How scientists finally confirmed rare pink seaweed as a new species

A rare pink seaweed found on the seafloor off the coast of Cornwall, England, has officially been confirmed as a brand-new species. Scientists made the announcement after more than 40 years of searching. The seaweed lives on a type of habitat called maerl beds, which are found in UK waters. Professor Christine Maggs first spotted the tiny plant during her PhD studies in the 1980s and never gave up on finding it again.

Maerl beds are carpets of coral-like seaweed that cover parts of the ocean floor. They are not actually coral — they are made up of thousands of pieces of calcified, or hardened, seaweed that lock together. These beds are home to a huge variety of sea life, including spider crabs, starfish, king scallops, and goby fish. Scientists say maerl beds are one of the richest habitats in the sea.

Prof. Maggs first saw the mystery seaweed back in the 1980s while studying maerl beds for her PhD. She spotted a small fragment of pink-striped seaweed that she had never seen before. She searched through scientific books and papers and found that no one else had described it either. She believed it was a new species, but she needed a bigger sample to prove it.

For decades, Prof. Maggs kept an eye out for the seaweed. She caught brief glimpses of it over the years — once even on an underwater creature called a sea squirt — but never found enough of it to study properly. Then, two years ago, a team of researchers diving in Cornwall collected a sample that seemed to match her mystery plant. When she heard the news, Prof. Maggs bought a wine fridge to store the sample safely, since it needed a cool, dark place to survive.

The divers who found the sample were working on a project organized by Natural England. Their job was to map and study seaweeds in Cornish maerl beds to check how healthy the habitat was. Marine biologist Francis Bunker kept noticing the tiny seaweed in the samples he collected. He suspected it might be the plant Prof. Maggs had been searching for, so he gathered as much as he could and sent it to her in London.

Prof. Maggs needed to grow the seaweed large enough to run a DNA test, which meant keeping it alive in her wine fridge. With help from Prof. Beatriz de Barros Barreto, who handled the DNA work, she was finally able to confirm that the seaweed was new to science. "That's why this has taken me 40 years," she explained. The findings are set to be published in a scientific journal called Phycologia.

The new species has been officially named ceramium ruenessianum, in honor of a colleague who spent 40 years studying this type of seaweed. A sample has been added to the Natural History Museum's official collection in London. As for a common name, the scientific divers' favorite is "pink-zebra weed," though "pink-banded bandit" and "ribbon claw" are also in the running. Prof. Maggs is even inviting the public to suggest names.

Seaweeds are among the oldest living things on Earth, having first appeared more than one billion years ago. They provide food for fish and safe places for fish to lay their eggs. Certain seaweeds are also used in human medicine, from treating acid reflux to helping heal wounds. Prof. Juliet Brodie, a leading seaweed expert, says protecting seaweeds is very important for keeping ocean ecosystems healthy.

Finding a new species is exciting, but it also helps scientists track the long-term health of maerl beds. Maerl beds in Britain are rare and are listed as a threatened and declining habitat under an international agreement called the OSPAR convention. There are four protected maerl sites in the UK, but the beds where the new seaweed was found are not yet formally protected. The UK government says it is weighing nature recovery against other priorities, like offshore wind energy and fishing.