Scientific name: |
Genypterus blacodes |
Other names: |
hoka, hokarari, rari (Maori), ashiro, kingu (Japan), kingklip (South Africa) |
Longline-caught ling is better than bottom trawled caught ling. An alternative choice is kingfish.
Ling is a bottom dwelling species of the eel family, which lives at depths of 300-700m throughout New Zealand. Ling is caught by bottom trawl and bottom longline fisheries and is often caught as bycatch in hoki and hake trawl fisheries.
The uncertainty of stock structure around the North Island, uncertainty over sustainability of some current catch limits, and the absence of an updated management plan for the fishery are concerns. Bycatch is of particular concern for both the trawl and longline fisheries. In the ling trawl fishery it is estimated that 160 seabirds are caught annually, and vulnerable deepwater sharks (e.g. shovelnose dogfish, seal shark and Baxter’s dogfish) including basking sharks, and protected corals. In the longline ling target fishery it is estimated that over 700 seabirds are caught annually and this includes the critically endangered Chatham’s albatross. Up to 2500 tonnes of fish are discarded annually in the ling longline fishery and the main fish bycatch species include spiny dogfish which makes up about 13% of the catch. Half of that is discarded.
The ling trawl and longline fisheries are certified from September 2014 for 5 years under the Marine Stewardship Council (an international body that assesses and awards sustainable fisheries certifications).
The main export markets are in Asia, particularly Hong Kong (25%), Australia, Spain, Brazil and Portugal. Exports were worth $48.1 million in 2015.
Asssessment output
Ling caught by midwater and bottom trawl and regional differences were assessed. Ling caught by longline rated higher, as an amber or ok seafood choice, while ling caught by bottom trawling rated red, worst choice seafood.
| Score: | Trawl – B, longline – B |
| Population size: | Unknown for some stocks – LIN 1 and LIN2 (most of the North Island), but likely to be greater than the target (40%Bo) for other stocks. Stock affinities of ling north of Cook Strait are unknown. |
| Annual catch limit: | Limit set at 23,192 tonnes since 2013. |
| Recorded catch: | Reported landings of 15,002 tonnes in 2014-15. Overall catches have been 55-65% of the limits over the last 5 years but there is an ongoing overfishing in LIN7 – West Coast South Island. |
| Stock trends: | Unknown for LIN 1 and LIN2 (non-Cook Strait), declining for LIN2/7 (Cook Strait); declining for LIN 7 (West Coast), stable for LIN 5 and 6, and increasing or stable for LIN 3 and 4. |
| MSY Status: | Unknown for LIN 1 and 2, estimated to be above target level for LIN 3 and 4 and LIN 5 and 6. |
| The Ministry of Primary Industries assessment plenary report includes: | For LIN1: The status in relation to targets and overfishing is unknown.
LIN2 (East Coast North Island): The status in relation to targets and overfishing is unknown. “The CPUE has declined by between about 50-60% since the start of the time series in 1992.” “Biomass is estimated to have declined from 1992 by 50–60%.” For LIN 2/LIN7 (Cook Strait – 40% of catch): “B2010 was estimated to be 54% B0; Likely to be at or above the target (40%Bo). Biomass is estimated to have been declining since 1999, but is unlikely to have dropped below 30% B0.” For LIN3 and LIN4: “B2014 was estimated to be about 57% B0; Very Likely to be above the target.” “Biomass is very unlikely to have been below 40% B0. Biomass is estimated to have been increasing or stable since 2003.” “Biomass is uncertain but current catch is unlikely to cause decline. Catches at level of the TACC are likely to cause the stock to decline by about 10% in 5 years.” For LIN 5 and 6 (but not Bounty Plateau): “B2014 was estimated to be between 70% and 101% B0; Virtually Certain to be above the target.” “Stock status is unlikely to change over the next 5 years at recent catch levels or the level of the TACC (i.e., 12,100 t).” For LIN7 (West Coast): “B2012was estimated to be about 71% B0; Very Likely to be at or above the target.” “Biomass is estimated to have been declining.” “This assessment is very uncertain but it is highly probable that B2012 is greater than 40% B0 and it could be much higher.” (MPI, 2016, p652-664). |
| Score: | Trawl – C, Longline – C |
