The invasive kelp Undaria pinnatifida is has now spread from Los Angeles to San Francisco Bay, despite eradication efforts.

Earlier, the northward spread of this sea weed – which can grow an inch a day and forms dense underwater forests – was believed to have been stopped at Monterey Bay, but this assumption turned out to be wrong when a biologist at the Smithsonian Environmental Research Center happened to notice a six-foot long piece of kelp attached to a boat in a yacht harbor in San Francisco Bay.

“I was walking in San Francisco Marina, and that’s when I saw the kelp attached to a boat,” said Chela Zabin, biologist at the Smithsonian Environmental Research Center in Tiburon, California. “It was six-foot long, and there is nothing here in the bay that gets to that size. I didn’t want to believe what it was, it’s depressing.”

Further investigation showed U. pinnatifida clinging not only to boat hulls in the marina but to docks and pier pilings as well.

U. pinnatifida was discovered in Los Angeles Harbour in 2000 and within a year reports of its presence had arrived from Catalina Island and Monterey Bay. A federal eradication program was put in place, but the funding dried up last year. Since then, volunteer divers have been the only ones combating the kelp.

Five quick facts about Undaria pinnatifida

• Undaria pinnatifida is a fast growing kelp native to the waters of Japan, China and South and North Korea.

• Within its native range it is an appreciate source of food and if you’ve ever tasted miso soup, this is what you were eating. The Japanese name for this species is wakame.

• U. pinnatifida has managed to establish itself in many different regions outside its native range, such as the Atlantic coast of Europe, the Mediterranean Sea, and the Argentinean coast. By attaching itself to vessel hulls it can hitchhike across the globe in search of new suitable habitats. This kelp can also enter ecosystems via imported oysters, and some people deliberately or accidently introduce U. pinnatifida to local ecosystems by cultivating it for cooking purposes.

• When U. pinnatifida spread to ecosystems not used to its presence, it can grow uncontrolled and prevent native kelp species from getting any sunlight. This can disturb the entire ecosystem.

• U. pinnatifida has been nominated to the list “100 worst invasive species in the world”.

In addition to the recently proposed areas in the Pacific Ocean, (See this and this) president Bush now says he wants to find even more regions of the Pacific Ocean to protect.

This Friday, Bush made public that he has asked the secretaries of the Interior, Commerce and Defense to identify additional areas of the Pacific Ocean that could be eligible for conservation. He also revealed that the Monterey Bay National Marine Sanctuary will be expanded by 585 square nautical miles and come to include the Davidson Seamount. Davidson Seamount is a 42 km long underwater mountain located roughly 120 km southwest of Monterey, California. The seamount rises 2400 meters off the ocean floor, but its highest point is still more than a kilometre below the surface.

The young white shark brought to the Monterey Bay Aquarium on August 27 has now been released back into the wild after 11 days on exhibit. She was captured on August 16 in Santa Monica Bay and has now been safely returned to the same waters. During her stay at the Monterey Bay Aquarium she lived in their million-gallon Outer Bay exhibit, but despite her relatively roomy accommodation she only fed once and the staff decided that she would be better of in the wild.

A white shark

“These decisions are always governed by our concern for the health and well-being of these animals under our care,” says Jon Hoech, director of husbandry for the Monterey Bay Aquarium.

On September 7, the young female was released in offshore waters in the Santa Barbara Channel at 1:30 p.m. (Pacific Time). Before being released, she was tagged with a tracking device that will provide researchers with data on her life in the ocean. For 148 days, the pop-up tag will collect information about geographical location, depths, and water temperature. After this period, the tag will pop free and deliver the collected data via satellite.

As of now, a total of four White Sharks with tracking tags have been released from the Monterey Bay Aquarium. The three other sharks did however stay longer at the aquarium before going a back to the wild; between four and six months. Together with their research partners, the Monterey Bay Aquarium has tagged and tracked 18 juvenile white sharks off Southern California as a part of their “White Shark Conservation Research Project”. The aquarium is also involved in the project “Tagging of Pacific Predators” (TOPP) led by Stanford University’s Hopkins Marine Station, which has tracked 143 adult white sharks off the Central Coast using data-collecting tags.

If you wish to know more about the white shark research at the Monterey Bay Aquarium you can visit www.montereybayaquarium.org/whiteshark/.