[Coral-List] BP Crude Oil Found in Heterotrophic Corals

Eugene Shinn eugeneshinn at mail.usf.edu
Wed Apr 10 15:45:44 EDT 2013

Dear Steve, I just read the paper you published with Porter, Sammarco, 
and Cake (I should have read it before my previous post) and agree that 
this was most certainly BP oil. The photo (figure 2) showing the slick 
not far from the platform is proof enough. In addition the samples were 
taken between 12 and 20 meters below the surface. That corals at that 
depth contained oil is clear evidence the oil contained Corexit. Without 
surfactants oil would have been restricted to  surface waters above the 
zone of coral growth. In my experience coral mucus resists absorption of 
untreated crude oil even when totally submerged in oil. That is what 
happened when I totally submerged /Acropora cervicornis/ in typical 
Louisiana crude for one hour (the coral grew when placed back in sea 
water). Below the surface slicks the amount of hydrocarbons dissolved in 
sea water from untreated crude is generally low. Experiments performed 
at Texas A and M in the early 1970s showed the maximum level of 
hydrocarbon that could be dissolved in sea water was around 19 ppm. What 
you have demonstrated is clearly many times greater. I conclude that is 
because of the surfactant Corexit.  In the mid 1970s I helped write the 
API oil spill clean up manual. I wrote the coral reef section. The main 
conclusion was that surfactants should not be used on  oil spills in the 
vicinity of coral reefs. I suspect you would agree with that conclusion. 
The paper you have published is excellent! It will be interesting to see 
how far westward this oil can be traced in corals. Is Tubastrea the 
exotic that had drawn so much attention lately? Gene


No Rocks, No Water, No Ecosystem (EAS)
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E. A. Shinn, Courtesy Professor
University of South Florida
College of Marine Science Room 221A
140 Seventh Avenue South
St. Petersburg, FL 33701
<eugeneshinn at mail.usf.edu>
Tel 727 553-1158
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