Sea Surface Temperature Affects the Reproductive Biology of Female Pearl Perch (Glaucosoma scapulare Macleay, 1881) in Queensland, Australia

Abstract

Pearl perch (Glaucosoma scapulare) are endemic to the east coast of Australia and have a long history of exploitation. Recent stock assessments indicate that the current rate of fishing mortality is unsustainable in the long term. To better inform the management of the pearl perch stock and to address gaps in our understanding of their reproductive biology, we investigated patterns in gonad development and estimated length- and age-at-maturity and batch fecundity from females collected from southern and central Queensland waters between 2018 and 2022. The mean gonadosomatic index (GSI) varied both temporally and spatially, with maxima in the austral autumn in southern Queensland and in summer in central Queensland, coinciding with sea surface temperatures between 25.26 and 26.32 degrees Celcius. The length- and age-at-maturity of females were 353mm (fork length, FL) and 4.42 years, respectively, and batch fecundity (B) was correlated to FL such that Ln(B)=2.45xLn(FL)+3.90. Our results will inform a management strategy to recover the stock to acceptable levels of exploitation.