* Environment groups warn of damage to marine life
* Trade-off between harming offshore wildlife or land
* Cleanup chemical maker Nalco says product is safe
By Deborah Zabarenko, Environment Correspondent
WASHINGTON, May 4 Oil-dispersing chemicals used
to clean up the vast BP spill in the Gulf of Mexico carry their
own environmental risks, making a toxic soup that could
endanger marine creatures even as it keeps the slick from
reaching the vulnerable coast, wildlife watchdogs say.
The use of dispersants could be a trade-off between
potential short-term harm to offshore wildlife and possible
long-term damage to coastal wildlife habitat if the oil slick
were to reach land.
The U.S. Environmental Protection Agency has approved 14
dispersants for use on oil spills, including Corexit,
manufactured by Nalco Holding Co. NLC.N of Naperville,
Corexit has been provided for use in the BP spill, and the
company has exhausted its inventory and is producing more, said
Mani Ramesh, Nalco's chief technology officer. Ramesh said
Corexit's active ingredient is an emulsifier also found in ice
cream; he disputed environmental groups' claims that it is
harmful to marine life.
Nalco stock rose more than 11 percent on Monday on news
that Corexit was being tested on the ocean floor near the
leaking wellhead. But it retreated 2.75 percent to 25.47 on
Tuesday in a broad U.S. market sell-off.
So-called dispersants work on an oil spill as dishwashing
detergent works on a greasy skillet: they break up oil into
tiny droplets that sink below the water's surface where
naturally occurring bacteria consume them. Without dispersants,
oil stays on the water's surface, where bacteria can't get at
them, Ramesh said.
The problem, according to Jackie Savitz, a senior scientist
at the marine environmental group Oceana, is that the
dispersants themselves can be toxic to wildlife. Dispersants
can also enhance oil's toxicity in the dispersion process.
This makes them simply the lesser of two bad options to
fight an oil spill such as the slick created by the April 20
explosion at BP Plc's (BP.N) Deepwater Horizon drilling rig,
"A decision is being made where it's the shore wildlife and
oysters and beaches versus the animals that live in the water,"
Savitz said by telephone. "When they use a dispersant, it's
taking the oil and essentially dissolving it in the water so
that it doesn't wash up on the beach.
"It's also good for public perception, because a lot of
people think it's only bad if it washes up onshore."
TURTLES, DOLPHINS AND WHALES
"Do you kill the fish or do you kill the birds?" Mark
Floegel of Greenpeace asked rhetorically.
The choice may be more complex. The judgment may be that
spraying these chemicals in the water column -- from the
water's surface to the sea bed -- directly affects wildlife
living there in the short term, but is meant to prevent the
slick from reaching shore, where it could cause long-term harm
to coastal wetlands and the species that live in them.
Sea turtles, dolphins and whales have been seen swimming
through the oil slick, and bluefin tuna spawning grounds were
not far from its southwest edge as of last Friday, according to
the National Oceanic and Atmospheric Administration.
Closer to shore are oyster beds and seagrass beds -- where
dolphins, birds, lobster, conch, scallops, shrimp and juvenile
fish seek food and shelter -- as well as barrier island bird
nests, loggerhead turtle nests, sea turtle nests and essential
fish habitat, Oceana said, citing NOAA and the Unified Command
working on the spill.
Allison Nyholm, a policy adviser at the American Petroleum
Institute, noted that current dispersants are different from
the thick solvents used in 1967 on an oil spill off the
California coast at Santa Barbara.
Nyholm did not directly respond to questions about possible
risks from dispersants to marine wildlife, saying there was
insufficient data to make this assessment.
But she stressed that dispersants are not spread on marine
life or birds: "Birds aren't naturally made to have dispersant
sprayed on them. You don't want to interject a chemical
reaction where you don't have to."
(Editing by Philip Barbara)