70% of our costal lines are endangered by the steady rise of sea level and exposed to an increasing erosion. Coastal protection scientists work intensely on sustainable solutions to counteract this process. The greatest loss of land masses is visible at the so called „soft” coasts, which includes the coasts of northwestern Europe. Sand is relentlessly being pumped up from the seabed and raised to artificial dunes on land and in front of endangered coastlines. These radical measures preserve habitats on land, but also intervene massively into ecosystems of the sea bed. „Biotolith“ is a concept for coastal attachment using bacteria that fossilize sand. These microorganisms are capable to grow in a net-like pattern inside the artificially raised sand masses and thus encourage their stabilization.