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Teraglin occur along the eastern Australian coast from southern QLD to Montague Island in NSW. The Eastern Australia biological stock is classified as sustainable.

Photo: CSIRO Australian National Fish Collection

Teraglin (Atractoscion atelodus) was recently distinguished as a distinct species that occurs only in eastern Australia, having formerly been known as Atractoscion aequidens which also occurs around southern Africa from Angola to South Africa (Song et al. 2017).  Within Australia Teraglin are distributed from southern Queensland to Montague Island in NSW.  Due to the species' limited latitudinal distribution along eastern-Australia, and the influence of the prevailing southerly flowing Eastern Australian Current in distributing larvae across this area Teraglin are considered to be a single biological stock in this region—the Eastern Australia biological stock.

Eastern Australia

This cross-jurisdictional biological stock has components in Queensland and New South Wales. The status presented here for the entire biological stock has been established using evidence from both jurisdictions.

Total harvest of Teraglin appears to have peaked during the late 1950s, when the New South Wales commercial harvest alone peaked at more than 200 t per annum [Stewart and Hegarty 2020, Stewart et al. 2015]. Since that time landings have declined steadily and in 2018-19 NSW commercial landings were less than 20 t, and landing from the entire stock estimated at around 50 t [Stewart and Hegarty 2020]. Stock-wide standardized commercial catch rates indicate that the available biomass of Teraglin may have declined slightly since 1997-98 but has been variable and with no obvious trend since around 2000 [Stewart and Hegarty 2020]. The stock was assessed in 2020 using data up to and including 2018-19 using a simple Catch-MSY model [Haddon et al. 2018, Martell and Froese 2013] using NSW commercial and recreational data 1950 to 2019, and an age-structured surplus production model using commercial and recreational catch data from Queensland and New South Wales 1997-98 to 2018-19, with a mean standardized catch rate weighted to be relative to each state’s harvest. The model outputs indicated that  biomass has been increasing in recent years to be at around 0.35 of the unfished biomass in 2018-19  [Stewart and Hegarty 2020]. The weight of evidence is that the biomass of Teraglin declined to be around 0.30 of the unfished level during the late 1990s and has since increased slightly to be well above the limit reference point of 0.2 of unfished levels. The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired.

The total harvest across the biological stock has declined substantially since the 1970s. The Catch-MSY model (using just NSW data) estimated that landings in that state exceeded the MSY (approximately 110 t per annum) frequently until the mid-1980s, and has been beneath that level since [Stewart and Hegarty 2020]. Estimated mean harvest rate exceeded F_targ between the 1970s to the early 2000s and declined thereafter to be below that since the early 2010s. Commercial fishing effort in terms of days fished when Teraglin were reported has declined since the late 1990s but has been relatively stable since the early 2000s [Stewart and Hegarty 2020]. The size composition in the landed catch between the 1970s and 2013-14, as well as a single age composition from 2011-12, indicated the fishery in New South Wales was based on a truncated population with relatively few fish greater than 3-4 years of age; however a catch-curve derived estimate of total mortality for 2011-12 suggested that fishing mortality was similar to natural mortality [Stewart and Hegarty 2020]. The weight of evidence is that fishing mortality was excessive during the 1970s to early 2000s, and since that time fishing mortality has declined substantially across the stock to be at a level under which the population is increasing. Teraglin grow reasonably quickly and mature at a relatively small size and young age [Hegarty 2016], indicating potential for relatively rapid population growth.  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 Australian biological stock is classified as a sustainable stock.

Teraglin biology [Hegarty 2016, Hutchins and Swainston 2006]

Distribution of reported commercial catch of Teraglin

New South Wales – Recreational (Catch) Murphy et al. [2020].

New South Wales – Indigenous (management methods) (https://www.dpi.nsw.gov.au/fishing/aboriginal-fishing

Queensland – Indigenous (management methods) for more information see https://www.daf.qld.gov.au/business-priorities/fisheries/traditional-fishing

Commercial catch of Teraglin 

1. Griffiths, MH, and Hecht, T, 1995, On the life-history of Atractoscion aequidens, a migratory sciaenid off the east coast of southern Africa. Journal of Fish Biology 47, 962-985.
2. Haddon M, Punt A and Burch P 2018, simpleSA: A package containing functions to facilitate relatively simple stock assessments. R package version 0.1.18.
3. Hegarty, A-M, 2016, Life history characteristics and fishery of teraglin, Atractoscion aequidens in New South Wales, Australia. Masters Thesis. University of Technology Sydney.
4. Hutchins, B, and Swainston, R, 2006, Sea Fishes of Southern Australia. Swainston Publishing and Gary Allen Pty Ltd, Wetherill Park, Australia.
5. Martell, S, and Froese, R. 2013, A simple method for estimating MSY from catch and resilience. Fish and Fisheries 14:504–514.
6. Murphy, JJ, Ochwada-Doyle, FA, West, LD, Stark, KE and Hughes, JM 2020, The NSW Recreational Fisheries Monitoring Program - survey of recreational fishing, 2017/18. NSW DPI - Fisheries Final Report Series No. 158.
7. Ridgway, KR, and Dunn, JR, 2003, Mesoscale structure of the mean East Australian Current System and its relationship with topography. Progress in Oceanography 56, 189–222.
8. Song, YS, Kim, JK, Kang, JH, and Kim, SY, 2017, Two new species of the genus Atractoscion, and resurrection of the species Atractoscion atelodus (Günther 1867)(Perciformes: Sciaenidae). Zootaxa, 4306(2), pp.223-237.
9. Stewart J and Hegarty A-M, 2020, Status of Australian Fish Stocks 2020 – NSW Stock status summary – Teraglin (Atractoscion aequidens).
10. Stewart, J, Hegarty, A, Young, C, Fowler, AM and Craig, J, 2015, Status of fisheries resources in NSW 2013–14, NSW Department of Primary Industries, Mosman, 391 pp.