Stock assessment, scientific advice, TACC setting, monitoring / control / surveillance / enforcement (MCSE) and compliance are all consistent with best practices. Collaborative management by Deepwater Group Limited (DWG) and the Ministry for Primary Industries (MPI) strengthens compliance. The MPI ranks the full quanitiative stock assessment applied to this stock as "high quality". The most recent assessment (MPI 2016) shows spawning stock increasing and likely to be stable over the next 5 years at recent catch levels. Fishing intensity remains well below the annual exploitation rate (U35%), correspondent to the lower boundary of the target biomass “safety” zone (B35%). Several closure areas are established to protect spawning grounds, juveniles (Hoki Management Areas) and vulnerable habitats (Benthic Protected Areas) from trawling. Bycatch of protected species are identified, quantified and monitored yearly. Mitigation measures for seabirds are successful. Industry Code of Practice for hoki trawling fisheries aims to protect smaller fish (<60 cm) and mitigate bycatch of marine mammals. The fishery has been certified by the Marine Stewardship Council since 2001.
Major sources of uncertainty in the assesment are with regard to migration patterns and stock structure of the species, and the true split in recruitment between the eastern and western stocks (MPI 2016). Influence of climate and oceanographic conditions on recruitment patterns is not known. Although, the capture rate has been decreasing, the capture of “high risk” seabird species continued as of 2013. Information on cumulative bottom trawl footprint in relation to BOMEC habitat class is still not available. There is some uncertainty about BPAs representativeness.
Last updated on 27 April 2017
Improvement Recommendations to Catchers & Regulators
- Monitor fishery and management system for any changes that could jeopardize MSC re-certification.
- Ensure benthic protected area network coverage is representative of all types of habitat classes.
Last updated on 15 February 2017
A new stock assessment was carried out in 2016 using research time series of abundance indices (trawl and acoustic surveys), proportions at age data from the commercial fisheries and trawl surveys, and estimates of fixed biological parameters (MPI, 2016). The full quanitiative stock assessment applied to the New Zealand Hoki stocks is ranked "high quality" by the assessment body, and employs state-of-the-art stock assessment methodology (Akroyd et al. 2012). The age-structured CASAL model with Bayesian estimation of posterior distributions considers both eastern and western stocks with no mixing of adults (MPI, 2016).
There are a number of areas of uncertainty in the stock assessment. Assessment reports have advised that the BMSY reference point estimates should be interpreted with caution, and that BMSY is not a suitable management target, largely because its estimation is based on assumptions for underlying elements that are uncertain (MPI, 2016). The 2016 selected model (base run 1.7), for example, assumes constant catchability (single q).
Stock structure and migration patterns, and the split of 2014 year class between eastern and western stocks with respect to projections, were noted as being the major areas of uncertainty in the 2016 assessment (five-year forecasts are conducted as part of the stock assessment procedure). In addition, there is increased uncertainty in the status of the western stock, stemming from a potential decline in the stock indicated by the 2014 Sub-Antarctic trawl survey (MPI, 2016). While the base case stock assessment model attributed the low abundance to observation and process error, there is risk that the survey reflected an actual change in biomass, in which case the stock status estimated by the model would have been inflated (MPI, 2015b; 2016).
Also of note is the considerable impact of annual variations in hoki recruitment on the fishery, and assessment reports have suggested a better understanding of the influence of climate and oceanographic conditions on recruitment patterns would be very useful for the future projection of stock size (MPI, 2015a; 2016). Lastly, there are sources of additional fishing mortality from incidental causes that are not incorporated in the assessment; and no information is available on illegal catches (MPI, 2012).
The process and results are transparent and available publicly online, and are peer reviewed. Updated estimates of hoki stock status are currently assessed every year (MPI, 2015b).
