Environmental Engineering Reference
In-Depth Information
As in terrestrial and freshwater systems, preventing the arrival of new species
is likely to be the most successful and cost-eff ective management strategy for
controlling marine AIS (Fig. 14.1b) (Simberloff 1996; Hewitt
et al
. 2004). h is
involves the eff ective management of common transport vectors, and the use of
preventative risk analysis techniques to identify and target pathways and species
that pose the greatest risk. Unfortunately, the highly connective nature of the mar-
ine environment, the ease of dispersal of reproductive propagules, and the presence
of unmanaged (or di cult to manage) human-mediated pathways often makes
prevention of AIS arrivals technically and fi nancially prohibitive (Stoner 1992;
Wittenberg and Cock 2001). As a result, practical and cost-eff ective 'post-border'
incursion response procedures and tools are also vital for managing the estab-
lishment, spread, and impacts of marine pest species (h resher and Kuris 2004;
Wotton and Hewitt 2004).
Despite general acknowledgement of the threats posed to environmental, eco-
nomic, social, and cultural values by marine pests, there has nonetheless been wide-
spread uncertainty among scientists, government agencies, and marine user groups
regarding how to deal with these threats. Without a structured approach to setting
priorities, management eff orts are largely ad hoc, and tend to lack focus and 'buy
in' from aff ected stakeholders. h is situation highlights the need for a comprehen-
sive risk-based approach to identifi cation and assessment of marine biosecurity
risks, and establishment of management priorities that will enable limited budgets
to be used most e ciently and eff ectively. An understanding of the feasibility, pros
and cons of vector management, and treatment methods is an important compo-
nent of this mix.
In this chapter we outline the common steps for managing marine species at all
stages of the introduction process and detail the range of management options and
tools available (e.g. vector management, risk assessment frameworks, surveillance
and monitoring, control, and eradication tools). Particular emphasis is placed on
the utility and development of specifi c response tools for use across a wide variety
of commonly occurring marine habitats.
It has long been recognized that human activities in the marine environment
have been a major pathway for the inadvertent spread of marine organisms well
beyond their natural dispersal ranges (e.g. Chilton 1910; Elton 1958; Skerman
1960; Carlton 1985). There are only a few examples documenting natural move-
ments of marine organisms across oceanic barriers, for example, those with long-
lived planktonic larvae (Scheltema 1971) or rafting ability (Winston
et al
. 1996;
Waters and Roy 2004). There are a large number of active pathways contributing
to the global transport of marine AIS, including maritime shipping, aquaculture,
fi shing, the aquarium trade, and research and educational activities (Ruiz
et al
.
