Possible environmental impact of Gulf oil spill

Reuters 28 Apr 10;

(Reuters) - A giant oil slick from last week's deadly offshore drilling rig explosion in the Gulf of Mexico threatens wide-scale coastal damage for four states.

Following are some possible impacts from the spill on the Gulf environment, commercial fisheries, wildlife and tourism.

FISHERIES

- A number of fisheries could suffer as a result of the spill. The Gulf menhaden fishery -- a species harvested mostly for fish meal and fish oil -- is America's third largest and in some seasons its second largest, according to Greenpeace. Menhaden are filter feeders and so they could be badly affected by the spill, as they pass tainted water through their filtering system. The season for Texas, Louisiana and Mississippi just opened on April 19th.

Omega Protein Corp -- which relies on the fishery for its core business -- said in a statement on Wednesday that: "We believe that the impact, if any, on our Gulf of Mexico fishing operations will be minimal."

- The northern Gulf of Mexico is a crucial spawning ground at this time of the year for the Atlantic population of bluefin tuna, which is critically endangered. Their eggs float near the surface and the larvae also stay near there after they first hatch. So, the spill has occurred at a critical time in their life-cycle.

"We expect a spill like this could dramatically decrease the amount of bluefin tuna larvae that are surviving," said John Hocevar, the Oceans Campaign director for Greenpeace USA.

- Losses could also be inflicted on the shrimp and oyster industries in Louisiana. Oysters are filter feeders and cannot swim to escape the slick. The prime oyster-gathering season in Louisiana starts on May 1.

BIRDLIFE

- Several areas that are important to bird populations could be potentially affected.

According to the National Audubon Society, places it has designated as "Important Bird Areas" or IBAs that could be threatened by the slick include, Chandeleur Islands IBA and Gulf Islands National Seashore IBA in Louisiana and Mississippi; also in Louisiana, the Delta National Wildlife Refuge and Pass-a-Loutre Wildlife Management Area.

Species at risk include, Louisiana's state bird, the brown pelican, which was only removed from the U.S. Endangered Species Act last year. They nest on barrier islands and feed near shore. Their breeding season has just started.

Other species that would not fare well, especially if the slick comes ashore, include the American oystercatcher and Wilson's plover.

TOURISM

- Depending on where the slick goes, a number of beaches could be adversely impacted in areas such as the northwestern part of Florida, which has been running televised ads aimed at attracting tourists to the area.

OTHERS

- Several species of sea turtles are currently moving through the Gulf, as their spring nesting seasons commences and they need to surface to breathe, so the slick at the water's top could damage their populations.

US oil burn begins as wind turns for the worst
Allen Johnson Yahoo News 29 Apr 10;

NEW ORLEANS, Louisiana (AFP) – Crews began controlled burns Wednesday of a giant oil slick in the Gulf of Mexico, but a cruel wind shift raised fears the spill could hit Louisiana's fragile shores by the weekend.

The leading edge of the crude was about 16 miles (26 kilometers) off the Louisiana coast by Wednesday evening and winds were expected to strengthen and crucially change direction on Thursday to start coming from the southeast.

Two skimming vessels dispatched by the US Coast Guard and energy giant British Petroleum (BP) swept the thickest concentrations of oil into a 500-foot (150-meter) fire resistant boom.

They then towed it to a five mile "burn zone" set up inside the slick roughly 50 miles south of the mouth of the Mississippi where it was set alight a few hours before nightfall.

"They lit it with a little float that has a fuel source on it that floats into the oil and ignites. It did successfully ignite," Coast Guard petty officer Cory Mendenhall told AFP.

The decision to start burning the slick, which has a 600-mile (965-kilometer) circumference, gained even greater import when the US government's weather service warned that the previously kind winds were about to shift.

"Stronger southeast winds are forecast to persist from Thursday night through Saturday night," a National Oceanic and Atmospheric Administration (NOAA) forecast chart presented to journalists showed.

"These onshore winds will move floating oil towards the delta with possible shoreline impacts by Friday night."

If large quantities of the crude, which is leaking from the debris of a rig that sank after a deadly explosion last week, drift into Louisiana's marshy wetlands, mopping up would be next to impossible.

It would be disastrous for natural parks full of waterfowl and rare wildlife and could also imperil the southern state's 2.4-billion-dollar a year fisheries industry, which produces a significant portion of US seafood.

As miles of inflatable booms were set up to protect the Louisiana coast, Governor Bobby Jindal evoked memories of Hurricane Katrina, which devastated his southern state in August 2005.

"As I've said many times before, we must hope for the best and prepare for the worst," Jindal said, after a flyover of the spill. "We're approaching this situation just as we would do before a hurricane comes ashore."

"We're doing everything we can to protect the livelihood of our citizens who make their living in the fishing industry and the wildlife that grace our coastal areas."

