Ecological implications of decommissioning subsea infrastructure in northwest Australia

In FY2019, BHP supported scientific research to examine the impact of seafloor infrastructure on fish in northwest Australia. This was to better understand the offshore decommissioning options for our Petroleum business.

A world-first research project by the University of Western Australia on the BHP Griffin subsea oil and gas pipeline found the pipeline had two to three times the value of commercial fish species in depths beyond 80 metres than in surrounding habitats.

The pipeline had higher biomass and abundances of larger-bodied, commercially important fish, such as goldband and saddletail snapper, compared to bare sand habitats in off-pipeline areas.

Surveys were performed from the pipeline’s inshore burial point and extended about 40 kilometres either side of the pipeline offshore to 140 metres water depth, covering an area of about 2,500 square kilometres.

This research will help our teams identify optimised closure outcomes for decommissioning oil and gas infrastructure. It highlights the ecological implications of decommissioning subsea infrastructure in northwest Australia and will better inform our decision-making at different depths.