Scientist's 40-year quest ends as 'pink zebra' seaweed confirmed as new species

In the quiet waters off Cornwall, beneath the surface where few venture, a scientist's four-decade obsession has finally resolved itself into a name. Prof Christine Maggs first glimpsed the seaweed in 1986 while researching maerl beds for her PhD—a fragment of pink-striped algae clinging to the calcified carpet of what looked like coral but was actually thousands of interlocking pieces of free-living seaweed. She had never seen anything like it. Neither, it turned out, had anyone else.

Maerl beds are among the richest habitats the sea has to offer, dense with life in ways that rival the famous coral ecosystems of warmer waters. But these particular underwater gardens exist in UK waters, largely unnoticed by the public. Maggs suspected her discovery was a new species, but she needed more material to prove it—enough to sequence, to examine, to formally claim. She searched through decades of literature. She continued hunting after her PhD ended. The seaweed became her constant companion, glimpsed occasionally on a sea squirt here, a fragment of maerl there, never quite enough to pin down with certainty.

Two years ago, researchers surveying the Cornish maerl beds found what they thought might be Maggs' phantom seaweed. Francis Bunker, a freelance marine biologist with the habit of carrying a magnifying glass on dives, kept spotting the same tiny red algae with its distinctive pink bands and pincer-like tips in the samples he collected. He gathered what he could and sent it to Maggs in London. She bought a wine fridge—the perfect dark, cool environment for the work ahead. "I just kept hoping that I would find out," she said. "It's been over four decades."

The seaweed was so small that Maggs needed molecular data to identify it conclusively. She grew samples in her wine fridge and worked with Prof Beatriz de Barros Barreto on DNA sequencing. The puzzle pieces finally fit. The seaweed was indeed new to science. A sample now sits in the Natural History Museum's official collection, and Maggs' findings will soon appear in the peer-reviewed journal Phycologia.

The discovery matters beyond the satisfaction of solving a personal mystery. Seaweeds are among the oldest forms of life on Earth, having evolved more than a billion years ago. They anchor entire ecosystems, providing food and breeding grounds for fish species that humans depend on economically. Their extracts treat everything from acid reflux to infected wounds. Yet maerl beds—rare in Britain and classified as threatened and declining under international environmental protection agreements—remain poorly understood. Finding a new species in these habitats underscores how much we still don't know about the underwater world we share.

There are currently four protected maerl sites in the UK, but the less-studied beds off south Cornwall, where this new species lives, have no formal protection. The government says protecting every example of every habitat may not be necessary, citing the need to balance nature recovery with offshore wind development and fisheries. The debate continues while the researcher-divers keep working, documenting and recovering species, naming them. Maggs' seaweed will be known scientifically as ceramium ruenessianum, honoring a colleague who has studied this type of species for four decades. Among the diving team, though, a favorite common name has already emerged: pink-zebra weed. Maggs is inviting the public to suggest others.