| Distribution: | Ling is widespread in water off the south of the North Island and off the South Island, but is mainly caught south of the South Island and over the Campbell Rise at 200-700m. |
| Maximum age (years): | 46 |
| Age at sexual maturity: | 5-9 years |
| Growth rate: | Variable |
| Reproductive output: | Medium to low |
| Age exploited: | 5 |
| Ability to recover: | Moderate to low |
| Score: | Trawl – E, longline – B |
| Fishing method(s): | Ling is mainly caught in either targeted bottom longline (32%) or bottom trawling operations. In LIN 3 and 4 (Chatham Rise and East Coast South Island), longlining represents 63% of the catch (2009-2014), while it is only 11% in LIN 5 and 6 (Southland and sub-Antarctic). On the West Coast and in the Cook Strait ling is mainly caught as a bycatch of the hoki trawl fishery. Midwater trawls represent less than 8% of the catch (mainly West Coast and Cook Strait) and many of those tows are on the bottom – more than 60%. Ling is also caught as bycatch in the hoki fishery and northern New Zealand scampi fishery. In the hoki fishery twin trawls are used to catch almost half the catch limit, which increases the benthic impact. The trawl footprint area varies but the Snares Shelf area, the Auckland Islands shelf, West Coast South Island, and NW and SW Chatham Rise were identified as amongst the highest frequency trawled areas in the New Zealand zone. |
| Habitat damage: | Bottom trawling: Bulldozes the sea floor, destroying complex biogenic structures including soft corals, sponges and long-lived bryozoans. Impacts include loss of biodiversity, loss of benthic productivity and modification of important habitat like breeding or juvenile areas.
Longline: Significantly less benthic impact than trawling but can include captures of a range of benthic species including corals, sponges, and bryozoans. |
| Habitat of particular significance: | Hasn’t been defined in New Zealand. |
| Bycatch: | Non-threatened bycatch includes deepwater sharks, juvenile fish like hoki, and non-target fish like hake and silver warehou, which are caught in West Coast hoki fisheries. About 10% of the catch is not hoki including ling and hake. |
| Ecological effects: | The combined effects of seafloor damage and alteration, high non-target fish bycatch, protected and threatened species bycatch can have considerable ecological implications. |
| Score: | Trawling – E, longline – E |
| Bycatch: | About 160 seabirds are caught annually in the ling trawl fishery and this includes threatened species (e.g. white-chinned petrels, Salvin’s albatross, flesh-footed shearwaters, and sooty shearwaters). Over 90 New Zealand fur seals are caught annually in the middle depth trawl fishery including about 20 caught targeting ling. The sub-Antarctic and Snares Shelf hoki fishery has a low capture rate for endangered New Zealand sea lions of about one a year. Protected coral species were reported caught in ling target fishery in LIN3, 4 and 6 (Chatham Rise, off Canterbury and sub-Antarctic). The corals caught include gorgonian, hydrocorals, black corals (Antipatharia) and stony corals (Scleractinia) – which includes reef-like, tree-like, and solitary small corals. As ling is also caught in the hoki fishery, the hoki bycatch is of concern: it is estimated that 192 fur seals are captured in the hoki fishery (5-year average). Based on the recent catch spread of hoki the main captures occur in the Cook Strait (54%), off West Coast of the South Island (24%), off east coast of the South Island and Chatham Rise (15%). The hoki fishery catches about half of the estimated fur seals caught by trawling. The sub-Antarctic and Snares Shelf hoki fishery has a low capture rate for nationally critical New Zealand sea lions of about one a year. The trawl fishery also captures about 1420 seabirds a year(5-year average): the main species are Salvin’s, southern Buller’s albatross and white-capped albatross, sooty shearwater, white-chinned petrel, and cape petrels. Protected coral species are also reported caught in hoki tows in most quota areas. The corals caught include gorgonian, hydrocorals, black corals (Antipatharia) and stony corals (Scleractinia) – which includes reef-like, tree-like, and solitary small corals. Other bycatch species include vulnerable deepwater sharks (e.g. shovelnose dogfish, seal shark and Baxter’s dogfish). These low productivity species also include threatened basking sharks (observed at one per year, but could be higher), deepsea skates and some other elasmobranchs.
