[Coral-List] Cyclic and fatal bleaching of giant barrel sponges

Pawlik, Joseph pawlikj at uncw.edu
Thu Aug 4 09:33:17 EDT 2005

Greetings Coral-listers and Porifera-listers,


Regarding the recent postings about bleaching of the giant barrel sponge, Xestospongia muta, in the Caribbean, our group has been monitoring bleaching of this sponge on reefs off of Key Largo since 1997 with funding and facilities support from NURP/UNCW.  We now have data for 626 individually tagged sponges, with over 5,700 digital images.  The population structure and levels of bleaching in Key Largo are similar to those we have observed throughout the Bahamas on reefs that are far from human impacts.  Cyclic bleaching is very common, not fatal, and probably not a "disease".   Fatal bleaching is rare, easily mistaken for cyclic bleaching, and usually associated with "sponge orange band" (SOB) syndrome, which may involve a pathogen.  Cyclic and fatal bleaching appear to be distinct phenomena.  We will be publishing our findings in a year or two, but until then, we have some general information at this web site, including photos:

Both cyclic and fatal bleaching appear to be Caribbean-wide, and have existed since at least the late 1980s.  If you have seen other kinds of mortality of Xestospongia muta , please contact me. 
Joseph R. Pawlik, Professor 
2003-2005: Associate Program Director 
           Biological Oceanography Program 
           Suite 725 
           National Science Foundation 
           Arlington, VA  22230 
UNCW Center for Marine Science 
5600 Marvin K Moss Ln
Wilmington, NC  28409  USA 
pawlikj at uncw.edu; (910)962-2377  FAX: (910)962-2410 
Website: http://people.uncw.edu/pawlikj/index.html 
PDFs: http://people.uncw.edu/pawlikj/pubs2.html 

More information about the Coral-List mailing list