For a fish introduced with the promise of better recreational angling, the largemouth bass has had a remarkably long afterlife in Spain. In 1955, Micropterus salmoides was brought from North America for sport fishing. Seven decades later, Spain lists it among its invasive alien species, while scientists and conservation authorities continue to grapple with the ecological consequences of its spread.
The story is not simply about a fish moving from one river to another. It is about how an introduction made for recreation can permanently alter food webs, and how difficult it becomes to reverse an ecological decision once a species establishes itself.
