[Coral-List] Corexit 9500 and corals

Carys Mitchelmore mitchelm at umces.edu
Thu May 20 00:30:19 EDT 2010


I havn't been following very many of the threads lately. But I see  
some people are asking about dispersant toxicity to corals. I would be  
happy to provide my 2 pennies worth on dispersants to corals generally  
(I co-wrote the NRC dispersant effect book in 2005 and wrote the  
section on corals!).

In addition I carried out a 2 year study (yet to be published although  
the interim reports are available from the funding agency; CRRC UNH)  
specifically on Corexit 9500 on the soft coral Xenia. Bottom line is  
at levels that may be environmentally relevant they were acutely  
toxic, they stopped pulsing (nearly instantly), they lost algae,  
ulcerated (not sure in which order) and with time (or higher doses)  
simply dissolved. Short-time low dose exposures showed delayed effects  
and much reduced growth after one month in recovery. Dispersed oil was  
worse (affected by the dissolved and droplet phases).

I'd be happy to help with any questions. I would also like to ask  
about the hydrous oxide stated to be in the dispersant? How did you  
find this information?

Best wishes,

Carys Mitchelmore
Associate Professor
University of Maryland Center for Environmental Science
Chesapeake Biological Laboratory
PO Box 38
(1 Williams Street)
MD 20688

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