Introduction
In the UK, macroalgae or seaweeds have been harvested from the wild for centuries and traditionally used for food, feed and fertilizers. Recently, seaweed biomass has been used to produce bio-stimulants, nutraceuticals, cosmetics, biofuel, bioplastic and biomaterial. An initial attempt to commercially farm seaweed in the 1980s-90s was not sustained. Over the last decade, a resurgence of interest in seaweed has led to the re-development of commercial seaweed aquaculture in the UK. However, no data or centralised information are available on current UK seaweed production from aquaculture or wild harvest.
Methods
A combination of literature review, web searches and interviews with seaweed producers, seaweed organisation and regulatory bodies in the UK has been used to determine the status of the UK seaweed industry, including estimates of current production (from both wild harvest and aquaculture), number/extent of farms, and species cultivated.
Results and discussion
The seaweed industry is growing in the UK, as the number of farms, seaweed-related businesses and marketed seaweed-products have increased since a previous study in 2016. Species harvested in the UK include brown seaweed (e.g. Saccharina latissima, Laminaria digitata, Alaria esculenta), red seaweed (Palmaria palmata) and green seaweed (Ulva spp.). Farms use various techniques (longline, droppers, etc.) to suit location, farm size, end uses and local environmental conditions. Growth of the UK industry is hindered by multiple issues, also common to Europe: obtaining licences and investment for prospective farms; lack of standards for farming and products; technological barriers; the need for social licence to operate; spatial planning. It is important to document current activities, so operational lessons (e.g. unproven niche markets; economies of scale and infrastructure; competition from wild harvest and imports) can be learnt by this emerging aquaculture sector.