Seaweed culture slow to grow in western world

Worldwide, seaweed culture is large. However, 98.9% is concentrated in seven Asian countries, and little is produced in the western world.

       At the Aquaculture Association of Canada (AAC) meetings recently held in St. Andrews, New Brunswick, Thierry Chopin of the Canadian Integrated Multi-Trophic Aquaculture Network (CIMTAN), University of New Brunswick, brought this to the delegates’ attention.

       If aquaculture is to make a major contribution to future food supplies, phycoculture must be developed in a more evenly distributed manner throughout the world, he stressed. At present some 23 million tonnes, worth US$6 billion are cultivated and harvested annually (the wild harvest is just over 1 million tonnes). About 220 species are cultivated with six genera including Saccharina, Undera, and Porphyra providing 98.9% of the production and 98.8% of the value.

       Three species are grown in Canada: Ascophyllum, dulse (Dilsea edulis) and Irish moss (Chondrus crispus), but Canadian seaweed culture (at sea or land-based) remains small.

       Chopin suggests that Integrated Multi-Trophic Aquaculture (IMTA) offers an opportunity to reposition the value and roles seaweeds have in coastal ecosystems. In particular the utilization of nutrients otherwise lost from cage culture of fish.

       Western, animal-biased aquaculture has to recognize and take advantage of the environmental- economic- and societal benefits, and ecosystem services that these extractive species can provide (nutrient bio-mitigation, oxygen provision, carbon sequestration and reduction of ocean acidification), which could be valued through a system of nutrient trading credits. These, he says, would be incentives to reverse historical challenges and lead to success stories based on a gradual implementation strategy for research, development and commercialization.

– David Scarratt