New European research project will tackle treatment of potentially harmful ballast water
A new three-year £3.5 million EU project has begun field tests of six methods of treating ballast water from ships in an attempt to prevent the spread to Europe of potentially harmful organisms from around the world.
On hearing the words ‘marine pollution’, toxic discharges or oil slicks are what usually spring to mind. However, another potentially dangerous form of pollution may come from discharged ballast water, which can cause irreversible change to local ecosystems, as well as sickness and death from introduced marine pathogens (see related story).
Many countries including New Zealand, Canada, Israel, Australia and the USA have already introduced rules covering ballast water discharge, while some ports have their own regulations (see related story).
Europe has lagged behind, but the EU funded MARTOB project, is a £3.5 million three year venture aiming is to test the most promising water ballast treatment procedures. All ballast water treatment have been examined, and now laboratory and sea trials are being carried out on six techniques – high temperature treatment, biological de-oxygenation, combination of UV/US, ozone treatment, hydrogen peroxide treatment (oxicide method) and hurdle technology.
The research consortium comprises 25 organisations including academics, marine consultants, research institutes, equipment manufacturers, classification societies, ship owners and shipping companies, with one of the lead partners being the Department of Maritime Technology at Newcastle University.
With legislation impending for the year 2003, the race is on to find safe, cost effective, technically feasible and practical ways of ensuring that the environmental and safety effects of discharged water ballast are minimised.
The use of ballast water is essential for the safe and efficient operation of shipping. When a ship takes on ballast – normally in coastal waters outside a port to make up for weight lost after unloading cargo – it also takes on thousands of microscopic organisms, including plankton species and pathogens. These organisms are then transported in the ship’s ballast tank and released when the ballast is discharged, often when the ship arrives at a distant port of call.
If they become established, such non-indigenous species can cause destructive and irreversible changes in the structure of biological communities, including serious population declines in, or extinctions of, native species.
Species introduced to Europe from ballast water include various bloom forming phytoplankton, a number of fouling organisms, marine benthic animals that compete with native communities and an American cord grass Spartina species, which crossed with the native species to form common cord grass that has since spread throughout Britain, replacing native salt marsh species.
Currently, the favoured method for reducing the risk of introducing alien species into aquatic environments is changing ballast while out at sea (preferably in deep ocean water). In this technique, ballast water loaded in port or taken on board while transiting inshore waters is exchanged for open ocean water during passage between ports of call. However, because one of the functions of ballast is ensure the stability of ships at sea, this technique is not popular with ship’s operators and crews as it may threaten the vessel’s safety.