Seaweed farming is undergoing a massive resurgence as a sustainable, high-value global industry.

Gardening · Published 3 October 2026 Swipe more like this →

In short: Once a source of soda ash for 18th-century glassmakers, seaweed is now being cultivated for everything from food and beauty products to carbon sequestration. While wild harvesting remains common, the shift toward commercial aquaculture is accelerating, promising a versatile, low-impact solution to modern nutritional and environmental challenges.

The UK seaweed industry has experienced significant fluctuations over the centuries, moving from the mass production of soda ash in the 17th and 18th centuries to iodine extraction in the 19th century. After a period of decline, the industry has seen a notable resurgence since 2016. While wild harvesting remains the primary method for many of the 74 identified seaweed-related businesses in the UK, the number of commercial farms has grown from just one in 2016 to at least 10 by 2021. This transition reflects a broader global trend where seaweed is increasingly viewed as a vital, carbon-negative crop capable of providing essential ecosystem services like nutrient uptake and habitat provision.

Globally, the industry is dominated by Asian production, with China and Indonesia accounting for the vast majority of output. The scale of this sector is immense, with world production exceeding 35 million tonnes in 2019. Beyond its traditional role in human diets, seaweed is being leveraged for its potential to mitigate climate change and improve water quality through nutrient bioextraction. Despite these benefits, the industry faces significant hurdles. In the Philippines, for instance, rising seawater temperatures have been linked to the spread of ice-ice disease, which can devastate crops. Furthermore, the environmental impact of farming practices—such as the removal of mangroves or seagrasses to make room for cultivation—remains a critical concern that requires careful management.

For the seaweed industry to reach its full potential, experts emphasize the need for greater collaboration between government, academia, and private stakeholders. Knowledge gaps persist regarding the long-term environmental impacts of large-scale farming, and there is a clear need for sustainable scaling strategies. As businesses diversify into nutraceuticals, bio-packaging, and animal feed, the focus is shifting toward balancing economic growth with ecological integrity. By addressing these challenges through research and innovation, the seaweed sector aims to solidify its position as a cornerstone of the future bio-economy, providing a scalable, low-input alternative to traditional terrestrial agriculture.

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