Oil spill response arrangements in Australia provide for a national oil spill model operated by the Australian Maritime Safety Authority (AMSA) in Canberra, and State-based coastal resource atlases, some of which also have trajectory modelling capabilities, operated by environmental or marine pollution agencies in each State.
In addition, the oil industry, especially the offshore exploration and production industry, has been very active in developing and implementing computerised models and atlases for their areas of operation, as a supplement to the Federal and State Governments' efforts.
AIMS has been involved in all of these areas. In early 1993 AIMS began marketing OILMAP in Australia. Developed in the United States, OILMAP is a user-friendly DOS based system which combines trajectory and fate modelling with a Geographic Information System (see Slick Talk # 5, Reef Research, June 1993).
Dr Brian King, an oceanographer with AIMS, has been working on improving the modelling capability of OILMAP since 1993. King has linked with the Australian Bureau of Meteorology (BoM) and Graeme Hubert of Global Environmental Modelling Services (GEMS), to integrate the basic OILMAP package with a number of more sophisticated atmospheric and oceanographic prediction systems.
Driven by OILMAP as the front-end, the integrated system uses a Bureau of Meteorology model to provide wind predictions for up to four days in advance, and a GEMS three-dimensional hydrodynamic model, linked with tidal data, to provide accurate surface current predictions.
The move to a three dimensional hydrodynamic model has significantly improved the accuracy of trajectory predictions. Because oil slicks are generally water surface phenomena (unless extremely rough seas push the oil down as in the 'Braer' spill off the Shetland Islands in 1993, or the oil weathers, mixes with sediment and debris and sinks), oil spill models have traditionally been two-dimensional and depth averaged only. This ignores the fact that water movements through depth and in the vertical plane can significantly affect surface flow and therefore the movement of an oil slick.
The AIMS OILMAP/BoM/GEMS system was field validated by hindcasting the 'Iron Baron' spill in Tasmania last year, and the results have led King to claim that it is 'the most accurate oil spill prediction system available in the world'. King is looking to publish his validation results later in 1996.
AMSA has recently reviewed its national oil spill modelling capability, with a view to upgrading or replacing the now somewhat dated OSSM system which has served the National oil spill plan for many years. AMSA is also looking at integrating oil spill trajectory and search and rescue drift modelling capabilities.
The AIMS OILMAP/BoM/GEMS system, with input from CSIRO and the National Tidal Facility, has been selected by AMSA as the winning contender. It is encouraging to see what is essentially an Australian development, devised by scientists from some of Australia's leading oceanographic institutions, become the Australian national oil spill prediction system.
On the industry front, King has successfully marketed OILMAP to West Australian Petroleum (WAPET), Apache Energy Corp, BHP Transport, BHP Petroleum, Esso Australia, MAXUS Energy and BHP Vietnam, with systems now up and running for the exploration, production and/or terminal operations conducted by these companies. Such advances in spill prediction capabilities can only be welcomed by spill response authorities. However, despite an ongoing review of literature, I have as yet been unable to identify a case where operational use of a computer model in a particular real-life spill situation has demonstrably resulted in decreased environmental impact from the spill. The over-riding objective of preventing or minimising environmental damage in oil spill response must be borne in mind when considering sophisticated and expensive oil spill response tools such as computer models. I wish to extend an invitation to readers to send any published papers which unequivocally show that use of a model in a particular incident has actually protected the environment to a larger degree than if the model was not used at all.
The AIMS research team is led by Dr Norman Duke and includes Dr Kathy Burns. Both scientists have researched the effects of oil spills on mangroves in Panama. Duke says that the AIMS program will be very much management oriented, seeking to provide clear, practical recommendations to oil spill response authorities on the protection, clean-up and restoration of mangroves.
For example, experience gained by Duke in Panama indicates that the highest priority should be given to protecting, or if impacted by oil, cleaning and restoring, the outer fringe of mangroves specifically. If the outer fringe can be retained, inshore mangroves have a greater chance of re-establishing naturally as they will be protected from physical disturbance. Caution must of course be exercised in transposing the findings of overseas research to the Australian situation, and one of the objectives of the AIMS research is to provide data which is directly relevant to Australia.
The AIMS research consists of a number of components to be conducted over three years. Initial short-term studies will look at the effects of oil, dispersants and oil/dispersants mixtures on mangrove seedlings in a controlled laboratory/nursery situation. Testing the effects of oil/dispersant mixtures is important as mangroves are more likely to be exposed to these rather than to straight dispersant in a real-life response scenario. Oil and dispersant types used will be those most likely to be spilt/used in tropical Australia.
Concurrent studies will be conducted in the field. A suitable field site has yet to be identified. Duke says that they are trying to find mangrove areas which are already earmarked for removal, for example as part of port development plans, so as to minimise the impacts of the research. Anybody who is aware of potentially suitable research sites should contact him (see below). AIMS will of course obtain all necessary environmental approvals before proceeding with any field studies.
Another component of the research plan is re-visiting old spill sites around Australia to investigate long- term effects. Factors such as mangrove regeneration and hydrocarbon levels in mangrove sediments will be measured, using standardised assessment protocols, to enable the modelling of impacts and recovery over time.
The whole program will be wrapped up with a synthesis of results and presentation of recommendations to authorities for incorporation into national oil spill response arrangements.
I have often argued that effective protection of the environment from oil pollution in Australia is limited by a dearth of scientifically derived information that is geographically relevant. This limitation forces scientific and environmental support personnel to provide advice to response managers without the benefit of certainty or at best based on overseas data. This initiative by APPEA and ERDC represents one of a number of recent positive steps being taken by various organisations to fill the data gaps.
What is still needed, however, is a truly national, integrated and coordinated oil spill research and development program with clearly established research objectives, priorities, strategic direction and formalised funding structure, under the auspices of the National Plan to Combat Pollution of the Sea by Oil.
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(Steve Raaymakers is currently Environment and Communication Manager with the Ports Corporation of Queensland. The views expressed through his continued authorship of 'Slick Talk' are not necessarily those of the Ports Corporation nor GBRMPA.)
For further information on OILMAP contact:
For further information on the |
Great Barrier Reef Marine Park Authority
PO Box 1379 TOWNSVILLE QLD 4810. Phone: (077) 500 700, Fax: (077) 726 093
E-mail: registry@gbrmpa.gov.au