Shoot first, and then ask questions: a look at aquarium fish imports and invasiveness in New Zealand

A risk analysis is being undertaken of threats to natural ecosystems in New Zealand from importation of aquarium fish. The literature on invasiveness reveals global concern about risks from introduced species, though the ecological bases for understanding risk potential seem imprecise and often conflicting. Moreover, whereas some principles espoused may allow identification of species that are high or low risk, these extremes form a continuum wherein the likelihood of establishment cannot be quantified. The likelihood that species, which establish, become seriously invasive is also not quantifiable. Responsible stewardship of natural ecosystems requires application of the precautionary principle. The number of fish species in the global aquarium trade is probably >5000. Many are poorly known, some undescribed, taxonomic authority for some species is obscure, and identification is problematic, especially of juveniles that lack diagnostic characters. Importation of aquarium fish is managed by the Ministry of Agriculture and Forestry (MAF), under the Biosecurity Act 1993. MAF's list of species approved for importation as aquarium fish contains c. 280 names; 178 of these names are genera, any species of which are allowed entry under the MAF protocols, e.g., the cyprinid genus Barbus, of which there are >820 species in the international database FISHBASE. Many listed species have never been imported, which would seem to bring them under provisions of the Hazardous Substances and New Organisms Act 1998. In practice this does not seem to be happening, suggesting that a review of protocols is needed to ensure that the law is being administered correctly.