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http://edit.niwa.co.nz/our-science/pacific-rim/publications/all/pacific-update/test-publication-issue-2010-1/managing-marine-pest-threats-at-port-vila,-vanuatu
Asia-Pacific Update 02, July 2010
Managing marine pest threats at Port Vila, Vanuatu
Star Wharf, Port Vila, Vanuatu. (Photo: Graeme Inglis)
NIWA biosecurity scientist Dr Graeme Inglis has recently been in Vanuatu, where he
joined a team whose task ultimately is to upgrade Star Wharf, Port Vila’s cargo wharf.
Graeme’s role was twofold:
(i) to provide basic training in marine pest surveys to staff from the Vanuatu Department
of Fisheries and Environment
(ii) to undertake an initial assessment of marine pest risks associated with demolishing
the wharf.
“The existing wharf is in a dilapidated condition,” says Graeme, “but it is a vital piece if
infrastructure for the economy of Vanuatu. The upgrade will allow for separate port
facilities for cargo services and the increasing number of cruise ships coming to Port
Vila.”
Graeme led a preliminary underwater survey of the wharf structure. This aimed to
establish the presence or absence of a suite of known, high-profile ‘target’ marine pests
from tropical waters. The survey team also collected a set of biological samples from the
wharf piles that will act as a reference in future surveys.
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What the divers found: fouling and marine life under Star Wharf. (Photos: Graeme Inglis)
Target non-native species found
The survey team found and provisionally identified five species on the target list of
potentially invasive non-natives. These were a barnacle (Amphibalanus (Balanus)
amphitrite), and four bryozoans (Amathia distans, Bugula neretina, Watersipora
subtirquata, and Zoobotryon verticillatum). These records await formal identification by
speciaist taxonomists.
All five species are now relatively widespread in tropical waters. They cause nuisance
fouling on ships, piers, buoys, and other man-made structures in marine environments.
When they occur in large densities they can increase drag on vessel hulls, increasing
operating and maintenance costs. They also can foul aquaculture facilities, increasing
costs and stock mortality.
Because of the high levels of fouling on wharf structures, Graeme recommended that,
when removed, any piles or other fouled structures should go to landfill rather than be
dumped at sea. This will mitigate the risk of distributing them further in Vanuatu’s
marine environment.
Graeme also strongly recommended that effective monitoring and early detection systems
for invasive pests should be introduced around Port Vila’s new port facilities. This
includes assessing the risk pathways and species of concern to Vanuatu, and increasing
local staff’s marine pest monitoring and management capability.
NIWA was contracted to Soros Associates Pty and EcoStrategic Consultants in this
project.
