[Coral-List] New paper: Coral colonization by Cliona delitrix excavating sponge

Andia Chaves-Fonnegra andiachaves at gmail.com
Fri May 20 11:10:52 EDT 2011


Dear Coral-list:

The following new paper has been recently printed:

Chaves-Fonnegra, A. y S. Zea. 2011. Coral colonization by the encrusting
excavating Caribbean sponge *Cliona delitrix*. Marine Ecology 32: 162-173.

If you want a pdf, contact me (andiachaves at gmail.com) or Dr. Sven Zea (
szea at invemar.org.co)



Abstract follows:

The Caribbean sponge *Cliona delitrix *is among the strongest reef space
competitors;

it is able to overpower entire coral heads by undermining coral polyps. It

has become abundant in reefs exposed to organic pollution, such as San
Andrés

Island, Colombia, SW Caribbean. Forty-four sponge-colonized coral colonies

were followed-up for 13 months to establish the circumstances and the speed

at which this sponge advances laterally into live coral tissue and the coral
tissue

retreats. *Cliona delitrix* presence and abundance was recorded at seven
stations

to interpret current reef space and coral species colonization trends. The
spread

of *C. delitrix* on a coral colony was preceded by a band of dead coral a
few

millimeters to several centimeters wide. However, the sponge was directly

responsible for coral death only when live coral tissue was within about 2
cm

distance; coral death became sponge advance-independent at greater
distances,

being indirectly dependent on other conditions that tend to accelerate its

retreat. *Cliona delitrix *advanced fastest into recently killed clean coral
calices;

however, sponge spread slowed down when these became colonized by algae.

The lateral advance of *C. delitrix* was slower than other *Cliona* spp.
encrusting

excavating sponges, probably owing to the greater depth of its excavation
into

the substratum. *Cliona delitrix* prefers elevated portions of massive
corals,

apparently settling on recently dead areas. It currently inhabits 6–9% of
colonies

in reefs bordering San Andrés. It was found more frequently in *Siderastrea

siderea* (the most abundant local massive coral), which is apparently more

susceptible to tissue mortality than other corals. Current massive coral
mortality

caused by *C. delitrix* could initially change the relative proportions of
coral

species and in the long-term favor foliose and branching corals.



--
Andia Chaves-Fonnegra
PhD. Candidate
NOVA Southeastern University
8000 North Ocean Drive
NSU Oceanographic Center
Dania Beach, Florida, 33004
USA



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