Variation in cownose ray Rhinoptera neglecta abundance and group size on the central east coast of Australia

J Fish Biol. 2020 Feb;96(2):427-433. doi: 10.1111/jfb.14219. Epub 2019 Dec 9.


Here, we provide baseline information about the relative abundance and group size of the Australian cownose ray Rhinoptera neglecta on the central east coast of Australia. Using drone monitoring over 2 years, we completed 293 transects, each 2 km in length, at four locations distributed along c.100 km of coast. In total, 5979 R. neglecta were observed with overall relative abundance (±SE) of, 20.4 (±3.3) individuals per transect. The numbers of R. neglecta varied among locations, with the highest density found off the beach adjacent to the river mouth at Evans Head. The number of rays observed also decreased with increasing wind speed. While some of this relationship was probably associated with visibility, R. neglecta may also move offshore during strong winds. We found no evidence that R. neglecta was under significant threat. Additionally, our cost-effective surveys demonstrate the utility of aerial drones in fisheries conservation biology.

Keywords: Rhinoptera; Australian cownose ray; RPA; UAV; beach; cow ray; drone; flap ray.

MeSH terms

  • Animal Distribution*
  • Animals
  • Australia
  • Fisheries / trends
  • Pacific Ocean
  • Population Density
  • Skates, Fish / physiology*
  • Wind