Seaweed species face widespread local extinction by 2100, landmark report warns

New report warns seaweed species face local extinction by 2100 and calls for global action to protect these vital marine habitats

Seaweeds are critical for human and planetary health, yet many species could face widespread local extinction by the end of the century, a new report led by the Natural History Museum in London concludes.

Released by the international research program GlobalSeaweed-SUPERSTAR, The State of the World’s Seaweeds outlines how climate change, overfishing, pollution and invasive species are driving dramatic shifts in seaweed diversity and distribution, with serious consequences for both ocean and human health. The report calls for urgent action to safeguard these vital marine species.

“A world without seaweeds means devastation to the functioning and food security of the Earth as we know it,” said Prof. Juliet Brodie from the Natural History Museum and co-author of the report. “A world with seaweeds that are healthy and thriving offers hope of a better future for the planet.”

Seaweeds, which include red, green and brown macroalgae, form the planet’s largest vegetated marine habitats – covering an area roughly the size of Australia. Their future, however, is increasingly uncertain. While seaweed farming supports millions of livelihoods in 56 countries – the vast majority in Asia – wild seaweed populations face mounting pressure from climate change, pollution and other human-driven threats.

“Seaweeds are often the unsung heroes of the marine world,” said Dr. Sophie Corrigan from the Natural History Museum and lead author of the report. “They form some of the largest marine habitats we have and underpin so many marine resources, as well as playing an important role in the function of other marine habitats such as cementing coral reefs together and protecting them from wave damage. Food, medicines and even the cosmetics industry rely on seaweed for the properties they can offer.”

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Despite their ecological and economic importance, there is currently no global data on the rate of seaweed habitat loss. Scientists predict that many species could face widespread local extinction (disappearance from specific regions, but not globally) and a shift toward higher latitudes (either north or south) by 2100, leading to an overall decline in global seaweed diversity and coverage.

“Safeguarding the future of seaweeds and realizing the full potential of seaweeds and their uses will require a global movement to unite governments, researchers, industries, charities, Indigenous Peoples and local communities in protecting seaweeds,” said Corrigan. “This report is an important step in that process.”

Findings will inform the Seaweed Breakthrough initiative – a new set of global conservation targets for governments, policymakers, farmers and local communities. The initiative will launch at the UN Ocean Conference in June and aims to drive coordinated action to protect seaweed ecosystems.

“While interest in kelp forests is rightfully building, other seaweeds have been left behind,” said Corrigan.  This is something we want to change, and we’re hoping that all seaweeds will benefit from the Global Biodiversity Framework’s 30by30 initiative as more protected areas are created or expanded in the coming years.”

Read the full report.