How are the world’s kelp forests actually doing? The Kelp Forest Alliance has just published its latest answer. The second edition of its State of the World’s Kelp Forests report came out in October 2026 and, according to Oceanographic, was launched at the UN biodiversity summit (COP17) in Yerevan, Armenia. It updates the first edition from 2024, drawing on kelp researchers and practitioners from around the world. Its overall picture is one of decline that varies a lot from place to place, alongside real and growing efforts to turn it around.
The report starts with why this matters. Kelp forests line roughly a third of the world’s coastlines. More than 950 million people live within 50 kilometres of one, and those coastal areas account for about 18 percent of global GDP. The report puts the potential value of kelp forests’ ecosystem services at more than US$500 billion a year, while stressing that this is an indicator of potential value, not money actually earned, and it estimates they draw down about 32 million tonnes of carbon dioxide a year, with wide uncertainty around that figure.
The bad news is familiar. Globally, roughly 40 to 60 percent of kelp forests have experienced reductions in abundance. Experts surveyed for the report rank ocean warming, including marine heatwaves, as the biggest threat, followed by overgrazing (often from urchins or fish whose numbers have boomed after predators were lost or warm-water species moved in) and then physical disturbances such as harvesting, coastal development and sediment. That pattern is playing out right now on Japan’s Izu Peninsula, where a new study links the complete loss of one bay’s kelp forest to record heat and a far longer grazing season for parrotfish.
Protection is where the clearest progress shows. About 23 percent of the global kelp biome now overlaps a protected area, up from 16 percent in 2024, and 13 regions have passed the 30 percent mark set by the global “30 by 30” target. But the report is frank about what those numbers hide: only 1.2 percent of the kelp biome can be confidently identified as highly protected, and for roughly a third of the kelp inside protected areas, nobody knows how strong the protection really is.
Restoration is growing too. The Alliance’s database now tracks 19,071 hectares of successful kelp restoration from 285 projects in 15 countries. More than three-quarters of that area, about 14,700 hectares, is in South Korea. “Restoration is expanding around the world, but progress remains uneven,” the report says, and it adds a caution: if the causes of loss, such as poor water quality or too many grazers, aren’t dealt with, restored kelp may fail to establish or persist. Restoration, in the report’s words, “should complement rather than replace efforts to protect existing kelp forests.”
The report also points to how little attention kelp gets in global policy: a 2023 analysis it cites found seagrass, salt marshes, coral reefs and mangroves were mentioned 8 to 43 times as often as kelp forests in international policy documents. There are signs that may be shifting. Japan already counts seaweed beds in its national greenhouse gas inventory, and the report notes that the IPCC has opened a path for seaweeds to be included in a methodology report due in 2027. The Alliance’s own Kelp Forest Challenge sets out what it thinks is needed by 2040: 3 million hectares protected, 1 million hectares restored, and about US$14 billion in funding. “Kelp conservation has reached an inflection point,” Aaron Eger, founder and programme director of the Kelp Forest Alliance, told Oceanographic. Whether it tips the right way depends on how quickly protection gets stronger and the pressures driving the losses get tackled.
Further reading: Kelp Forest Alliance, “State of the World’s Kelp Forests Report 2026,” 2nd edition (2026); Hutchins, R., “Six in ten kelp forest regions degraded, but recovery efforts persist,” Oceanographic (2026).