9.7 DOMESTIC SHIPPING AND BALLAST WATER EXCHANGE

The Committee is aware that exchange of ballast water at sea is not always considered practical for all interstate shipping⁴⁵⁹ In recognition of the implications that this may have for domestic shipping entering Victoria, the Committee undertook further analysis of routes taken by coastal vessels en route to Victorian ports from other Australian ports within 48 hours steaming⁴⁶⁰ The objective of this analysis was to determine the ability of vessels undertaking short voyages of 48 hours or less to undertake ballast exchange en route to Victoria.

The IMO Guidelines for international vessels recommend that ships exchange ballast at depths of greater than 2000m. Due to the underwater topography of Australia's coastline and the general routes taken by coastal shipping, the Committee recognises that it would be neither physically possible nor economically feasible for vessels trading interstate to rearrange their courses to facilitate ballast water exchange at such depths. More recent research has, however, indicated that 60-100m is sufficiently deep to carry out effective ballast water exchange (pp205-206)⁴⁶¹

Using data provided in the Victorian ballast water study⁴⁶²the Committee has identified the most frequent last-port-of-call for domestic vessels entering each Victorian port. The normal courses taken by domestic vessels travelling those routes within 48 hours steaming were drawn using navigational charts⁴⁶³ the distance in nautical miles between ports was calculated, and steaming times were listed for different average vessel speeds (Appendix G). The Committee arrived at the following conclusions from these analyses.

First, the analysis showed that the average depth over which these domestic vessels travel exceeds 60m (60 metres = 33 fathoms). The Committee finds, therefore, that most domestic vessels can fulfill the depth requirement for effective ballast water exchange en route to Victorian ports.

Second, the average times for re-ballasting and ballast exchange were compared with steaming times. The Committee found that most vessels would have ample time to exchange their ballast. Some vessels trading the Bass Strait routes from Bell Bay, Burnie, Launceston and Devonport to Victoria may, however, have difficulty completing a full ballast exchange within steaming times. The Committee notes, however, that these vessels comprise mainly small roll on/roll off vessels which carry minimal quantities of ballast and the Spirit of Tasmania passenger ferry which does not discharge ballast.

The Committee has been advised that most vessels travelling from Hobart to Victoria should be capable of carrying out full ballast exchange, although exchange might be interrupted due to depth constraints while travelling through Banks Strait⁴⁶⁴ Alternatively, vessels could re-route their course to steam north around Flinders Island adding an extra 3-4 hours onto the voyage time⁴⁶⁵

All vessels trading intrastate between Victorian ports will not be able to exchange ballast within normal steaming times. The Committee recognises that the Victorian Ballast Water Management System must address this issue. Consultation by the EPA with Victorian ports, the Department of Natural Resources and Environment and the shipping industry is required in order to develop alternate strategies for ballast water management for these vessels.