Reindert Nijland was the first to discover the Asian shore crab in the Netherlands in 2000, and decided then and there that invasive crab species deserved more scientific attention. Most invasive crab species arrive here through ballast water of large ships. The Asian shore crab (Penseelkrab) was not the first or the only one. In 1874 already the estuarine mud crab (Zuiderzeekrab) arrived from North America. Also the Japanese shore crab(Blaasjeskrab) is a new species here. In the radio program Vroege Vogels Reindert discusses the crabs and their impacts.