A special ballast water treatment system is purifying the water that whooshes through a pump from the Carquinez Strait into the Moku Pahu, a double-hull bulk carrier that ferries raw sugar from Hawaii to California.
The ballast water balances the ship as the system removes organisms thinner than the width of a hair. If the treatment system performs as expected, it will join a handful of emerging technologies that represent the shipping industry's best hope for meeting a state deadline to remove exotic species from ballast water discharge -- or face stiff penalties.
The shipping industry brings 8.4 million metric tons of cargo into California each year, but vessels also unload unwelcome stowaways: exotic species that catch a ride in the ballast water that ships pick up at sea. Local scientists say more of these species have invaded the bay-Delta estuary than anywhere else in the world -- and some are very destructive.
"An invasive species, once it's established, and once it starts to reproduce, it's there forever," said Maurya Falkner, head of the State Lands Commission's Marine Invasive Species Program. The commission has spent more than $400,000 since 2006 to find technological solutions to the ballast discharge problem -- including the system installed on the Moku Pahu by Boston-based Ecochlor.
California recently set the nation's strictest standards for discharge of ballast water from newly constructed ships, standards that would prohibit even the smallest organisms from escaping into coastal or inland waters.
It would affect ships built after 2012, which won't be delivered until 2014 at the earliest, and existing ships don't have to comply with the law until 2020. About 700 ships discharge ballast water in California each year, and 5 percent of the fleet is replaced each year.
Despite a lengthy phase-in, the push to achieve such a high standard is making those in the shipping industry nervous. This summer, the shippers seized on a review of 46 ballast water treatment systems that concluded none can achieve the state standard 100 percent of the time, although at least eight systems have demonstrated the "potential" to comply.
The report also predicts that in a year and a half, the technology will be ready to move forward without delay.
Still, industry representatives used the report to press for an extension.
"Our disagreement is that there's no guarantee that these systems can consistently meet California standards," said John Berge, vice president of the Pacific Merchant Shipping Association. "If it doesn't, we're kind of stuck in a noncompliant situation with no remedy."
State officials maintain that it would be a huge mistake to build in more delays with so many promising technologies. Ballast water discharge remains essentially unregulated in California and across the U.S., but that's beginning to change.
Cargo ships and cruise liners take on millions of gallons of water to balance their loads during transocean crossings; they then discharge the water at ports of call. California requires ships to exchange their ballast water in the middle of the ocean, where fewer organisms live.
But, officials acknowledge, the process filters out only some species, and a multitude of microscopic sea life inhabits the ballast tanks. Discharged in coastal waters or the Sacramento-San Joaquin River Delta, they have the power of a colonizing force, invading the habitat and co-opting the food sources native species depend on.
Some invasive species have had dramatic effects on the San Francisco Bay. The Asian clam has caused the collapse of some local commercial fisheries by consuming the phytoplankton the fish need for their food. And scientists recently made the connection between the Japanese bubble snail and swimmer's itch, a rash similar to poison oak that has affected children at Crown Beach in Alameda since 2005.
Ballast water can also transport cholera around the world.
"It's very likely that the number of exotics that we haven't caught is probably in the ballpark, if not larger, than the number that we have caught," said Andrew Cohen, director of the Center for Research on Aquatic Bioinvasions.
The Bay Area has made impressive strides in the past few decades to counteract pollution sources, but the invasive species problem keeps growing.
Cohen counted 234 non-native species in the bay as of 1995, but, he says, that number could easily surpass 300 species now -- without even counting viruses and bacteria.
None of those species would have a chance if subjected to Ecochlor's ballast water purification system, says Tom Perlich, the company's founder and president. Ecochlor uses chlorine dioxide to kill exotic organisms, and it has been field-tested on the Moku Pahu since 2007.
Despite its name, chlorine dioxide is chlorine-free. It's an unstable compound that disinfects the water and then dissolves into a harmless gas within hours.
Other systems use ultraviolet light similar to advanced wastewater treatment, chemicals or onshore filters to clean the water.
Results from tests in the summer confirm that the Ecochlor system has the ability to meet California's restrictive standards, Perlich said.
"Many ship owners are interested in the technology -- we just have to get our approvals behind us and then we're going to be cranking up the production."This story was produced in partnership with KALW 91.7 FM. Tune in to KALW's Crosscurrents today at 5 p.m. to hear sounds from the battle against invasive aquatic species.
Contact Julia Scott at 650-348-4340.