How useful are port surveys focused on target pest identification for exotic species management?

► Of Australian port surveys (98%) did not employ experts to identify all taxa. ► Of Australian port surveys (10%) did not document native taxa. ► Of introduced species detected in surveys, 49% had cogeneric natives. ► Focus of port surveys on target species compromised their outcomes. Monitoring surveys are an important tool for detecting new arrivals of exotic species, for documenting patterns of invasion, and exotic species impacts. Faced with time and cost constraints, these surveys are increasingly focused on lists of target pest species, identified as being most likely to arrive and cause significant harm. We used the national survey of Australian international ports for introduced marine pests as a case study to assess: (1) the taxonomic rigor of surveys focused on detection of target species; and (2) how the ability of port surveys to inform invasion patterns is dependent on taxonomic approach. Our analysis of the 46 available reports revealed common sub-optimal taxonomic practices that compromised their utility to identify abiotic conditions that are good predictors of biological invasion. Thus, although surveys for target species may provide information on the distribution of a handful of species, they may fail to do much else.