Seaweed farming is gaining attention as a potential solution to climate change and an alternative to traditional agriculture. Seaweeds capture carbon, absorb nutrients, and provide habitats for marine animals. However, the industry must be well-studied and regulated, and it’s unclear whether that’s always happening. Seaweed is sensitive to changes in ocean temperature and could be affected by climate change. Disease is also a concern, and seaweed farming could cause new diseases to sprout or spread. Additionally, the industry could have negative impacts on ocean chemistry and the food chain if seaweed is grown in massive quantities. Overall, most biologists and industry specialists agree that seaweed farming can present a far lower ecological risk than most other industrial or agricultural activities, but the ecological and social costs of commercialized seaweed farming at an industrial scale could be too high. Instead, small, artisanal-scale seaweed farming that supports local communities and industries while considering Indigenous rights could be a good solution.
The Benefits and Drawbacks of Seaweed Farming
Seaweed farming is becoming increasingly popular globally, with production of the underwater plant rising more than sixfold over the past 30 years. Although it has a long history in Asia, it is now also thriving in emerging markets in the Americas, Europe, and Africa. However, many are wondering whether this expansion is a good thing, given the negative environmental impacts of monoculture farming on land.
Cascadia Seaweed, a kelp farming company based in Vancouver Island, British Columbia, is focused on creating animal feed and soil additives from their seaweed, as well as producing snack products such as protein puffs and tortilla chips. The company, which claims to be the largest cultivator of seaweed in Canada, is set to expand its production from 50 wet tonnes to 200 wet tonnes this spring, as farms small and large continue to pop up all over the world. According to Phyconomy.net, Alaska, Maine, France, and Norway have all more than doubled their seaweed production since 2018, with each region now producing hundreds of tonnes per year.
While many see this expansion as a positive development, some are wary of the potential environmental consequences of the seaweed farming boom. Monoculture farming on land has led to a range of environmental problems, and there are concerns that similar issues could arise in the ocean. Vincent Doumeizel, a senior adviser on oceans to a United Nations program working toward corporate sustainability, believes that a “seaweed revolution” is necessary to feed the growing global population. Doumeizel and the Safe Seaweed Coalition, an umbrella research and industry group founded to promote safe expansion of the industry, argue that humanity could and should be harvesting 15 times more seaweed by 2050.
As the seaweed farming industry continues to grow, it will be important to balance the benefits of producing a sustainable source of food and other products with the potential environmental drawbacks. By learning from the mistakes of monoculture farming on land, it may be possible to ensure that seaweed farming remains a positive force for good.
Seaweed Farming: The Pros and Cons
Seaweed is rich in protein and nutrients and has the potential to provide an additional 10% of the world’s food supply while using just 0.03% of the ocean’s surface area, according to the Safe Seaweed Coalition. A “seaweed manifesto” edited by Vincent Doumeizel, a senior adviser on oceans to a United Nations program, argues that seaweed could be the saviour of many environmental and social problems. Seaweed farming is environmentally friendly, requiring no fresh water, pesticides, or fertilizers, and can overlap with other ocean uses such as offshore wind farms.
Seaweed farming also creates a habitat for sea life, absorbs runoff nutrients, and soaks up CO₂. It is believed that seaweed farms have the potential to counteract ocean acidification and contribute to long-term carbon sequestration, but the evidence is still scanty.
Many large environmental organizations support the idea of seaweed farming expansion, including the World Wildlife Fund, Oceans 2050, and the Nature Conservancy. The Intergovernmental Panel on Climate Change’s special report on the oceans also highlighted that coastal ecosystems like mangroves could reduce the risks and impacts of climate change.
However, some people are skeptical of the seaweed farming boom, given the negative environmental impacts of past rapid expansions in aquaculture. Fish farms have spread diseases, and shrimp aquaculture has led to the destruction of mangroves to make room for farms. It is vital to find a balance between the benefits of seaweed farming and the potential environmental drawbacks.
