[Coral-List] Tunicate-killing coral spreading (Emily McGrath)

[Emily McGrath]

Dear Coral Listers,
    Like Mark, I have been following the tunicate vein with great interest,
particularly in regards to the subject of fish population/predation and the
connection to increased populations of *T. solidum *throughout the
Caribbean. As an intern for the CIEE Research Station in Bonaire, I had the
opportunity to volunteer for the Bonaire National Marine Park studying the
abundance and distribution of the colonial tunicate throughout the park. As
Dr. Goreau mentioned, the entirety of the island is a marine park, has
strict fishing regulations, and is heavily protected. As a result it boasts
some of the highest fish diversity in the Caribbean (and with a healthy
population of the aforementioned fish; i.e. parrotfish, surgeonfish, and
wrass).
   Throughout all of my diving on the island, I never witnessed the
predation of the tunicate by any organism; I attributed this to literature
found regarding the ability of *T. solidum* to store several toxic compounds
throughout the test, gonads, larvae, etc. Even while observing spawning, I
never witnessed consumption of their large, swimming larvae (my buddy said
she even saw a mysid shrimp take one and immediately release it). If others
have witnessed predation activity on the tunicates in the southern
Caribbean, or aware of any such literature, I would greatly welcome
references.
      As a side note: one might exercise caution while removing the tunicate
from mid-morning until mid-afternoon (the daily spawning period of Tri-D;
times vary by location but have been defined by Bak et al. in Curacao and
Bonaire). As it may be difficult to remove the entirety of the mat in one
fell swoop, tears often result and the large larvae will often escape and
begin to swim immediately -- a good way to help spread this
already worrysome organism.

    Emily McGrath