3. Sampling

The next step was to get samples of seawater directly from the plume to see what chemicals were in it.  “We weren’t stabbing arbitrarily hoping to find something,” said WHOI chemist Chris Reddy. “We used a hunter-gatherer strategy: Sentry had hunted for the plume, told us exactly where to look, and we gathered right there within it.” The samples were dispatched to a laboratory and analyzed to look for more than 100 different compounds. The research team’s findings, published in Proceedings of the National Academy of Sciences in July 2011, showed that the plume contained a preponderance of only six petroleum hydrocarbon compounds: benzene, toluene, ethylbenzene, and xylenes.