Leaving the fish bowl: the ornamental trade as a global vector for freshwater fish invasions

Abstract

Despite its social and economic benefits, the trade in ornamental species (henceforth, ‘ornamental trade’) has become a major source of non-native fish introductions into freshwater ecosystems. However, the ornamental trade as a vector for introductions of non-native freshwater fishes is not well defined. We developed a framework incorporating elements of the biological invasion process and a typical ornamental fish trade supply chain to fill this gap. Records of non-native ornamental fishes introduced to freshwater environments of Australia, Belgium (Flanders), Canada (British Columbia), China (Guangdong), the Philippines, Poland, Singapore, the United Kingdom (England), and the United States of America (Florida) were reviewed to explore the pervasiveness of these introduced fishes in the wild. These regional case studies confirmed the prominence of the ornamental trade as a global vector for freshwater fish introductions beyond their natural range. Additionally, we examined freshwater fishes associated with the ornamental trade to identify ‘risky’ species that could establish in recipient regions based on climate match. All regions assessed were at risk of new fish introductions via the ornamental trade, with the number of ‘risky’ species ranging from seven to 256. Further, there appears to be taxonomic bias in the freshwater ornamental fish trade, with 74% of the species belonging to just 10 families (of 67). Current prevention and management approaches and associated polices, regulations and legislation on aquatic non-native species within assessed regions fit five general categories: import controls, risk assessment, whitelist, blacklist, and release ban. However, these prevention/management efforts may not be sufficient to reduce the invasion risk associated with the ornamental fish trade. Recommendations including species- and vector-based risk assessments, better recording of species import consignments, increased public education and industry engagement, and early detection and rapid response are discussed in this review.

Keywords:

• aquarium trade
• biological invasion
• climate match
• invasive species
• propagule pressure
• risk assessment

Acknowledgements

We thank M. Munawar, A. Zhan, MFIS-China Organizing and Scientific Committees, and the Aquatic Ecosystem Health & Management (AEHMS) Secretariat for their efforts in organising the Marine and Freshwater Invasive Species: Solutions for Water Security conference in Beijing, China, which led to the conception of this paper.

Supplementary material

Supplementary data for this article can be accessed on the publisher’s website.

Additional information

Funding

We are grateful for the support from Fisheries and Oceans Canada, to F.T. Chan and T.W. Therriault; Cefas and the UK Department of Environment, Food & Rural Affairs, to G.H. Copp; the MFIS-China Organizing Committee to D.C.J. Yeo; the Central Public-interest Scientific Institution Basal Research Fund CAFS (No. 2018GH11 and 2019GH09), to H. Wei and D. Luo; the National Science Centre, Poland (decision No. DEC-2011/01/D/NZ8/01807), to G. Zięba; the Florida Department of Agriculture and Consumer Services, the Florida Fish and Wildlife Conservation Commission, and the U.S. Department of Agriculture to J.E. Hill, and the PADI Foundation (No. 40551) to A.S. Gilles Jr.