While international trade has meant that marine invasion to the West Coast has been occurring since the late 1860s, the global economy has greatly accelerated the process. So much so that now, there are areas like San Francisco Bay which amount to a “global zoo” of invasive species, where as many as 500 plants and animals from waters afar have established in U.S. waters.
The species can attach themselves to the hulls of cargo ships and the water some vessels take on as ballast, but have also come from home aquariums that have been emptied into bays.
Not only have the species upset marine ecosystems, but there are staggering costs associated with the phenomenon as well, in tens of billions of dollars.
“Mitten crabs from China eat baby Dungeness crabs that are one of the region’s top commercial fisheries. Spartina, a ropey seaweed from Europe, chokes commercial oyster beds. Shellfish plug the cooling water intakes of power plants. Kelps and tiny shrimp-like creatures change the food web that fish, marine mammals and even humans depend on,” the AP reported.
If anything, the Fukushima disaster will only make matters worse, since the problem has been growing for years. A 2004 study published by the scientific journal Ecological Economic, for example, estimated then that some 400 threatened and endangered species in the U.S. were facing wipe-out due to invasive species.
That said, scientists admit it’s too early to tell how badly Japan’s tsunami debris will worsen the situation already here in the U.S.
“It may only introduce one thing,” Andrew Cohen, director of the Center for Research on Aquatic Bioinvasionsin Richmond, Calif., said. “But if that thing turns out to be a big problem, we would rather it not happen. There could be an economic impact, an ecological impact, or even a human health impact.”