Final Research Report

FINAL RESEARCH REPORT

Date: 30 July 2010

Research Provider: NIWA Project Code: ENV200305 Project Title: To review the current threat status of selected associated or dependent species Report Title: Summary of Work to date for ENV200305 Principal Investigator: S.J. Baird Author: S.J. Baird; J. Booth; W. Lyon Project Start Date: I October 2003 Expected Project End Date: 31 July 2010

EXECUTIVE SUMMARY

This report provides a summary of the life of this project with respect to the progress achieved and the planned direction for future work. NIWA was awarded this contract in 2003 and, in consultation with the Ministry of Fisheries, agreed on a framework for assessing the threat status of selected marine species. However, due to staff changes at the Ministry of Fisheries and the ongoing development of the Ministry’s strategy for the environment, a lack of direction impeded any real progress beyond the first output commitment from NIWA. Subsequently, interest was reinvigorated. In consultation with the Ministry, agreement on an assessment methodology was reached and this is described in the body of this report.

For a record of the project activity, the original tender, original methodology, and resulting species summaries collated by NIWA are attached as appendices; however, these appendices represent work based on the original methodology and were undertaken about 5 years ago, at a time when the Ministry was developing environmental and harvest strategy management processes that are now in place. Thus, much of the information requires updating.

OBJECTIVES

Overall Objective: 1. To review the current threat status of selected associated or dependent species.

Specific Objective: 1. To assess the current threat status of selected associated or dependent species.

INTRODUCTION

This report provides a summary of progress to-date on Ministry of Fisheries project ENV200305: to review the current threat status of selected associated or dependent species. The main body of the report describes the methodology framework agreed by the Ministry in 2009–10 as the way to progress an assessment of the threat status of marine species in New Zealand waters.

Other documentation relevant to the project is presented in chronological order in the appendices. The appendices contain the background documents and work completed at the beginning of the project. These are included to indicate the original scope of the work (where it could be readily defined) and as evidence of work completed to date – though much of this work is now out-of-date.

The tender for this project (Appendix 1, p. 8) stated: a) that the review should not include chondrichthyans or protected species, which at that time included marine mammals, most seabirds, and a small number of coral and fish species; b) the emphasis was to be on associated or dependent teleosts and marine invertebrates; and c) the expected approach would be to adapt existing classification frameworks (such as those used by the Department of Conservation, World Conservation Union (IUCN), or the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES)).

The main requirements of the project were to consult with fisheries managers of the Ministry of Fisheries to develop a list of species to be assessed and to run an assessment workshop following an agreed methodology with the participation of scientific experts. The primary output from the project would aid fishery managers in the consideration of the environmental effects of fishing and the development of performance indicators.

The brief for this report is simply to collate and present what has been done under this project, not to summarise the current international knowledge, nor to provide the current Ministry of Fisheries rationale or potential use of the output from threat assessments.

Initial approach

When the tender for ENV200305 (Appendix 1) was released we sought clarification from the Ministry of Fisheries through discussions with officials working on the draft Strategy for the Environment (the predecessor of the Strategy for Managing the Environmental Effects of Fishing (SMEEF)). Although, some estimates of bycatch were available through projects such as ENV1999/02 (Anderson et al. 2001), there was an apparent lack of knowledge about many of these species and the draft environmental strategy document stressed the importance of knowledge of the effects of fishing on non-target catches, including effects of changes in fishery management regimes.

Our accepted tender bid detailed the process we would undertake to assess the current threat status of selected associated or dependent species (Appendix 2, p. 11): in consultation with Ministry of Fisheries, develop an agreed list of species and determine a suitable methodology for assessment; provide brief summaries of information for each species; undertake an assessment workshop; and document the assessment results in a summary report with the relevant species information.

Our approach was: a) to suggest species (25 teleosts and 25 invertebrates) from two areas where we knew there was at least some available information from bycatch studies, and where the communities represented different habitats and different fishing pressure — Chatham Rise and Bay of Plenty; and b) to review the available threat classification systems and their relevance for the New Zealand marine environment (Appendix 3, p. 15). There were delays in receiving comment from the Ministry of Fisheries due to staff unavailability and then changes in personnel. The Ministry of Fisheries agreed on the species and we proceeded to produce species summaries (Appendix 4, p. 30; Appendix 5, p. 61). The review work shown in Appendix 3 was presented to the Aquatic Environment Working Group in May 2005 and was received with very little comment or feedback. No minutes were produced from the meeting and we halted work on the project until we were able to establish a direction from the Ministry of Fisheries and an acceptable methodology.