Last updated on 15 February 2017
Scientific advice on Total Allowable Commercial Catch (TACC) is consistent with the degree of confidence in the stock assessment and reflecting uncertainties. Stock assessment is performed by the Hoki Working Group (HWG) under the Ministry for Primary Industries (MPI) but they do not make management decisions. Management is conducted by the MPI and the Deepwater Group Limited (DWG) and policy has been successful in maintaining the stock at safe levels.
Scientific advice equals the set TACC that in 2016 corresponds to 50,000 tonnes for the eastern stock (MPI, 2015b; 2016). Tree TACC options were consulted in 2015: TACC= 160,000, 150,000 or 155,000 tonnes (MPI, 2015b). According to MPI (2015c), Option 2 (150,000 tonnes: 60,000 Eastern stock and 90,000 tonnes Western stock) represents a conservative and responsive approach to the possibility that hoki abundance in the western stock has decreased. MPI suggests a reduction in the TACC to potentially avoid a larger decrease in future (MPI, 2015b,c).
Last updated on 1 March 2017
The target management strategy for the stock is to maintain the reproductive biomass (SSB) above B35-50%, correspondent to the fishing target U35%=0.22 (the lower level). Other biological reference points were adopted in 2009: Soft limit is a “biomass level below which a stock is deemed to be overfished or depleted and needs to be actively rebuilt”, is 20% of the average spawning stock biomass (B20%=111,200 tonnes) that would have occurred if had there been no fishing (B0=556,000 tonnes) and assumed to be Blim; Hard limit is a “biomass level below which a stock is deemed to be collapsed where fishery closures should be considered in order to rebuild a stock at the fastest possible rate”, is 10% of B0. A target biomass reference point is defined at 35% of the average spawning stock biomass (B35%=194,600 tonnes) that would have occurred if had there been no fishing (B0) (MPI, 2016).
BMSY is estimated at 29% of B0, but is not considered to be a suitable management target for a number of reasons: 1) uncertainty - it assumes perfect knowledge of the current biomass and stock-recruit relationship (which is poor); 2) it requires a highly responsive harvest strategy that adjusts TACCs annually, which is an unlikely scenario; and 3) its close proximity to the soft harvest limit would permit the limit to be easily and potentially frequently breached given circumstances such as periods of low recruitment, like those observed between 1995-2001 for the Western stock (MPI, 2012; 2016).
Last updated on 1 March 2017
The 2015-2016 spawning stock biomass (SSB) was estimated to be 325,000 tonnes (58% B0), continuing a trend of very stable biomass for the past several years (MPI 2016). The estimate is less than 1/2 of the estimated 40-year peak of 609,910 tonnes 1983, but up from the low of 154,300 estimated for 2006. The estimated biomass is considered Virtually Certain (> 99%) to be at or above the lower end of the target range and “exceptionally unlikely” (<1%) to be below both Soft and Hard limits and overfishing to be occurring (MPI 2016). A strong year class was indicated for 2011. Fishing intensity (exploitation rate) decreased between 2004 until 2011, and has remained stable since that time (around 0.09) and well below U35% (0.22). Landings in 2014-2015 exceeded the TACC (60,000 tonnes) at 64,600 tonnes (sum of Cook Strait, East Coast South Island (ECSI), Chatham Rise & ECSI and East Coast North Island (ECNI) landings). Landings increased in all areas between 2015 and 2016, by amounts ranging from 9% to 29%, except in the ECNI, where there was a decrease of just under 40% (MPI, 2016).
Last updated on 1 March 2017
Fishing patterns have changed considerably since the late 1980s, due to TACC changes and re-distribution of fishing effort (MPI 2016). Hoki fishing in the region expanded in the 1970s due to foreign vessels until 1978 when the EEZ was defined and catch limits introduced. From 1989 onward, effort redistributed in the fishing grounds and catches in the eastern stock increased rapidly until 1998. After an almost ten-year declining trend and accompanying successive TACC reductions in an attempt to shift catches to the western stock, the 2003 assessment revealed the eastern stock was in a healthier state than the western stock. Effort has since shifted back to the eastern stock, stabilizing catches at around 60,000 tons.