Longline: In the ling target bottom longline fishery, over 700 threatened seabird species are caught annually. This includes the critically endangered Chatham’s albatross and other threatened species (e.g. white-chinned petrels, grey petrels, Salvin’s albatross, flesh-footed shearwaters, and sooty shearwaters). The main fish bycatch species are spiny dogfish, sea perch, sharks, skates and ribaldo. Spiny dogfish makes up about 13% of the catch and half of that is discarded. Other sharks caught include vulnerable deepwater sharks (e.g. shovelnose dogfish and seal shark). Up to 2500 tonnes of fish are discarded annually in the ling longline fishery. |
| Score: | Both trawling and longline – C |
| Management component: | Single species but stock structure around most of the North Island is unknown. |
| Score: | Both trawling and longline – C |
| Quota Management Species: | Yes, since 1986. |
| Catch limits: | Yes |
| Management plan: | Deepwater management plan for 2010-15 is out of date, and has yet to be reviewed and replaced. Ling 3 to 7 are a target species in the current plan. There is no operational plan and the old deepwater plan lacks key environmental standards. The National Plans of Action on Seabirds and Sharks are more relevant to bycatch issues but they are slow to be implemented. There is no approved inshore plan to cover Ling QMA 1 and 2. |
| Stock assessment: | Quantitative assessment for LIN 3 and 4 (2014), 5 and 6 (2014), 7 (2013), 6 Bounty (2006) and for LIN2/LIN7 (Cook Strait) (2010). |
| Research: | A 10-year planned deepwater research plan has been replaced (after 5 years) with an annual planning process with unclear commitments. Ling has some targeted assessments in the main fisheries. |
| Observer coverage: | Observer coverage in the hoki target fishery is 27.3%, 8.3% in the scampi trawl fishery, and 8% in middle depth trawl (which includes ling). In the target ling longline fishery it is about 17% for both small and large longliners. The scampi and middle depth trawl is unlikely to be spatially or temporally representative of the fishing effort. |
Fisheries map
Taken from the Ministry for Primary Industries’ Plenary report for fisheries management.
References
Report from the Fishery Assessment plenary, May 2016: stock assessments and yield estimates. Part 2: John Dory to Red Cod. Science Group, Ministry for Primary Industries; Ministry for Primary Industries (2016) Aquatic Environment and Biodiversity Annual Review 2015. Compiled by the Fisheries Management Science Team, Ministry for Primary Industries. 682p. The Guidebook to New Zealand Commercial Fish Species, 2007 Revised Edition, The New Zealand Seafood Industry Council Ltd. Seafood NZ, 2016. New Zealand Seafood Exports to December 2015. 133p; SeaFIC website 2004. Annual Review Report for Deepwater Fisheries for 2014/15. MPI Technical Paper No: 2016/09. Prepared by the Ministry for Primary Industries. March 2016. 103p. S.J. Baird, D. Tracey, S. Mormede, M. Clark (2013) The distribution of protected corals in New Zealand waters. Prepared for DOC, February 2013. 96p. MFish (2010) National Fisheries Plan for Deep-Water and Middle-Depth Fisheries, 2010. 51p. Ballara, S.L. (2015) Descriptive analysis of the fishery for hake (Merluccius australis) in HAK 1, 4 and 7 from 1989–90 to 2012–13, and a catch-per-unit-effort (CPUE) analysis for sub-Antarctic hake. New Zealand Fisheries Assessment Report 2015/12. 60 p. Ballara, S.L.; Horn, P.L. (2015) A descriptive analysis of all ling (Genypterus blacodes) fisheries, and CPUE for ling longline fisheries for LIN 3&4 and LIN 5&6, from 1990 to 2013. New Zealand Fisheries Assessment Report 2015/11. 55 p.