[Coral-List] Michael Risk - C. delitrix as measure of bioerosion

[Albert Norström]

I'm another one of those people from the "its about time we discussed  
clioniid sponges" camp. I'll keep my post short, since most of what I  
have to say on the subject has already been said. However, one thing  
has struck me as very peculiar. While the coral-macroalgal shifts in  
the Caribbean  have garnered much attention (in the general  
"degradation of reefs literature", but also in the interesting phase- 
shift discourse), little  has been said about the spread of  
bioeroding sponges such as C.delitrix. Why so? It seems that both  
phenomena are widespread throughout the Caribbean and that, as is the  
case with macroalgae, sponges are now dominants in systems previously  
dominated by hard corals.

Is this simply due to macroalge being more conspicuous benthic  
organisms, and that clioniids are more difficult to include in  
classic measures of benthic cover? Is it because, they exhibit faster  
turn-over rates, thus making these "sponge phases" less persistent  
over time? (note: I have a hard time believing any of those reasons...).
>


> Albert Norström
> PhD Student
> Dept. Systems Ecology
> Natural Resource Management Group
> Stockholm University
> SE-106 91 Stockholm
> Sweden
> Tel: +46 (0)8 16 44 84
> Email: <mailto:albert at ecology.su.se>albert at ecology.su.se
> Fax: +46 (0)8 15 84 17
> Personal page: <http://www.ecology.su.se/staff/personal.asp? 
> id=119>http://www.ecology.su.se/staff/personal.asp?id=119
>