Following an over decade-long decline in SSB, to a 28%B0 level in 2006, the most recent assessments report increases in biomass up to a levelling off point in the last several years. An even steeper decline in is apparent in fishing intensity (exploitation rate) from 2004 until 2011, and has remained flat since (MPI, 2016). Recent recruitment (2002–2009) is estimated by the model to be just below the long-term average for this stock, below average in 2010, 2012 and 2013, and well above average in 2011 and 2014 (MPI, 2016). The projections indicate that if year classes recruit to the eastern stock as expected, and at assumed 2016 eastern fishery catch levels, biomass will continue to remain roughly constant over the next 5 years.
Last updated on 3 February 2016
An ecosystem approach to fisheries management is a future objective. Managers’ decisions have on occasion become more precautionary in response to industry concerns over sustainability. A management strategy with a target biomass range of 35-50% of virgin biomass, is defined for the hoki fishery.
The TACCs are recommended by the Minister, consistent with the Fisheries Act 1996, and in agreement with the industry. The target for eastern and western areas combined was set at 150,000 tonnes for 2013-2014, 160,000 tonnes for 2014-2015, and back to 150,000 tonnes for 2015-2016 (MPI 2016). The allocation for the eastern stock has consistantly been set at 60,000 tonnes since 2010, while the remaining western area portion has varied. Increased catch allocated to the western stock from 2009-20010 through 2014-2015 intended to protect juvenile hoki from both stocks occurring in the Chatham Rise, where the majority of hoki from the eastern stock are harvested (MPI, 2013b). For 2015-2016, It was estimated that 40,000 tonnes of the eastern stock catch limit would come from spawning fish and the remaining 20,000 tonnes would be non-spawning.
Other management measures include restrictions on vessels, limiting fishing by chartered vessels to outside the 12 mile Territorial Sea. The spawning area of Cook Strait is off-limits to larger vessels and several large areas, Benthic Protection Areas (BPA), have been voluntarily closed to bottom trawling since 2007 (MPI, 2012). A Code of Practice for directed hoki trawling was introduced by the former Hoki Fishery Management Company in 2001 to protect small fish (under 60 cm) and was updated in 2009 to specifically manage four areas of juveniles’ distribution – Hoki Management Areas (HMA) that aim to improve stock recruitment and comprise closed areas to hoki fishing but are accessible to other species fishing – and move vessels in any area catching more than 20% of juvenile hoki, revised to smaller than 55 cm (NZG, 2010; MPI, 2012; Akroyd et al, 2012). The fishing activity on these HMA is motorized by the MPI that provides a quarterly report to industry (MPI, 2014b).
The National Deepwater Plan (5 years duration) will be reviewed during 2015/16. Detailed information on management measures can be found in the Annual Operational Plan for Deepwater Fisheries 2015/16.
New Zealand hoki was first certified by the Marine Stewardship Council (MSC) as sustainable in 2001 and re-certified in 2007 and 2012. Certification includes Eastern and Western stocks. The single condition of the most recent re-certification regards the impact of the fishery in the habitat was closed out by the first surveillance audit and no changes occurred by the second surveillance audit. Several recommendations have been suggested to improve the fishery (Akroyd et al, 2012; Akroyd and Pierre, 2013; Akroyd and Pierre, 2014).
Last updated on 16 March 2011
Last updated on 16 February 2017
Quota limits for the hoki fishery were first introduced in late 80s, when the New Zealand’s EEZ was declared. Historically, compliance with formal catch regulations has been high, even after successive TACC reductions. Since the 2004-2005 definition of separate catch limits for eastern and western stocks, set TACCs for the eastern stock have never been exceeded (MPI, 2012). For 2012-2013 season the catches were 60,300 tons, 300 tons higher than the set TACC. The TACC was exceeded by a larger margin in 2014-2015, by 4,600 tonnes (MPI 2016). For 2013-2014, catches were slight below the TACC (MPI, 2015a). Chatham Rise is the most important catch area in the eastern stock area (36,500 tons in 2012-2013) (MPI, 2014a). The partnership between MPI and DWG strengthens compliance (Akroyd et al, 2012).
