Researchers are puzzling: Rare animals are reappearing on the North Sea coast after 100 years. A report in the Beach Explorer app or www.beachexplorer.org helps to solve the mystery of washed-up seahorses.

Dead animals can also be handed in at national park in Lower Saxony. In Schleswig-Holstein, however, seahorse that have been washed up should be left lying around. A photo with a euro coin next to it helps to determine the exact location and time of the discovery.