Araara, Jackfish, Silver Trevally
Trevally is caught around the North Island and the north of the South Island, with the main catches from the northern coasts of the North Island. Trevally is taken in the northern coastal mixed trawl fishery, mostly in conjunction with snapper. Since the mid-1970s trevally has been taken by purse seine, mainly in the Bay of Plenty, in variable but often substantial quantities.
Recreational fishers catch trevally by set net and line methods. Although highly regarded as a table fish, some trevally may be used as bait.
Trevally is managed by Fisheries New Zealand using the Quota Management System (QMS).
The risk assessment covers over 80% of all trevally caught commercially in New Zealand.
For more information, download the full Risk Assessment Report.
The risk assessment framework is used to assess the relative environmental risks of Australian and New Zealand wild-caught fisheries on fish stocks and the aquatic environment.
Assessments are undertaken for each species according to multiple ‘units of assessment’ (UoAs). The UoA is a combination of target species/stock and the gear type used by the fishery. Each UoA is assessed against three components for target species, bycatch and ecosystems, and management systems. Each component has a number of performance indicators, which have associated criteria, scoring issues, and scoring guideposts. For each UoA, each performance indicator is assigned a risk score according to how well the fishery performs against the scoring guideposts. The summary of risk scores by UoA is presented in the table below.
An assessment of the future ‘outlook’ over the short to medium-term (0-3 years) is provided against each component. Outlook scores are provided for information only and do not influence current or future risk scoring.
All risk assessments are conducted by an independent third party. The process only takes a few days and includes opportunities for management groups and the government to provide input and peer review.
The information presented on this page is extracted from the independent species Risk Assessment Report.
Risk Assessment Summary
Component 1 of the risk assessment looks at the health of the population of target species including the current fishing effort and estimates a risk of overfishing.
TRE 1 is believed to contain two biological stocks: East Northland to Hauraki Gulf, and Bay of Plenty. Stock assessments for each of these stocks were rejected by the Northern Inshore Working Group in 2015 and 2016. These assessments have not been finalised and will be updated once the new catch-at-age data become available. Relative abundance series were increasing for both Bay of Plenty and East Northland/Hauraki Gulf. The Ministry stock status table does not draw a conclusion about the status of the stock in relation to reference points.
The TRE 7 stock was most recently assessed in 2015 using an age-structured population model. The Ministry concluded that it is very likely (> 90%) the stock is at or above the target reference point. Accordingly, there is strong evidence the stock is highly likely to be above the point of recruitment impairment and fluctuating at or around a level consistent with maximum sustainable yield.
While there is no formal mathematical harvest control rule for these stocks, there is clearly a process in place to identify, examine and respond to issues of stock decline, and a suite of available tools to implement reductions in exploitation if needed. Action taken to reduce the catch limits in response to stock declines in several New Zealand fisheries provides evidence that the management system is willing to reduce exploitation as the point of recruitment impairment is approached.
Bycatch and ecosystems
Component 2 of the risk assessment looks at the risks around bycatch species and other environmental impacts of the fishery.
New Zealand’s inshore trawl fisheries are complex, multi-species fisheries, harvesting a wide range of inshore finfish species. The composition of the catch can vary considerably in space and time based on variations in recruitment, changes in market demand, and the like. Information on the retained portion of the catch is very strong, reported, and verified through the QMS reporting arrangements. For some stocks, this is sufficient to assess the impact of the fishery on the main other species with respect to status and detect any increase in risk. However, the available quantitative information is not sufficient in all cases.
Information on the discarded portion of the catch is limited. Observer coverage in inshore fisheries has historically been very low (or absent from some sectors), and the main information on overall catch composition comes from independent trawl surveys, which may not be an accurate reflection of commercial catch composition (for example different gear may be used). There is also limited reporting of discards in commercial catch returns. Given the absence of discard information for all sectors, it is not possible to assess impacts and the fishery has been assessed as precautionary high risk. The introduction of electronic monitoring in some sectors may help to better characterise discards.
The risks of the inshore trawl fishery to endangered, threatened and protected (ETP) species have some regional differences in risk based on the distribution of ETP species. The main potential ETP species interactions in the inshore trawl fisheries are with seabirds and marine mammals.
Risks to seabirds associated with New Zealand’s commercial fisheries have been assessed through a hierarchical series of risk assessments. In the most recent assessment, only one species of seabird, black petrel, had a median risk ratio higher than 1 (or upper 95% confidence limit higher than 2). For all other species, current rates of fishing-related mortality were not expected to hinder the achievement of management targets (i.e. the risk ratio was < 1). The specific contribution of inshore trawl fisheries to black petrel potential fatalities is not known, but the total estimated captures in trawl fisheries represent a small fraction of the overall estimated captures for black petrel. Based on rates of observer coverage, it is estimated that between 400 – 600 seabirds are captured in New Zealand’s inshore trawl fisheries each year. There is also evidence from the most recent risk assessment that risk to black petrel has declined since the introduction of the current National Plan of Action - Seabirds in 2013. Accordingly, the direct effects of the inshore trawl fisheries appear highly unlikely to hinder the recovery of ETP seabird species.
Between 2002–03 and 2014–15, there were six observed captures of New Zealand fur seals, and no observed captures of New Zealand sea lions, in inshore trawl fisheries. Estimated captures of fur seals in the same period ranged from 40 to 114 annually. New Zealand fur seals are the most common seals in New Zealand and are listed as ‘least concern’, with an increasing population trend. There are no national or international limits on incidental captures of fur seals. Based on this it appears highly likely that current rates of capture are not hindering the recovery of either species.