Last updated on 3 February 2016
The interaction of the fishery with Protected, Endangered and Threatened (PET) species is not considered to be unacceptable but the impact is cumulative with other fisheries so should be monitored carefully. Details about population status and interactions with fisheries are summarized in the Aquatic Environment and Biodiversity Annual Review and in Akroyd et al (2012).
PET seabirds (all from IUCN 2010 Red List) such as Sooty shearwater Puffinus griseus (Near Threatened), White capped albatross Thalassarche steadi (Near Threatened), Salvin’s Albatross Thalassarche salvini (Vulnerable), Buller’s albatross Thalassarche bulleri (Near Threatened), White-chinned Petrel Procellaria aequinoctialis (Vulnerable) are by-catch of the hoki fishery. Management of seabird interactions with New Zealand’s commercial fisheries is now being driven through the Seabird National Plan of Action (NPOA-Seabirds). Work is ongoing between MPI and industry to reduce the risk of this fishery to key seabird species. A Vessel Management Plan is in place to document fish waste management procedures and reduce the interaction with seabirds (Akroyd et al, 2012). Seabird scaring devices for all trawlers >28 m in length and “paired streamer lines”, “bird baffler” or “warp deflector” while trawling are mitigation measures mandatory since 2006; catch of White capped albatross decreased since then (MPI, 2012). In 2012-2013 an estimated 215-333 seabird captures occurred in the hoki fishery, accounting for about 13% of seabird captures in the trawl fisheries (Abraham et al., 2013 in MPI, 2015a). The average capture rate in hoki trawl fisheries over the last ten years is about 2.16 birds per 100 tows, which is considered a low rate relative to other New Zealand trawl fisheries (MPI, 2015a). Captures of Salvin’s, Buller’s and white-capped albatross continued in 2013, although with a small rate of capture (2.13% of the observations) emphasising the appropriateness of ongoing management to reduce these captures, e.g., the use of effective warp strike mitigation devices and processing waste management strategies (Akroyd and Pierre, 2014, MPI, 2014a). Hoki fishing effort contributes approximately one third of the total risk to Southern Buller’s albatross (MPI, 2013b). The results of the 3rd surveillance audit indicated that the rate of seabird captures increased, with total captures in 2014/15 being the highest since 2002/03, consisted largely of sooty shearwater (low risk species). Captures of the higher risk Buller’s and Salvin’s albatross were similar to previous years (Akyrod et al., 2016).
Marine mammals such as New Zealand fur seals Arctocephalus forsteri (Least Concern; IUCN 2008 Red List) and New Zealand sea lions Phocarctos hookeri (Vulnerable, IUCN 2008 Red List) are identified as incidental catches but are not threatened by the fishery (Boyd, 2011). During the 2012-2013 fishing year it is estimated that 242 (mean) fur seal mortalities occurred in the hoki fisheries (MPI, 2015a). However, results from the 3rd surveillance audit suggest that, with total captures in 2014/15 being the lowest since 2002/03 (Akroyd et al., 2016). Additionally, fur seal population is believed to be increasing and it is unlikely that the current level of mortality is affecting the long term viability of the national population (MPI, 2013b). NZ sea lions are rarely captured and observed catches are outside the fishing area here regarded (MPI, 2012). The fishery does not interact with dolphins or whales (Boyd, 2011). In order to reduce incidental fur seal catches, a set of Marine Mammal Operational Procedures (MMOP) was agreed conjunctly between the government, industry and NGOs. Active monitoring of interactions will continue (MPI, 2013b). Furthermore, fur seals are protected by the Marine Mammals Protection Act (MMPA) 1978. As is one of the main fisheries that contribute to the annual catches (MPI, 2012a), the hoki fishery is included in one of the National Deepwater Plan (NDP) objectives to avoid and minimize the capture of these marine mammals.
