UH Scientists Find ʻAggressiveʻ Algae

New species of algae at Pearl and Hermes Atoll. (Photo courtesy: NOAA/National Marine Sanctuaries).

Scientists discovered a new, aggressive, fast-growing species of algae in Papahānaumokuākea Marine National Monument that may be a major threat to coral reefs and the sealife reefs support, the University of Hawaiʻi announced on Tuesday.

The researchers say they are worried because the algae species forms mats that are almost eight inches thick that can smother reefs and the corals, native algae, and other organisms. It also has a “tumbleweed-like” growth and appears to easily detach and spread.

According to UH, the species was not widespread when first detected by NOAA divers in 2016. However, a 2019 visit to the same area revealed that it is now growing in mats that are up to several thousand square meters each at Pearl and Hermes Atoll.

“I think this is a warning of the kinds of changes that are to come for the northwestern Hawaiian Islands. We have, not until now, seen a major issue like this where we have a nuisance species that’s come in and made such profound changes over a short period of time to the reefs,” Alison Sherwood, UH Mānoa College of Natural Sciences Interim Associate Dean and Professor of Botany, said in a press release.

“Researchers are definitely concerned about this alga. This is something that’s been seen, just in the sheer abundance of it at Pearl and Hermes Atoll. It’s covering the native reef, and what it’s doing when it does that is covering over the native species and genera of corals that live there.”