Standard Presentation (15 mins) Australian Marine Sciences Association 2022

Marine ecology of oil and gas structures in the Gippsland Basin, Australia, and their value to local fisheries (#150)

Tiffany Sih 1 , Katherine Cure 2 , I. Noyan Yilmaz 3 , Dianne McLean 4 , Peter Macreadie 5
  1. Blue Carbon Lab, Centre for Integrative Ecology, Deakin University, Queenscliff, VIC, Australia
  2. Australian Institute of Marine Science, Perth, WA, Australia
  3. Blue Carbon Lab, Centre for Integrative Ecology, Deakin University, Burwood, VIC, Australia
  4. Australian Institute of Marine Sciences, Perth, WA, Australia
  5. Blue Carbon Lab, Centre for Integrative Ecology, Deakin University, Burwood, VIC, Australia

The Gippsland Basin is the location of Australia’s oldest offshore oil and gas (O&G) structures, with hydrocarbon production beginning in the 1960s. The Bass Strait flows over this area with active fisheries producing seafood to the major population centres of Melbourne, Sydney and beyond. Since Australia’s maritime legislation restricts activities to outside of 500 metres from O&G structures as a security exclusion zone, these O&G structures may serve as de facto marine protected areas that may have flow-on effects to local fisheries. What is the habitat value of O&G infrastructure to marine life in the Bass Strait and how might future O&G decomissioning affect local marine ecosystems and fisheries? We analysed industry-collected remotely operated vehicle (ROV) imagery for information on what fish and invertebrates were found on and near O&G structures and compared this data with reported data from fishing vessels operating in this region collected by the Australian Fisheries Management Authority (AFMA) from 2008-2018. We quantified relative species richness and abundance of two platforms and two pipelines and compared the species composition with retained and discarded catch reported by commercial fishers operating in Commonwealth fisheries. We found diverse communities of fishes and invertebrates around O&G structures, with a different subset of species inhabiting pipelines than platforms. We found some overlap between the species that were targeted by fishers and found around O&G structures. Species composition data from fisheries often groups species making the data coarse and under-representative of true species diversity. Fishery-independent data from ROV imagery or other methods greatly augments our understanding of deepwater marine communities. Combining data sources provides a holistic look at these novel ecosystems and provides better insight into future decommissioning scenarios.