Striped Trumpeter Biological Data
Striped Trumpeter is a relatively large and long-lived species targeted by recreational and commercial fishers in deeper offshore waters (>50m) using handline, with some offshore dropline and inshore gillnet use. Catches of this species have historically been reported from all areas around the state, with the exception of the central north coast. In 2021/22, fishing activity was focused mainly on the southeast and west coasts for dropline and handline gear types (see Sharples et al. 2023). Commercial catches of Tasmanian and Commonwealth fishing boats peaked at 110 tonnes in the early 1990s, falling to 50 tonnes in 2000/01 and have remained ≤ 10 tonne for most years between 2008/09 and 2021/22 (Sharples et al. 2023). The recreational sector has targeted Striped Trumpeter as an important species. In 2000/01 and 2012/13, estimated recreational catch was less than the commercial catch (Lyle 2005; Lyle et al. 2014). However, estimates of recreational catch in 2011/12 and 2017/18 were substantially higher than the commercial catch.
Management of Striped Trumpeter stocks has changed significantly over time, incorporating Tasmanian commercial operators and Commonwealth operators. Trip limits and a temporal closure during spawning are currently in place. However, the minimum legal size is below the size at maturity and the population of Striped Trumpeter has previously been found to be ageing, suggesting that recruitment is limited, potentially because the spawning biomass of the population has been depleted. Commercial catch trends appear to reflect the influence of strong year classes assumed to have entered the fishery before 1998/99. This was followed by a lack of recruitment and associated declines in catches in the early 2000s. Industry representatives suggest that the trip limit of 250 kg from 2000 provided a disincentive for operators to target the species, which might have contributed to the continued reduction in dropline and handline effort since 2000/01.
Monitoring of the length and age composition of Striped Trumpeter around Tasmania has relied upon the donation of fish frames from recreational, charter and commercial fishers and fish processors. This has been supplemented by fishery independent sampling by IMAS researchers typically during the spawning period to obtain data on length and age at maturity.
