[Coral-List] Panama oil spill study

John.Cubit John.Cubit at noaa.gov
Tue May 4 19:39:59 EDT 2010

I was one of the principal investigators on the effects the 1986 Bahia 
las Minas Oil Spill, the spill on the Caribbean coast of Panama to which 
Gene refers.  I specifically investigated  impacts of the oil on the 
algae, sea grasses, and invertebrates on semi-intertidal and shallow 
subtidal reef flats.  To address Gene's remarks, we designed our 
studies  to avoid confounding impacts of the oil spill with the 
potential effects of seasonal and longer-term changes in reef flat 
populations, including the kinds of phenomena that Gene raises.   We 
used comparisons of impacts along oil-exposure gradients and comparisons 
of oil-exposed and non-exposed reference sites, not blind 
"before-and-after" changes. From our vantage point at the Smithsonian 
Galeta Marine Laboratory, we also made direct observations of biota 
dying while being directly immersed in oil but not dying in matched 
habitats that were not immersed in oil.  We used "before-and-after" 
comparisons to show that such simplistic methods are NOT valid to 
determine causes of loss in a varying environment--substantiating the 
old adage that correlation does not prove causation.   For example, at 
the time of the spill, Galeta Reef was the site of a long-term 
environmental studies program that had documented that certain groups of 
reef flat biota die-off naturally during the seasonal reef emergences 
that were underway when the spill occurred.  These seasonal mortalities 
were not attributed to the spill.  In response to Gene's statement about 
the demise of Diadema, the same long-term environmental studies program 
also documented the mass-mortality of Diadema three years before the 
Bahia Las Minas spill.  No one attributed this loss of Diadema to the 
oil spill. 

The studies of the Bahia las Minas spill were funded by a contract from 
MMS.  Comprehensive reports of the individual spill studies were 
authored by 16 investigators and have been published by MMS in a 3 
section set edited by Jeremy Jackson and Brian Keller.  The sections are 
available for downloading at this MMS website:

John Cubit

Eugene Shinn wrote:
> Yes, the Panama study of oil effects was the largest most expensive 
> study of oil effects of its kind. I heard much about it from 
> representatives of the agency that funded the study. One aspect of 
> the study not fully  appreciated when the 1989 Science article that 
> described results of the 1986 spill was published was that  the 
> Caribbean-wide coral disease episode had stepped up dramatically 
> between 1983 and 84. Bleaching would follow in 1986 and 1987. In 
> retrospect one can safely speculate that much of the documented 
> coral, and Diadema demise, as well as seafan disease, would have 
> happened in Panama even if there had been no oil spill. With 20 20 
> hindsight one has to wonder how much of the coral demise at Panama 
> was actually caused by the spill? In fact, disease was already 
> showing up in un oiled control areas in Panama according to personal 
> communications with some of the representatives of the agency that 
> funded the study.
>      The reef at Goleta point is an enigma. I visited the reef with 
> Harold Hudson in 1974 to examine Ian MacIntyre's coring rig while he 
> was doing his ground breaking study with Peter Glynn. The weather was 
> beautiful, the water was warm, and there was the full compliment of 
> Atlantic corals on the basically Acropora palmata reef, but water 
> visibility was limited to about 30 feet. When we asked researchers at 
> the laboratory about the poor water visibility we were told that what 
> we saw was as good as it gets, and that during the monsoon season the 
> water looks like coffee with cream! We were told, "The water gets so 
> murky that experimental settling plates on the reef were coded with a 
> braille system so that divers could distinguish one panel from 
> another." Surprisingly the corals appeared healthy. That was 1974 
> before the beginning of serious and ongoing coral diseases affecting 
> corals throughout the Caribbean.  Gene

John Cubit, Ph.D.
Regional Resource Coordinator, Southwest Region
NOAA Assessment and Restoration Division, Suite 4470  
501 W. Ocean Blvd.  
Long Beach, CA 90802  
John.Cubit at noaa.gov  
tel 562 980-4081  
fax 562 980-4084  
Cell phone (for urgent matters and travel contact) 562 810-4949

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