Table 1: Stock status determination for Pink Ling
Jurisdiction |
Commonwealth, New South Wales |
Stock |
Western (CTS, GABTS, GHaTS) |
Eastern (CTS, GHaTS, OTLF) |
Stock status |
| |
|
Sustainable |
Undefined |
Indicators |
Spawning stock biomass, fishing mortality |
Spawning stock biomass, fishing mortality |
CTS = Commonwealth Trawl Sector; GABTS = Great Australian Bight Trawl Sector (Commonwealth); GHaTS = Gillnet, Hook and Trap Sector (Commonwealth); OTLF = Ocean Trap and Line Fishery (New South Wales)
Clear and persistent differences in size and age composition, and substantial differences in trends in catch rates indicate the existence of different stocks east and west of South Cape, Tasmania (147°E). However, no genetic differences have been identified between these areas1. The stocks were previously managed as a single stock, but in 2013 it was agreed that they would be managed separately. For the purposes of this report, separate eastern and western biological stocks are assumed.
Before 2013, Pink Ling was managed as a single stock. About 54 per cent of the catch was taken from the eastern biological stock until 2009. Catches have been close to the single stock total allowable catch (TAC) over the past decade, and assessments indicate that catches exceeded sustainable levels for the eastern biological stock over that period.
Western biological stock
In 2013, the Australian Fisheries Management Authority’s Slope Resource Assessment Group accepted an updated stock assessment for Pink Ling2 that assumed separate stocks. The western stock experienced a 20 per cent decline in standardised catch rates between 1986 and 2009. The 2013 assessment estimated the biomass of the western stock to be at 58 per cent of unfished spawning biomass, well above the management target (48 per cent of unfished spawning biomass)2. The stock is not considered to be recruitment overfished3. The assessment estimated a long-term yield of 661 tonnes (t), and this was adopted as a 3-year recommended biological catch. Western catches were below this level in 2012 and 2013, and the assessment indicates that this level of fishing mortality will not result in the stock becoming recruitment overfished.
On the basis of the evidence provided above, the western biological stock is classified as a sustainable stock.
Eastern biological stock
Most of the eastern Pink Ling catch is made in the Commonwealth trawl and autoline fisheries within the Southern and Eastern Scalefish and Shark Fishery. Catches of eastern Pink Ling in this fishery have declined steadily from about 1000 t per year in 2000 to less than 400 t per year in 2013. The New South Wales Ocean Trap and Line Fishery in the same region also takes Pink Ling; the New South Wales catch increased from about 10 t in 2000 to about 50 t in 2013.
The 2013 updated two-stock assessment2 determined that the status of the eastern stock declined steadily from 1975, reaching the limit reference point (20 per cent of unfished spawning biomass) in about 2009, indicating that the stock was recruitment overfished at that stage. Based on the 2010 stock assessment, the Commonwealth TAC for this assumed single stock was reduced from 996 t for 2012–13 to 834 t for the 2013–14 fishing season. As a result of management and industry efforts to reduce catches in the east in response to this TAC decrease, the eastern stock contribution (283 t) to total Pink Ling catch declined to about 43 per cent in 2013.
The eastern fishery experienced a 54 per cent decline in standardised catch rates between 1986 and 2009, but is assessed to have increased thereafter. The 2013 assessment2 estimated the biomass of the eastern stock to be above the limit reference point, at 26 per cent of unfished spawning biomass, but with a 15 per cent probability of being below the limit. The assessment was used as the basis for considered projections of rebuilding to the target biomass at a range of alternative future catch levels, from 0 t (projected to rebuild to target by 2019) to 500 t (projected to rebuild to target by 2047). The above evidence indicates that the biomass of this stock is unlikely to be recruitment overfished.
The Australian Fisheries Management Authority implemented a combined Commonwealth Pink Ling TAC of 996 t for the 2014–15 fishing season, with the intention of administering this as separate 3‑year TACs of 349 t for the eastern stock and 647 t for the western stock. This level is above the short-term RBC level derived from the harvest strategy decision rule for the eastern stock. However, limiting eastern catches to 349 t is projected to rebuild the eastern biological stock to the management biomass target by about 2026, with a less than 10 per cent risk of the stock being below the limit reference point in 2015 and beyond. It remains to be seen whether the stock does indeed continue to trend upwards at this catch level. Given uncertainty in the reliability of projections, it is not yet clear whether fishing mortality is below the level required to rebuild towards the target.
