|Position:||North-West coast offshore Australia
21° 29’ S 113° 58’ E
|Depth:||400m - 550m|
|Water Temperature:||No data|
|Dates:||21 March - 1 April 2005|
|Gas & Oil Company||Woodside Energy|
Dr. Adele Pile, University of Sydney
The science goals for this project are to expand upon the baseline environmental surveys carried out in the area on behalf of Woodside Energy Ltd. Detailed ROV megafaunal video surveys will be carried out providing quantitative data on megafaunal ecology; particularly abundance, diversity and distribution in this area. This survey will allow a more detailed and targeted approach to be used for any subsequent surveys. In addition we will set up some artificial substrates to monitor settlement of organisms into the area.
This has been a highly successful mission as a result of 8 days of ROV operations. We completed six 100 m video transects for megafaunal abundance, diversity and distribution in the area. Transects were conducted randomly away from the BOP and extend to 100 m from the drill site. Videos will be analyzed for megafaunal diversity and habitat mapping during 2005. There is only one habitat type at ENCO 1 and 2, soft bottom. There is no evidence of any rock formations or hard bottom of any type. The drill spoil extends out to about the 30 m contour expect for transects where the second well head occurred. Preliminary analysis indicates a low density and diversity of megafauna. The main component of the megafaunal community is consistent with soft bottom communities and includes echinoderms (asteroids, echinoids, ophoroids, and holothurians) a host of crustaceans and some bottom dwelling fish.
We deployed baited traps both within and outside of the drill spoil to attract mobile megafauna. Experimental plots were established on 23-25 March 2004. Three sites were established at the headings of 80°, 151°, and 220° from the BOP. Within each heading bottle traps were deployed at approximately 75 m (outside the drilling disturbance) and 30 m (inside the drilling disturbance). Traps were examined every 24 hrs, depending on ROV availability, and video taped for 5 minutes.
A variety of prawns, crabs, and fish were attracted to the bait traps. Some smaller organisms even entered the traps to consume the bait. Initial examination of the data suggests that there is no difference in the diversity of organisms that visit the traps (inside vs outside the drill spoil), there appears to be a greater number of organisms visiting the bait traps outside of the drill spoil area. Further analysis will elucidate any trends in the data.
We have elected to forgo the deployment of the settlement plates due to servicing of the ROV and problems with the anchoring of the Jack Bates. The experiment is ready to deploy at the next drill site. ROV operations have been given full instructions on how to deploy this experiment.
We will conduct the same habitat mapping and bait trap experiments at other Enfield drill sites. This will allow us to compare biodiversity and processes between the locations. We will prepare a report for Woodside Energy Ltd. after analysis of all the data. We expect to publish these results in leading peer reviewed journals such as Marine Ecology Progress Series or Deep Sea Research.
New ROV protocols and record sheets have been sent to the Jack Bates ROV team so that future video transects and species observations can be made on behalf of Woodside Energy Ltd. and SERPENT. It is also hoped that the digital stills system has now been fully installed and we hope to see the results very soon. It is envisaged the camera be used as often as possible to document the species resident in this area.
A visit will be made to the rig in May to carry out outreach and to examine further results from the Enfield area and to check on the status of the digital camera. It is also hoped that a cameraman from TVE making a documentary about SERPENT and Enfield will accompany the SERPENT team member on this trip.
Once analysis is complete from this area a further progress report will be filed.
For further information please contact:
Dr Adele Pile, SERPENT Project, Australia Region, University of Sydney. firstname.lastname@example.org
Thanks as always to our valued project partners