On 21 August 2009 the Montara wellhead platform drill rig owned by PTTEP Australasia suffered a well head accident, resulting in the uncontrolled discharge of oil and gas. The discharge of oil and gas was stopped on 3 November 2009.
The Australian Maritime Safety Authority coordinated the emergency spill response in accordance with Australia's National Plan to Combat Pollution of the Sea by Oil and Other Noxious and Hazardous Substances (the national plan).
The Department of the Environment, Water, Heritage and the Arts (now known as the Department of the Environment and Energy) engaged in the response through both a Wildlife Plan of Action and by taking on the role of Environmental and Scientific Coordinator under the national plan.
Montara Commission of Inquiry
On 25 May 2011, the Minister for Resources and Energy released the Australian Government's final response to the Report of the Montara Commission of Inquiry.
Environmental monitoring plan
The Australian Government, in conjunction with the company responsible for the rig, PTTEP Australasia, developed a long-term environmental monitoring program to understand the longer term impacts of the spill on the marine environment. The plan, known as the Monitoring Plan for the Montara Well Release Timor Sea, consisted of five operational monitoring studies - which were implemented during the response to the incident - and seven scientific monitoring studies. Implementation of the scientific studies was determined by information provided by the operational studies and components of other scientific studies.
Experts from the Australian Institute of Marine Science, CSIRO and relevant state and territory agencies provided input into the monitoring plan and into its implementation to ensure that it was appropriate and robust.
The monitoring plan covered both short-term and long-term environmental effects of the Montara oil spill. It included marine life surveys, wildlife and habitat studies, continued water quality testing and shoreline ecological assessments.
Environmental monitoring studies
The views and opinions expressed in these studies are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment and Energy.
While reasonable efforts have been made to ensure that the contents of these studies are factually correct, the Commonwealth does not accept responsibility for the accuracy or completeness of the contents, and shall not be liable for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the contents of these studies.
Operational monitoring studies
Operational, or Type I, monitoring is undertaken during a response to an oil spill event. It is focused on providing information of use in planning or executing the response and provides data in a time-frame that is usable in that context. The environmental monitoring plan outlines five operational monitoring studies.
Scientific monitoring studies
Scientific, or Type II, monitoring was focused on objectives such as estimating environmental damage and post response recovery. Some scientific monitoring studies were undertaken over extended periods after the oil spill immediate response.
Implementation of the scientific monitoring component of the environmental monitoring plan was managed by PTTEP Australasia in consultation with the Department, and drew on the advice of a Technical Advisory Group. Individual studies were undertaken by contracted companies, institutions, government agencies or other parties. The environmental monitoring plan outlined seven scientific monitoring studies.
In total 7 scientific monitoring studies were carried out under the environmental monitoring plan. The studies created a significant body of knowledge which has greatly improved the understanding of biodiversity in the Timor Sea and will help inform future management of the marine environment.
The final scientific monitoring study under the environmental monitoring plan has been completed and the report is now available:
Questions and answers - Montara environmental monitoring - results
Study S6 – Shoreline Ecological Ground Surveys – The status of seabirds and shorebirds at Ashmore Reef, Cartier Island and Browse Island – final impact assessment for the Montara oil spill
The purpose of the monitoring plan was to assess trends in breeding populations of seabirds and visiting populations of migratory shorebirds.
A report on the pre-impact assessment and first post-impact field survey was released in June 2010. This report informed the design of the monitoring program and provided baseline data.
The post-impact assessment aimed to quantify population trajectories for seabirds and shorebirds at Ashmore Reef Commonwealth Marine Reserve (CMR), Cartier Island Commonwealth Marine Reserve (CMR) and Browse Island Nature Reserve (NR) in the periods before (prior to August 2009) and after (April 2010 to November 2014) the Montara well release.
Surveys were undertaken every April and November from 2010-2014, at six sites in the Sahul Shelf region; four sites within Ashmore Reef Commonwealth Marine Reserve (CMR), Cartier Island and Browse Island.
At the four Ashmore sites, counts of adults and active nests were undertaken for each seabird species, where possible, and complete counts of shorebirds were undertaken by visiting all high tide roosts. Survey teams traversed Cartier and Browse Islands by foot, and counted all birds present.
Criteria were established for this study, based on expert opinion, to define significant impact on seabird and shorebird populations at the sites. Data collected during these surveys was then compared to data collected during previous studies (prior to the Montara spill).
