A mini submarine takes you through a maze of small tunnels, past tiny, colorless creatures. Some paddle, others meander through the water. This unknown world under our feet can be seen in a traveling exhibition that starts on October 21 in the Senckenberg Museum of Natural History in Görlitz. “Groundwater is alive!” she says and casts the spotlight on a cold, dark living space that hardly gets any attention and yet is so important.
70 percent of all the water from our taps comes from underground. All substances that get into the soil and are not absorbed by plants and other organisms end up in the groundwater sooner or later. Bacteria cover the walls of the water-bearing soil layers like a lawn and use the nutrients to generate energy and to multiply. At the same time, they break down pollutants. Worms, small crabs and woodlice, in turn, graze on the bacterial lawn. Ideally, what remains is clear, residue-free water of drinking quality.
Experts have so far discovered 250 to 500 species of animals throughout Germany in this shadowy world. Many can hardly be distinguished from each other on the outside, only their genetic fingerprint reveals the diversity.
They’ve actually led a pretty carefree life so far, says museum director and zoologist Willi Xylander: “The conditions underground are constant all year round: the water is between ten and twelve degrees warm.” Evolutionary processes are correspondingly slow. “So-called well crabs haven’t changed over 300 million years, they’re sort of living fossils,” says Xylander. One of them is the species with the wondrous name Parabathynella badenwuerttembergensis. It only occurs in that state.
But diversity is under threat, Xylander warns: “Excessive amounts of nutrients and rising temperatures favor species that previously could only exist closer to the surface.” These migrate further down into the ground. This changes the subterranean community and can degrade the quality of the groundwater.