Interest in the project was revived with the arrival of Dr Pamela Mace at the Ministry of Fisheries. The combination of her international, recent and ongoing experience in this field (for example, Mace et al. 2002) and recent clarification within the Ministry of Fisheries with respect to environmental principles and management has resulted in further discussions between NIWA and the Ministry of Fisheries — the results of which are presented below as the way to proceed, with the lead taken by Dr Pamela Mace. The focus has moved from the original community-based approach to one directed at commercial fish species using the internationally accepted CITES based assessment process. The reader is directed to the background review in Appendix 3 and to FAO (2001) and Mace et al. (2002) for the rationale and examples of the CITES approach summarised below.

AN EXTINCTION RISK MODEL PROPOSED FOR NEW ZEALAND MARINE SPECIES

Worldwide there are examples of populations of both commercial and non-commercial aquatic species becoming at risk of extinction through anthropogenic and/or natural causes. Among the non-commercial species may be those associated with the target commercial species.

The Ministry of Fisheries is classifying extinction risk for New Zealand aquatic species using a system based on one developed by FAO (FAO 2001), it in turn being derived from National Marine Fisheries Service (Mace et al. 2002), CITES (the CITES Notification), AFS (American Fisheries Society; Musick (1999)), and IUCN (Red list) systems. The Ministry of Fisheries views the FAO system as being the one most suitable for use with aquatic species—both commercial and non-commercial. However, this extinction risk classification system still needs to be brought into a New Zealand context, and the system—and its modifications—are summarised here, drawing heavily in its wording on FAO (2001) and Mace et al. (2002).

The DOC threat classification system (Hitchmough 2002, Molloy et al. 2002) is not considered to be suitable for many marine species, especially exploited ones.

Population units The extinction risk classification can be applied to various population units of any particular taxon. It may be, on the one hand, the extinction risk for the taxon throughout the New Zealand region, or, at the other extreme, it may be for the population of the taxon in one locality.

For example, consider orange roughy. The level of extinction risk might be estimated for the entire New Zealand population; for ORH 7A (equivalent to the Distinct Population Segment and, if genetically distinct, to the Evolutionarily Significant Unit, discussed by Musick (1999)); or for some subpopulation of orange roughy such as that associated with a particular seamount.

The Ministry of Fisheries should decide the population unit (‘population’ from now on) for which they wish to consider extinction risk.

Risk categories The classification system to be used for each population has five levels of extinction risk, determined for each mainly on the current estimated biomass relative to an undisturbed/unfished baseline estimate. (Surrogates for this estimate of extent-of-decline are given below.) • Very high concern , where the population is <2% of the baseline • High concern , where the population is 2–5% of the baseline • Moderate concern , where the population is 5–20% of the baseline, depending on the productivity of the species (see below) • Low concern , where the population is >5–20% of the baseline, depending on the productivity of the species • Data deficient , a group for which there is too little information to make any defensible risk rating

The following are considered to be relevant metrics for the extent of decline. • Biomass of populations/stocks • Number of individual organisms in a population • Area inhabited (area of distribution) • Range (for migratory species) • Percentage coverage (for sessile species) • Numbers or biomass of new recruits (recruitment)

Modifying factors There are factors that may increase or decrease the risks to a population, which may therefore necessitate modification to the estimated level of extinction risk. The wide range of potential taxon-associated modifying factors means that each population must be considered on a case-by-case basis.

Vulnerability factors that could increase concern: • Life history characteristics such as low fecundity, slow growth rates, high age at first maturity, and long generation time (see discussion of these in Appendix 1in Mace et al. (2002)) • Low absolute numbers or biomass • Restricted area of distribution • Selectivity of removals • Distorted age, size or stage structure of a population • Social structure including sex ratio, social hierarchy, social dominance etc. • Low population density, particularly for sessile or semi-sessile species • Vulnerability at different life stages (e.g. during migration or spawning) • Specialised niche requirements such as diet and habitat • Specialised associations such as symbiosis and other forms of co-dependency • Strong aggregating behaviour such as schooling • Fragmentation or concentration in one location • Reduced genetic diversity • Severe loss of or extent of habitat • High degree of endemism • Existence of and vulnerability to disease • Presence of and vulnerability to invasive species • Existence of rapid environmental change (e.g. shifts in ecological or climatic regimes)

Mitigating factors that could decrease concern: • Life history characteristics such as high fecundity, rapid growth rates, low age at first maturity, and short generation time • High absolute numbers or biomass • Existence of natural refugia • Adaptations to small population size • Selectivity of removals

Productivity of a species and historical-extent-of-decline The most important property of species and populations in relation to risk of extinction is thought to be their resilience (Musick 1999, Mace et al. 2002)—the `ability to rebound after perturbation'—which is closely related to the allied concept of the `ability to sustain exploitation'. This is best reflected by the productivity of the species, with more productive species generally being more resilient than less productive species. Because there is no single absolute number that provides a good measure of risk of extinction for all exploited fish species, it is generally preferable to consider the decline in size of a population relative to a previous reference baseline.