Basking shark Cetorhinus maximus – listed in CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) and in the IUCN 2005 Red List as Vulnerable – is the only protected fish not under the Quota Management System (non-QMS) that is occasionally caught as bycatch, although the number of reported catches has been declining. There are no direct mitigation measures. Mandatory reporting of catches of protected species serves to monitor interactions; projects are undergoing to understand the interactions (MPI, 2012; Akroyd et al, 2012). MSC points one recommendation to understand the biological status of all Pale ghost shark Hydrolagus bemisi (Least Concern; 2003 IUCN Redlist) stocks. Porgeable Lamna nasus and school Galeorhinus galeus sharks (both considered as Vulnerable in the 2006 IUCN Redlist) are QMS bycatch species and currently not considered to be threatened by the fishery (Akroyd et al, 2012). The New Zealand National Plan of Action for the Conservation and Management of Sharks (NPOA–Sharks) includes several actions to improve the monitoring of shark by-catch (MPI, 2013b). ). In the most recent surveillance audit was mentioned that other protected species captures reported by observers in the 2012/13 fishing year included basking sharks (2), dusky dolphin (1), New Zealand fur seal (37), New Zealand sea lion (1), and pilot whale (1).
The impact on protected corals (Antipatharia, Gorgonacea, Scleractinia, Stylasteridae) should also be understood and monitored (Akroyd et al, 2012).
OTHER TARGET AND BYCATCH SPECIES
Last updated on 1 March 2017
Hoki was 84.7%, 85.9% and 88% of the catch in 2012-2013, 2013-2014 and 2014-2015 respectively (MPI, 2016). Data on bycatch and discarded species are obtained through both the recording of catches and observers’ reports. Composition and proportion of commercial and non-commercial species vary between the fishing areas and seasons (Ministry of Fisheries, 2011a).
Main non-target species that are predominantly managed under the Quota Management System (QMS) and are at least 1% of catches are considered as key bycatch species. Species that are not-QMS are usually discarded, incidentally captured and of little commercial value (NDP, 2012). By-catch of non-QMS fish species constitutes a small proportion (<5%) of the total hoki catch (MPI, 2013b). For the all fishing areas and between 2014-2015 (proportion in weight of catches) of main captured species were: hoki (88.0%), ling (2.4%), javelinfish (1.4%), rattails (1.1%) and hake( 1.8%) (MPI, 2016). None of the captured species is considered to be a concern (Akroyd et al, 2012). In hoki target fisheries off the west cast South Island, Chatham Rise and Sub-Antarctic the main bycatch species are hake, ling, silver warehou, jack mackerel and spiny dogfish; while in Cook Strait, the main bycatch species are ling and spiny dogfish (MPI, 2016). Total annual discard estimates ranged from about 5,500 to 29,000 tons per year between 2000–01 and 2006–07 (MPI, 2013). According to Anderson (2014), the species showing the greatest decline in by-catch rate between 1990-2012 were skates, slender jack mackerel and dogfishes. The species showing the greatest increase were floppy tubular sponge (Hyalascus sp.) and umbrella octopus (Opisthoteuthis spp.). However, this increase also could resulted of an improved identification of these species. Any increase to the Hoki TAC (2015-2016 season) was considered unlikely to have an unacceptable impact on the key by-catch species in the hoki fisheries (MPI, 2015b).
