Environmental Engineering Reference
In-Depth Information
human population centres implicates aquarium releases, although the typically
low number of individuals recorded for each taxa means that physical removal of
most species could be eff ectively undertaken given su cient will (Semmens
et al
.
2004). h is latter study highlights the importance of a rapid response to a poten-
tially solvable problem. At least one tropical marine fi sh, the Indo-pacifi c lion fi sh,
is now so fi rmly established in the south-eastern USA that eradication is unlikely
(Whitfi eld
et al
. 2002). Quantitative models to estimate propagule pressure, based
on uncertainty, number of fi sh traded, and fi sh buyer behaviour, that may serve
as a useful method for aquarium trade risk assessment, have been developed by
Gertzen
et al
. (2008).
The majority of ornamental aquarium fi sh aquaculture is concentrated in trop-
ical developing countries, particularly in South East Asia. Coincidently, equatorial
developing nations also contribute more than 80% of world food aquaculture
production. A recent evaluation of invasive fi shes in ASEAN countries identifi ed
79 introduced species although only 12 were considered to have become invasive,
and only in some countries (Ponniah and Husin 2005). Information on species
introduced for food aquaculture was much greater than that for ornamental species
although knowledge of the extent of invasiveness and the biological impacts of
alien species was typically poor.
At least 90% of freshwater ornamental aquarium fi sh traded worldwide are
cultured rather than collected from the wild; however, only a small fraction of
ornamental marine fi sh are currently farmed. Future expansion in the aquacul-
ture of ornamental marine fi sh and invertebrates is likely given concerns about
the overexploitation of coral reefs and the signifi cant collateral mortality (up to
90%) caused by the capture of wild collected specimens by high-risk methods like
cyanide fi shing (Rubec
et al
. 2001). h is industry poses a signifi cant risk of release
if aquaculture of such species occurs in areas where the organisms do not naturally
occur (Tlusty 2002).
Aquaculture is one of the fastest growing sectors of the global food economy.
Throughout the period 1970-2000, growth in fi nfi sh aquaculture averaged
greater than 10% per annum, with annual production reaching 14 million tonnes
in 2000. In that year, aquaculture provided 73.7%, 65.3%, and 1.4% of global
freshwater fi nfi sh, salmonid fi nfi sh, and marine fi nfi sh landings, respectively,
exceeding US$28 billion (FAO Inland Water Resources and Aquaculture Service
2003). Aquaculture has become a leading vector for the introduction of invasive
species worldwide and is also responsible for numerous other threats to ecosystem
function and integrity. In a classic mismanaged example of aquaculture biological
control, diploid black carp were permitted to be used for combating an outbreak of
trematode infestation in channel catfi sh ponds in Mississippi in 1999. Previously
