The blue crab colonized the Ebro Delta and surrounding waters in only two years of an exponential expansion, which started five years after the first detection. A study led by the Doñana Biological Station – CSIC and the Ebro Delta Natural Park shows that the expansion and the abundance increase of the blue crab have caused multiple, rapid and severe declines, including some affecting endangered species. The blue crab has rapidly become a keystone species in the Ebro Delta and can have...