Scientists are predicting that the spreading oil slick in the gulf will soon be picked up by "the powerful Loop Current, a surge of warm water that circulates in the eastern Gulf of Mexico," a Los Angeles Times blog said Tuesday. -- The current moves around, and on Tuesday it moved north, within 30 miles of the oil. -- Once in the Loop Current, "[t]he oil could then contaminate the Everglades National Park, along with mangrove swamps, coral reefs, sea grass and the animals and fish that depend on them, they said. Beaches in Miami and along Florida's eastern coast could be tarred." -- An oceanographer at the Univ. of S. Florida "said he could not predict the exact timing. 'But it appears to be imminent,' he said. 'It looks like it is going to happen sooner rather than later . . . The Loop Current moves very fast.'" -- Coral reefs may be particularly hard hit, since "Chemical dispersants are very toxic to coral reefs," Richard Dodge, director of the Oceanographic Center and National Coral Reef Institute at Nova Southeastern University in Florida, said. -- BP appears to be privileging the use of chemical dispersants, however. -- "[M]ore than 150,000 gallons of a detergent-like chemical intended to blend oil and water . . . [will] use the Gulf waves as a giant wash tub to scrub the oil from the water, eventually dropping it to the seafloor where deep-sea microbes will feast on it for centuries," Bloomberg Businessweek reported Wednesday. ...
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GULF OIL SPILL: FLORIDA BRACES FOR IMPACT
By Margot Roosevelt
Los Angeles Times
May 4, 2010
As the powerful Loop Current, a surge of warm water that circulates in the eastern Gulf of Mexico, moved north within 30 miles of the spill, scientists predicted that it would catch the the oil and sweep it around the Florida peninsula. The oil could then contaminate the Everglades National Park, along with mangrove swamps, coral reefs, sea grass and the animals and fish that depend on them, they said. Beaches in Miami and along Florida's eastern coast could be tarred.
“Where it hits will be devastating,” said James Fourqurean, a sea grass ecologist with Florida International University. “But it is not going to hit everywhere.”
“Filaments of the Loop Current are within tens of kilometers of the oil spill,” said Robert H. Weisberg, an oceanographer at the University of South Florida who has been modeling the movement of the spill. Once the current catches the spill, he said, “the speed of the current is such that it only takes a week before oil will be at entrance of the Florida straits and another week until it gets as far as Miami. . . . Whether the oil gets into the Florida Bay or the Everglades depends on what local winds are doing when oil is flowing past.”
Weisberg said he could not predict the exact timing. “But it appears to be imminent," he said. "It looks like it is going to happen sooner rather than later . . . The Loop Current moves very fast.” As for the oil's trajectory, he said, “Whatever comes will flow west of Dry Tortugas and towards Cuba before it comes back north.” For the oil to get into the vicinity of shallow water in the Florida Bay, Weisberg said, the current "would have to take oil into passes from south to north. It is difficult to get a lot of oil into the Florida Bay."
Elaborating on the nature of the Loop Current, Weisberg explained, “The Loop Current is always there. The question is how far north it extends. The current extends father north into gulf until it sheds an eddy. A piece breaks off and moves west. The rest shifts to south. That process of moving north and eddy shedding repeats itself. It happens every eight to 16 months. Right now it is in the process of moving north."
Weisberg said that if the oil remains in deep water, “there is not an immediate threat to the western coast of Florida.” But he added, “The longer the oil leaks, the more it gets in shallow water along the northern coast, and it make its way south closer to shore.“
“Fortunately," he said, "we are coming out of a strong wind season and going to a weaker wind season.” As for Miami’s beaches, he said, “whether oil makes landfall anywhere depends on what the winds are doing at that point in time. It is likely there could be oil on beaches in Miami.“
If oil gets into the Florida Bay, which is part of the Everglades ecosystem, “it would be a horrible thing to happen, “ said Fourqurean, the sea grass ecologist, who has studied the Florida Bay for 25 years.
