The new analysis corrected an announcement made last week by Alaska-based NOAA scientists who had initially concluded the material was a conglomeration of microscopic eggs or embryos deposited by some form of crustacean.
Scientists from NOAA’s Center for Coastal Environmental Health and Biomolecular Research, based in Charleston, South Carolina, did a follow-up examination on a sample sent from Alaska and determined the material was fungal, not the product of crustaceans, the agency said.
The material is consistent with spores from fungi that cause “rust,” a disease that infects plants by causing a rust-like color on them, NOAA said.
“The spores are unlike others we and our network of specialists have examined; however, many rust fungi of the Arctic tundra have yet to be identified,” Steve Morton, a scientist with the NOAA Charleston lab, said in a statement.
The gooey material first appeared early this month in the water and on coastlines of Kivalina, an Inupiat Eskimo village of 400 on the Chukchi Sea coast.
Residents initially feared the material might be pollution from the nearby Red Dog Mine, the world’s largest zinc producer. But early tests showed it was a biological material, not mining waste or a petroleum product.
The sticky orange material, which dried into a powder, has washed away from Kivalina, said Julie Speegle, a spokeswoman for NOAA’s National Fisheries Service in Alaska.
Speegle said the material was likely harmless.
“Rust is a disease that only affects plants, so there’s no cause for alarm,” she said, adding that details about its origins remained a mystery.
“There just has not been a lot of research done on rust fungi in the Arctic. This is one that we’ve never encountered before that we know of,” she said.
