Abstract: | Dissolution of Triassic-Jurassic, intrusive salt deposits within 150 m of the sea floor produces a hypersaline brine seep (∼200 0/00) at 71 m water depth on the East Flower Garden Bank. The anoxic, sulfide-rich brine supports large populations of sulfur oxidizing bacteria. Toxic effects of the brine on surrounding epifauna, infauna and fishes are limited to the brine and a very narrow surrounding zone. Leafy algae, coralline algae, foraminifers, sponges, bryozoans, anemones, polychaetes, sipunculids, amphipods and pelecypods live on the hard substratum within 2 cm of the brine-seawater interface. Sixty meters from the brine outflow, at dilutions of 50 to 1, the carbonate sand harbors polychaetes, ostracods, nematodes, amphipods, tanaidaceans, isopods, copepods, pelecypods and gastropods. Certain species of fish momentarily enter the brine and brine-seawater mixtures. |