The use of seaweed in various sectors from sushi to industrial applications has expanded dramatically in recent years, raising concerns among experts about the long-term sustainability of this industry.
Seaweed is widely appreciated as a natural product that offers many benefits. It is widely used as a fertilizer and to control beach erosion; and more recently as an additive in animal feed; nutraceuticals, cosmetics and skin care products; and even in industrial products such as paint and gels. The rapid growth in the range of valuable uses that have been found for seaweed has fueled a surge in the seaweed industry, which could lead to it experiencing some of the same drawbacks that initially affected both the aquaculture and agricultural sectors.
“The seaweed industry in Asia has been growing rapidly for the best part of 60 years, but Europe has only recently woken up to the economic potential of seaweed cultivation,” says Nicholas Owens, Director, Scottish Association for Marine Science (SAMS). “Interest in the West has been sparked by the wide range of seaweed applications, from health foods through to fuel, that can be produced in a sustainable way and has little environmental impact.”
In order to prevent the seaweed industry suffering some of the pitfalls experienced by the agriculture and aquaculture sectors, a global team of scientists has compiled a policy brief that provides advice to this growing, billion dollar industry in an effort to help it follow best practices and avoid costly mistakes, supported by relevant examples from the aquaculture and agriculture sectors.
“The growth of the seaweed industry in the past half century constitutes an important success story and it continues to expand to the benefit of some of the world’s most impoverished people,” explains Vladimir Smakhtin, Director, United Nations University Institute of Water, Environment and Health (UNU-INWEH). “But the industry needs to learn fast from other sectors to ensure that it remains sustainable.”
Seaweed farming began in the late 1950s and has since grown into a massive industry that provides sustainable work opportunities in developing countries, such as China (which produces more than half of all the seaweed produced globally), Indonesia, the Philippines and South Korea. Seaweed farms around the world currently produce over 25 million metric tonnes of seaweed annually. The value of the global seaweed crop, estimated to be around US$6.4 billion in 2014, is higher than the global value of lemons and limes.
Benefits Provided by the Seaweed Industry
Besides the valuable uses that seaweed as a product provides, the industry itself offers many benefits. With the collapse of fisheries around the world, seaweed cultivation offers an alternative source of income to help compensate for the losses associated with declining fisheries. And compared to other types of aquaculture, it is perceived as being more eco-friendly as there is no input of nutrients in the way of fertilizer or feed. As a result, it is often promoted as an ecologically sound alternative to aquaculture or destructive fishing practices such as dynamite fishing. In many regions, the growth in seaweed cultivation has indirectly reduced over-fishing, as it has provided coastal communities with an alternative source of income, making them less dependent on fishing as a livelihood. In some areas, it has given women access to employment opportunities they never had before.
Fish farms are also beginning to appreciate the benefits of including seaweed in their aquaculture facilities, as it provides shelter for juvenile fish and/or crustaceans such as shrimp to hide, and serves as a natural filter that removes excess nutrients to improve water quality and prevent eutrophication of fish ponds.
Problems Associated with Rapid Growth of the Seaweed Industry
However, experts warn that rapid expansion in any industry can have unforeseen negative impacts on both the environment and the communities that depend on these industries for their livelihoods.
Communities who become dependent on a single crop for their sole source of income, are extremely vulnerable should a disaster such as a disease outbreak result in the loss of the crop. For example, between 2011-2013 a bacterial attack on seaweed in the Philippines resulted in the loss of a crop with an estimated value of over US$310 million, with a devastating impact on the communities that depended on that crop for their livelihood.
To avoid scenarios like this, experts suggest that the seaweed industry puts measures in place to prevent the introduction of pathogens and non-indigenous pests; promotes genetic diversity within seaweed stocks; and build capacity by creating awareness of common farm management errors to prevent unnecessary losses due to disease and/or natural disasters.
Furthermore, according to co-author, Nidhi Nagabhatla, Program Officer, UNU-INWEH, “there is an ever-increasing demand being placed on the marine environment through renewable energy, traditional aquaculture, fisheries and transport, so we must ensure that any new industry works alongside these sectors in order to preserve, and indeed improve, the health of our oceans.”
“Rapidly increasing seaweed cultivation globally will be good for commerce and open up a range of new products, but we must also try to minimize any negative effects that this industry may have on coastal marine environments, says lead author, Elizabeth Cottier-Cook, from the Scottish Association for Marine Science. “The seaweed industry must be developed in a sustainable way that considers not just how to maximize profits but maintain the highest biosecurity standards to prevent the introduction of pests and disease. It will also be crucial to develop new indigenous disease-resistant strains of seaweed, wherever possible.”