Beyond Ballast Water: Aquarium and Ornamental Trades as Sources of Invasive Species in Aquatic Ecosystems

Abstract

Although ballast water has received much attention as a source of aquatic invasive species, aquariums and trade in aquarium and ornamental species are emerging as another important source for species likely to invade aquatic habitats. These species are spread throughout the world in a generally unregulated industry. The recent focus on the aquarium trade as a possible mechanism for environmentally sustainable development poses an especially dangerous threat, although this has so far escaped the attention of most environmentalists, conservationists, ecologists, and policy makers.

Ornamental fish in pet stores in Greece: a threat to biodiversity?

“…It is accepted that other factors such as the long tradition in fish keeping, the developed aquaculturebased ornamental fish sector, the strong position in the international chain of trade networks as well as improved living standards and the presence or emergence of a dynamic middle class may be more important for species diversity in regional pet markets. In fact, it is estimated that more than 11 million USA households possess at least one aquarium (Padilla & Williams, 2004) representing 10.8% of pet owners (Tlusty, 2002). Nevertheless, the Hellenic aquarium fish market has made considerable progress and currently a major part of domestic sales is controlled by a few high standard retail chain stores.…”

“…Severe ecological impacts are evident on native species (Ceccherelli & Cinelli, 1997), whereas the extinction of native fish populations by predation and/or resource competition has also been documented (Pimentel, 2010). However, the aquarium trade has received lesser attention from environmentalists, conservationists, ecologists, and policy makers as opposed to the attention given to the trade of terrestrial endangered species (Naylor et al, 2001;Chapman et al, 2003;Padilla & Williams, 2004). This could be attributed to the established set of conservation priorities by international bodies, governments and the public's general views about the natural environment and accordingly their focus on 'flagship' species belonging to higher taxa primarily (i.e.…”

“…One of the major potential vectors of introduction of non-indigenous aquatic species (Katsanevakis et al, 2013) is through the importation of live aquarium species. The aquarium trade has been linked to over 150 species invasions in natural ecosystems around the world (Fuller, 2003;Siguan, 2003;Padilla & Williams, 2004). Severe ecological impacts are evident on native species (Ceccherelli & Cinelli, 1997), whereas the extinction of native fish populations by predation and/or resource competition has also been documented (Pimentel, 2010).…”

How do freshwater organisms cross the “dry ocean”? A review on passive dispersal and colonization processes with a special focus on temporary ponds

“…What Old Romans called ''Mare Nostrum'' was crossed by several trade routes and people living on its shores have been sailing across it since at least 5,000 years, founding settlements and actively transporting goods (and drinking water) all around the lands surrounding this sea (Abulafia, 2011). Further to historical reasons, other more recent human activities still contribute to freshwater organisms dispersal: construction of canals connecting separated watersheds (Dumont, 1995), recreational boating (Albrecht et al, 2009;Bruckerhoff et al, 2014), trade in ornamental species for aquaria (Padilla & Williams, 2004;Marrone & Naselli-Flores, 2011;Havel et al, 2014), and ecotourism and/or scientific field-work (Waterkeyn et al, 2010) have been found to be responsible of dispersal and new species (even invasive) introductions. Trading of living fish for sport and professional fishing can be also responsible for the accidental introductions of (micro)organisms and a huge number of nonindigenous species are reported as ''invaders'' in freshwater ecosystems at a high frequency (Ruiz & Carlton, 2003;Havens & Beaver, 2014).…”

Responses of Aquatic Non-Native Species to Novel Predator Cues and Increased Mortality

“…Vectors for pelagic and benthic aquatic species often have a greater potential to transport more individuals and species compared to terrestrial equivalents (Lodge et al 1998). Ballast water (Carlton & Geller 1993, Hutchings 1993, Hewitt & Campbell 2007, vessels (Johnstone & Coffey 1985, Hewitt & Campbell 2007, and shipments of organisms for aquaculture or the pet trade (Padilla & Williams 2004, Hewitt & Campbell 2007 can transport nearly intact communities consisting of thousands of individuals (Lodge et al 1998). Given the potential for biotic interactions to influence community structure, the composition of the recipient range community should play an important role in an aquatic habitats vulnerability to invasion.…”