Standard Talk (15 mins) Australian Society for Fish Biology Conference 2022

Spatially structured relationships between white banana prawn catch and riverine flow in the Northern Prawn Fishery, Australia (#157)

Mischa Turschwell 1 , Ben Stewart-Koster 1 , Rob Kenyon 2 , Roy Deng 2 , Danial Stratford 3 , Justin Hughes 3 , Carmel Pollino 3
  1. Australian Rivers Institute, Griffith University, Nathan, QLD, Australia
  2. CSIRO Oceans and Atmosphere, St Lucia, QLD, Australia
  3. CSIRO Land and Water, Canberra , ACT, Australia

Water resource development can lead to the significant alteration of natural flow regimes, which can have impacts on the many aquatic species that rely on both freshwater and estuarine environments to successfully complete their lifecycles. In tropical northern Australia, annual catches of commercially harvested white banana prawns (WBP) are highly variable in response to environmental conditions, namely rainfall and subsequent riverine flow. However, little is known about the spatial extent to which flow from individual rivers influences offshore WBP catch. In this study, we quantify how the relationship between WBP catch in the Gulf of Carpentaria is influenced by flow from the Mitchell River, Queensland Australia. We used a Bayesian framework to model both prawn presence and catch per unit effort, and found evidence that multiple components of the flow regime contribute to fishery catch. We also found evidence to suggest that the relationships between prawn presence and flow were spatial structured across the fishing ground. Our results suggest that attributing fishery catch to a single river remains challenging, though highlights the importance of maintain natural flow regimes to support a highly valuable commercial fishery species in the face of potential water resource development.