Environmental Engineering Reference
In-Depth Information
stand to lose from a containment or control programme. Finally, a need for stronger
public support of containment and control programmes may arise when the ben-
efi ts that are predicted to derive from them are largely 'public-good' benefi ts.
Eff ective containment or control programmes will require less eff ort and fewer
resources as they proceed. Changes in the relative contributions of the various
stakeholders could be justifi ed or required as a result. However, some level of eff ort
will always be required to ensure an acceptable level of control or containment.
Even in an ideal situation where, for example, a biological control has greatly
reduced population density and growth rate, there will be a need for a continuing
commitment to monitor the status of the invasive species.
To make progress against contentious invasive species it is important to resolve
confl icting interests. Confl icts can relate to a species being detrimental to one
group of stakeholders but benefi cial to another; or to an attitude of neutrality by
one group in the face of negative consequences for others. Examples include plant
species that are commercially exploited or cultivated for ornamental purposes but
which are also invasive (Grice 2006). 'Resolution' of these confl icts almost inevit-
ably involves costs to both sides of the debate. Possible scenarios include:
•
Prohibition of commercial exploitation of a species that is invasive. This
presents a potential opportunity cost to some stakeholders.
Regulated commercial exploitation of a species; regulation could involve
•
restricting where the species may be cultivated and establishing protocols for
that cultivation. This approach is really only applicable to species that are
exploited as 'domesticated' populations, rather than to exploitation of feral
populations.
Control of commercially valuable species in locations where they are not
•
exploited. This applies to productive species that are already widely natural-
ized or that cannot be contained for other reasons. It is effectively the case for
widespread, introduced pasture species in Australia, (e.g.
Cenchrus ciliaris
,
Andropogon gayanus
)
that have negative consequences for natural ecosystems
and effort to control them is generally restricted to threatened conservation
reserves. Such a scenario will, rightly or wrongly, tend to put the onus for over-
coming impacts on those responsible for lands whose values are threatened,
rather than on those who benefi t from the commercialization of the invasive
species. Various regulatory mechanisms, such as levies to growers, could be
used to transfer some of the costs from those who experience the negative
consequences of a commercially-valuable, invasive species to those who enjoy
the benefi ts.
The progress and consequences of containment and control programmes must be
monitored. This provides feedback so that a programme can be modifi ed, or for
