Dumping pet fish in California waterways invites invasive species

A University of California Davis study has found that those dumping pet fish into waterways may be contributing to the spread of invasive species downstream, according to a release. The report says 13 invasive species have been introduced to California waters through the practice.

Although the number is low when considering there are over a hundred species imported each year into the ports of San Francisco and Los Angeles alone, the report notes that 69 percent of the species placed in California waterways successfully established themselves. Most species’ misplacement is due to aquarium enthusiasts who dump the fish in an effort to keep them alive or give them freedom.

UC Davis researchers found there is no tracking system for following fish after they arrive at a port. Further complicating control efforts is the fact that exotic fish are available for purchase over the Internet, making their import harder to track.

The study was funded by the California Ocean Protection Council and California Ocean Science Trust.

Image: The highly predatory lionfish is among the species that could enter California waters  through the aquarium trade. (Credit: Magnus Manske, via Wikimedia Commons)