Dr Samantha Jove, professor of Marine Sciences and leader of a team of marine scientists from University of Georgia who were among the first to report huge underwater oil plumes thousands of feet below the GOM surface, has reported that recent submarine surveys of the ocean floor in the BP Macondo spill region show little sign of recovery. As stated in a recent chat on Science Now, her journey to the sea bottom revealed a total lack of infaunal organisms (worms,) and holothurians (sea cucumbers,) as well as dead brittle stars, a few sickly crabs, and oiled, dead corals. Flocculent (oil mousse) deposits were found at every site sampled and there was a striking lack of evidence of microbial degradation leading her to conclude that, “[s]ome component of the microbial community that degrades such complex carbon structures is ‘stuck’.” In response to questions regarding the potential for dispersants to affect such microbial activity, Dr. Mandy replied, “[d]ispersants could influence microbial activity–we are trying to get dispersant from NALCO to study its impacts on pure cultures and natural microbial communities. And, I have heard that ammonium sulfate was added to the dispersant to alleviate nitrogen limitation of the oil degrading microorganisms…” Dr. Mandy, who suffers from asthma, claimed she had breathing difficulty in the area around the wellhead before it was capped, and where people were suffering burns. While sampling oily sediments, she and several team members suffered red rashes – a condition she had never experienced working in oily mud previously.
Dr. Mandy’s blog is Gulf Oil Blog
The BP Macondo Deepwater Horizon spill in the Mississippi Canyon region of the Gulf of Mexico is estimated to have released between 62500 to 68000 barrels of oil per day (bopd) for 84 days (a barrel is 42 US gallons or 159 liters) between the dates of April 22, 2010 and July 14, 2010.
What is rarely, if ever mentioned though, is the accompanying gaseous hydrocarbon release. In the February 13, 2011 publication of Nature Geoscience, Dr. Joye has estimated that the gaseous component of the spill amounted to 500,000 tons of low-molecular-weight hydrocarbon gases, methane to pentane.
Sampling data from various stations within 20km of the wellhead showed elevated alkane concentrations exceeding background by up to 75000 times in discrete layers between 1000m and 1300m in depth. Among these were regions with low alkane levels which also showed severly depleted O2 levels, suggesting oxygen depletion via oxidation of the alkanes by organisms such as Methylosinus sp., Pseudomonas butanovora, Gordonia sp., and Mycobacterium vaccae. Oxygen levels are further depleted by microorganism consumption of disolved and dispersed oil. The reduction of limited available oxygen resources by microbial metabolism of oil and gasses poses a very significant hazard of reducing the oxygen concentration below 63uM, the level at which many oxygen-requiring animals become stressed and die. This situation may well lead to multiple anoxic (oxygen starved) dead zones around the spill site.