For the past three years a highly invasive form of brown kelp, native to Japan, has spread throughout the San Francisco bay. Researchers worry that the alien seaweed could threaten native species and ecosystems in the Pacific Ocean.

The seaweed, more often referred to as Wakame, is a common ingredient in Miso soup and multiplies at an extremely quick rate. Since it was discovered at the San Francisco Yacht Harbor and the South Beach Harbor in 2009, it has already drastically altered the Bay's ecosystem by driving out native kelp.


The discovery of the dangerously invasive species initially sparked widespread alarm among marina workers and biologists who have worked endlessly to get rid of the alien species. Wakame is also responsible for wreaking havoc on ecosystems in Argentina, New Zealand and parts of Europe.

Last year, the Smithsonian Environmental Research Center found the brown kelp clinging to several more places along the Bay including Fort Mason, Pier 39, Fisherman's Wharf, and along the Hyde Street pier. The worst areas of infestation are around AT&T Park and Half-Moon Bay.

The dangerous plant, known scientifically as Undaria pinnatifida, is known to grow on almost any surface and stretch over an inch a day to more than nine feet total. The seaweed can thrive in both cold and warm saltwater.

Wakame can be killed by immersing it in fresh water or subjecting it to heat; however, there is currently no money to fund these tactics. Removing the seaweed is currently an all-volunteer effort.

If the seaweed is not checked, it will eventually eradicate native California counterparts, including the iconic giant kelp that fills the Pacific Ocean. The various fish and other animals that rely on the giant kelp to survive will also suffer as a result.

Click through the slideshow below to see other invasive species affecting ecosystems worldwide:

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  • Asian Carp

    With no natural predators and a tendency to starve other species by eating all the plankton, these fish are wreaking havoc in the Mississippi River and are swimming (dangerously) towards the Great Lakes.

  • Rabbits

    In Australia, European rabbits have lived and populated, unchecked, for decades, causing millions of dollars in damage and destroying the already delicate Australian ecosystem.

  • Cane Toads

    Originally introduced as pest control in Australia, the Central America-natives have no natural enemies and secrete a deadly poison. These toads and their voracious apetites are a serious threats in Florida and Texas as well.

  • Kudzu

    Known as "the vine that ate the South", Kudzu can grow up to a foot a day and is known to consume power lines, trees, and buildings. Originally from Asia, the bright vine is hard to uproot and now covers seven million acres of the southeast.

  • Gray Squirrel

    Possibly the most loathed animal in Britain, the North American gray squirrels are giving the British- native red squirrels the squirrel pox, and eating seven times more than the red coats. The British have responded by eating the gray squirrels.

  • Killer Bees

    Africanized honey bees first came to the US in 1990 and have since infiltrated much of the south and southwest. Although their venom is no more poisonous than regular honeybees, they are known to sting many more times and are not good honey producers.

  • Starlings

    Released into Central Park by a Shakespeare fanatic in 1890, the Starlings roost in hordes of 1 million, eat massive amounts of food, and their dropping carry multiple infectious diseases.

  • Northern Snakehead

    This fish has teeth like a shark and the ability walk on land and has been spotted wreaking havoc everywhere from New York to California.