A hotspot of non-native marine fishes: evidence for the aquarium trade as an invasion pathway

Invasions of non-native species in marine ecosystems can be ecologically damaging and economically costly. Identifying ‘hot-spots’ of non-native species and their sources of introduction is necessary to maximize the effectiveness of invasion quarantine programs. We use a large spatially explicit marine fish database to show that there are a surprising number of non-native fishes on the reefs of southeast Florida, USA. Two likely sources explain the occurrence of non-native marine fishes in this region: introductions through ballast-water exchange, and introductions from aquaria. Data on international shipping patterns and marine fish imports were used to evaluate the culpability of these 2 vectors. Our results suggest that the introductions are the result of aquarium releases. Prevention of further releases and invasions will require education, outreach, and enforcement efforts directed at marine aquarists and the aquarium industry.