The Decision Support System will be a computer based system with access to the risk assessment database, and will take quarantine and other port authorities in Australia to the point of risk decision-making on each vessel arriving in a port.
10 The introduction of the above document was accompanied by a detailed presentation, including information on target pest species identified as high risk organisms on the basis of a set of criteria developed by the Australian Ballast Water Management Advisory Council (ABWMAC). A hypothetical demonstration of the Risk Assessment Framework, including the various levels of the layered risk assessment, was also presented. The participants of the Working Group welcomed the presentation and requested Australia to report at future meetings of this Group on further experience gained with the Decision Support System as well as its risk assessment framework.
Ballast water exechange tests
11 Brazil presented results of computer simulation tests in order to evaluate the performance of its dilution method for oil tankers (MEPC 40/10/4). These were compared with the efficiency of simulated flow through methods, i.e., by overflowing the ballast tanks. The tests showed that the dilution method was more efficient than the flow through method, using the same basis, i.e., one inlet and one outlet. The water entering on deck and passing through the narrow side shell area (dilution method) produced better flow effects than the water entering through the double bottom's large horizontal area (flow through method).
12 The Working Group considered the results and welcomed the activities carried out by Brazil, acknowledging that the dilution method might indeed be an effective treatment method. Brazil was encouraged to carry out on board ship a full scale test and to report the results of such a test to a future meeting of the Committee.
Vessels with limited amounts of ballast water
13 The International Council of Cruise Lines (ICCL) noted that discussions held so far within this Group on ballast water management in relation to the potential introduction of aquatic species had focused on the vast quantities of ballast water carried by tankers, bulk and combination carriers (MEPC 40/10/5). The ICCL was concerned at the impact that legally binding provisions on ballast water management may have on the many small vessels and other ships that carry only limited amounts of ballast water. For example, an exchange of ballast water at deep sea as recommended in existing guidelines was inappropriate for many vessels while maintaining the required margins of damage stability. It was further pointed out that many ships may not traverse deep sea areas during normal operations. Consideration should be given to exempting from legally binding provisions vessels under a certain size or those which carry only limited amounts of ballast water. Exemption of vessels with ballast water treatment systems designed to kill aquatic organisms and pathogens should also be considered.
14 The Working Group undertook to review the ICCL proposal when further developing its guidance for the effective implementation of legally binding provisions.
Guidelines or Code
15 Norway made a proposal that the Committee should consider the adoption of the guidelines that are being developed by the Ballast Water Working Group to facilitate the implementation of legally binding provisions in the form of a code (MEPC 40/10/6). Such a "Code for the control and management of ships' ballast water to minimize the transfer of harmful organisms and pathogens" should then be integrated in a new chapter to MARPOL 73/78 as soon as possible.
