The secret ecosystem thriving in undersea lakes of despair

Today's tiny wonder: Brine pools and seep mussels

The mussels are doing alright.

Clinging on to a fragile wall of mud and rock, these mussels stand in a strange goldilocks zone of death and nourishment: the edges of a brine pool.

Formed deep beneath the sea, brine pools contain water so salty and dense that they create a lake distinctly separate from the rest of the ocean.

They are also incredibly deadly and have even been dubbed “pools of despair”. A creature falling inside a brine pool will nearly always immediately die, though their body remains perfectly preserved by the waters that killed them.

Yet despite this, life finds a way to thrive. Seep mussels and even fish have found bountiful nutrients in the boundary where oxygen, salinity, temperature and acidity sharply shift.

Metanotrophic bacteria, found in the mussels’ gills, help them survive by consuming methane from the pool and releasing carbon and energy for sustained life.

…and of course, the mussels act as fodder for bigger creatures such as the hag fish above, who in turn enable more ecosystems as they go live out their lives.

Beneath the sea, beside lakes of death, creatures thrive in such fascinating ways. What a wonder.

Learn more:

Video: Exploring the Alien World of Brine Pools by OceanX
Video: Brine pool: Hot tub of despair|Nautilus Live by EVNautilus
Article: "Lake" At Bottom of Gulf of Mexico Kills Nearly Anything That Swims in it by labroots

Photo credits: EVNautilus and OceanX