*

Redbait is one of Australia’s small pelagic fish species and stocks are sustainable. The eastern and western stocks are caught in Commonwealth waters. 

Photo credit: Ken Graham

The stock structure of Redbait in Australia has not been studied. However, based on spawning dynamics, Redbait from eastern Australia is likely to be a single stock (Bulman et al. 2008). Redbait within the Commonwealth Small pelagic Fishery (SPF) is assessed and managed as separate stocks in the eastern and western subareas. 

Assessment of the stock status of Redbait is presented at the biological stock level—Eastern and Western.

Eastern

The Eastern stock of Redbait is caught in the Commonwealth managed Small Pelagic Fishery (SPF), and in Tasmanian fisheries. Stock status classification takes account of catches in all jurisdictions.

Redbait was a by-product species of a purse-seine fishery known as the Jack Mackerel Fishery that targeted Common Jack Mackerel off Tasmania from the early 1980s to 2000 [Kailola et al. 1993]. The Jack Mackerel Fishery became the SPF in 2001 [AFMA 2009], which was also when mid-water trawling replaced purse-seining as the dominant fishing method [Grammer et al. 2022]. 

Total catches of Redbait (Commonwealth and State) were less than 2,000 tonnes (t) per year from 1984–85 to 2000–01 but increased in 2001–02 and peaked at 7,450 t in 2003–04. Annual catches decreased through the mid-2010s but increased to 2,412 in 2019–20 [Noriega and Steven 2020]. Commonwealth catch for 2021–22 was 1,890 t, down from 2,011 t in 2020–21 [Noriega et al. 2022]. State catches of the Eastern stock have been negligible or confidential in recent years and are not available for 2021–22. 

The Commonwealth manages Redbait under a harvest strategy that has been tested using management strategy evaluation (MSE) [AFMA 2017] that included ecosystem and population modelling [Smith et al. 2015]. Exploitation rates applied to each species provide a high likelihood that stocks will be maintained, on average, at the target reference point of 50% of the unfished biomass, with a less than 10% chance over 50 years of falling below the limit reference point of 20% of the unfished biomass. Spawning biomasses of 86,990 t and 50,782 t were estimated for the Eastern stock using the daily egg production method (DEPM) in 2005 and 2006, respectively [Neira et al. 2008].

The recommended biological catch (RBC) for 2021–22 (3,444 t) was based on the mean of the biomass estimates of Neira et al. [2008] and applying the Tier 2 exploitation rate for Redbait of 5% in the SPF harvest strategy [AFMA 2021]. After factoring in state catches, the total allowable catch (TAC) for the SPF was set at 3,444 t for the 2021–22 fishing season. In 2020, a DEPM survey was conducted and produced an estimate of spawning biomass of ~54,000 t [Grammer et al. 2022]. This estimate and the Tier 1 exploitation rate of 10% in the SPF harvest strategy was used to recommend an RBC (5,400 t) and TAC (5,370 t) for the 2022–23 fishing season [AFMA 2022].Recent catches of the Eastern stock have been below the RBC calculated using the harvest strategy. This level of fishing mortality is unlikely to have substantially reduced spawning biomass. 

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, the above evidence indicates that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, the Eastern biological stock of Redbait is classified as a sustainable stock.

Western

The Western stock of Redbait is caught in the Commonwealth managed Small Pelagic Fishery (SPF) and in Tasmanian fisheries. Stock status classification takes account of catches in all jurisdictions.

Total catches of the Western stock of Redbait were low prior to 2001–02, with no Commonwealth catches reported. Commonwealth catches increased from 1,100 t in 2001–02 to a peak of 3,228 t in 2006–07, and decreased steadily thereafter, with no reported catch between 2010–11 and 2014–15. Commonwealth catches were taken again in 2015–16 (1,157 t) and 2016–17 (1,140 t), but no catch was reported in 2017–18 or 2018–19. Commonwealth catch was 9 t in 2019–20. No Commonwealth catch was reported for 2020–21 or 2021–22 [Noriega et al. 2022]. No state catches have been reported in recent years.

The Commonwealth manages Redbait under a harvest strategy that has been tested using management strategy evaluation (MSE) [AFMA 2017] that includes ecosystem and population modelling [Smith et al. 2015].  Exploitation rates applied to each species provide a high likelihood that stocks will be maintained, on average, at the target reference point of 50% of the unfished biomass, with a less than 10% chance over 50 years of falling below the limit reference point of 20% of the unfished biomass.A spawning biomass of 66,787 t (95% confidence interval 28,797–190,392 t) was estimated for the Western stock using the DEPM in 2017 [Ward et al. 2019]. 