Decline can be expressed in two fundamentally different ways: • The overall long-term (historical) extent-of-decline • The recent-rate-of-decline

The extinction risk classification system proposed for use places emphasis on the historical-extent-of- decline. An historical-extent-of-decline to 5–20% of the reference baseline, depending on the productivity of the species, means that the population may be considered at risk. Ranges of 5–10% are used for species with high productivity, 10–15% for species with medium productivity, and 15–20% for species with low

productivity (Table 1, from FAO 2001). These guidelines need to be used in conjunction with the modifying factors given above, and, whenever possible, with a rigorous and quantitative scientific evaluation to refine the estimate of risk of extinction.

A recent-rate-of-decline could be considered as a surrogate for historical-extent-of-decline when a baseline population size cannot be estimated. It may also be useful as an indicator of the urgency of the need for remedial action. A rate-of-decline that would bring population size down from its current extent- of-decline to the equivalent level of ‘Moderate concern’ extent-of-decline within 10 years is the key criterion. Calculations for the rate-of-decline necessary to reduce a population to this level over a 10-year time horizon are summarised in Table 2 (from FAO 2001), where low productivity is equated with an extent-of-decline guideline of 20% of the baseline, medium productivity with a guideline of 15% of the baseline, and high productivity with a guideline of 10% of the baseline; i.e., the upper bounds of the suggested ranges are used. Other percentages within the suggested ranges may be more appropriate for some species.

Table 1. Proposed indices of productivity for exploited fish species, where M is the natural mortality rate, r is the intrinsic rate of increase of a species, K is the von Bertalanffy growth rate, tmat is the age at maturity, tmax is the maximum age, and G the mean generation time.

Productivity Parameter Low Medium High M < 0.2 0.2–0.5 > 0.5 r < 0.14 0.14–0.35 > 0.35 K < 0.15 0.15–0.33 > 0.33 tmat (years) > 8.0 3.3–8.0 < 3.3 tmax (years) > 25.0 14.0–25.0 < 14.0 G (years) > 10.0 5.0–10.0 < 5.0 Example species orange roughy, many sharks cod, hake sardine, anchovy

Table 2: Cumulative 10-year rate-of-decline (and corresponding average annual rate-of-decline) that would drive a population down from the current population level to the extent-of-decline threshold (as a percentage of the specified baseline) within 10 years. There should rarely be need for concern about exploited fish species at or above 50% of the baseline. But if recent-rates-of-decline below are met or exceeded, then the population can be considered at risk. If fewer than 10 years of data are available, annual rates over a shorter period could be used to extrapolate beyond existing data where there is evidence that the decline is continuing and is not simply part of a short-term fluctuation. Productivity Current population as % of baseline Low Medium High 100% 80% (15%) 85% (17%) 90% (21%) 90% 78% (14%) 83% (16%) 89% (20%) 80% 75% (13%) 81% (15%) 88% (19%) 70% 71% (12%) 79% (14%) 86% (18%) 60% 67% (10%) 75% (13%) 83% (16%) 50% 60% (9%) 70% (11%) 80% (15%) 40% 50% (7%) 63% (9%) 75% (13%) 30% 33% (4%) 50% (7%) 67% (10%) 20% 0% 25% (3%) 50% (7%) 15% 0% 0% 33% (4%) 10% 0% 0% 0% 5% 0% 0% 0%

Quantitative assessment When sufficient data are available to allow reliable quantitative assessments to be conducted, the results from these should supersede simpler criteria or single indices for inferring risks of extinction. Even in data-poor situations, appropriate quantitative analyses should be used to the extent possible to ensure that indices of population status are as accurate and precise as possible. In situations where few or no quantitative data exist, qualitative information, analogies with other populations or species, and consideration of the modifying factors should be used in combination to develop an informed judgment about the likely status of a population with respect to the suggested criteria and guidelines.

Recommended way forward Populations of both commercial and non-commercial species—fishes and invertebrates—should be assessed for risk of extinction in the first trial use of this system in New Zealand. The Ministry of Fisheries should provide a seminar on the approach for the threat classification and background material on the biology, and (where relevant) the fishery, for each species/population should be considered by a panel of experts who would ascribe a risk rating to each—‘Low concern’, ‘Moderate concern’, ‘High concern’, or ‘Very high concern’. [The ‘Data deficient’ group should be kept as small as possible.] The reasons for the decisions should be documented, along with the background information.

ACKNOWLEDGEMENTS Thanks to Pamela Mace of Ministry of Fisheries for providing clarity in the direction of the Ministry of Fisheries for this project. This work was funded by the Ministry of Fisheries under project ENV200305.

