The Prehistoric Underwater Lakes That Kill Everything They Touch

A deep-sea brine lake with a shoreline lies 3,300 feet under the Gulf of Mexico. Brine lakes like it were long presumed lifeless, a death trap for anything that strayed in. So what actually lies at the bottom of one? The first clue to these underwater lakes, also called brine pools, came from the Red Sea. In 1948 the Swedish research ship Albatross found deep water there that was too warm and salty. In 1965 the American research vessel Atlantis II sent a sampler down more than a mile. It came back at 133 °F packed with hot black mud. The first people to see a brine lake directly were aboard the Navy submarine NR-1. In 1989 oceanographer Ian MacDonald and the crew found a mussel-ringed pool off Louisiana. In 2014 the exploration ship Nautilus and its robot Hercules found the Jacuzzi of Despair. Its crater stands 10 feet above the sea floor and spills brine like a waterfall. Biologist Erik Cordes of Temple University lists crabs and fish among its usual victims. The Gulf's brine lakes form from salt laid down roughly 165 million years ago, as Pangaea tore apart. Geologists call it the Louann Salt, more than two miles thick in places. Under enough weight the salt rises, breaks through the sea floor and dissolves into heavy brine. The largest brine lake, the Orca Basin, holds more than 700 feet of brine. A brine lake keeps what settles into it, because nothing stirs the mud on its floor. Cores from the Orca Basin held Sargassum seaweed that had sunk a mile and a half. In 2020 geologist Sam Purkis cored 1,200 unbroken years of layers in the Gulf of Aqaba. Animals do live at a brine lake, at least around the rim. Mussels ring these lakes by the thousand, and bacteria in their gills burn methane. Fossil methane springs packed with clams near Pueblo, Colorado, trace that life back 75 million years. In 2010 biologist Roberto Danovaro reported tiny animals called loriciferans in mud from the L'Atalante basin. A second team disputed that in 2015, and nobody has settled it. The real story is stranger than a death trap, because these lakes work more like a vault. In Bavaria, Germany, a Jurassic floor of heavy, oxygen-free brine turned to stone. That Solnhofen limestone is 150 million years old and has yielded more than 600 species. Among them is Archaeopteryx, with feathers pressed into the rock. Two pieces are on display in Thermopolis, Wyoming, and one is 32 feet long. What does that slab hold, and what lies at the bottom of a brine lake? #wildsparks #BrinePool #DeepSea #deepsealakes