Off the coast of Mexico’s Baja Peninsula lies a dark, still, deep place. It is called the Soledad Basin, and in it lies a garden of bacteria so large you can see them with your own eyes.
A 250-m high ridge on the edge of the Soledad basin traps water inside. No strong currents disturb its depths. High above, coastal upwelling of cool, nutrient-rich water feeds a wealth of life, whose remains rain into the basin. There, they fuel life so well that virtually all oxygen is used up consuming it. For most animals, it is a dead zone. But for these giant bacteria and a few newly-discovered hangers-on, it is paradise.
That kind of bacteria is Thioploca, and for bacteria, they have an astounding lifestyle. While most bacteria top out at a few micrometers, they grow long, thick filaments 40-50 micrometers wide inside tubes that can reach half a millimeter in diameter and 20 centimeters (8 inches) long. They sprout prolifically from the floor of Soledad, reaching concentrations of about 50,000 sheaths per square meter. In places where conditions are right, Thioploca has been found in growing in thick mats up and down the western coast of the Americas, as far south as Peru and Chile. There are more stunning images of Thioploca — including shots of much more luxuriantly carpeted sea floor cores than the image at the top of this post depicts — worth viewing over at Flickr.