Stock assessment of Australian pearl perch (Glaucosoma scapulare) with data to December 2019

Abstract

Pearl perch, Glaucosoma scapulare, are endemic to sub-tropical offshore-waters along the east coast of Australia. Pearl perch form a single genetic stock in ocean waters between Rockhampton (23.20◦ S) in Queensland and Port Jackson (33.5◦ S) in New South Wales. The species live at least 25 years and have a maximum observed size of 75 cm total length. Sexual maturity is reached at 2–4 years of age (between 25 and 45 cm total length).
This assessment builds on a previous assessment that estimated the stock was at 10–40% of unfished levels in 2014. This stock assessment includes updates to input data and methodology.
This assessment used a single-sex, age-structured population model, fit to age and length data, constructed within the Stock Synthesis modelling framework. The assessment modelled the dynamics of the fishery across seven fishing sectors: 1) Queensland (Qld) charter line, 2) Qld commercial line, 3) Qld recreational, 4) New South Wales (NSW) charter line, 5) NSW commercial trap fishing, 6) NSW commercial line, and 7) NSW recreational.
Sixteen scenarios were run, covering a range of modelling assumptions. Base case (Project Team recommended) results estimated spawning biomass to be 22% (14–46% range across scenarios) of unfished spawning biomass at the beginning of 2020.