San Francisco targets non-native kelp

Scientists in San Francisco said a team of divers has been recruited to rid marinas of an exotic form of fast-growing seaweed.

The scientists said the kelp, Undaria pinnatifida, is native to Japan and China and was first discovered at the San Francisco Yacht Harbor and the South Beach Harbor in May, the San Francisco Chronicle reported Thursday.

The species can grow an entire inch in a single day, said experts with the Smithsonian Environmental Research Center satellite lab at San Francisco State University’s Romberg Tiburon Center.

There was no mistaking it for anything else but Undaria, said Chela Zabin, a Smithsonian staff biologist.

The scientists said the exotic species is a threat to native forms of seaweed, including the giant kelp and bull kelp that provide shelter for fish, otters and other marine animals.