Sunday, April 6, 2014

Back in the WHOI lab (April 2, 2014)

Highly viscous, fresh oil on a vertical
glass plate moved only a
few centimeters after 15 minutes
at room temperature.
(Photo credit: Bob Swarthout)
The Port of Houston is one of the largest and busiest ports in the U.S. and is home to the second largest collection of petrochemical processing facilities in the world. About 38 oil tankers navigate the port on an average day in addition to hundreds of barges moving cargo related to petrochemical processing. Given this high volume of petrochemical ship traffic it seems inevitable that collisions between ships like the one that happened on March 22 will occur and it is likely that the area has been impacted by smaller spills in the past.

On our last day of sample collection we encountered evidence of some of these other oil spills. On the Bolivar Peninsula to the north of the spill site at the Fort Travis Seashore Park seawall, we found small samples of fresh oil, but large patches of older oil that was more like concrete and had to be chiseled from the rock. Further north, in the Bolivar Flats Shorebird Sanctuary we found no fresh oil, but did find a tarball that was possibly from an older oil spill and was the consistency of a hockey puck. After collecting these last samples, we shipped everything back to the laboratory.

“Hockey puck” tarball found on Bolivar Peninsula that may be from a previous oil spill.
(Photo credit: Bob Swarthout)

Oil extracts fluoresce under an ultraviolet light
showing the presence of large amounts of hydrocarbons.
(Photo credit: Bob Swarthout)
With the oil samples now in the laboratory, we have started our analyses. This bunker fuel oil is extremely viscous and hardly moves when sample jars are turned upside-down at room temperature. Examining a preliminary extract of the hydrocarbons in the oil with an ultraviolet light shows that it is loaded with fluorescent compounds. It will take some time to analyze all of the samples, but our comprehensive fingerprinting analyses will be able to definitively determine which samples were from the March 22nd spill and which were from other sources. And, analyzing samples collected over the next few months will show us a great deal about how the chemicals in this type of oil weather over time.

Posted by: 
Robert Nelson, Research Specialist
Woods Hole Oceanographic Institution 

Bob Swarthout, Post-Doc
Woods Hole Oceanographic Institution




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