Management controls to reduce bycatch and discards include restrictions prohibiting bigger vessels (>45 m) to operate near the coast, agreed catch splits between eastern and western stocks and an Industry Code of Practice for hoki trawling fisheries aiming to protect smaller fish (<60 cm) and mitigate bycatch of marine mammals. HMAs contribute when the catch is more than 20% of juveniles (Ballara, 2010; Ministry of Fisheries, 2011; MPI, 2012).
A framework for sustainability risk assessment of fish by-catch in deepwater fisheries in New Zeland is presently under development (Roux et al., 2015).
Last updated on 3 February 2016
Mid-water trawling is expected occasionally to interact with the seabed ecosystem; even more, the impact is considered to be cumulative. Some habitat classes – Benthic-Optimised Marine Environment Classification (BOMEC) 7, 8, 9 – were identified in an Ecosystem Risk Assessment conducted by Boyd (2011) and were considered of special vulnerability. The MSC re-certification of the fishery (achieved in 2012) defined one condition that was closed by the first surveillance audit: the fishery is highly unlikely to reduce habitat structure and function to a point where there would be serious or irreversible harm. However, there are still significant gaps in knowledge. During the 3rd surveillance audit, concerns were raised about the veracity of the BOMEC classification such that alternative methods of evaluating impact were being considered. A new recommendation was raised to review at the next audit the research work to assess bottom trawl footprint and impact by BOMEC habitat class, or an improved tool when available (Akroyd et al., 2016a). By the 4th surveillance audit (Akroyd et al. 2016b), it was reported that the BOMEC habitat classification scheme was considered to be of limited value for assessing trawl and dredge impacts on benthic fauna and habitats in New Zealand waters; and development of a spatially explicit, risk-based approach was understood to be the preferred approach. Meanwhile, the recommendation remained open.
In light of an industry proposal, BPAs within New Zealand’s EEZ, corresponding to 32% of its total area, were closed to bottom trawling (and dredging) in 2007 on a permanent basis (MPI, 2009; MPI, 2012). However BPAs are considered as “not representative” since do not protect BOMEC 9 in Chatham Rise where high fishing intensity exists (Akroyd et al, 2012). Generally benthic bycatch is small, except for sponges (NZG, 2010). Baird et al., (2013) mentioned that although all coral orders were represented in the hoki bycatch, about 80% were stony corals.
The species is a key component in the ecosystem; and the importance of understanding prey-predator relationships between hoki and other species is emphasized in stock assessments (MPI, 2012; 2013; 2016).
Last updated on 15 February 2017
Currently a network representative of New Zealand’s marine habitat and ecosystems is being established and the process is involving stakeholders. The implementation of the Marine Protected Areas (MPA) policy will primarily address the territorial sea until 2013 since BPAs already protect 30% of the EEZ seabed. Meanwhile, the classification system and the updated knowledge will be included in the protection standard (DoC, 2008; MPI, 2009). There is some controversy about the representativeness of these BPAs. The current BPAs were to be reviewed after 2013 and if existing BPAs were found not to be representative then further closures were to be considered (NZG, 2010).
The Hoki Operational Procedure (HOP) is applied to all vessels greater than 28 m and includes four closing areas to protect juvenile hoki: Cook Start, Canterbury banks, Mernoo Bank and Puysegur Bank (MPI, 2014b).
Some areas are protected by marine reserves (created since 1975 are already 30) under the Marine Reserves Act 1971, Fisheries Act closures, and cable protection zones and overall protected areas (including fisheries closures on seamount) represent now over 3% of the New Zealand marine environment (DOC, 2011). In January 2016, NZ government published a document for consultation proposing A New Marine Protected Areas Act. This document, which will be in consultation until March 2016 provides four categories of MPA: marine reserves , species-specific sanctuaries, seabed reserves and recreational fishing parks. The goal of this proposal is to congregate all the matters on this topic in a single document and improve the decision-making process. However, it seems that the proposed approach will lead to legislation that affects the territorial seas (i.e. out to 12 miles) only. A better clarification on the situation of the existing BPAs is needed.