Standard Presentation (15 mins) - Edits Required Australian Marine Sciences Association 2022

Does an overabundance of prey influence the fine-scale movement of rays: drone-based tracking of rays in estuarine systems  (#264)

Molly Grew 1 , Troy F Gaston 1 , Vincent Raoult 1
  1. The University of Newcastle, Ourimbah, NSW, Australia

Currently, there is a lack of knowledge on how rays use estuarine systems. However, it is important to understand the fine-scale movement of rays in estuaries to identify critical habitats that need protection. How rays use estuarine systems can be influenced by an abundance of prey. In Wallis Lake, due to the commercial oyster leases, there is an abundance of oysters. My aim is to compare the fine-scale movement and behaviour of rays in an estuarine system with and without an abundance of oysters using drones. The fine-scale movement and behaviours of rays will be observed in Wallis Lake and Burrill Lake, NSW. In these estuaries, drone transect surveys will be flown over different habitat types such as seagrass, bare sediment, and oyster leases, determining what habitats rays are typically found in. Drones will also track ray movements and analyse their behaviour (foraging, resting, swimming) in regard to these habitat types. These data will indicate the habitats the rays are foraging in and how an abundance of prey influences fine-scale movement and behaviour. I expect rays in Wallis Lake will spend a significantly greater amount of time foraging in and around the commercial oyster leases than rays from Burrill Lake.