REFERENCES

Anderson, O.F.; Gilbert, D.J.; Clark, M.R. (2001). Fish discards and non-target catch in the trawl fisheries for orange roughy and hoki in New Zealand waters for the fishing years 1990–91 to 1998–99. p. New Zealadn Fisheries Assessment Report 2001/16 . 57 p. FAO (2001). Second technical consultation on the suitability of the CITES criteria for evaluating the status of commercially- exploited aquatic species. Windhoek, Namibia, 22–25 October 2001. Hitchmough, R. (2002). New Zealand threat classification system lists. Threatened Species Occasional Publication 23. 210 p. Mace, P.M.; Bruckner, A.W.; Daves, N.K.; Field, J.D.; Hunter, J.R.; Kohler, N.E.; Kope, R.G.; Lieberman, S.S.; Miller, M.W.; Orr, J.W.; Otto, R.S.; Smith, T.D.; Thompson, N.B. (2002). NMFS/Interagency Working Group Evaluation of CITES Criteria and Guidelines. NOAA Technical Memorandum NMFS-F/SPO-58 . 70 p. Molloy, J.; Bell, B.; Clout, M.; de Lange, P.; Gibbs, G.; Given, D.; Norton, D.; Smith, N.; Stephens, T. (2002). Classifying species according to threat of extinction. A system for New Zealand. Threatened Species Occasional Publication 22 . 26 p. Musick, J.A. (1999). Criteria to define extinction risk in marine fishes. Fisheries 24(12) : 6–14.

PUBLICATIONS

None to date. The initial output requirement for this project is attached as Appendix 3.

DATA STORAGE

All references used for the species accounts are in storage at NIWA, Greta Point, Wellington.

LIST OF APPENDICES

Background information for ENV2003/05 is contained within these appendices. The purpose of appending the following items is to ensure that the initial tender and bid for the project and the initial work completed by NIWA for the Ministry of Fisheries is collated together. The species summaries represent information available at the time of preparation. The invertebrate summaries were completed mainly during 2004 and the fish species in 2005–07, and thus are now out-of-date. For example, some species (for example, prawn killers, for which the information was collated in 2004) were included in the Quota Managment System in October 2007. However, the summaries are included here for completeness.

Appendix Page

Appendix 1:ENV200305 tender document 8

Appendix 2: ENV200305 NIWA bid 11

Appendix 3: Initial output to the Ministry of Fisheries 12 March 2004: Inital agreed approach and methodology 15

Appendix 4: Invertebrate species summaries for the Appendix 3 community-based approach 30

Appendix 5: Fish species summaries for the Appendix 3 community-based approach 61

APPENDIX 1: ENV200305 TENDER

Project: Review of the current threat status of associated or dependent species

Project Code: ENV2003/05

Start Date: 1 October 2003

Completion Date: 30 September 2004

Overall Objectives:

1. To review the current threat status of selected associated or dependent species.

Specific Objectives:

2. To assess the current threat status of selected associated or dependent species.

Reporting Requirements:

Objective 1 1. To submit to the Chief Scientist Ministry of Fisheries a Final Research Report as specified in Research Reporting form 4 or a draft Fishery Assessment Report as specified in Fishery Assessment Document form 1 by 31 July 2004. 2. To present the report detailed in 1 above to a meeting of the Aquatic Environment Working Group in July-September 2004 in Wellington. Presentations to more than one meeting of the Working Group may be required in Wellington. 3. To submit to the Chief Scientist, Ministry of Fisheries a draft Working Group Report as specified in Fishery Assessment Document form 2 by 30 September 2004.

Note: Note that protected species will not be reviewed, as their threat status is already regularly reviewed by both the International Union for the Conservation of Nature (IUCN) and the Department of Conservation.

Chondrichthyans are unlikely to be reviewed under this project as a March 2003 IUCN workshop in Australia with New Zealand expert participation will review the threat status of all Australasian chondrichthyans.

Accordingly, the list is likely to include associated or dependent teleosts and marine invertebrates identified in previous research into non-target catches in various New Zealand fisheries (e.g. see NZ FAR 2001/16).

Rationale:

General What is the threat status of the associated or dependent species currently incidentally captured in New Zealand fisheries? Threat status can be determined by reviewing available information about the species and using that information in an expert workshop to make an assessment using an existing threat classification system.

One of the proposed key elements of the Environmental Management Strategy with respect to the effects of fishing on non-target catches is an assessment based on ‘threat status’. Even if this is not a part of the final Environmental Management Strategy , a review of the threat status of associated or dependent

species is important for the management of the interaction between fisheries and the marine environment (especially with respect to s. 9 (a) of the Fisheries Act 1996).

For many of these species our knowledge is relatively poor. However, technical expert workshop approaches have been shown to be reasonably robust in summarising available information in such situations.

It is expected that this project will use an existing framework rather than developing a new threat classification system from first principles. Some modification of an existing framework to the New Zealand marine environment may be appropriate.

The outputs of the classification will be utilised by Fishery Managers in a variety of ways, in particular when considering the potential environmental effects of changes in TACCs across a range of fisheries, and when assessing the adequacy of Fisheries Plans proposed by stakeholders.