Seaweed farming has the potential to be a sustainable source of food and other products, but it is crucial to ensure that it does not become another example of monoculture farming, which has led to environmental problems on land. By learning from past mistakes, it may be possible to ensure that seaweed farming remains a positive force for good.
Seaweed Farming: The Pros and Cons
Seaweed has been a significant part of the human diet for millions of years, with some researchers suggesting that it may have played a role in the evolution of the hominin brain. Today, seaweed farming is a rapidly expanding industry worldwide, with the potential to provide a sustainable source of food and other products.
However, some are skeptical about the seaweed farming boom, concerned about potential hazards like imported diseases or unwanted ecosystem changes, or that big businesses may grab leases to large swaths of the ocean. While some regulations exist regarding which seaweed species can be grown where, in many places, it’s a free-for-all, which makes some observers nervous.
Safe Seaweed Coalition member Elizabeth Cottier-Cook notes that more work is needed to balance the risks of large-scale seaweed cultivation against the benefits. Meanwhile, some advocates are concerned that the optimism surrounding seaweed farming’s potential may overlook potential environmental hazards.
Seaweed beds are an essential part of coastal ecosystems worldwide, and over 10,000 types of green, brown, and red algae have now been catalogued. Despite the name “weed,” seaweed is algae, not plants, growing from a holdfast on rocks in shallow waters and floating up toward the surface. Some grow quickly, while others are perennial or annual.
While seaweed farming is environmentally friendly and requires no fresh water, pesticides, or fertilizers, and can overlap with other ocean uses like offshore wind farms, it is crucial to ensure that it does not become another example of monoculture farming, which has led to environmental problems on land.
Seaweed has the potential to provide an additional 10% of the world’s food supply while using just 0.03% of the ocean’s surface area, according to the Safe Seaweed Coalition. Seaweed farming creates a habitat for sea life, absorbs runoff nutrients, and soaks up CO₂. While evidence quantifying how seaweed farms help with sequestering carbon long term to tackle climate change is still thin on the ground, many large environmental organizations support the idea of seaweed farming expansion.
It is crucial to find a balance between the benefits of seaweed farming and the potential environmental drawbacks. By learning from past mistakes and finding appropriate regulatory frameworks, it may be possible to ensure that seaweed farming remains a positive force for good.
The Benefits of Seaweed Farming
Seaweeds are more than just slimy underwater plants. They are a versatile and nutrient-rich ingredient with many potential uses. They can be consumed raw or cooked, used as animal feed, added to fertilizers, and even used to reduce methane in cow burps. Seaweed extracts are commonly used as stabilizers in various consumer products, such as toothpaste and ice cream.
Seaweed Production
In 1969, only half of the world’s seaweed was grown on purpose, and most came from wild harvests. However, seaweed cultivation has since boomed, with 34.7 million tonnes produced in 2019, making up nearly 30% of all seafood produced by aquaculture worldwide. The majority of this production takes place in Asia, with Indonesia’s seaweed farms accounting for 40% of the country’s fisheries output and employing around a million people. In contrast, the Americas contribute just 1.4% to global seaweed production, and Europe only 0.8%.
The Potential for Seaweed Farming
Despite the booming industry, the potential for seaweed farming remains vast. A recent study estimated that seaweed could add 10% to the world’s food supply using just 0.03% of the ocean’s surface. Substituting 10% of human food with seaweed by 2050 could also spare 110 million hectares of land for other purposes, equivalent to the size of Bolivia. Seaweed farming has a lower carbon footprint than land-based agriculture, requires no freshwater or pesticides, and can overlap with other ocean uses, such as offshore wind farms.
The Risks of Seaweed Farming
Despite the benefits, there are concerns that seaweed farming could bring hazards such as imported diseases or unwanted ecosystem changes. Past rapid expansions in aquaculture, such as fish and shrimp farming, have brought their share of environmental concerns. The seaweed industry requires more research to assess the risks of large-scale cultivation, and there is a need for an adequate regulatory framework to protect from well-funded actors’ large-scale experiments.
