Environmental Engineering Reference
In-Depth Information
1
preventing invasive species
Glynn Maynard and David Nowell
The saying 'prevention is better than cure' applies to the entry of invasive species
but this is diffi cult to achieve, particularly in the absence of physical or ecological
barriers to the movement of invasive species, or where human activities and vec-
tors provide pathways for their entry. For the purposes of this chapter, the term
'invasive species' applies to those that enter and establish in a new area and have
the ability to spread aggressively, to intrude or overwhelm other organisms. This
can apply to organisms affecting human food safety, human health and culture,
and agricultural, natural terrestrial, and aquatic ecosystems.
Biosecurity
includes
all policies and measures that a country implements to minimize these harmful
affects, ranging from preventing the entry of unwanted species into an area to their
management if they do enter. Biosecurity is a broader concept than
quarantine
(system), but at times these terms are used interchangeably. Together they are usu-
ally integrated measures that cross over all sectors that relate to the protection of
the environment in general.
Internationally the term
quarantine
is used in several ways. In the broad sense
it refers to all activities aimed at preventing the introduction, and/or spread, of a
species of concern. In a narrower sense, it is the o cial confi nement of organisms
that have a risk of invasiveness (FAO 2007a). In this chapter, the broader sense of
quarantine refers to a quarantine system and the narrower sense refers to a quaran-
tine facility, quarantine procedure, or quarantine measure. All of these systems or
measures are tools used to reduce the likelihood of entry of invasive organisms.
We stress that accurate identifi cation of the species involved is critical to all
aspects of biosecurity and invasive species management to enable appropriate deci-
sions or actions.
The impacts of invasive species range from negligible to extremely high and they
can be diffi cult to understand. Certain components are clearly quantifi able, such
