Scientists have discovered four new species of algae in waters 200 to 400 feet deep at Papahanaumokuakea Marine National Monument.

Heather Spalding, a postdoctoral researcher at the University of Hawaiʻi Department of Botany who was the lead author of the study on the new species, said she was blown away by the abundance and size of the limu, a culturally important Hawaiian food.

She said the limu looked more like alage found in a shallow-water lagoon than the types found in deep water. The new species was similar to limu palahalaha, or sea lettuce.

Scientists have discovered four new species of algae, or limu, at Papahanaumokuakea. The photo of the algae here was taken by a diver at 188-feet deep at Kure Atoll.
Scientists have discovered four new species of algae, or limu, at Papahanaumokuakea. The photo of the algae here was taken by a diver at 188-feet deep at Kure Atoll. Daniel Wagner/NOAA

Spalding has been collaborating with NOAA’s Office of National Marine Sanctuaries for several years studying samples collected by NOAA divers working in the monument, according to a news release Tuesday.

She and her colleagues at UH and the University of Washington’s Friday Harbor Laboratories conducted DNA analyses that showed that the species are very different than those found in Hawaii’s shallow waters, even though they are very similar in appearance, the release says.

Heather Spalding examines a limu specimen at the University of Hawaii at Manoa.
Heather Spalding examines a limu specimen at the University of Hawaii at Manoa. Daniel Wagner/NOAA

The scientists consulted with the Native Hawaiian community to develop names for the new species. One is Ulva iliohaha, which refers to the foraging behavior of ilioholoikauaua, the endangered Hawaiian monk seal, one of the best-known residents of Papahanaumokuakea, the release says.

“These findings redefine our understanding of algal distributions in Hawaii, and hint at the great number of other new species that are likely to be discovered in the future from these amazing deep-water reefs,” said Daniel Wagner, Papahanaumokuakea research specialist with the Office of National Marine Sanctuaries, in the release.

Read the full study here.

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