Fourqurean said that about 7,000 square miles of sea grass, flowering plants that live under the ocean, are located along the Florida Shelf, the Florida Keys National Marine Sanctuary, Florida Bay, and Biscayne Bay. Sea grasses form the base of the food chain for commercial and economically important species of fish and other animals in South Florida, he added.
Forqurean said that the Florida Bay is “a net evaporation basin. More water evaporates out than water is rained into it. It is a sink. . . . If a surface slick runs along the southern tip of the Florida peninsula, it could be pulled into the Florida Bay and could remain resident there for years. And Florida Bay is part of Everglades National Park.”
However, Forqurean added that “one of the good news pieces is that sea grasses are relatively resistant to oil spills. The only time that sea grasses are drastically harmed is when oil ponds up at low tide and inches across the bed. The bad news is that all the animals that shelter in sea grass beds are very susceptible to oil. Especially larval forms. Oil is very, very toxic to animals. . . . Animals that live completely submerged are poisoned by slightly soluble components of the oil. Oil has elements that are toxic to anything with gills. . . .Turtles and manatees have to breathe air so they come up to the surface. And oil on the surface is sludgier, so that is a physical problem as well as directly toxic.”
Jerome Lorenz, an ecologist with Audubon of Florida, said the oil spill is “a major concern” for mangroves, a tropical tree that lines the shores in south Florida. “If oil enters the ecosystem, it would blanket the surface and destroy the productivity of wetlands,” he said. “Once it is in there, it can’t be cleaned. It will take decades to get the oil out of the system."
Mangrove forests are essential in feeding a variety of birds and crocodiles, and their productivity is crucial to the health of the Everglades, Lorenz said, adding that most colonies of giant wading birds occur in mangrove swamps. Oil could have a devastating effect on game fish species as well as wading birds, such as Roseate spoonbills, osprey, herons, pelicans, he said. "Game fish spend a portion of their juvenile life in those habitats. Redfish, snapper species, sea trout…”
Richard Dodge, director of the Oceanographic Center and National Coral Reef Institute at Nova Southeastern University in Florida, said, “The third part of the triumvirate of Florida coastal ecosystems are the coral reefs. The United States has a lot of coral reef ecosystems, and Florida has 84% of U.S. coral reef ecosystems. So when you look at mangroves, sea grass, and corals, you are looking at a huge economy that generates lots of jobs."
Dodge said that corals, a combination of animals and plants, are affixed to the ocean floor, like sea grass. "So floating oil on top of the water can be benign," he said. "But it depends on the duration and the frequency. Oil can dissolve in the water column and have toxic materials, if you have a big spill or chronic spills.”
Dodge said that if the slick is thin, the oil mixes with water and becomes emulsified, and typically travels along as a layer under the surface. “That could have a direct effect on coral reefs,” he said. “If the oil is emulsified, more toxicity is available. The effect on coral reefs could be copious: effects on reproductive health, bleaching, mortality.“ But he added, “Fortunately oil spills usually are floating and corals are fairly deep.”
Dodge added that when reefs are nearby, “The method of choice to mitigate the oil is not dispersants . . . Chemical dispersants are very toxic to coral reefs. “
“Coral reefs are almost at their breaking point already,” he said. "Global warming is leading to bleaching from higher temperatures, and ocean acidification. And all the pollution effects. We don’t want to add more insults to an ecosystem that is a source of concern.”
BP's CLEANUP USES DETERGENT-LIKE CHEMICAL TO ATTACK OIL SLICK
By Jessica Resnick-Ault
May 5, 2010
BP Plc is fighting the oil slick menacing the Gulf Coast with more than 150,000 gallons of a detergent-like chemical intended to blend oil and water.
The chemicals use the Gulf waves as a giant wash tub to scrub the oil from the water, eventually dropping it to the seafloor where deep-sea microbes will feast on it for centuries, said James N. Butler, a professor emeritus of applied chemistry at Harvard University who has studied dispersants.
