Oral Presentation Australian Society for Fish Biology Conference 2017

A comparison of fish assemblages associated with two gas flowlines and the adjacent seafloor. (#36)

Todd Bond 1 2 , Timothy J Langlois 1 2 , Michael D Taylor 1 , Julian C Patridge 1 , Dianne L McLean 2
  1. School of Biological Sciences, University of Western Australia, CRAWLEY, WA, Australia
  2. Oceans Institute, University of Western Australia, CRAWLEY, WA, Australia

Large-scale marine infrastructure is a feature of many of the World’s territorial seas, of which, much is associated with the extraction of oil and gas and the extensive array of its subsea pipelines. The North West Shelf region of Western Australia is no exception and its now ageing infrastructure will soon need to be replaced or decommissioned. Despite the extensive coverage of subsea pipelines, little is known of their influence on the fish community. We used remote baited video to assess the abundance and diversity of fish on two subsea pipelines in 130m of water on the North West Shelf and compared this to surrounding areas without subsea infrastructure. Preliminary review of footage revealed increased abundance and diversity of fish on the pipeline compared to off. Important commercial fish species (Lutjanus malabaricus, Lutjanus sebae and Pristipomoides multidens) appear to have higher abundance on the pipeline compared to surrounding areas. This work begins to understand the influence of subsea infrastructure on fish and commercially important fish species and should be considered in any discussions on decommissioning. Furthermore, we recommend a review on methods to sample fish on subsea pipelines in water deeper than 100m.