Drawing on the expertise of 21 institutions worldwide, the United Nations University's Canadian-based Institute for Water, Environment and Health, and the Scottish Association for Marine Science, a UNU associate institute, have published policy advice to the multi-billion dollar industry to help it avoid expensive mistakes and pursue best practices.
The authors note that seaweed farms now produce more than 25 million metric tonnes annually. The global value of the crop, US$6.4 billion (2014), exceeds that of the world's lemons and limes.
Seaweed farming has grown from the late 1950s into an industry offering sustainable employment in developing and emerging economies, notably China (which produces over half of the global total of seaweed - 12.8 million tonnes) and Indonesia (27 per cent of global production - 6.5 million tonnes). Other major producers include the Republic of Korea and the Philippines.
Problems of rapid expansion
"The rapid expansion of any industry, however, can result in unforeseen ecological and societal consequences," according to the authors.
Communities that come to depend on a single crop for their livelihood become highly vulnerable to a disease outbreak, as happened in the Philippines between 2011 and 2013 when a bacteria that whitens the branches of a valuable seaweed species caused a devastating loss to the communities involved, estimated at over US$ 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