The outputs of this research will likely be useful in the further development of environmental performance indicators for fisheries. The research also further develops an existing tool in a way that should allow better assessment of the potential effects of fishing in low information fish stocks.

As threat status is seen as a core element of the Environmental Management Strategy it is appropriate to initiate this research now to better inform the implementation of the Environmental Management Strategy .

The proposed methods have been previously shown effective, even for relatively data poor species, in making a reasonable assessment of the threat status of species. The information will be of use to Fisheries Managers in addressing the effects of fishing on associated or dependent species, especially where considering alterations in management regimes that may alter the threat status of the associated or dependent species. Accordingly, this research programme is a high priority.

Objective 1 A list of species to be assessed will be developed in consultation with Fisheries Managers. Note that protected species will not be reviewed, as their threat status has already been reviewed by both the IUCN and the Department of Conservation. Chondrichthyans are unlikely to be reviewed as a March 2003 IUCN workshop in Australia will review the threat status of all Australasian chondrichthyans. Accordingly, the list will include associated or dependent teleosts and marine invertebrates identified in previous research into non-target catches in various New Zealand fisheries (e.g. see NZ FAR 2001/16).

A brief background on each species to be assessed should be collated. The background documents should summarise readily available information pertinent to threat classification. A workshop process involving relevant technical experts working in a variety of New Zealand scientific organisations should then undertake the threat assessment using the agreed system, the background documents and their professional expertise.

The outputs are expected to be summary sheets detailing the threat status for each species and the justification for that threat status.

Strategic Relevance This research addresses the environmental principles of the 1996 Act and the strategy for marine environment research “…to develop and apply methods to ensure the use of fisheries resources is compatible with the requirements to avoid, remedy or mitigate any adverse effects of fishing on the marine environment, to maintain biological diversity and to protect habitat of particular significance for fisheries management”. This project forms a part of the Aquatic Environment research themes ‘…to determine the direct effects of fishing on associated or dependent species…’ and to ‘…to explore the indirect effects of fishing on associated or dependent species….’. This project is therefore consistent with the Aquatic Environment Research section of the Ministry of Fisheries Strategic Research Directions document.

This project also has very strong links to the proposed risk characterisation elements of the Environmental Management Strategy .

Weighting of Objectives Weightings indicate the relative importance of each of the objectives. The weightings for the objectives in this project are (in order): 1.0.

APPENDIX 2: ENV200305 NIWA BID

Overall Objective: 1. To review the current threat status of selected associated or dependent species.

Specific Objective: 1. To assess the current threat status of selected associated or dependent species.

GENERAL OVERVIEW:

Introduction Under the 1996 Fisheries Act, the Ministry of Fisheries must address the environmental principles and the strategy for marine environment research “…to develop and apply methods to ensure the use of fisheries resources is compatible with the requirements to avoid, remedy or mitigate any adverse effects of fishing on the marine environment, to maintain biological diversity and to protect habitat of particular significance for fisheries management”. Further to this is the need “...to determine the direct effects of fishing on associated or dependent species…” and to “…to explore the indirect effects of fishing on associated or dependent species….”.

One of the proposed key elements of the Environmental Management Strategy (currently being developed by the Ministry of Fisheries) with respect to the effects of fishing on non-target catches is an assessment based on ‘threat status’. Even if this is not a part of the final Environmental Management Strategy , a review of the threat status of associated or dependent species is important for the management of the interaction between fisheries and the marine environment (especially with respect to s. 9 (a) of the Fisheries Act 1996).

Non-target catches are generally either managed fisheries (inside or outside the QMS), or, associated or dependent species. For most of the associated or dependent species that are caught incidentally in fisheries, assessments of threat status have not been undertaken and our knowledge is relatively poor. This is a level of complexity that is missing at present in the consideration of the potential environmental effects of changes in TACCs across a range of fisheries, and when assessing the adequacy of Fisheries Plans proposed by stakeholders. The information will be of use to Fisheries Managers in addressing the effects of fishing on associated or dependent species, especially where considering alterations in management regimes that may alter the threat status of the associated or dependent species.

We understand that in the current context “threat” is primarily the perceived threat of extinction of a species. Threat status can be determined by reviewing available information about the species and using that information in an expert workshop to make an assessment using an existing threat classification system. The proposed methods have been previously shown effective, even for relatively data poor species, in making a reasonable assessment of the threat status of species. The outputs of this research will also be useful in the further development of environmental performance indicators for fisheries. The research also further develops an existing tool in a way that should allow better assessment of the potential effects of fishing in low information fish stocks.

