Oil Spill Findings

USF’s College of Marine Science

Summary of Oil Spill Findings

June 8, 2010


    1. No dark-colored liquid oil was found at any location or depth during the second Weatherbird II cruise.
    2. Oil was found in the form of weathered emulsified oil (“mousse”) and in the form of invisible oil particles, which is not visible to the naked eye. Emulsified oil forms particles that have a brown or orange exterior and a chocolate-colored interior. Emulsified oil particles have been referred to as “tarballs” by the media.
    3. Low-to-heavy emulsified oil concentrations at the surface were encountered at stations DSH07, DSH08, and DSH_slick1. A wide size range of emulsified oil particles, ranging in size from 1/8 inch to approximately 8 inches long, were observed floating at the surface under calm conditions. Large numbers of the smaller-sized mouse particles were observed to be suspended below the surface down to at least 10 ft below the surface.
    4. Invisible oil particles concentrations (total petroleum hydrocarbons, TPH) in surface water samples collected from among emulsified oil particles were in the range of hundreds of part per billion. This invisible oil particles was determined by NOAA scientists to have originated from the Deepwater Horizon site.
    5. Invisible oil particles collected from depth (400 and 1000 m, or approximately one-quarter mile and two-thirds mile deep) also had TPH concentrations in the range of hundreds of parts per billion, similar to the concentrations found in water near surface emulsified oil particles. Work is continuing to analyze samples from additional depths and locations.
    6. Invisible oil particles collected at depth has a chemical fingerprint that is similar to that of surface samples, except lower-weight molecules were underrepresented, which USF scientists interpreted as being the results of microbial degradation (consumption). 

To view a Special Report on USF researcher's actions involving the Gulf Oil Spill, click here.