The world’s ocean are a vast habitat for countless creatures that settle, spawn, dig or feed on the seafloor. They also influence the shape of the ocean floor. How exactly this takes place has been scarcely investigated so far. In an interdisciplinary study, geoscientists, biologists and oceanographers, have examined crater-like depressions on the seafloor of the North Sea. They were able to show that these directly relate to the habitats of porpoises and sand eels, and for the first time provide a conclusive explanation for the importance of vertebrates in shaping the seafloor.