Management of Ships’ Ballast Water and Biofouling - Prevention of Pollution of the Marine Environment from Vessels - page 64

Chapter 4
Management of Ships ' Ballast Water
and Biofouling

4.1 Introduction

Apart from conventional vessel-source pollution, other problems—such as harmful
aquatic organisms carried by ballast water and introduction of aquatic invasive
species by bio-fouling—are also having devastating effects on the world marine
environment. 1 An unfortunate by-product of maritime transportation is the spread
of invasive aquatic species. Historically, many pandemic vectors moved from one
country to another through this system. For example, British ships were responsible
for carrying the vector of the Cholera pandemic Vibrio Cholerae from its endemic
heartland in Bengal, India to China, Japan, Indonesia and Europe. A World Health
Organisation (WHO) report holds maritime transportation responsible for over a
100 disease outbreaks between 1970 and 2000. In a study conducted in 1994, Vibrio
Cholerae was found in ballast and bilge water of five ships docked in an American
port, of which four had taken ballast water from cholera-infected countries. 2
To maintain stability, vessels carry ballast waters. Most ships carry some ballast
water and may discharge all or some of the ballast water after arriving in a port.
Vessels have been using ballast water since the 1880s. 3 Before that time rocks,
sand, soil, and almost anything cheap were used for ballast. However, like water,
dry ballet was also responsible for spreading invasive species in the port States;
in particular by the spread of species of insects and other arthropods, mollusks,
and plants. 4 Carlton identified that ballast water contains four kinds of living
communities: