Environmental Engineering Reference
In-Depth Information
•
The often extended time periods required for the chemical to be in contact
with the organism.
Problems associated with the effective application (e.g. suitable delivery sys-
•
tems, dilution, containment within areas of interest).
Additionally, the use of toxic chemicals in aquatic environments is often cost-
prohibitive, since they often require repeat treatments to be eff ective (McEnnulty
et al
. 2001). Since most chemicals used for controlling AIS are general biocides,
non-target biota in treatment areas are also killed, though communities generally
return to former levels within less than 1 year (Bax
et al
. 2002). Some toxicants,
such as copper, may continue to persist in the environment long after the target
invader has been eliminated (Gavach
et al
. 1999), aff ecting non-target species by
direct toxicity or through bio-accumulation.
Despite a number of attempts worldwide, very few marine pest species have been
successfully eradicated (but see Culver and Kuris 2000; Bax
et al
. 2002; Kuris 2003;
Miller
et al
. 2004; Wotton
et al
. 2004; Anderson 2005). However, it is possible in
many cases to effectively manage new species introductions despite the unique
and diffi cult challenges associated with marine pest incursions. Signifi cantly, each
attempt to eradicate or control marine pest incursions builds on our knowledge
of marine biosecurity and adds to the development of management options and
treatment tools. These include the identifi cation of critical success factors that dic-
tate the overall outcomes of such programmes, primarily:
•
Early identifi cation and detection of the invader.
•
Expert knowledge about the biology and ecology of the invader.
•
Suffi cient resources to fund a programme to its conclusion.
•
The existence (or ready development) of effective control procedures for the
target pest organism.
Monitoring and review during and after the incursion response.
•
•
et al
. 2000; Bax
et al
. 2001; Wotton and Hewitt 2004; Wotton
et al
. 2004; Anderson 2005;
Coutts and Forrest 2007).
With regards to eradication, it is critical to be able to detect and remove all tar-
get organisms, or at least reduce pest densities to levels that cannot sustain a viable
population. Failure to achieve the latter has proven to be the major stumbling
block for many attempted eradications in the marine environment (e.g. Coutts
and Forrest 2007).
Eff ective management strategies for preventing new incursions must begin with
pre-border strategies to assess the risks posed by diff erent species, the likely vec-
tors for their arrival, and attributes of 'at risk' recipient environments. However,
the lack of completely eff ective pre-border management tools means that the
Implementation of protocols to prevent reinvasion (Myers
