Preventing Ballast Water Invasive Species Propagation

Ballast water is used to stabilize ships at sea, being pumped-in to weigh down a ship for safe navigational conditions when the ships hull is not filled with cargo for a voyage. Controlling the amount of ballast water embarked helps to reduce stress on the hull while providing transverse stability when underway. The correct use of ballast also makes ship propulsion more efficient and increases maneuverability. By correctly controlling the amount and location of ballast within the hull an officer can compensate for weight lost due to fuel and water consumption during a voyage, always maintaining optimum stability.

Just by reading the paragraph above it becomes clear to any landlubber that ballast water is vital for safe ship operations. What many may not understand is that shipping moves over 80% of the world’s commodities and transfers approximately 3 to 5 billion tons of ballast water all over the world each year. The use of ballast water is absolutely essential to the safe and efficient operation of modern shipping, providing balance and stability to un-laden ships. Unfortunately it also poses a serious ecological, economic and health threat. The introduction of invasive marine species into new environments by ships’ ballast water, attached to ships’ hulls and via other vectors has been identified as one of the four greatest threats to the world’s oceans and to biodiversity globally. The other three are land-based sources of marine pollution, overexploitation of living marine resources and physical destruction of marine habitats.

In response to the threats posed by invasive marine species, the United Nations Conference on Environment and Development (UNCED) held in Rio de Janeiro in 1992, in its Agenda 21 called on the International Maritime Organization (IMO) and other international bodies to take action to address the transfer of harmful organisms by ships. The shipping industry has also been very active in helping to address invasive marine species and participates actively in the IMO Marine Environment Protection Committee (MEPC) Ballast Water Working Group. The International Chamber of Shipping (ICS) and the International Association of Independent Tanker Owners (INTERTANKO) and Classification Societies, such as ABS, DNV and ClassNK, have published Model Ballast Water Management Plans. They give practical guidance for the implementation of the IMO Guidelines on-board ships and have been essential in maintaining control over invasive species present water ballast by establishing forms of water treatment that can reduce the risks of invasive species propagation. In future posts we will look at the advised methods of controlling/destroying invasive species present in water ballast.