There is no evidence of the Montara oil spill having a significant impact on seabirds and shorebirds in the Sahul Shelf region. The islands of Ashmore Reef CMR continue to support internationally significant numbers of seabirds and shorebirds. Small numbers of seabirds and shorebirds frequented Cartier Island and Browse Island; from an avian perspective neither of these sites are internationally significant.
Fifteen species of seabird were confirmed breeding at Ashmore Reef CMR, and numbers of breeding seabirds exceeded 100,000 individuals during a single year, which is double previous estimates. In an Australasian context, Ashmore Reef CMR supports a high level of seabird diversity.
Up to 33 migratory shorebird species with populations of over 10,000 individuals also used Ashmore Reef during the post-impact monitoring period. Declines in numbers of shorebirds at Ashmore Reef CMR and the control site could not be attributed to the Montara oil spill. The overall and species-specific declines reflected ongoing declines in shorebirds throughout the flyway, including recent evidence that shorebird populations that occupy island systems are declining at a greater rate than core or mainland wintering sites.
It was previously thought that Ashmore Reef CMR was a stop-over site for Palaearctic breeding shorebirds, but the study found that Ashmore Reef CMR is an important ‘wintering’ site in its own right.
The study provides significant baseline information against which the efficacy of future management actions and potential impacts may be assessed.
The Department was responsible for the implementation of a plan of action to help any wildlife that might be affected by the oil spill in Commonwealth waters and to respond to any possible impacts in Commonwealth marine reserves in the region. The Department worked closely with the Australian Maritime Safety Authority and other relevant federal and state agencies to implement the plan of action to help any wildlife that was affected by the oil spill in Commonwealth waters and to respond to any possible impacts in nearby Commonwealth marine reserves. The plan was developed by a wildlife expert from Queensland's Department of Environment and Resource Management who coordinated the wildlife response to the Moreton Bay oil spill.
Report Wildlife: if oil affected wildlife is observed in Commonwealth waters please see below for instructions on how to report the incident. Please report wildlife found in State waters to the Oil Pollution hotline on 08 9480 9924
For more information on the region visit https://parksaustralia.gov.au/marine/parks/north-west/
The then Minister for Environment Protection, Heritage and the Arts, Peter Garrett AM MP, formally exempted the company's use of a floating jack up oil rig to relieve pressure on the leaking oil well under the Environment Protection and Biodiversity Conservation Act 1999. He did this on grounds that it was in the national interest to do so because the consequences of allowing the spill to continue whilst an environmental impact assessment was prepared would have been far worse than any impacts that might arise from actions to stem the flow of oil.
What is the impact to wildlife?
Have birds been affected by the oil spill?
A small number of birds found in the region were affected by the oil spill. The birds were identified as common noddies, brown boobies and sooty terns.
Birds found in the region were treated by a qualified wildlife expert on-site at Ashmore marine reserve. The process involved capturing the animal, stabilisation and providing onsite care; birds that required additional care were transferred to a veterinary clinic.
The Australian Government and the West Australian Government established a joint wildlife response centre at Broome. A suitable site was identified and prepared. Fortunately this centre was not required.
Rehabilitated wildlife recovered from the ocean were released back into the wild once wildlife experts considered them fully recovered.
There were two confirmed reports of oil affected sea snakes and one green turtle collected in the vicinity of the oil spill.
No other confirmed reports of affected wildlife were received despite extensive aerial and water-based patrols in the area. There were no confirmed reports of oil affected whales or other cetaceans. There is no available evidence at this time to suggest that the migratory or breeding patterns of any wildlife have been affected. This will continue to be monitored in the long term.
There are no sea grasses known to be in the immediate vicinity of the oil spill. However, the Australian Government, in conjunction with the company, is undertaking a number of steps to assess the impact of the oil spill. These assessments will provide a clear picture of the impact of the spill on the marine environment.
If you observe oiled wildlife or habitat, contact the relevant state environment agency immediately. Instructions will be given over the phone to suit the specific situation.
If people in WA observe oiled wildlife in a coastal area they should immediately call WA's Oil Pollution hotline on 08 9480 9924.
Information that is useful in responding includes:
- the time of day
- the location of the animal
- the general condition of the animal - how much oil is on it? is movement laboured?
- identification of the animal to species level if possible
- photographs of affected wildlife and/or affected surrounds
- information on how many other individuals of the same species are in the vicinity (flying, swimming, nesting etc).