Marine biosecurity: management options and response tools - Invasive Species Management - page 214

disposal. In Australia and New Zealand for example, management options for the
control of undesirable marine organisms have been well described (McEnnulty
et al . 2001; Stuart 2002), and the National Introduced Marine Pest Information
System (NIMPIS) database provides a rapid response toolbox detailing control
and eradication attempts for selected marine species (NIMPIS 2002a). h e range
of tools available for marine systems are described in section 14.3.2.
14.3.2 Response tools
Nearshore marine environments at risk from AIS encompass a diverse range of
habitats and ecosystems, and therefore require a varied range of response tools.
Given that the majority of vectors for AIS transport are anthropogenic in nature
(shipping, aquaculture, fi shing, etc.), it is not surprising that most introduced
species establish in environments subject to high levels of human development
and disturbance (e.g. ports and harbours) rather than in less impacted areas such
as open coast (Wasson et al . 2001). Within these developed environments AIS are
typically more prevalent on artifi cial surfaces and structures rather than natural
substrata (Glasby et al . 2007). It is not surprising, therefore, that most existing
incursion response tools focus on the control of marine AIS within modifi ed habi-
tats, and in particular on artifi cial surfaces and structures. Despite this, relatively
pristine habitats are also susceptible to invasion (Wyatt et al . 2005), which stresses
the need for incursion response tools for the control of AIS in such areas. In the
following sections we discuss the diversity of tools available for managing new
species incursions within artifi cial and natural habitats, including discussion of
management tools for human vectors (e.g. recreational vessels) that have a signifi -
cant role in the spread of alien species post-border. In many cases, a number of dif-
ferent response tools are employed simultaneously in an attempt to maximize the
chance of success in eradicating or controlling AIS. Table 14.1 provides a summary
of presently available treatment methods, detailing their appropriate application,
stakeholder and community acceptability, chance of success, legal considerations,
benefi ts, and limitations.
14.3.2.1 Physical removal
The most effective method of treating vessels infected with introduced fouling
species is to remove them from the water (e.g. dry-docking or slipping) and to
scrape the hull clean of all fouling biota. Regular application of antifouling paints
can then be used to minimize the recurrence of fouling assemblages (Floerl et al .
2005a). Removing a vessel from the water can however be time consuming and
expensive, often leading to delays in the treatment of infected vessels. One com-
mon alternative to land-based treatment is in-water defouling, where divers remove
fouling biota in situ, using mechanical brush systems or scrapers. Unfortunately,
this technique can actually enhance the recruitment of some taxa onto the recently
cleaned surface if all traces of existing biota are not removed (Floerl et al . 2005b).
Additionally, viable organisms and/or fragments of defouled material released into