Factors Affecting Invasion Potential

Availability of Aquarium Species

Aquarium fish are imported, but are also bred in commercial and home-based facilities. They are available in a variety of settings including chain and independently owned pet stores, non-pet oriented retail locations, local breeders, aquarium club auctions and the internet. Different venues cater to different markets and to some extent they carry different species. An examination of import data, interviews with local breeders, visits to retail outlets and analysis of web sales demonstrated the following findings:

Key Findings

Release Potential

Release potential results from a combination of species’ and aquarists’ characteristics. Fish with characteristics like large size and/or an aggressive temperament are more likely to be relinquished than smaller, docile fish. Additionally, where fish are sold can be related to their propensity to be released to the extent that the market is segmented by purchase location. Characteristics that predispose aquarists to release are their values and knowledge and the degree to which they are connected to other aquarists. In-person questionnaires, a decision model and web-administered surveys were used to assess release potential. These occurred in three phases and the information from one phase was used to refine the questions asked during the next phase.  The key findings are summarized below.

Key Findings

Survival and Reproduction Potential

Using data collected from the Availability Potential (i.e. LEMIS, breeder interviews, and pet store interviews and fish surveys) research, seven species ranging from native to known to be invasive in the region were chosen for investigation. Minimum and maximum environmental optima for each species were determined using the information compiled in the species charts. Each species minimum and maximum environmental optima were compared to the local water quality conditions and graphed seasonally. The reproductive season of each species (typically summer) was highlighted on the graphs. The winter season was highlighted on the water temperature graphs to show  potential lethal minimum water temperatures.

	Brays Bayou	Buffalo Bayou
Salinity
pH
Water Temperature
Dissolved Oxygen

Next Steps

Information from the project describing Availability potential (social and market networks through which aquarium species are exchanged), Release potential (social factors driving release of aquarium species), and Survival /reproduction potential (the ecological potential of invasion for a species released into the local environment) will be incorporated into an invasion potential scorecard. Once developed, the invasion potential scorecard will serve as a useful decision tool for natural resource managers. The scorecard will aid in the identification of appropriate management approaches such targeted education and outreach strategies. The scorecard may also be used to determine whether a full risk assessment is necessary and could be a cost- and time-saving first step when used as a pre-risk assessment screening tool.