and onto beaches. Wherever you are in the world, seaweed will not be the same. Whether under the sea or under the soil, maintaining this diversity is essential.
One of the world’s fastest proliferating plants, seaweed farming has been widely practised for centuries in countries throughout Asia, as well as along the coastlines of South America, Australia, and Africa. Recently, global seaweed production has grown at pace, increasing by almost 75% in the past decade. By 2027, the global commercial seaweed market is projected to be worth USD 95 billion. Most recently, Amazon announced a joint project with European consortium North Sea Farmers to create a 10 hectare offshore seaweed farm. In the UK alone, seaweed-related businesses have more than doubled since 2016.
Seaweed is often quoted as being able to absorb up to twenty times more CO2 per acre than land forests. As a power statistic, it is easy to see why many are calling seaweed a ‘miracle crop’ climate solution.
For a start, seaweed is sensitive to temperature changes. In some regions – particularly across Asia which has an established cultural tradition of seaweed production – warming waters are already beginning to threaten the viability of aquaculture by reducing yields and increasing susceptibility to pests and diseases. Even on the Isle of Wight, a UK government commissioned report into potential areas for aquaculture production deemed the surrounding Solent unsuitable due to high water temperature.
Seaweed is a vital habitat for many marine species: as nurseries for juveniles, shelter for small gastropods and crustaceans, resting places for larger fish, thoroughfare and snacking ground for cetaceans. While it is important that we avoid actions that degrade these habitats, habitat destruction can also come from overabundance.
If seaweed grows too much, too fast, it can trigger algal blooms which prevent oxygen and sunlight from reaching the species below. If it is grown in the wrong place, it can disrupt surrounding native species. Balance is key.
Circular startup Sway uses regenerative ocean farming to source its seaweed packaging solutions
Despite seaweed’s many positive climate effects, therefore, it is important that we do not just plant wherever there is commercial will and way. Without proper consideration, large-scale seaweed farming could lead to ecological risks such as the unintentional introduction of invasive species which change the structure or nutrient profile of the ecosystem.
Amid the rush on seaweed, it is vital that enthusiasm for this virtuous and versatile underwater crop is harnessed and scaled in ways that are sensitive to the ocean’s fluctuating and structurally diverse ecosystems, maintaining the genetic diversity of wild populations and the organisms they support, and not inadvertently replicating the harms of farming on land. Just as creating a nature-positive agricultural system on land requires a diverse mix of species appropriate for local contexts, it is important that farming the sea is approached from these same principles of circular design.
Some startups are already embedding these principles of regeneration into their ocean farming operations; Sway, for example, have spoken of the need to ensure that seaweed solutions are guided by local ecologies and in accordance with scientific research in order to be truly regenerative.
Regenerative aquaculture in practice: securing climate benefits while avoiding overexploitation
While the ocean holds significant economic and environmental opportunities, we need to ensure that we are not using marine spaces to solve land-based challenges at the expense of the marine ecosystems. This means shifting from exploitative and extractive methods of ocean-based farming to models that proactively strengthen marine biodiversity and enhance the ocean’s capacity to absorb, convert, and store (collectively: sequester) carbon.
Beyond an arbitrarily designated pool of water in which we artificially feed, fatten, and farm fish and other organisms, aquaculture offers significant regenerative potential.
Farming the ocean regeneratively: GreenWave
Business in the ocean: a careful equilibrium
Beneath the hopeful headlines, however, lies a more nuanced picture.
One way of making sure that aquaculture functions as a solution is by situating it in areas where there is a specific problem or ecological imbalance caused by the linear economylinear economyAn economy in which finite resources are extracted to make products that are used - generally not to their full potential - and then thrown away ('take-make-waste').. This is the approach of GreenWave: a regenerative ocean farming system which turns barren patches of ocean and degraded coastal ecosystems into thriving multitrophic areas that allow cultivation to take place while enabling biodiversity to prosper. GreenWave operates on a polyculture model in which a variety of seaweed and shellfish species are grown on and around a series of vertical underwater structures.
Other new entrants to regenerative ocean farming seek to repurpose the physical structures – or “dead assets” – of a legacy linear economy. This was central to the original vision of Blue Symbiosis Founder Joshua Jay Castle, who won the 2021 XPrize for his proposal to use the towerlike underwater structures of decommissioned oil rigs to support a diverse regenerative aquaculture system. As with GreenWave, potential pilot sites are prioritised according to their proximity to ecological imbalance, such as sargassum belts – masses of matted seaweed adrift in the ocean caused by nutrient runoff, warming, and pollution. Some of this excess seaweed will be extracted and processed into bioplastics, biofuel, textiles, or building materials, while species specially cultivated to rebalance will be grown and farmed for high-protein food extracts.
On the surface, such situational startups make perfect sense. But, because of the nature of ocean complexity, the process isn’t simple. Joshua says: “We don’t have as much interaction with the ocean as we do on land. We might think we have – you know, we go for a swim once a week, but it’s nothing compared to what exists beneath the surface. It’s just so much more complicated to understand and calculate it. Even the experts don’t really understand it. So it’s very difficult to actually know how to regenerate it properly.”
