This past Friday marked the departure of the National Oceanic and Atmospheric Administration’s ship Pisces from Mississippi into the Gulf of Mexico. This trip is part of a continued response to the BP Deepwater Horizon oil spill incident and aims to accumulate and interpret information about the oil released, as well as the effects on the water and sea floor surrounding it.
This ongoing testing is set to continue from Florida to Louisiana and into the Gulf of Mexico. Several boats and barges have already been sent out and have been collecting data by sampling the water columns near the spill location.
The Pisces is part of a multifaceted attempt to analyze the sea floor sediment potentially affected by the oil. UCSB geochemistry and geomicrobiology professor David Valentine is the acting chief scientist for this mission. He is joined by associates from East Carolina University, California Institute of Technology and the U.S. Geological Survey.
Valentine and the rest of the crew intend to document and investigate the chemicals typical of oil found near the spill site.
“The compounds that are being analyzed are the standard toxic compounds that are known [to exist] in oil,” Valentine said in a dockside press release. “These include aromatic hydrocarbons as well as other hydrocarbon components.”
The products that are being tested tend to be very low in concentration and, as such, are very difficult to analyze. The process to analyze the compounds must be handled carefully, and the testing has been broken into two parts: water and sediments.
The water testing has been occurring all summer, and the sampling itself is mostly completed. The data from the samples is currently being analyzed as they come in on a daily basis. The team in charge of the testing is trying to determine whether there are gaps in the research that must be filled or if they have completed their research and are therefore ready to produce a comprehensive conclusion on their studies.
The second part of the testing is the sediment sampling. This is where the research vessels, the Ocean Veritas and the Pisces, come into use. These ships are expected to have all the necessary sediment samples within the next couple weeks. The same teams that are embarking on the trips will be analyzing the information they find and determining whether additional sampling would be required.
The near-shore sediment sampling has already been completed, and the findings from this indicate a lack of oil compounds. In addition to this, the water sampling has shown that dilution has occurred from water being mixed in and the microbes which continue to decrease the amount of oil in the areas near the plumes used for testing. The concentration has lowered to such a level that it is being measured in units as small as parts per billion, so more and more sophisticated instruments are necessary to accurately gauge the oil content in the water. Though the layer of oil in the water column is still present — and used to be much thicker — it is much thinner now and continues to degrade over time.
The current testing to see if oil has fallen into the sediment will require similarly powerful testing procedures.
“We are doing extensive coring operations,” Valentine said. “Onboard we have the mass spectrometers that we need to quantify the amount of oil that may be there.”
The vessel is also equipped with a Toad Camera system that is deployed behind the ship and is towed along above the sea floor, taking 2,000 images of the sea floor every five hours. With this, the team hopes to measure the distribution of oil, if there is any, to understand the patterns of deposition. This is followed up by the coring to understand how much oil is actually there.
The Pisces is expected to be out performing tests until Oct. 4, but the teams will be releasing information periodically via live mission log updates which can be found at www.missionlog.noaa.gov. Information on the Pisces vessel and other NOAA ships can be found at www.moc.noaa.gov. For further updates on the response, visit www.restorethegulf.gov.