If a hurricane should hit the already oil-slicked Gulf of Mexico, it could mean that oil could be stirred up, infiltrating new, ecologically sensitive areas — or disperse more quickly, experts say.
It's a guessing game at this point.
The 2010 Atlantic hurricane season is promising to be extremely active, according to the Maryland-based National Oceanic and Atmospheric Administration (NOAA), which released its hurricane outlook Thursday in Washington, D.C.. It is predicting 14 to 23 named storms, meaning ones with winds of 62 km/h or higher, eight to 4 hurricanes (winds of 117 km/h or higher) and three to seven major hurricanes, which include Category 3, 4 or 5 storms, with winds of 178 km/h or higher.
Hurricanes, oil a potent mix
Oil cleanup efforts in the Gulf of Mexico will overlap with the 2010 Atlantic hurricane season that starts in June.
In the event of a major storm "oil on the bottom in shallower areas could be stirred up" due to strong wave action, Kelly Hawboldt, associate professor, faculty of engineering and applied science at Memorial University in St. John's, N.L., told CBC News Friday.
Hawboldt, an expert in environmental safeguards for offshore oil platforms, said that such an event could cause oil that had settled to the bottom to be redistributed, potentially ending up in surface areas of the ocean that are home to birds and other animals.
"Anything that occupies that water interface — all the animals that hang out there — they are all vulnerable to it," Hawboldt said.
A storm could also create a greater number of tar balls, globs of oil that coalesce and take a very long time to degrade. "That stuff getting redistributed on the coast would be very bad," she said.
Other experts have said that high winds could also hamper cleanup efforts, as boats aiding in the process will have to evacuate the area and booms used to contain slicks will be unable to remain in place.
Hawboldt said a storm could also help disperse slicks, a process which could increase microbial degradation of the oil.
"The more you break up the oil, the easier it is to degrade. This degradation is the function of nutrients, oxygen, sunlight," she explained, adding that it's a process that can take "days, months, years."
Overall, it's unclear what exactly will happen. The only precedent is Hurricane Katrina, which in 2005 led to nearly 50 oil spills in the lower Mississippi corridor, according to John Pine, director of the Disaster Science and Management Department of Geography and Anthropology at Louisiana State University. Pine published a case study on Hurricane Katrina and its impact on coastal and ocean environments in the June 2006 issue of Oceanography.
Pine looked at one spill, by Murphy Oil Corp., which involved the release of 3.1 million litres into a highly populated area called St. Bernard Parish, located southeast of New Orleans. Following the oil spill, 1.2 million litres were recovered, 742,000 litres were contained, 1.2 million litres evaporated and 22,712 litres were never recovered.
The Murphy spill affected 1,700 homes in a residential neighbourhood nearby and infiltrated local canals. It also affected marshes and other coastal environments.
One possible long-term impact is a decrease in biodiversity in the areas of the Gulf affected by the spill, said Hawboldt. She said that years after the Gulf War of the 1990s, in which an enormous amount of oil was dumped into the Persian Gulf, oil-degrading microbes flourished but other microbial populations dropped off dramatically.
"If this outlook holds true, this season could be one of the more active on record," said Jane Lubchenko, undersecretary of commerce for oceans and atmosphere. "The greater likelihood of storms brings an increased risk of a landfall. In short, we urge everyone to be prepared."
According to NOAA, the seasonal average is 11 named storms, six hurricanes and two major hurricanes. The reason for the increase in storms this year is threefold: reduced wind shear due to the dissipation of El Nino; higher-than-average sea surface temperatures; and a trend toward tropical storms which began in 1995.
This forecast could also cause further spread of the oil released by the spill in the Gulf of Mexico. The Deepwater Horizon, the offshore oil rig leased by BP that exploded in late April, is still leaking from the wellhead riser, and experts worry the oil's reach could be increased considerably in the event of a storm or hurricane.
Dispersants could do more harm than good
BP is currently adding gallons of dispersants to the oil leak, attempting to break up the oil via chemical means. It's a move that has angered many environmental groups, including the U.S. Environmental Protection Agency, as the type of dispersants used and their quantities are unknown. The agency is concerned that essentially a huge scientific experiment that could have big implications for human and animal life is being carried out.
Dispersants are products with two component parts — one half is more soluble in oil than in water and one half is more soluble in water than in oil. Composed of substances such as polymers, sulfates and glycol, these proprietary blends break up oil slicks into smaller droplets so that they can then be further degraded by microorganisms.
Environmental and public health groups say dispersants can cause human illness, and kill mammals and aquatic life. They also point out that manufacturers of the products do not have to disclose their ingredients.
According to Kelly Hawboldt, associate professor, faculty of engineering and applied science at Memorial University in St. John's, N.L, dispersants are chemically toxic if used in the wrong concentrations. She says that given the current scenario in the Gulf, in which the exact quantities of gushing oil are unknown, it's hard for scientists to know just how much dispersant to use. And with unknown quantities at play, the potential for misuse is high.
"I know they've been distributing boatloads," she told CBC News. "You wouldn't want to be putting [dispersants] on for the next month."
Lubchenko said that a hurricane in the Gulf could mean "that some of the oil on the surface will be transported through the storm surge. Where the oil on the surface is transported will depend on the track of that hurricane."
Craig Fugate, administrator with the Federal Emergency Management Agency (FEMA), said that there is little information on how a hurricane could affect an oil spill the magnitude of the BP disaster. He says scientists are now working on models of how the oil might come ashore or dissipate.
But he says that right now human safety is paramount for FEMA. "If the story after the hurricane is the [oil] cleanup, I'm [a] happy person."
On May 20, U.S. President Barack Obama issued a presidential proclamation during National Hurricane Preparedness Week, urging U.S. citizens to develop a plan for storm season before it begins.
"These precautions include developing a family disaster plan, maintaining an emergency supply kit, securing homes, businesses, and belongings and learning evacuation routes," he wrote in an address posted on NOAA's website last week.
"To help Americans meet the challenges of severe weather, my administration is focusing on preparedness and response before, during, and after hurricanes," Obama wrote.
"We are improving accountability and co-ordination between all levels of government, modernizing our emergency communications and empowering more families to prepare themselves."