Based on the most recent spawning biomass for the Western stock and applying the Tier 1 exploitation rate of 10% for Redbait in the SPF harvest strategy, the 2021–22 RBC was set at 6,678 t [AFMA 2021]. After factoring in state catches, the total allowable catch (TAC) for the SPF was set at 6,680 t. Recent catches of the Western stock have been below the RBC calculated using the harvest strategy. This level of fishing mortality is unlikely to have substantially reduced spawning biomass. 

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. Furthermore, the above evidence indicates that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired.

On the basis of the evidence provided above, the Western biological stock of Redbait is classified as a sustainable stock.

Redbait biology [Neira et al. 2008; Ewing and Lyle 2009; Furlani et al. 2000]

Distribution of reported commercial catch of Redbait

Commonwealth – Commercial (Catch) Commonwealth data is presented for 2021–22 financial year. 

Commonwealth – Recreational The AustCommonwealth – Commercial (Catch). Commonwealth data are presented for 2021–22 financial year. 

Commonwealth – Recreational. The Australian Government does not manage recreational fishing in Commonwealth waters. Recreational fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters, under its management regulations.

Commonwealth – Indigenous. The Australian Government does not manage non-commercial Indigenous fishing in Commonwealth waters, with the exception of the Torres Strait. In general, non-commercial Indigenous fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters.

Commercial catch of Redbait - note confidential catch not shown

1. AFMA 2009, Small Pelagic Fishery Management Plan 2009, Australian Fisheries Management Authority, Canberra, Federal Register of Legislative Instruments F2010L00081, 51 pp.
2. AFMA 2017, Small Pelagic Fishery harvest strategy, June 2008, last revised April 2017, Australian Fisheries Management Authority, Canberra.
3. AFMA 2021, Species summaries 2021, Small Pelagic Fishery (SPF), SPFRAG Comments December 07 2020, Australian Fisheries Management Authority, Canberra.
4. AFMA 2022, Species summaries 2022, Small Pelagic Fishery (SPF), SPFRAG Comments December 07-08 2021, Australian Fisheries Management Authority, Canberra.
5. Bulman, C, Condie, S, Findlay, J, Ward, B and Young, J 2008, Management zones from small pelagic fish species stock structure in southern Australian waters, report for the Fisheries Research and Development Corporation 2006/076.
6. Ewing, GP and Lyle, JM 2009, Reproductive dynamics of redbait, Emmelichthys nitidus (Emmelichthyidae), from south-eastern Australia, Fisheries Research 97: 206-215.
7. Furlani, DA, Williams, A and Bax, N 2000, Fish biology (length and age). In: Habitat and fisheries production in the South East Fishery ecosystem, final report to the Fisheries Research and Development Corporation, Project No. 94/040, (eds N.J. Bax and A.Williams). Division of Marine Research, CSIRO Marine Laboratories, Hobart.
8. Grammer, GL, Ward, TM, Ivey, AR and Keane, JP 2022, Spawning biomass of redbait (Emmelichthys nitidus) in the east sub-area of the Small Pelagic Fishery during October 2020, report to AFMA, SARDI publication F2022/000081-1, SARDI Research Report Series no. 1131, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.
9. Kailola, PJ, Williams, MJ, Stewart, PC, Reichelt, RE, McNee, A and Grieve, C 1993, Australian Fisheries Resources, Australian Bureau of Resource Sciences, Canberra.
10. Neira, FI, Lyle, JM, Ewing, GP, Keane, JP and Tracey, SR 2008, Evaluation of egg production as a method of estimating spawning biomass of redbait off the east coast of Tasmania, final report, FRDC project 2004/039, Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Hobart.
11. Noriega, R and Steven, AH 2020, Small Pelagic Fishery, in Patterson, H, Larcombe, J, Woodhams, J and Curtotti, R (eds), Fishery status reports 2020, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
12. Noriega, R, Davis, K and Dylewski, M 2022, Small Pelagic Fishery, in Patterson, H, Bromhead, D, Galeano, D, Larcombe, J, Timmiss, T, Woodhams, J and Curtotti, R (eds), Fishery status reports 2022, Australian Bureau of Agricultural and Resource Economics and Sciences, Canberra.
13. Smith, A, Ward, T, Hurtado, F, Klaer, N, Fulton, E and Punt, A 2015, Review and update of harvest strategy settings for the Commonwealth Small Pelagic Fishery: single species and ecosystem considerations, report for FRDC project 2013/028, CSIRO Oceans and Atmosphere Flagship, Hobart.
14. Ward, TM, Grammer, GL, Ivey, AR and Keane, JP 2019, Spawning biomass of redbait (Emmelichthys nitidus) between western Kangaroo Island, South Australia and south-western Tasmania in October 2017, report to AFMA, SARDI publication F2019/000053-1, Research Report Series no. 1011, South Australian Research and Development Institute (Aquatic Sciences), Adelaide.