A variety of threat classification systems are available, including a system developed specifically for both the terrestrial and marine environment in New Zealand (the Department of Conservation Threat Classification System (Molloy et al. 2002)). At an international level the IUCN system is also widely used, however, one of the key drivers for the development of the Department of Conservation Threat Classification System was to develop a system specifically suited to New Zealand. This system uses seven levels of threat from nationally critical to range restricted and has been applied to protected species in the marine environment as well as some marine fishes, sharks and rays, and some marine invertebrates (Hitchmough 2002). The DOC classification of some marine fishes is based on the perceived threat of extinction as judged by the experience and knowledge of marine biologists. We understand that the list of species covered in the requirements for this project will be based on species associated with or dependent on Quota Management Species in New Zealand commercial fisheries and as such will supplement the

DOC classification. Members of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) are also currently working on an appropriate classification system for fishes.

Objective 1 A list of species (or groups of species) to be assessed will be developed in consultation with fisheries managers. Note that protected species will not be reviewed, as their threat status has already been reviewed by both the IUCN and the Department of Conservation. Currently the IUCN are reviewing the threat status of chondrichthyans, but a standardised classification approach to most of the teleost and invertebrate associated or dependent species has not been undertaken. Given the different fisheries in the New Zealand EEZ, the number of associated or dependent species is potentially very large and the available information may be very limited. Thus it may be practical to look at groups of species or at habitat- associated communities (maybe also with groups of associated species).

A brief background on each species (or group of species) to be assessed will provide summaries of readily available information pertinent to threat classification. These summaries will be used in a workshop process involving relevant technical experts working in a variety of New Zealand scientific organisations to complete a threat assessment using an agreed classification system, the background documents and professional expertise. As part of this process we will draw on the experience of NIWA staff (Malcolm Francis and Larry Paul) who are currently contributing to the IUCN review of the status of chondrichthyans. The output from this will be a report containing summary sheets detailing the threat status for each species and the justification for that threat status.

OBJECTIVE 1: To assess the current threat status of selected associated or dependent species. This objective requires 5 key activities:

Development of the list of species Agreement on the classification system Summaries of information for each species Assessment of threat status by relevant experts Completion of summary report

Methods:

1. Development of the list of species We understand that the species chosen for threat classification will be determined after discussion with Ministry of Fisheries fishery managers. The first task in this process will be to determine and define the basis on which to choose the species (or groups of species). For example, it may be that, for management purposes, one method would be to pick a variety of communities representative of different habitats within the EEZ (for example, the South Tasman Rise (Anderson & Clark 2002), the Bay of Plenty (Cryer et al. 2002), the Chatham Rise (Bull et al. 2001), the east coast of the South Island (Beentjes et al. 2002), or the Hauraki Gulf (Kendrick & Francis 2002)). The associated or dependent teleost and invertebrate species that have been identified from these communities could form the basis of an initial list for discussion with Ministry of Fisheries managers.

We are aware that the identification of some of the species, especially the invertebrates, may be less than robust, necessitating grouping of species. The second part of the process would be to review all the relevant readily available literature, such as that on bycatch and discards (e.g., Anderson et al. 2001, Francis et al. 2000) and the atlases of distributions (e.g., Hurst et al. 2000, O’Driscoll et al. 2003). It may also be useful to review the verified fish communities’ species list NIWA prepared from research trawls for a FRST project. Further information could be collated from the NIWA and MoNZ invertebrate databases. The last part would involve creation of a list (in agreement with the Ministry of Fisheries) that represents species (or groups of species) that are present in the communities and also represented in other areas of the EEZ.

Milestone: 31 December 2003 Agreed list complete.

2. Agreement on the classification system We will review the frameworks of the IUCN and DOC classification systems (and, if available, the CITES classification for fishes) and determine (in discussion with the Ministry of Fisheries) the suitability of these frameworks for the list of species. We understand that the DOC framework was set up to offer a similar system to that used by IUCN, but with criteria more appropriate to New Zealand. We anticipate using this system as it is or with some (defined) modification, if considered necessary. We will circulate a draft copy of the classification framework to experts in the marine fishes and invertebrates fields (including the Ministry of Fisheries managers) for comment before a final agreed version is complete.

Milestone: 31 December 2003 Agreement on the classification system achieved.

3. Summaries of information for each species We will use readily available literature to collate pertinent summary information on each species on the list. These summaries will include headings such as: overview description distribution and relative abundance ecology and life history (including, where known, associated and dependent species, and parameters on age/size at maturity, longevity/maximum size, size at birth, average reproductive age, reproductive periodicity, annual rate of population increase, natural mortality) exploitation and threats conservation and management

Milestone: 31 March 2004 Summaries of information for each species complete.

4. Assessment of threat status by relevant experts We will run a workshop to assess the threat status of those species on the agreed list. The workshop participants will include experts who specialise in teleosts and invertebrates. We envisage that these experts will represent various scientific organisations and universities in New Zealand (and possibly from overseas, particularly Australia) and that they will include the same group that commented on the agreed classification system. Prior to the workshop, the agreed list, classification system, and background documents will be circulated to the participants. It may be sensible to run two workshops, one for the teleost species and one for the invertebrates. During the workshop, experts will agree on the appropriate threat classification for each species.

