Hoki

Hoki in western New Zealand is a little depleted but fishing pressure is well controlled.Hoki has been caught around New Zealand since the 1970s. Catches peaked at around 250,000 tonnes in the 1980s and have since declined to around 100,000t.Stock assessments are carried out annually by Fisheries New Zealand. The most recent assessment was published in 2022 using data up to 2021. The next assessment is expected in 2023.It is thought that there are two separate but interlinked stocks of hoki around New Zealand: eastern and western. This rating covers the western stock. For this stock, it is not clear how the current fishing intensity compares to the reference points. Therefore, Route 2 (data limited) scoring has been applied. Hoki is considered to have low resilience to fishing.Biomass (B) is measured as %B0 - an estimate of the current biomass as a proportion of the pristine level in the absence of fishing. The proxy for Maximum Sustainable Yield is a target range of 35%-50% B0. A soft limit – at which point a rebuilding plan is triggered – is set at 20%. A hard limit – at which point the fishery should be considered for closure – is set at 10%. In the western stock, the pristine biomass is estimated to be around 1.1 million tonnes. Biomass was at a low in the mid-2000s, at around 20%. It then recovered before declining again. In 2022 the estimated level is 327,000-362,000t, equating to 28-31% B0. The stock is below the target range, and therefore is in an overfished state.Fishing intensity (U) was at or near all-time highs in 2002–2003 and is now substantially lower. The target is not to deplete biomass below the biomass target, expressed as U35-50% B0. Due to complications in calculating fishing intensity when there are multiple fisheries and stocks, a simplified version is calculated as the catch in biomass divided by the estimated spawning stock biomass (SSB). A specific figure for U is not provided by the stock assessment, but estimates are given. The estimates vary depending on which values for recruitment are being used - recent (2009-2018) or long-term (1975-2020). For recent recruitment, U is above the range and for long-term recruitment it is below it. The assessment indicates that the probability of the current catch or catch limit causing overfishing to continue or to commence is 'as likely as not', with a 40-60% probability.Assuming future annual catches stay at around 45,000 tonnes, projections for the next 5 years indicate that the western biomass will increase under the long-term recruitment scenario, or remain constant under recent recruitment. Given that the stock is currently in a marginally depleted state, this implies that a constant catch may prevent the stock from recovering unless recruitment improves.However, this fishery is very well managed. There is a harvest control rule (HCR) which is responsive to stock status and has good compliance. In 2021, the fishing industry voluntarily shelved 10,000t of the agreed catch limit (110,000t), effectively reducing it 100,000t. This was split into 55,000t for the eastern stock and 45,000t for the west. Given the precautionary and responsive approach to setting catch limits, we currently consider there to be no concern for fishing pressure. Should fishing pressure increase or the stock decline further in future assessments, this conclusion may be revised.

Hoki in New Zealand is well-managed, with limits on where and how it can be fished. Catch limits are in place, and fleets have voluntarily reduced their catches to below these limits.This is a deep water fishery that takes place within New Zealand’s EEZ. Management of New Zealand deep water fisheries is through a joint framework, agreed between the government (Fisheries New Zealand) and representatives of the fishing industry (Deepwater Group). Over 90% of New Zealand hoki catches are Marine Stewardship Council certified, and the certified fleets are coordinated by the Deepwater Group. There are no conditions on the certification.There is a harvest control rule, which aims to keep the stock at a level that can support Maximum Sustainable Field. For hoki, this is a range of 35%-50% of unfished levels (B0). A soft limit – at which point a rebuilding plan is triggered – is set at 20%. A hard limit – at which point the fishery should be considered for closure – is set at 10%.The main management measure is a total allowable commercial catch (TACC), which is divided between the eastern and western stocks. The TACC is based on advice from annual stock assessments. The TACC was reduced from 150,000t to 115,00t in 2019, and then to 110,000t in 2021. The fishing industry voluntarily shelved a further 10,000t, effectively making the limit 100,000t. This was split into 55,000t for the eastern stock and 45,000t for the west. Therefore, catch limits appear to be responsive to stock status.Between 1996 and 2021, the TACC has been exceeded in 10 years, but never by more than 6%. In the most recent 5 years, The TACC has averaged 136,000 tonnes and estimated catch has averaged 121,600t, making catches 90% of the TACC. Compliance with catch limits therefore appears to be good.However, the impact on the two stocks varies. The eastern stock is currently in the target range (51-55% B0), but the western stock is below it (28-31% B0). Assuming future annual catches stay at recent levels (65,000t in the east and 45,000t in the west), projections indicate that both stocks will remain at those levels. Therefore, setting the recent catch limit in the west at 45,000t may not allow the stock to recover. Most of the catches from the western stock are from spawning fisheries, while most of the eastern catches are from non-spawning fisheries.In addition to catch limits, there is the Hoki Operational Procedure, which began as a voluntary code of practice before it was formalised into the OP. These aim to protect spawning and juvenile (smaller than 55cm) hoki. Hoki are thought to mature at 65-70cm.There are four Hoki Management Areas (HMAs), where there is a high abundance of small hoki. Vessels over 28m cannot target hoki in these areas. There are also four Hoki Seasonal Spawn Areas (HSSAs), which are closed to trawlers targeting hoki for one week during peak spawning time. Two of these areas are permanently closed to trawlers over 46m. There is also a general recommendation that vessels move from areas where catches of juvenile hoki comprise more than 20% of the hoki catch by number.Fisheries New Zealand (FNZ) sets annual targets for observer coverage for each fishery to obtain biological data, monitor compliance and estimate protected species interactions. For hoki in 2022/23, this is 20-30% of effort, depending on the location. Since 1994, all vessels over 28 m have been required to have Vessel Monitoring System (VMS) for satellite tracking of locations. Paper-based catch reporting has been replaced by near-real-time Geospatial Position Reporting and daily Electronic Catch Reporting. There is also at-sea and aerial surveillance, supported by the New Zealand Defence Force.An independent review in 2017 found the management system to be appropriate, with good stakeholder engagement and a strong regulatory framework.