Oil, at the rate of 42,000 gallons a day, is spewing from the riser pipe that connected the Deepwater Horizon platform to the wellhead before the rig sank last Thursday, two days after a huge explosion that killed 11 workers.

The widow of one of the dead has filed a lawsuit accusing the companies that operated the rig -- BP, Transocean and US oil services behemoth Halliburton -- of negligence.

The accident has not disrupted offshore gulf oil production, which accounts for more than a quarter of the US energy supply.

BP, which leased the semi-submersible rig from Houston-based contractor Transocean, has been operating four robotic submarines some 1,500 meters (5,000 feet) down on the seabed to try and cap the well.

They have failed so far to fully activate a giant 450-tonne valve, called a blowout preventer, that should have shut off the oil as soon as the disaster happened but only partially reduced the flow.

As a back-up, engineers are frantically constructing a giant dome that could be placed over the leaks to trap the oil, allowing it to be pumped up to container ships on the surface.

Another Transocean drilling rig is also on stand-by to drill two relief wells that could divert the oil flow to new pipes and storage vessels.

But that would take up to three months and the dome is seen as a better interim bet even though engineers need two to four weeks to build it.

Coast Guard Rear Admiral Mary Landry, who is leading the government's response to the disaster, warned on Tuesday that if BP fails to secure the well it could end up being "one of the most significant oil spills in US history."

Coast Guard sets oil slick ablaze
Chris Baltimore, Reuters 28 Apr 10;

HOUSTON (Reuters) - The U.S. Coast Guard on Wednesday set a "controlled burn" to battle a giant oil slick from last week's deadly offshore drilling rig explosion, as the spill threatened wide-scale coastal damage for four U.S. Gulf Coast states.

The leaking well, 5,000 feet under the sea off Louisiana's coast, has created an oil sheen and emulsified crude slick slightly bigger than the U.S. state of West Virginia, the Coast Guard said.

Eleven workers are missing and presumed dead after the worst oil rig disaster in almost a decade. Swiss-based Transocean Ltd's Deepwater Horizon rig sank on April 22, two days after it exploded and caught fire while finishing a well for BP Plc about 40 miles southeast of the mouth of the Mississippi River.

The burn began at 5 p.m. CDT (2200 GMT), an agency spokesman said. Workboats were to pool segments of the spill inside a fire-resistant "boom," essentially a floating corral, to be towed to a remote area for burning, the Coast Guard said.

The agency said it planned "small, controlled burns" of several hundred gallons each lasting about an hour and invisible from shore.

BP, which owns the well, is spending millions of dollars a day on what it has called the largest oil spill containment operation in history, involving dozens of ships and aircraft.

"We will not rest until we have done everything to bring this under control," said Andrew Gowers, head of group media for London-based BP, likening the spill's consistency to "iced tea" with the thickness of a human hair.

'VERY SERIOUS'

At midday Wednesday, the edge of the spill was 23 miles off the Louisiana coast, near fragile estuaries and swamps teeming with birds and other wildlife. A shift in winds could push the spill inland to the Louisiana coast by this weekend, according to forecasters at AccuWeather.

Tarballs and emulsified oil streamers could reach the Mississippi Delta region late on Friday, said Charlie Henry, an expert with the National Oceanic and Atmospheric Administration.

Along with a large seafood industry, the area contains key wildlife habitats in the Pass-A-Loutre Wildlife Management Area and Breton National Wildlife Refuge on the Louisiana coast, which are teeming with nesting birds.

"It's premature to say this is catastrophic," said Coast Guard Rear Admiral Mary Landry, who is heading the federal cleanup effort. "I will say this is very serious."

The spill could be devastating for fishermen and oystermen that rely on estuaries and swamps along the Mississippi River for their livelihood. For a factbox of potential environmental impacts, follow the link.

"We're sitting here half praying and half with our fingers, toes and everything else crossed," said Byron Encalade, president of the Louisiana Oysterman Association in Pointe A La Hache, who lost five boats when Hurricane Katrina hit in 2005.

As the oil spill grows, so does the chance that it will affect efforts by the U.S. Congress and President Barack Obama to open more offshore areas to limited oil and gas drilling.

"This brings home the issue that drilling despite all the advancements in technology is still a risky business," said Athan Manuel of the Sierra Club, an environmental group.

Preparations were underway to deploy thousands of feet of floating booms in Louisiana, Mississippi, Florida and Alabama in an attempt to contain the oil slick, the Coast Guard said.

The Louisiana accident is the worst oil rig disaster since 2001, when a rig operated by Petrobras off the Brazilian coast exploded and killed 11 workers.

The spill is not nearly as big as the Exxon Valdez disaster, which spilled about 11 million gallons (50 million liters) of oil into the Prince William Sound in Alaska in 1989. BP's well is spewing about 42,000 gallons (190,900 liters) of oil a day into the ocean, the Coast Guard estimates.

(Additional reporting by Kristen Hays in Houston and Pascal Fletcher in Miami; Editing by Mary Milliken and David Gregorio)