Stout Whiting Fishery Summary : Commercial Quota Setting for 2017

Abstract

This fishery assessment report describes the commercial stout whiting fishery operation along Australia’s east coast between Sandy Cape and the Queensland-New South Wales border. The fishery is identified by a T4 symbol.
This study follows methods applied in (O'Neill & Leigh, 2016a) and extends the results of that study by using the latest data available up to end of March 2016. The fishery statistics reported herein are for fishing years 1991 to 2016.
This study analysed stout whiting catch rates from both Queensland and New South Wales (NSW) for all vessels, areas and fishing gears. The 2016 catch rate index from Queensland and NSW waters was 0.86. This means that the 2016 catch rate index was 86% of the mean standardised catch rate. Results showed that there was a stable trend in catch rates from 2012 to 2016, as in the previous study (O'Neill & Leigh, 2016a), with the 2015 and 2014 catch rates 85% of the mean catch rate.
The fish-length frequency and age-length-otolith data were translated using two models which showed:
• Where patterns of fish age-abundance were estimated from the fish-length frequency and age-length data, there were slightly decreased estimated measures of fish survival at 38% for 2014, compared to fish survival estimates in 2013 at 40%. The 2014 and 2015 estimated age structure was dominated by 1+ and 2+ old fished, with a slightly higher frequency of age 2 - 3 fish for 2015.
• Where only the age-length data were used, estimates showed that from 2011 to 2014 the survival index increased. The estimated survival index increased from 35% in 2013 to 64% in 2014, indicating stronger survival of fish as they recruited and aged.
Together the stout whiting catch rate and survival indicators showed the recent fishery harvests were sustainable.
Since 1997, T4 management (Stout Whiting Fishery) is centred on annual assessments of total allowable commercial catch (TACC). The TACC is assessed before the start of each fishing year using statistical assessment methodologies, namely evaluation of trends in fish catch rates and catch-at-age frequencies measured against management reference points. The TACC has been under-caught in many years.
For setting the 2017 T4 stout whiting TACC, the calculations covered a range of settings to account for the variance in the data and provide options for quota change. The overall (averaged) results suggested:
• The procedure where the quota was adjusted based on previous TACC setting in year 2016 gave a recommended TACC for 2017 of between 1100 and 1130 t.
• The procedure that focussed directly on optimising the average harvest to match target reference points gave a recommended TACC for 2017 of between 860 and 890 t.
Use of these estimates to set TACC will depend on management and industry aims for the fishery.