Invasive Kelp reaches San Francisco

The AP is reporting that the invasive Asian kelp Undaria pinnatifida has arrived in San Francisco. According to a 2004 paper, First Report of the Asian kelp Undaria pinnatifida in the Northeastern Pacific Ocean it was first identified in southern California in early 2000, and it had spread as far north as Monterey Harbor by the summer of 2001.

From its native range in the northwestern Pacific, Undaria has now been introduced to the northeastern and southwestern Atlantic and the southwestern and northeastern Pacific, through a combination of intentional transport for cultivation, accidental transport with oysters, as fouling on vessel hulls, and possibly other means. In the northeastern Pacific, water temperatures are suitable for its establishment from at least Baja California to British Columbia, where it is likely to grow well in sheltered and partially sheltered waters.

Now from the AP: Fast-growing kelp invades San Francisco Bay

SAN FRANCISCO (AP) — A fast-growing kelp from the Far East has spread along the California coast from Los Angeles to San Francisco Bay, worrying marine scientists and outpacing eradication efforts.

In May, scientists for the first time found the invasive seaweed called Undaria pinnatifida clinging to docks at a yacht harbor in San Francisco Bay, fouling boat hulls and pier pilings.