Science Advisory Report 2021/032

Science Advice on the Potential of Introducing Live Organisms by the Aquarium, Water Garden, and Live Food Trades in Canada

Summary

• An analysis was conducted to determine the movement of live aquatic organisms (freshwater, marine, and estuarine fishes, invertebrates, and plants) into and within Canada through the aquarium, water garden, and live food trades, which involved identifying the number and spatial distribution of ports of entry, distributors, retailers, and end users.
• Based on a four-month period in 2018, the greatest number of live organisms were imported via the live food trade (82 million), followed by the aquarium (4 million) and water garden (3 million) trades. The movement of live organisms within Canada is documented from ports of entry to distributors, but not from distributors to retailers and end users.
• Imported aquarium species included 585 fishes, 100 invertebrates, and 56 plants. A subset of these species (145 fishes, 3 invertebrates, and 52 plants) were assumed to be imported for water gardens. Thirty-two fish species and 54 invertebrate species were imported via the live food trade.
• For the aquarium and water garden trades, the top three ports of entry were Windsor, ON; Mirabel, QC; and Calgary, AB. Organisms were distributed via major distribution hubs in Innisfil, ON; LaSalle, QC; and Calgary, AB. Despite differences between the pathways regarding estimated rural-versus-urban ownership, propagule pressure was highest around major urban centers as a function of human population density.
• Major ports of entry for live food included Ottawa, ON; Richmond, BC; St-Stephen, NB; and Toronto, ON. Major distribution hubs were Montebello, QC; Chilliwack, BC; and Cap-Pelé, NB. Similar to the other two pathways, live food retailers and end users clustered around major cities.
• Based on the estimated proportion of the Canadian population involved in each pathway, estimated release rates, and the estimated average number of organisms released per event, a baseline scenario predicted that ~347,650 (95% confidence interval (CI): 346,555–348,776), ~305,367 (95% CI: 304,307—306,479), and ~288,502 (95% CI: 287,457—289,563) organisms were released into the wild over a one-year period via the aquarium, water garden, and live food trade pathways, respectively. These predictions represent approximately 2.7%, 2.7%, and 0.1% chance of organisms imported through the aquarium, water garden, and live food trade pathways being released, respectively. Sensitivity analyses suggest these estimates vary with model parameters.
• Depending on management objectives, major nodes in the distribution network may serve as critical control points. For example, high-traffic ports of entry along the international border may provide the greatest opportunity for managing the highest number of organisms and species arriving to Canada.
• Projected releases of organisms into the wild were not uniform across Canada. Statistically-significant hot spots of release activity were identified around major cities. Actions targeting end users near these locations could influence release behaviour to reduce propagule pressure.
• Online sales, domestic production, and cultural or other forms of release behaviour by end users (e.g., vandalistic) were not considered, but could be important sources of organism release into the wild.
• Several prominent uncertainties were identified. The accuracy and availability of import records data limited the ability to track organism arrival to Canada, intended uses, destinations, and species identities. The inability to track species from distributors to retailers and end users limited species-specific projections. Limited data exists to describe the amount and distribution of end users and their release behaviours, which may differ across Canada.

This Science Advisory Report is from the June 1-3, 2020 National Peer Review for Science Advice on the Potential Risk of Introducing Live Organisms by the Aquarium, Water Garden, and Live Food Trades in Canada. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Scheduleas they become available.

Science Advisory Report 2021/032 (PDF, 1,193 KB)

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