Brine Pool: Hot Tub of Despair | Nautilus Live

Brine pools, on one hand, provide the basis for life through chemosynthesis for creatures living near them on the bottom of the ocean. On the other hand, the fluid they contain is extremely toxic to many forms of sea life. Here we see creatures that have ventured inside the dangerous interior of the brine pool and failed to return. During two cruise legs in May of the 2015 E/V Nautilus field season, we deployed remotely operated vehicle (ROV) Hercules to examine some of the cold seep features of the deep Gulf of Mexico. At some seep sites, seawater interacts with ancient salt deposits found deep in the seafloor, producing a highly saline fluid (brine) that can be more than four times more saline than seawater. When this brine is expelled, it is far denser than the overlying seawater and does not mix very easily with it. In some cases, the brine forms large pools, rivers or lakes. This highly saline environment is toxic for most organisms, but we did encounter beds of mussels and fields