Cold-water corals were found at active sites in Pompeia Province (Gulf of Cádiz). Since seeped fluids are harmful for the corals, we approached the environmental conditions that allow corals to colonize carbonates while seepage occurs. As a result, we propose that chemosynthetic microorganisms (i.e. sulfide-oxidizing bacteria and AOM-related microorganisms) play an important role in the colonization of the corals at these sites by feeding on the seeped fluids and avoiding coral damage.