Seaweed may not be the first consumer product (or even the tenth) that comes to mind when thinking about aquaculture. Nevertheless, the sector is creeping on trend with total global production now valued at around USD 6 billion (EUR 4.8 billion).
Of the 24.9 million metric tons (wet weight) of seaweed harvested in 2012, some 23.8 million metric tons came from aquaculture with a handful of Asian countries – led by China and Indonesia – dominating production, according to the latest statistics from the Food and Agriculture Organization of the United Nations (FAO).
While the world production of farmed seaweeds more than doubled between 2000 and 2012, consumer demand is growing at an even greater rate and to continue to meet this in the long term, seaweed aquaculture needs to perform “on a much grander scale,” reckons Dr. Prannie Rhatigan, public health doctor and author of “The Irish Seaweed Kitchen.”
Correctly called “marine algae,” seaweeds have been described as “the most nutritious form of vegetation on the planet,” and are “definitely parallel” in terms of vitamins, minerals and trace elements, said Rhatigan. They are also very high in antioxidants. In fact, some brown varieties have antioxidants that are unique only to them.
There is huge diversity in the seaweed family. For example, there are approximately 700 different species in the waters surrounding the United Kingdom and Ireland alone. Nevertheless, all species around the world are broadly classified as reds, greens or browns.
“But the reds are as different from the browns as we are from birds. They are really quite different in terms of their properties,” said Rhatigan.
“The essential thing about seaweeds is they are palateable. They range from mild to very spicy, and from nutty to a chicken flavor. They are quite diverse. In terms of their carbohydrate and protein components, again these vary enormously: their protein can range from a cereal and vegetable level to a soy bean and animal level.
“Seaweed has a huge health potential as well as being a wonderful food. I can see the seaweed industry really taking off. Currently though, they are vastly underrated, underexplored and underresearched.”
Rhatigan stressed that while we are surrounded by them, seaweeds must be harvested sustainably and that a problem would quickly ensue if everybody was to suddenly begin taking wild seaweed from their shoreline.
“That’s where aquaculture comes in: By growing on longlines or in tanks, there isn’t a problem,” said Rhatigan.
While Asia leads production, there are many new things happening globally in the field of seaweed aquaculture, she said. In Canada, for example, the aquaculture ranges from Halifax where they are growing Chondrus crispus (commonly called “Irish moss”) in huge tanks to Vancouver which is growing kelp on longlines in the Pacific. Meanwhile in her native Ireland, which has been working on seaweed hatchery and production techniques for many years, there is longline production in Cork, Belfast and some experimental areas in Galway.
Despite there being an increasing number of consumers looking to eat seaweed, a major hurdle — the so-called “yuck factor” associated with the acceptability of new foods — still needs to be overcome before it becomes a truly mainstream product. Rhatigan acknowledges the barrier but believes seaweed is a product that can be introduced to children at a very young age and that older seaweed newcomers should start with something mild to overcome any such misgivings.
“Seaweed is very flexible. It can be a small component of a dish or it can be the star ingredient,” she said.