Seaweed Farming with Cascadia Seaweed
Cascadia Seaweed is a company looking to fill the market hole for seaweed farming in the Americas and Europe. Their farming process is straightforward, taking sugar kelp trimmings from local wild plants in the autumn and spreading their spores onto twine in a nursery made of a couple of tanks in adapted shipping containers. After about a month, the babies are transported to ocean farms, where the twine is rewrapped around long lines anchored a few meters below the surface. Here, they grow until early spring, and by March or April, several-meter-long fronds are ready for harvest. The company also leaves about 10% of their seaweed out in the water as a habitat service and to provide source material for the next year’s crop.
The Future of Seaweed Farming
The potential for seaweed farming is vast, but the industry needs to find a balance between expanding and mitigating risks. Many large environmental organizations support the idea of expanding seaweed farming to help the oceans, the planet, and people. However, seaweed aquaculture requires further research attention, especially with regards to the ecosystem’s benefits and drawbacks. With the right balance of research and regulation, seaweed farming could offer a sustainable way to feed a growing population while helping the environment.
Seaweed Farming: Benefits, Risks and Complications
Seaweeds have been part of human diets and industries for thousands of years. They are used as food, fertilizer, and raw materials for diverse products from biofuels to toothpaste. The wild harvest has been the main source of seaweed until the last few decades when seaweed farming expanded to almost 35 million tons in 2019, representing nearly 30% of all seafood produced by aquaculture globally.
Seaweed Farming Expansion
Most seaweed production takes place in Asia, while the Americas contribute 1.4% and Europe 0.8% of global seaweed production. Nevertheless, companies such as Cascadia Seaweed are aiming to expand the market hole for seaweed farming elsewhere. Cascadia’s process starts in autumn when sugar kelp trimmings are taken from local wild plants, and their spores are spread onto twine wrapped around pipes in a nursery composed of tanks in adapted shipping containers. After a month, the babies are transported to ocean farms, where the twine is rewrapped around long lines anchored a few meters below the surface. Seaweed grows until early spring and is then ready for harvest, leaving 10% of their seaweed out in the water to provide habitat services and source material for the next year’s crop.
Ecosystem-Scale Benefits
Some propose that expanding kelp farming could benefit ecosystems by restoring lost biodiversity or creating habitat for fish. However, seaweed farming’s potential to provide ecosystem-scale benefits has little hard evidence. Research funding by the European Union is trying to plug those gaps. A survey of more than 20 experts and almost 300 research papers was conducted to find hard evidence of wider ecosystem-scale benefits, but results were inconclusive. Kelp forests have declined globally at around 1.8% per year, but some spots improve while others face extreme declines. Seaweed farms are not necessarily the solution in the spots facing declines. California, for example, with its rough coast, is too challenging for easy farming. In British Columbia, wild kelp beds are relatively healthy, implying that farms aren’t necessary to repair the ecosystem, although some bare patches could benefit from kelp.
Risks and Complications
Seaweed farming could cause harm to ecosystems in various ways. A dense kelp forest in a spot where one did not previously exist could affect the light and nutrients in the surrounding water, which is not necessarily beneficial. Additionally, seaweed farming presents far-reaching negative impacts on ocean chemistry and the food chain if it is scaled up globally. Growing large quantities of a single crop could raise monoculture problems, notoriously proven problematic for biodiversity and resistance against extreme weather or disease. Foreign imports also pose risks, such as an Asian red seaweed introduced in Hawai‘i for aquaculture that has spread several kilometers and smothered some coral reefs.
Seaweed farming faces challenges
Seaweed farming is seen as a potential solution to mitigate the effects of climate change and to provide a sustainable source of food and energy. However, it is not without its challenges.