Bottom trawling can damage or remove seabed habitats. It may also bycatch vulnerable species. In New Zealand, habitats are protected by closed areas and measures are in place to reduce seabird bycatch.Around 50-70% of hoki catches are by bottom trawling, with the rest by midwater trawling. Observer coverage has increased from 28% in 2015/16 to 48% in 2020/21. New Zealand also monitors the footprint of its trawl fisheries. This oversight helps to obtain accurate data on fisheries impacts.Bottom trawling for hoki, like trawling for other species, is likely to have effects on benthic community structure and function and there may be consequences for benthic productivity. Around 90% of New Zealand's waters have never been trawled, primarily because they are too deep (over 1,250m). The hoki trawl footprint from 1989-2019 has been estimated at about 167,650 km2. This is 4.1% of New Zealand's waters, and 12% of the ‘fishable area’ (depths of less than 1,600 m that are not closed to trawling). The hoki trawl footprint has been declining over time. In the 2018–19 fishing year, it was 24,392 km2, equivalent to 0.6% of NZ waters and 1.8 % of the fishable area.Roughly 30% of New Zealand’s exclusive economic zone (EEZ), which extends out to 200 nautical miles, is closed to bottom trawling. In the territorial sea, within 12nm of the coast, vessels over 46m are prohibited from trawling and 21% of the area is protected from trawling of all types. The network of closed areas was selected to be representative of marine habitats, and protects 52% of New Zealand's seamounts and 88% of hydrothermal vents. Some closed areas also protect marine mammals, recreational areas and submarine cables. Therefore, habitats are protected to some extent from bottom trawling.There may be a bycatch of other species in this fishery. Hoki, hake, and ling made up 84%, 2%, and 3%, respectively, of the observed catch in target hoki trawls. Other species include silver warehou and white warehou. Together, these are considered one combined fishery and account for 90% of catches. The three first species are MSC certified. The main non-target species caught in the combined fishery off the west coast South Island and Sub-Antarctic are rattails, javelinfish, and spiny dogfish.Incidental captures of protected species have been recorded. In New Zealand, protected marine species include all marine mammals, all seabirds (except black-backed gulls), all sea turtles, some corals, and some fish. The fish species are black-spotted grouper, white pointer sharks, spinetail devil rays, manta rays, basking sharks, nurse sharks, giant grouper. New Zealand has National Plans of Action (NPOAs) for protecting sharks and seabirds.In the hoki fishery, there are recorded interactions with fur seals, basking sharks, and seabirds.Estimated captures of New Zealand fur seals in the hoki fishery have accounted for 44% (749 out of 1,691) of all fur seals caught in the EEZ between 2002/03 and 2017/18. However, this species is abundant and classified as ‘least concern’ by the Department of Conservation because population levels are increasing. Therefore, this fishery is not preventing the population from increasing.It is mandatory to report all captures of basking sharks. Capture rates appear to be relatively stable. There were 8 captures from the observed fleets (30% of total tows) between 2009/10 and 2019/20. Risk assessments carried out via NPOA-Sharks conclude that there is a low risk of unsustainable fishing impacts for most shark species, including basking sharks.Seabirds are attracted to fishing activities and can get entangled in wires or nets, or suffer damage by flying into trawl warps. In the 2019/20 fishing year there were 113 observed seabird captures in hoki trawl fisheries, and an estimated total of 239 captures. Observed captures since 2002/03 have been dominated by six species: Salvin’s, southern Buller’s, and New Zealand white-capped albatrosses, and sooty shearwaters, white-chinned petrels, and cape petrels. NPOA-Seabirds lists Salvin's and southern Buller's albatrosses as high risk species. For Salvin's albatross, the inshore trawl fishery is the highest risk, followed by the hoki trawl fishery which has a medium risk. For southern Buller's albatross, the hoki trawl fishery has a medium risk, but has a higher risk score than any other fishery.Mitigation methods such as streamer (tori) lines, Brady bird bafflers, warp deflectors, and offal management are used in the hoki trawl fishery. Warp mitigation was voluntarily introduced from about 2004 and made mandatory in April 2006. Trawlers over 28m must use a seabird scaring device such as paired streamer lines, bird baffler, or warp deflector.New Zealand sea lions are rarely captured by vessels trawling for hoki, with only 3 recorded captures since 2002/03. Spatial overlap is low. Three common dolphins have been observed captured in the hoki trawl fishery since 2002/03.Hoki is the species with the highest biomass in the bottom fish community of the upper slope (200–800 m), particularly around the South Island and is considered to be a key biological component of the upper slope ecosystem. Understanding the predator-prey relationships between hoki and other species in the slope community is important, particularly because substantial changes in the biomass of hoki have taken place since the fishery began. The diet of hoki overlaps with that of alfonsino, arrow squid, hake, javelinfish, Ray’s bream, and shovelnose dogfish. Hoki are prey to several piscivores, particularly hake but also stargazers, smooth skates, several deepwater shark species, and ling. The proportion of hoki in the diet of hake averages 38% by weight and declined from 1992 to 2008, possibly because of a decline in the relative abundance of hoki.