“It’s just like dish soap on grease,” Butler said. “The dispersant molecule has one end that likes oil, and the other that likes saltwater, and so it breaks into droplets,” he said in an interview.
While dispersants can help reduce the thick oil slick, the oil will still be out there, said Carl Hacker, resident ecologist at the University of Texas School of Public Health in Houston. The oil molecules could linger for a “geologic” period of time, perhaps thousands of years, said Terry Wade, deputy director at the Geochemical and Environmental Research Group at Texas A&M University in College Station, Texas.
BP engineers are working around the clock to find a way to stop the well from pouring more crude into the Gulf. Even if the company succeeds, it still has an oil slick estimated in recent days to be 600 miles in circumference to clean up. If BP can’t stop the oil at sea, it’s predicted to wash ashore in the coming days, killing wildlife and imperiling fish, shrimp and oysters in a region that supplies a third of the U.S.’s seafood.
“Once the oil reaches the shore, there are very few options,” said Pedro Alvarez, chairman of civil and environmental engineering at Rice University in Houston.
BP is mounting a multipronged defense against the oil slick, using skimmer boats to scoop oil from the water’s surface, placing booms to repel it from shorelines, and burning the oil at sea. None of those methods, including dispersants, will be able to eliminate the oil threat, according to researchers who have studied cleanups.
When oil hits land, it takes five to 10 years for a shore to recover following a spill, said Alvarez at Rice University. Using dispersants and other biotechnology can cut that time to two to four years, he said.
The Environmental Protection Agency, National Oceanographic and Atmospheric Administration and other federal agencies had to calculate a trade-off when approving the use of dispersants to control the spill, Charlie Henry, scientific support coordinator for NOAA, said in a press conference yesterday.
The chemicals are low in toxicity, but spread the oil further, potentially exposing more sea life, Henry said. The agencies decided that using chemicals at sea was preferable to allowing the oil to come ashore, where it would have a more deadly effect on wildlife and fisheries, he said.
BP has been pleased with the early results of an effort to inject dispersants deep into the water directly above where the oil’s escaping, said Bill Salvin, a BP spokesman at the Joint Information Center in Robert, Louisiana.
Oil is leaking from pipes connected to a wellhead on the seafloor nearly a mile below the water’s surface. The flows of crude followed an April 20 explosion that killed 11 workers and sank the Deepwater Horizon drilling rig owned by Transocean Ltd. and leased by BP.
BP conducted two tests of the undersea application, spraying about 3,000 gallons over the leaks in each test, Salvin said. Sonar monitors showed less oil rising to the surface after the dispersants were applied, he said.
Nalco Holding Co., of Naperville, Illinois, is providing much of the dispersants to BP for the oil fight. Dispersants include surfactants -- the same key molecules that make dish soap or detergent active, said Charlie Pajor, a spokesman for the dispersant manufacturer.
Nalco has sent all of the dispersants it held in stock to combat the Gulf oil spill, and is manufacturing more at a plant outside of Houston, Pajor said. BP currently has an additional 230,138 gallons on hand.
To work most effectively, the oil and chemicals need to be blended thoroughly, said Butler, the Harvard professor. BP is relying on waves and currents and winds at sea to mix the dispersant with the oil.
If BP is successful at injecting the dispersants deep underwater, the most sensitive creatures close-by will be marine organisms in the earliest stages of their lives, said Peter Wells, former head of coastal and water science at Environment Canada.
Crustaceans, shrimp-like organisms, and plankton could easily ingest the oil if it was broken into small enough particles and distributed through the water column.
Naturally seeping oil in the Gulf already feeds some microbes, but such organisms aren’t very prevalent, because other sources of food are more appealing, said Wade of Texas A&M.
“It’s like going into the super-market and instead of buying a steak or a potato, eating the floor tiles,” he said.
Eventually, microbes will digest the oil, but it could take thousands of years, he said.
--With assistance from Jim Polson in New York. Editors: Susan Warren, John Viljoen.