Dispersed Oil Found in the Gulf in Navarre, Florida. How Predictable.

Last week I had the opportunity to accompany Coastal Geologist Rip Kirby from the University of Southern Florida on a search mission.  The quarry was oil, and Rip was confident that we would find it.  Spurred on by the latest report from the Coast Guard that there was very little oil off of the Gulf Coast, where they found only two of 5,000 samples to contain oil, Rip was determined to test a hypothesis.  The Coast Guard tests were done in random locations, but just like the oil as it hits the shore, this near neutrally buoyant dispersed oil settles in very predictable locations.  Rip hypothesizes that this oil is gathering in depressions along the ocean floor, and we set out to test that theory.

As we exited the Destin harbor we came across an area of orange, dispersed oil floating on the surface of the water.  I was taken aback as I hadn’t seen that type of oil in almost a month, and to see it so far to the East was a little baffling.  In fact, that oil has come ashore this weekend in Southern Louisiana confirming a report from a friend that had been briefed by Unified Command about a  1 mile long by 100 foot wide swath of oil just off of the Louisiana coast last Thursday night.  This oil has now come to rest on 16 miles of shoreline in Plaquemines Parish, and in Barataria Bay, as there are virtually no skimmers left in the water to combat this oil.  

Back to Florida.  We ran a transect in 40 feet of water to the west out of Destin looking for underwater gullies where we would look for the oil.  In our first transect we didn’t find any obvious depressions, but there was a small concave area that was worth a free dive.  This first site was not quite what we were looking for in terms of contour, and appeared to be clean.

Geologist, Rip Kirby dives in to check out the bottom.   

We then started our North/South transects, and marked a waypoint at the first depression that we hit.  We continued to cruise a little bit to see if we might find something better but returned to the first location that looked good on the sonar.  The divers geared up, and I actually went for a swim, maybe not the smartest thing I’ve done as more science is gathered about the toxicity of the dispersants to humans.

The plan was for the divers to move along in a row, down the depression looking for oil.  They had a buoy with them that would show their position so we could pick them up after the 40 minute dive.  We didn’t have to go anywhere, as the buoy didn’t move.  As soon as they hit the bottom they saw that it was much darker than was normal, and noticed that all of the Sand Dollars were a dark blackish brown.  When they resurfaced Rip described an area devoid of life, with shells of dead crustaceans along the bottom.  Besides the one Remora that came to check the divers out, no other fish were seen on the dive, and yes of course, the darker substrate was oil.  By oil we mean a Corexit/oil mixture.

Rip with his sample jars at the site of the second dive. 

The samples are in the lab, but Rip has figured out a way of identifying the dispersants using UV light.  Both forms of Corexit fluoresce in this type of light, and all of the samples showed both forms of dispersant, and smelled of petroleum.  A sample was also taken of the water itself, and when it settled out, a centimeter thick layer of Corexit 9500 settled out in the bottom of the jar.

Student Diver, Kyle Saleeby holds up one of the  discolored Sand Dollars for inspection.

As we were preparing to head back to port we noticed a Greater Shearwater sitting on the water.  It didn’t fly and was very close, in fact, it was swimming toward us.  One attempt to rescue the bird was made, in which it flew weakly in a labored manner, and it was decided that we were not equipped to rescue the bird in our large boats without any nets.  The bird like most birds seen these days did not exhibit any obvious sign of oiling, but it did have severely worn flight feathers.  It was molting symmetrically, and the older yet to be molted secondaries, primaries and rectrices were worn straight to the shaft.  I have never seen this type of feather wear in a Greater Shearwater before, and it is exactly what we are witnessing in many of the Gulls, Terns and Pelicans along the Gulf Coast.  The theory is that as the birds preen their feathers with fervor to try and remove oil they are doing a lot of damaged to their feathers.

The Greater Shearwater that we found, and had to leave behind. 

When we finally got back to the hotel, Rip used his light on a couple of samples I had in my truck, and ion the process showed that everything I have in the back of my truck is contaminated with dispersants.

This boot was last worn on July 23rd on Grand Terre Island.  The Orange is Coerexit 9500, and the magenta is the more toxic 9527.  Both have not broken down in two months, as well as the oil that remains on the shoes.

Read the original story at American Birding Association – Gulf Coast Oil Spill