On the basis of the evidence provided above, the eastern Australian biological stock of Pink Ling is classified as an undefined stock.
Table 2: Pink Ling biology4,5
Longevity and maximum size |
25–30 years; 1600–1750 mm TL |
Maturity (50%) |
7–12 years; 700–1000 mm TL |
TL = total length
Figure 1: Distribution of reported commercial catch of Pink Ling in Australian waters, 2013 (calendar year)
Table 3: Main features and statistics for Pink Ling fisheries in Australia, 2013 (calendar year)
Jurisdiction |
Commonwealth |
New South Wales |
Fishing methods |
Commercial |
Demersal trawl |
✓ |
|
Autoline hook |
✓ |
|
Bottom longline hook |
✓ |
✓ |
Recreationala |
|
|
Unknown |
Indigenousb |
|
|
Unknown |
Management methods |
Commercial |
Limited entry |
✓ |
✓ |
Total allowable catch |
✓ |
|
Spatial closures |
✓ |
|
Recreationala |
|
|
None |
Indigenousb |
|
|
None |
Active vessels |
|
42 in CTS
4 in GAB
16 in GHT |
18 in OTL |
Catch |
Commercial |
564 t in CTS
8 t in GABTS
254 t in GHaTS |
49 t in OTL |
Recreationala |
|
Unknown |
Indigenousb |
|
Unknown |
Markets |
Domestic |
✓ |
✓ |
Export |
✓ |
|
CTS = Commonwealth Trawl Fishery; GABTS = Great Australian Bight Trawl Sector (Commonwealth); GHaTS = Gillnet, Hook and Trap Sector (Commonwealth); OTL = Ocean Trap and Line (New South Wales)
a 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.
b The Australian Government does not manage noncommercial Indigenous fishing in Commonwealth waters, with the exception of the Torres Strait. In general, noncommercial Indigenous fishing in Commonwealth waters is managed by the state or territory immediately adjacent to those waters.
Figure 2: Commercial catch of Pink Ling in Australian waters, 2001 to 2013 (calendar years)
There can be a substantial level of bycatch in the fish trawl sector. In 2006, mandatory requirements for otter trawls to use 90 mm square-mesh codend panels were introduced to reduce the catch of small species and juvenile fish6.
Interactions also occur with animals protected under the Environment Protection and Biodiversity Conservation Act 1999, including marine mammals (dolphins, seals and sea lions), seabirds, some shark species and seahorses and pipefish (syngnathids). These interactions are reported quarterly by the Australian Fisheries Management Authority7 and on-board observer programs are used to validate the reporting in commercial logbooks.
In 2007, the South East Trawl Fishing Industry Association released an industry code of practice that aims to minimise interactions with fur seals, as well as addressing the environmental impacts of the fishery more generally8. Operators have developed other mitigation protocols that have further reduced seal mortalities, including using breakaway ties that keep the net closed until it is below depths that seals regularly inhabit, adopting techniques to close the trawl opening during recovery to minimise opportunities for seals to enter the net, switching off gantry lights that are not required during night trawling to avoid attracting bait species and seals, and dumping offal only when the boat is not engaged in deploying or hauling gear8.
In 2011, AFMA mandated individual vessel seabird management plans9. The seabird action plans are used in the Commonwealth Trawl Sector to mitigate the impacts of trawling on seabirds. Seabird mitigation measures include warp deflectors (‘pinkys’), bird bafflers (a system of ropes and PVC piping that protects the warp cable) and seal excluder devices.
The effects of trawl fishing on the marine environment are assessed through an environmental risk assessment and risk management framework and mitigated through spatial closures, and the implementation of bycatch and discard workplans in the Commonwealth Trawl Sector and Great Australian Bight Trawl Sector fisheries.
Pink Ling is a deepwater species living in close association with the seabed at depths of 200–900 m10. The species is relatively nonmigratory and does not appear to move in response to changes in ocean currents or water temperature. Stock assessments indicate that annual recruitment is usually somewhat variable, but occasional years of higher recruitment may be partly environmentally driven2.
a Australian Bureau of Agricultural and Resource Economics and Sciences
b Department of Primary Industries, New South Wales