Risks of invasive species and diseases
Seaweed farming can pose risks of introducing invasive species or diseases into an ecosystem. For instance, foreign imports of farm spores have driven down local seaweed species in the Philippines. Meanwhile, in Hawaii, an Asian red seaweed that was brought in for aquaculture in the 1970s has spread several kilometers from where it was introduced, smothering some coral reefs. Disease is also a concern, as bacterial infections such as ice-ice have caused significant losses in seaweed crops in the Philippines.
Genetic diversity and adaptation
More research is needed to understand the genetic diversity of seaweeds and how to select suitable parent algae for propagation without disrupting local adaptations. Cascadia Seaweed is currently limiting itself to parent algae found within 50 kilometers of its farm, but experts say this is a precautionary measure and more research is necessary. The University of Wisconsin-Milwaukee is studying seaweed genetics to see if bringing in other genetic variants would be beneficial or detrimental to local genetics.
Impacts on the ecosystem
While seaweed farming can capture carbon, absorb nutrients, and provide habitat for marine life, it can also have unintended negative impacts on the ecosystem. Seaweed farms can potentially shade out other organisms, promote the growth of nuisance algae, and disrupt the light and nutrient balance in the surrounding water.
Conclusion
As seaweed farming continues to grow globally, it is crucial to carefully manage its potential risks and benefits to ensure sustainability and avoid unintended consequences.
Seaweed farming is being touted as a possible climate change solution, but the effects of climate change itself could pose challenges to this emerging industry. Kelp, in particular, is sensitive to temperature changes, which can harm its growth and render it susceptible to disease outbreaks. The warming of Australian waters in 2010-2011, for instance, destroyed kelp forests, while in British Columbia, warm waters triggered the growth of encrusting bryozoans, which weigh kelps down and impair their ability to photosynthesize. Experts note that while seaweed farming presents lower ecological risks than most other industrial or agricultural activities, it still needs to be well-studied and regulated. However, Pew Charitable Trusts points to red tape and bureaucratic difficulties in obtaining aquaculture permits in the United States. In Maine, for example, the Seaweed Commons and regulatory agencies are still debating the allowed size and scope of kelp farming operations. In British Columbia, the regulatory framework for seaweed farming is still evolving. Researchers like Anne Salomon of Simon Fraser University are studying the impact of seaweed farming on the environment and aiming to address issues such as nutrient levels, temperature, light, and bryozoan growth. Her team is also investigating ways to balance ecological and social concerns, including Indigenous rights.
It’s important to note that kelp farming’s benefits have not yet been scientifically established at the ecosystem scale. Research has been done to understand the ecological risks and benefits of seaweed farming, with one 2016 study suggesting that kelp forests are declining globally at approximately 1.8% per year. Still, the study’s authors noted that farming is not an effective way to “repair” the ecosystem in areas where kelp forests are in decline. Another concern is the possibility of introducing invasive species to an ecosystem through seaweed farming. In the Philippines, for instance, foreign farm spores have driven down local seaweed populations. Disease outbreaks are also a potential issue, with bacterial infections like ice-ice drastically reducing seaweed crops in some areas.
Overall, while seaweed farming presents potential benefits, more research and regulation are needed to ensure that the industry develops sustainably and without harming the environment.
Kelp farming at small, artisanal scale is good for supporting local communities, local industries and local sovereignty, but commercializing it at an industrial scale can have ecological and important social costs. This is according to Anne Salomon, a Simon Fraser University marine ecologist. It is essential to involve Indigenous communities in decision-making, especially those living along the coast. Monoculture is a mistake that should not be repeated in the ocean, as it is in land agriculture. Kelp farming presents a far lower ecological risk than most other industrial or agricultural activities. However, more research is necessary to understand the ecosystem impacts of the industry, including potential risks of new diseases, and the effects of climate change, especially the warming waters that could encourage disease outbreaks.
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