Expanding number of
valuable uses drives astonishing growth of seaweed farming
United Nations University
A rising number of valuable uses being found for seaweed -- from
food and fertilizer to pharmaceuticals and industrial gels -- is driving the
rapid growth of an industry that could easily and needlessly drop into some of
the same pitfalls previously experienced in both agriculture and fish farming.
Drawing on the expertise of 21 institutions worldwide, UN
University's Canadian-based Institute for Water, Environment and Health, and
the Scottish Association for Marine Science, a UNU associate institute, today
published policy advice to the burgeoning, multi-billion dollar industry to
help it avoid expensive mistakes and pursue best practices, backed by relevant
case studies involving crops like bananas and shrimp.
The authors note that seaweed farms now produce more than 25
million metric tonnes annually. The global value of the crop, US$6.4 billion
(2014), exceeds that of the world's lemons and limes.
Seaweed farming has grown from the late 1950s into an industry
offering sustainable employment in developing and emerging economies, notably
China (which produces over half of the global total of seaweed -- 12.8 million
tonnes) and Indonesia (27% of global production -- 6.5 million tonnes). Other
major producers include the Republic of Korea and the Philippines.
Among the industry's many wide-ranging benefits:
Consequently, it has been actively promoted
by government initiatives, particularly in many developing countries where communities
have reduced access to alternative livelihoods or are involved in destructive
fishing methods like dynamite fishing.
Increasingly, seaweed cultivation is also being integrated with
intensive fish farming to provide nursery grounds for juvenile commercial fish
and crustaceans, and to filter undesired nutrients, improve the marine
environment and reduce eutrophication.
Indirectly, seaweed farming has reduced over-fishing in many
regions, providing coastal communities with an alternative livelihood. In some
places, women have become economically active for the first time.
Most of the seaweed produced is used for human consumption with
much of the remainder used largely as a nutritious additive to animal feed or
as a fertiliser.
In the last decade, seaweed cultivation has been rapidly
expanding thanks to growing demand for its use in pharmaceuticals,
nutraceuticals and antimicrobial products, as well as biotechnological
applications.
Seaweed today is used in some toothpastes, skin care products
and cosmetics, paints and several industrial products, including adhesives,
dyes and gels. Seaweed is also used in landscaping or to combat beach erosion.
Problems of rapid expansion
"The rapid expansion of any industry, however, can result
in unforeseen ecological and societal consequences," according to the
authors.
Communities that come to depend on a single crop for their
livelihood become highly vulnerable to a disease outbreak, as happened in the
Philippines between 2011 and 2013 when a bacteria that whitens the branches of
a valuable seaweed species caused a devastating loss to the communities
involved, estimated at over US$ 310 million.
The authors say the industry needs to guard against
non-indigenous pests and pathogens, to promote genetic diversity of seaweed
stocks and to raise awareness of mistakes in farm management practices (such as
placing the cultivation nets too close together, making the crop more
vulnerable to disease transfer and natural disasters).
"In addition, the illegal use of algicides / pesticides,
with unknown but likely detrimental consequences for the wider marine
environment, user conflicts for valuable coastal resources and rising
dissatisfaction over the low gate prices for the crop can all result in
negative impacts on the industry."
The experts note that increasing demands being placed on the
marine environment and competition for maritime space (renewable energy,
aquaculture, fisheries, et cetera) necessitates coordination and co-operation
between different users, an ecosystem-wide management approach and marine
spatial planning (MSP) for aquaculture, alongside regulation to protect the
wider marine environment.
In a nutshell, the key points for the seaweed industry come down
to:
- Biosecurity -- preventing the introduction of disease and non-indigenous pests and pathogens
- Investing in risk assessment and early disease detection
- Building know-how and capacity within the sector
- Cooperative planning to anticipate and resolve conflicts between competing interests in finite coastal marine resources, and
- Establishing management policies and institutions at both national and international levels
Citation:
Cottier-Cook, E.J., Nagabhatla, N., Badis, Y., Campbell, M.,
Chopin, T, Dai, W, Fang, J., He, P, Hewitt, C, Kim, G. H., Huo, Y, Jiang, Z,
Kema, G, Li, X, Liu, F, Liu, H, Liu, Y, Lu, Q, Luo, Q, Mao, Y, Msuya, F. E,
Rebours, C, Shen, H., Stentiford, G. D., Yarish, C, Wu, H, Yang, X, Zhang, J,
Zhou, Y, Gachon, C. M. M. (2016). Safeguarding the future of the global seaweed
aquaculture industry. United Nations University and Scottish Association for
Marine Science Policy Brief. ISBN 978-92-808-6080-1. 12pp.