The Transfer of Harmful Aquatic Organisms and Pathogens with Ballast Water and Their Impacts - Global Maritime Transport and Ballast Water Management: Issues and Solutions - page 49

Teredo Navalis
The shipworm, which is not actually a worm, but a 'worm-like' mollusc, which
bores into wood, is one of the oldest invaders known. They naturally spread with
wooden material, within the hulls of wooden vessels from early times and is so
widely spread that its native origin has become obscured. It was fi rst recorded in
Europe in 1731 (Sellius 1733 ), when it destroyed wooden dyke gates in the
Netherlands, causing a terrible fl ood. At this time the Dutch believed it was intro-
duced from Asia, possibly sent as a punishment from God ( www.waddensea.
org ) . Many naval engagements at sea may have been lost on account of the weak-
ening effects of the boreholes on the hull and many vessels will have been dis-
abled and wrecked on account of this damage. It was also proposed that the
vessels of the Spanish armada, while waiting in French and Portuguese harbours
to prepare for the invasion of England in 1588, may have been weakened in sta-
bility by the ship-worm so that the fi ght was lost. It was proposed that the 'ship-
worm' originated in the North Atlantic area (Schütz 1961 ) on account of its
tolerance to low temperatures. This could support a possible origin from northern
or southern Atlantic waters. Nowadays T. navalis is known to occur in Northern
Europe, Indonesia, Japan, Australia, Brazil, the Atlantic and Pacifi c US and
Canadian coasts. Many attempts were made to deter their colonisation of hulls
over the centuries. Today they continue to have impacts, but on account of the
usage of steel as vessel hull material, these impacts are to harbour pilings, as has
happened in recent years on the Kiel Canal, Germany.
Transfer and Impacts of Human Pathogens
Human pathogens and microorganisms are also transferred with ship's ballast water
(Ruiz et al. 2000 ; Drake et al. 2001 , 2007 ; Casale 2002 ; Dobbs and Rogerson 2005 ;
Dobbs 2008 ).
Particular strains of cholera, have and continue to, threaten human health world-
wide. There is evidence that ships spread the pathogenic strain of this bacterium,
Vibrio cholera O1. In 1991 the virulent form was found in Mobile Bay, Alabama, in
the Gulf of Mexico (McCarthy and Khambaty 1994 ). It appeared in oysters that had
fi ltered the virus arising from the discharges of ballast water (Motes et al. 1994 ).
During a standard inspection, the US Food and Drug Administration isolated Vibrio
cholerae O1 from the stomach content of a fi sh caught in Mobile Bay. The strain
was similar to that found in Latin America where many humans died (Casale 2002 ).
Indeed, the epidemic occurring in Peru was directly related to ships ballast dis-
charges and spread to many regions in South America. In 1991 more than a million
people had become infected; and by 1994 there were >10,000 victims although it is
believed that their number was underestimated due to inappropriate coverage. This