Water flows. The movement of marine ecology means that understanding the interconnecting (and often highly individualistic) factors in any potential site for ocean extraction is vital. Because of the way in which nutrients and carbon are cycled in the ocean’s biological pump, introducing aquaculture into areas without full consideration of flows and facets could cause more harm than good. Understanding this underwater complexity helps to mitigate against the risk of well-intentioned interventions triggering negative consequences.
This can be achieved by embedding the principles of circular design thinking from the outset: exercises such as zooming in and out within an ecosystem context can help uncover root causes and reveal underlying factors.
Adopting a locally sensitive approach is essential. For example, while the environmental–economic rationale and scientific research for using seaweed to reduce methane from cattle burps is compelling, the species studied grows only in tropical areas and contains high concentrations of ozone-damaging bromoform. Overplanting, overharvesting, and shipping it around the world could risk doing more harm than good.
In recognition of this, researchers from the Institute for Global Food Security (IGFS) and the School of Biological Sciences at Queen’s University, Belfast, have been trialling a more local approach by adding native seaweed supplements to the diets of UK and Irish cattle. If successful, this could pave the way for a more distributed system whereby ecosystem-appropriate seaweed is grown – helping to restore vital oxygen balances at a local level as well as drawdown carbon from the surrounding atmosphere.
From sea urchins to sea otters: restoring ecosystem imbalance
Species-level overabundance as a symptom of ecosystem imbalance can be seen in proliferating sea urchin populations. While this is primarily a problem in areas that have been overfished on an industrial scale, urchins are also taking excessive hold in areas that have seen ecological destruction from climate change-induced extreme weather, further illustrating both the direct and indirect impacts of a linear economy.
In a healthy marine environment, sea urchins play a critical role in maintaining the balance of vital ocean ecosystems. Global kelp forests – which are currently declining at an annual rate of 1.8% – are a rich food source for these spiky species. Sea urchins are ferocious and fantastic feeders, helping break off tough kelp fronds into bite size pieces for other marine detritivores. By scavenging on unwelcome algae they also help to prevent eutrophication from nutrient imbalance and reduce the impact of invasive species.
Image credit: Theo Vickers Marine Wildlife Photography
But a lack of predation – not only from overfishing but species such as the Californian sea otter whose populations have been decimated by human activity – combined with warming water has had the opposite effect. Urchins are now destroying, rather than supporting, underwater ecosystems. These stripped areas – often called ‘urchin barrens’ – of the seafloor exist all over the world, leaving empty spaces where there were once underwater forests and reducing the ocean’s carbon sequestration capabilities and ability to support significant levels of biodiversity. Similar symptoms of once symbiotic relationships pushed out of balance by the cumulative pressures of our linear economy can be found throughout the ocean, from anemone and clownfish to crabs and sponges.
Urchinomics – an aquaculture company that aims to profitably restore marine ecosystems by paying divers to harvest overgrazing urchins and farming them in land-based systems to sell for local restaurants – addresses this symptom while providing economic benefit to fishing communities and helping to diversify food systems. This example takes a highly targeted approach to ocean regeneration and shows us how, sometimes, solutions at sea mean strategically taking away in order to restore ecosystem balance.
This is an example of the need for both upstream and downstream solutions to global challenges at sea. In the above scenario, the upstream solution is tackling the big picture of global climate change, with circular economy solutions playing a key role – thereby reducing overall climate-related threats to keystone ocean species like the urchin-eating sea otter. Meanwhile, downstream solutions, such as making use of the economic value of a species made overabundant through imbalance, is an important step towards that overall goal.
Whether we approach it through the lens of urchins or otters, the application of whole system thinking is essential for anyone looking to explore, invest, or start up in the business of ocean regeneration. Viewing the economic opportunity presented by ocean spaces through a circular economy mindset can help us address the root causes of its many complex problems and surface its multifaceted solutions.
Key considerations for regeneration at sea
For businesses and policymakers looking to embolden regeneration of the ocean, three broad considerations can inform actions:
Consider the context
Spend time mapping underwater systems, as you would on land systems, to ensure that any interventions are appropriate to the surrounding ecosystems.
Ask questions like:
What flora and fauna naturally exist there?
How do they interact?
What does regeneration look like for those species?
What impact might any intervention have on the flow of currents and species in these waters?
Be aware of balance
At sea, balance is everything. It is essential that we both maintain this balance – in sea life populations, oxygen, habitats, temperature, current – where it exists, and restore it where it has been disrupted.
Ask questions like:
Is the ecosystem I’m interacting with in balance?
What might my activities be disrupting?
How can my activities secure the balance of this ecosystem?
Respect diversity
The ocean holds a wealth of resources that can help alleviate many land-based pressures of the linear economy. But we must not replicate its negative impacts by pursuing underwater monocultures. Rather, robust regenerative ocean farming systems safeguard and strengthen ocean ecosystems by supporting a diverse mix of species.
Ask questions like:
Are my practices supporting biodiversity?
Does my product design or product portfolio embody diversity?
How can my activities strengthen or maintain diversity in this ecosystem?
The story of our one global ocean changes day by day. Knowledge gaps widen and narrow in parallel. Science evolves, technology erupts, and research rolls forward – and not all developments will be positive. But it is not yet too late to change that story for the better; from the easternmost tip of the Isle of Wight to the edge of Belfast Lough and every speck of sea in between.
It’s time to heed the call of the ocean and regenerate the world’s life support system.
Thank you to all the contributors and experts who generously shared their insights in the development of this two-part article series.
