Poster Presentation Australian Society for Fish Biology Conference 2022

Guess who? Identifying the source species of fish choruses recorded along the Australian southern continental shelf (#210)

Lauren A Hawkins 1 , Benjamin J Saunders 2 , Christine Erbe 1 , Iain M Parnum 1 , Robert D McCauley 1
  1. Centre for Marine Science & Technology, Curtin University, Bentley, Western Australia, Australia
  2. School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia

Soniferous fish can vocalise continuously over prolonged periods. In doing so, they raise background noise levels, producing a phenomenon known as a chorus. Fish produce choruses in association with life functions. Each chorus type typically displays a unique set of spectral characteristics and spatiotemporal patterns. Long-term passive acoustic monitoring of fish choruses can provide information on fish distribution, courtship, spawning behaviours, habitat use, and in some circumstances, the abundance of populations. For this to be successful, the source species producing the chorus needs to be known. Many fish choruses have been reported in Australian waters, yet very few source species have been identified. This pilot study was the first step in an attempt to identify the source species of three fish choruses recorded in the Bremer Bay Canyon, in south-west Western Australia. A hydrophone and an unbaited underwater video recorder were deployed simultaneously for four hours over dusk and dawn within a 24-hour period in December 2019. The underwater video recordings captured the presence of a variety of fish species, including large schools of fish. Two of three previously recorded fish choruses were detected on the hydrophone recordings; however, both choruses were low in intensity and no individual fish calls could be discerned. This suggested the source of the choruses was calling a distance away from the deployment location. Future research will incorporate the use of hydrophone and underwater video recorder arrays to more effectively localise where the choruses are being produced in the canyon, at what depth within the water column, and match those vocalisations to fish species captured on underwater video recorders.