There is are sea sponges that produce 
5-Bromo-DMT Shulgin mentioned this in TIHKAL. According to Wikipedia's sources on 5-Bromo-DMT they are 
Verongula rigida (0.00142% dry wt.),
Smenospongia aurea* & 
Smenospongia (= Polyfibrospongia) echina*Another brominated DMT analogue was also found in Verongula rigida; 
5,6-diBr-DMT (0.35% dry wt.)
*
WikipediaSource wrote:Djura, Peter et al. (1980). "Some Metabolites of the Marine Sponges Smenospongia aurea and Smenospongia (= Polyfibrospongia) echina". Journal of Organic Chemistry
 Fascinating compounds, but those are very low %ages. 
(although the 0.35% 5,6-diBr-DMT content of V.rigida is decent I guess)
Perhaps these compounds are inactive, or even potently toxic.
Also, remember that both sea sponges & coral grow incredibly slow.
Even if these DMT analogues producing sea sponges & coral could be
fed special nutrient-diets to increase DMT/DMT analogues production,
it would still be useless for producing spicey/medicinal compounds on 
a decent scale, unless there also would be a way of drasticaly increasing their growth rate.
If significantly increasing the growth rates of any of these spicey corals & sponges
is possible, then that would be very interresting.