August 24, 2010 - A new study from the Earth Sciences Division of the Lawrence Berkeley National Lab finds that the oil spilled into the Gulf of Mexico from the ruptured BP well degraded at a rate that was "much faster than anticipated," thanks to the interaction of a newly-found and unclassified species of microbes with the oil particles. Berkeley Lab's Earth Sciences Division and the Energy Biosciences Institute examined a dispersed oil plume that was formed at a depth of between 3,600 and 4,000 feet and extended some 10 miles out from the wellhead.

"Our findings show that the influx of oil profoundly altered the microbial community by significantly stimulating deep-sea psychrophilic (cold-temperature) gamma-proteobacteria that are closely related to known petroleum-degrading microbes," said Terry Hazen, a microbial ecologist and principal investigator on the study. The cold-temperature bacteria "appears to be one of the major mechanisms behind the rapid decline of the deepwater dispersed oil plume that has been observed," Hazen said. here's more from Vivian Kuo at CNN.

 

August 24, 2010 - A report released last week by the Georgia Sea Grant and the University of Georgia concludes that up to 79 percent of the oil released into the Gulf of Mexico from the Deepwater Horizon well has not been recovered and remains a threat to the ecosystem.

The report, authored by five prominent marine scientists, strongly contradicts media reports that suggest that only 25 percent of the oil from the Deepwater Horizon oil spill remains.

“One major misconception is that oil that has dissolved into water is gone and, therefore, harmless,” said Charles Hopkinson, director of Georgia Sea Grant and professor of marine sciences in the University of Georgia Franklin College of Arts and Sciences. “The oil is still out there, and it will likely take years to completely degrade. We are still far from a complete understanding of what its impacts are.”

Co-authors on the paper include Jay Brandes, associate professor, Skidaway Institute of Oceanography; Samantha Joye, professor of marine sciences, UGA; Richard Lee, professor emeritus, Skidaway; and Ming-yi Sun, professor of marine sciences UGA.

The group analyzed data from the Aug. 2 National Incident Command Report, which calculated an “oil budget” that was widely interpreted to suggest that only 25 percent of the oil from the spill remained.

Hopkinson notes that the reports arrive at different conclusions largely because the Sea Grant and UGA scientists estimate that the vast majority of the oil classified as dispersed, dissolved or residual is still present, whereas the NIC report has been interpreted to suggest that only the “residual” form of oil is still present.

Hopkinson said that his group also estimated how much of the oil could have evaporated, degraded or weathered as of the date of the report. Using a range of reasonable evaporation and degradation estimates, the group calculated that 70-79 percent of oil spilled into the Gulf still remains. The group showed that it was impossible for all the dissolved oil to have evaporated because only oil at the surface of the ocean can evaporate into the atmosphere and large plumes of oil are trapped in deep water.

Another difference is that the NIC report estimates that 4.9 million barrels of oil were released from the wellhead, while the Sea Grant report uses a figure of 4.1 million barrels since .8 million barrels were piped directly from the well to surface ships and, therefore, never entered Gulf waters.

On a positive note, the group noted that natural processes continue to transform, dilute, degrade and evaporate the oil. They add that circular current known as the Franklin Eddy is preventing the Loop Current from bringing oil-contaminated water from the Gulf to the Atlantic, which bodes well for the East Coast.

Joye said that both the NIC report and the Sea Grant report are best estimates and emphasizes the need for a sustained and coordinated research effort to better understand the impacts of what has become the world’s worst maritime oil spill. She warned that neither report accounted for hydrocarbon gasses such as methane in their oil budgets.

“That’s a gaping hole,” Joye said, “because hydrocarbon gasses are a huge portion of what was ejected from the well.”

August 23, 2010 - On Monday Louisiana state biologists investigated whether a large fish kill at the mouth of the Mississippi River was caused by oil or dispersants from the BP spill in the Gulf of Mexico. The fish were found in the Mississippi River Gulf Outlet, a 76-mile shipping shortcut from the Gulf of Mexico to New Orleans that was dug by the U.S. Army Corps of Engineers in the 1960s. The shortcut is like a dead-end canal. Preliminary testing by the state indicated that the cause of the fish kill was "hypoxia" or lack of oxygen. Hypoxia is most often caused by an excess of nitrogen and phosphorus from agricultural fertilizer or human waste, but it could also be caused by chemical dispersants, which were used extensively after the oil spill. More from Margot Roosevelt LATimes

The cause of the fish kill may be be related to the dead zone at the mouth of the Mississippi caused by agricultural run-off and other industrial activities. The massive dead zone is caused primarily by nitrogen and phosphorous run-off from fertilizers, soil erosion, animal wastes, and sewage. The Mississippi River Basin drains much of the United States, from Montana to Pennsylvania and includes the Mississippi River Valley, Minnesota, Iowa, Illinois, Wisconsin, Missouri, Tennessee, Arkansas, Mississippi, and Louisiana. In a natural system, these nutrients aren't significant factors in algae growth because they are depleted in the soil by plants. However, excess nitrogen and phosphorus from human activities overwhelms the system such that algae growth is no longer limited - algal blooms develop, the food chain is altered, and dissolved oxygen in the area is depleted. The size of the dead zone fluctuates seasonally, as it is exacerbated by farming practices. It is also affected by weather events such as flooding and hurricanes. More from Monika Bruckner Montana State University.

 

 

 

August 20, 2010 - A recently completed tudy of water samples taken in June has confirmed the existence of a huge plume of dispersed oil deep in the Gulf of Mexico. The study suggests that the oil has not broken down rapidly and might pose a threat to wildlife for months or even years. The study, the most ambitious scientific paper to emerge so far from the Deepwater Horizon spill, casts some doubt on recent statements by the federal government that oil in the gulf appears to be dissipating at a brisk clip. However, the lead scientist in the research, Richard Camilli, cautioned that circumstances could have changed in the last two months. Here's the full story from Justin Gillis and John Collins Rudolph at NYTimes.