Brine Pool Formation
On a recent dive, the E/V Nautilus team encountered spectacular brine lakes in the Gulf of Mexico. Brine lakes and rivers form when salts leach out of the seafloor creating incredibly saline water that becomes trapped in pockets and can't mix with the seawater around it. As a result, deep sea lakes of very salty water form with their own surface tension and waves.
On this leg of the expedition, we will return to cold methane seeps and brine pools investigated during the 2014 season to continue an examination of the symbiosis between the mussels that live at the seeps and the bacterial symbionts that they host. Previous work has shown that different species of Bathymodiolus mussels have different combinations of symbionts that allow them to survive under varied conditions at the seeps. The symbionts utilize hydrogen sulfide or methane. Sulfide-oxidizing symbionts use the energy from sulfide to grow using CO2 as their sole carbon source.