Milestone: 30 April 2004 Assessment of threat status complete.

5. Completion of summary report Following the workshop we will produce summary sheets with attached documents including the decision processes for the agreed list of species and the classification and the background information for each species. These will be circulated to the workshop participants for comments before the final report is completed.

Milestones: 31 July 2004 Submit to the Chief Scientist, Ministry of Fisheries a Final Research Report, or a draft Fishery Assessment Report. 30 September 2004 Present the report detailed in 1 above to a meeting of the Aquatic Environment Working Group in July-September 2004 in Wellington. 30 September 2004 Submit to the Chief Scientist, Ministry of Fisheries a draft Working Group Report.

References Anderson, O. F.; Gilbert, D. J.; Clark, M. R. (2001). Fish discards and non-target catch in the trawl fisheries for orange roughy and hoki in New Zealand waters for the fishing years 1990 −91 to 1998 −99. New Zealand Fisheries Assessment Report 2001/16 . 57 p. Anderson, O.; Clark, M. (2002). Analysis of bycatch in the South Tasman Rise orange roughy fishery. Final Research report prepared for Objective 5 of Ministry of Fisheries Project ORH2001/03. Beentjes, M. P.; Bull, B.; Hurst, R. J.; Bagley, N. W. (2002). Demersal fish assemblages on the continental shelf and upper slope of the east coast of the South Island, New Zealand. New Zealand Journal of Marine and Freshwater Research 36(1) : 197–223. Bull. B.; Livingston, M.; Hurst, R.; Bagley, N. (2002). Upper-slope fish communities on the Chatham Rise, New Zealand, 1992–1999. New Zealand Journal of Marine and Freshwater Research 35(4) : 795–815. Cryer, M.; Hartill, B.; O’Shea, S. (2002). Modification of marine benthos by trawling: towards a generalization for the deep ocean? Ecological Applications 12 (6) : 1824–1839. Francis, M. P.; Griggs, L. H.; Baird, S. J.; Murray, T. E.; Dean, H. A. (2000). Fish bycatch in New Zealand tuna longline fisheries, 1988–89 to 1997–98. NIWA Technical Report 76 . 79 p. Hitchmough, R. (Comp.) (2002). New Zealand Threat Classification System lists ― 2002. Threatened species occasional publication 23 . 210 p. Hurst, R. J.; Bagley, N. W.; Anderson, O. F.; Francis, M. P.; Griggs, L. H.; Clark, M. R.; Paul, L. J.; Taylor, P. R. (2000). Atlas of juvenile and adult fish and squid distributions from bottom and midwater trawls and tuna longlines in New Zealand waters. NIWA Technical Report 84 . 162 p. Kendrick, T. H.; Francis, M. P. (2002). Fish assemblages in the Hauraki Gulf, New Zealand. New Zealand Journal of Marine and Freshwater Research 36(4) : 699–717. Molloy, J.; Bell, B.; Clout, M.; de Lange, P.; Gibbs, G.; Given, D.; Norton, D.; Smith, N.; Stephens, T. (2002). Classifying species according to threat of extinction. A system for New Zealand. Threatened species occasional publication 22 . 26 p. O’Driscoll, R. L.; Booth, J. D.; Bagley, N. W.; Anderson, O. F.; Griggs, L. H.; Stevenson, M. L.; Francis, M. P. (2003). Areas of importance for spawning, pupping or egg-laying, and juveniles of New Zealand deepwater fish, pelagic fish, and invertebrates. NIWA Technical Report 119 . 377 9.

APPENDIX 3: INITIAL OUTPUT TO THE MINISTRY OF FISHERIES 12 MARCH 2004 — Initial agreed approach and methodology

Review of current threat status of associated or dependent species

Suze Baird and John Booth NIWA 12 March 2004

1. Background Milestones 1 and 2 of Project ENV2003/05 require development of lists of species, of both fishes and invertebrates, for which a threat status is to be determined; agreement on a threat status classification system; and approval of both by the Ministry of Fisheries. This document provides a basis for gaining this approval from the Ministry of Fisheries for the species lists and the classification system.

Our approach has been to first summarise available classification systems and then to suggest 25 fish species and 25 invertebrate species and the criteria we have used for choosing these species.

2. Review of classification systems The threat classification systems we have investigated include: IUCN Red list (IUCN 2001), Department of Conservation Threat Classification System (Molloy et al. 2002), Committee on the Status of Endangered Wildlife in Canada (COSEWIC) (COSEWIC 2003), Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) (FAO 2000a,b), and American Fisheries Society (AFS) (Musick 1999).