With regards to Hector's and Maui dolphin, given the very low median estimates of annual fatalities in the trawl sector, it is unlikely that the trawl fishery will hinder the recovery of either species. However, given the preliminary estimates of risk for common dolphins, including the possibility that the risk ratio from commercial fishing may be up to twice their sustainability threshold, and the inshore trawl fishery is considered an important contributor to risk for this species. The installation of on-board camera monitoring for some sectors of the fleet (phased in from 1 October 2018) will likely assist in better estimating the extent of interactions between marine mammals and inshore trawl vessels.
Between 2002–03 and 2014–15, there were no observed captures of any birds, pinnipeds, or dolphins in minor purse seine fisheries.
The final results from the New Zealand Marine Mammal Risk Assessment are expected in 2017.
Component 3 of the risk assessment looks at the risks around the management systems of a fishery.
The Fisheries Act 1996 (the Act) and subsequent amendments provide a binding legislative and legal framework for delivering the objectives of Components 1 and 2. Sections 10, 11, and 12 of the Act establish the requirements for the decision-making process, and Section 10 further requires the use of the best available information for all decisions. The Act requirement for best available information leads to scientific evaluation in advance of decisions. The Act further requires consultation with such persons or organisations as the Minister considers are representative of those classes of persons having an interest in the stock or the effects of fishing on the aquatic environment in the area concerned including Maori, environmental, commercial, and recreational interests.
While objectives broadly consistent with Components 1 and 2 are specified in the Act and Fisheries 2030 and are therefore implicit in the fishery specific management system, it is not clear that explicit short and long-term objectives for inshore trawl fisheries are in place at this stage. Nevertheless, the fishery management system is subject to regular internal review through the fisheries Plenary reporting process and decision making is guided by the Harvest Strategy Standard. The Ministry for Primary Industries implements a comprehensive peer-review process for all scientific research that is used to inform fisheries management decisions.
It is clear that sanctions to deal with non-compliance exist for a range of offences, and these sanctions are regularly applied by the Ministry for Primary Industries. The Ministry operates a comprehensive monitoring control and surveillance system including:
- fishing permit requirements;
- fishing permit and fishing vessel registers;
- vessel and gear marking requirements;
- fishing gear and method restrictions;
- vessel inspections;
- control of landings (e.g. requirement to land only to licensed fish receivers);
- auditing of licensed fish receivers;
- monitored unloads of fish;
- information management and intelligence analysis;
- analysis of catch and effort reporting and comparison with landing and trade data to confirm accuracy;
- boarding and inspection by fishery officers at sea; and
- aerial and surface surveillance.
In addition, the Ministry has a fishery outreach programme of informed and assisted compliance, in which enforcement agents work with the industry in a proactive way to ensure understanding of regulations and to prevent infractions. In combination with at-sea and air surveillance supported by the New Zealand joint forces, vessel activity can be monitored and verified to ensure compliance with regulations and with industry-agreed codes of practice.
Summary of main issues
Main issues highlighted by the assessment are:
- The position of several target stocks against reference points is not known, as is the probability that current catch or Total Allowable Commercial Catch will result in a decline in biomass below soft and hard limits
- Observer coverage in inshore fisheries has been very low historically, and very limited information is available on composition and volume of discards.
- The inshore trawl fisheries interact with a range of ETP species. Although recent risk assessments indicate the extent of estimated captures of seabird species should not hinder recovery, there is uncertainty over the impact of the fishery on common dolphins. Preliminary results from the New Zealand Marine Mammal Risk Assessment identified common dolphin as the marine mammal species most at risk from commercial fishing.
- The widespread nature of bottom trawling suggests that fishing is the main anthropogenic disturbance agent to the seabed throughout most of New Zealand’s EEZ. Recent research suggests moderate and high levels of trawling intensity occur in a relatively small proportion of areas shallower than 200m. The capacity of seabed communities to recover from trawling disturbance is not well known.
- There have been concerns about compliance with quota species retention provisions amongst inshore fisheries.
The outlook below provides a qualitative judgment about the likely future performance of the fishery against the relevant risk assessment criteria over the short to medium-term (0-3 years). Assessments are based on the available information for the species and take into account any known management changes.
- Target species (TRE 1) - Improving: Relative abundance series were increasing for both areas. New stock assessments are expected to be completed once new catch-at-age data become available.
- Target species (TRE 7) - Stable: The stock is above the target reference point and fishing mortality is lower than the rate that, if applied constantly, would result in maximum sustainable yield.
- Target species (TRE 1_PS) - Stable: Although variable, recent levels of fishing intensity have been at or around the rate that, if applied constantly, would result in maximum sustainable yield.
- Bycatch and ecosystems (TRE 1_Trawl & TRE 7_Trawl) - Improving: The information base to examine the ecosystem impacts of inshore trawling is growing. The introduction of electronic monitoring on at least some inshore fleets should improve understanding of catch composition and allow more sophisticated assessments of the impact of the fishery on non-target species. ETP species risk assessments have been continuously refined over recent years, resulting in reductions in estimated risks from inshore trawling. Habitat research is ongoing with new studies planned to better understand the dynamics around impact and recovery. Ecosystem modelling is also underway to better understand the trophic impacts of inshore fishing.
- Bycatch and ecosystems (TRE 1_PS) - Stable: Additional work to understand the status of bycatch species may reduce the other species risk score.
- Management systems - Stable: No major changes are expected to management system risk scoring.