Aquarium Owners and Fish Release

Non-native invasive species (NNIS) are plants and animals that are introduced and successfully establish reproducing populations in ecosystems in which they do not naturally occur.  Nearly 300 non-native species have been identified as being invasive or potentially invasive in the Houston-Galveston region ¹.  NNIS are problematic because they can out-compete, prey upon, hybridize with, or introduce disease to native species.  In addition, invasive species can impact ecosystem services such as the provision of food and water, recreation and tourism, flood mitigation, and aesthetic value.  Invasive species are economically expensive to various economic sectors in terms of control costs and losses.

The aquarium industry is one of many introduction pathways for aquatic non-native species in the Houston-Galveston region.  For example, the commonly available Loricariid catfish (also called pleco or amored catfish) has been found in White Oak Bayou, Greens Bayou, Brays Bayou, and others.  Armored catfish may compete with native algae-eaters for food, and have been documented as burrowing into levee walls and bayou banks which may threaten their stability  and increase sediment loads in the water. Local species of colonial nesting water birds such as the neotropic cormorant have been seen trying to feed on the heavily spined species of fish.

Invasion Potential

In order to become invasive, an aquarium species must be available to aquarists, make its way into the natural waters (i.e. be released), and survive and reproduce in its new environment. Therefore, we analyzed three attributes of invasion potential: availability, release, and survival and reproduction. The conceptual model illustrated in the figure below guided our methods and analysis. Each stage of the conceptual model builds upon the previous stage and at each stage we asked questions about various species characteristics that were relevant to their establishment as an invasive species.  Go to Key Findings to see the results of this analysis.

 References

¹Lester, L. J., and L.A. Gonzalez. 2004. Galveston Bay Invasive Species Risk Assessment Project Final Report. Webster, Texas: Texas Commission on Environmental Quality, Galveston Bay Estuary Program.

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