The King's aquatic desires: 16th-century fish and crayfish introductions into Spain

Abstract

Humans have introduced species out of their native areas for millennia, and characterising these historical introductions can provide insights into the long-term progress of invasion processes. Here, archival sources and other historical documents are used to describe the motivations, negotiations and actions leading to fish and crayfish introductions into Spain in the second half of the 16th century. King Philip II of Spain brought to the Iberian Peninsula several gardening customs from central Europe, including the construction of fish ponds and their stocking with different aquatic species, many of which were naturally absent from Iberia. These interests led to the introduction of pike (Esox Lucius, Esocidae), common carp (Cyprinus carpio, Cyprinidae), tench (Tinca tinca, Cyprinidae) and Italian crayfish (Austropotamobius italicus, Astacidae). Historical documents allowed describing introduction events, their early management and their outcomes with high temporal, spatial and taxonomic precision. These results introduce a centuries-long view on the history of the presence of these introduced species in the Iberian Peninsula, where they have all been successful invaders in different historical periods. This work exemplifies the large potential of archival documents to inform about long-term human–nature relationships, with implications for present-day environmental management (e.g. setting conservation targets). However, this potential has been only sparsely explored, arguably due to the lack of interactions between humanities and natural sciences. Interdisciplinary historical ecology research should be promoted in order to build robust and applicable knowledge on the long-term variability of ecosystems and their biota.