As invasions slow down, biosecurity must move inward

Phillip Joschka Haubrock , Ronaldo Sousa, Antonin Kouba, J. Robert Britton

Rates of non-native-species first records and establishment are slowing. This is encouraging, but it changes rather than resolves the biosecurity problem imposed by biological invasions. As external establishments decline while national non-native-species pools remain compositionally distinct, a growing share of remaining invasion opportunity should lie in redistribution among connected jurisdictions and subsequent within-country spread. Free-trade regions are particularly susceptible because internal movement is intense, whereas biosecurity remains concentrated at external borders. Simultaneously, deglobalization and consequent reshoring and economic regionalisation are reorganising trade towards shorter and more spatially concentrated transport corridors. We argue that this creates a timely policy opportunity: maintain external prevention while extending biosecurity systematically to intra-regional pathways and within-country spread. Successful prevention should make biosecurity move inward, not retreat.