In our tender we explained that, apart from the CITES system (which is much less relevant than these other two), we would examine only the IUCN and DOC systems. We note that the Ministry of Fisheries Draft Strategy for Managing the Environmental Effects of Fishing (version 31 March 2003) proposes that the latter be used to assess that status of species that constitute non-target catch. This system has already been applied to some marine fishes, sharks and rays, and some marine invertebrates (Hitchmough 2002). We understand that the DOC framework, though based on the IUCN system, was set up to provide criteria more appropriate to New Zealand. However, we felt it important to also consider other systems currently in use that may have some applicability for New Zealand marine organisms.

The IUCN system provides the basis for all these systems, but each has developed differently to accommodate varying demands. The underlying assessment criteria include rarity (as applied to the number of mature individuals), habitat specialisation requirements, endemicity or range size, and population decline. All these systems involve the participation of individuals who are experts in the taxa being assessed, in the assessment process and as reviewers of the assessment.

In the next sections we will briefly summarise the systems and discuss similarities and differences. Please note that we describe more fully the IUCN system, since all the others are some form of derivative of it. We refer the reader to summaries of listing systems that we consider less appropriate to classification of marine fishes and invertebrates in New Zealand waters. We also describe the DOC system in more detail because it was originally designed for use in New Zealand and has been used to classify some marine fish and invertebrates.

2.1 IUCN Red List This system was developed to classify species at high risk of global extinction, and as such was initially set up with a goal to provide a global assessment.

“This system is designed to determine the relative risk of extinction, and the main purpose of the IUCN Red List is to catalogue and highlight those taxa that are facing a higher risk of global extinction (i.e. those listed as Critically Endangered, Endangered and Vulnerable). The IUCN Red List also includes information on taxa that are categorized as Extinct or Extinct in the Wild; on taxa that cannot be evaluated because of insufficient information (i.e. are Data Deficient); and on taxa that are either close to meeting the threatened thresholds or that would be threatened were it not for an ongoing taxon-specific conservation programme (i.e. Near Threatened)” ( http://www.redlist.org ).

The categories and criteria are given below. Threat Categories: o Extinct, Extinct in the Wild, Critically Endangered, Endangered, Vulnerable, Near Threatened, Least Concern o Data Deficient, Not Evaluated (do not reflect threat status: use DD only where no alternative)

Threat Criteria: o A. Declining population (past, present, and/or projected) o B. Geographic range size and fragmentation, decline or fluctuations o C. Small population size and fragmentation, decline or fluctuations o D. Very small population or very restricted distribution o E. Quantitative analysis of extinction risk (e.g. Population Viability Analysis)

The system is rigorous in the rules and regulations for assessment, documentation, and publication (e.g., see IUCN 2003). The system can be applied consistently, allows comparison over a wide range of taxa, and provides clear guidelines to evaluate different factors that affect extinction risk. End-users can easily extract the rationale for the listing. Assessments have been made predominantly for birds and mammals (see http://www.redlist.org). Most of the marine fishes that have been evaluated belong to groups that include sturgeons, rockfishes, sharks, and rays. The latter groups were recently assessed on a regional and global basis (Cavanagh et al. 2003). An example of a fish evaluation is: Gadus morhua VU A1 bd (ver. 2.3 (1994)) 1.

Within the categories listed above, there is a range of quantitative criteria for “threatened” (IUCN 2001). Where any one of these is met, the taxon is added to the listing. Some criteria are more appropriate for some taxa than others and thus each taxon must be evaluated against each criterion. For those taxa that lack rigorous quantitative data, rules to evaluate them by the use of estimation/inference/projection are provided. Similarly, IUCN recognises the problems of spatial scale for those taxa for which the classification is based on geographic range or habitat size: for example, where the distribution is mapped on a coarse scale, there are fewer unoccupied areas compared with mapping on a finer scale. Formal rules are not set for these concerns, but the IUCN summaries alert experts to pick appropriate scales for each taxon based on the origin and the comprehensiveness of the distribution data. Protocols for dealing with uncertainty, whether it be from natural variation, vagueness in terms and definitions, and/or measurement error are also described (Annex 1 in IUCN 2001). When a taxon is being re-evaluated, all criteria must be evaluated.

The criteria for each threat category evaluate reductions in population size, geographic range (extent of occupation and area of occupancy), a measure of the number of mature individuals, and a measure of the probability of extinction in a given timeframe. Within each category these parameters are linked at different levels of abundance or geographic range to provide a decreasing scale on which to evaluate a taxon.

1 VU A1 bd is defined as - A taxon is Vulnerable when it is not Critically Endangered or Endangered but is facing a high risk of extinction in the wild in the medium-term future. An observed, estimated, inferred or suspected reduction of at least 80% over the last 10 years or three generations, whichever is the longer, based on: an index of abundance appropriate for the taxon and actual or potential levels of exploitation.

Recently, guidelines to assessment of species under the Red List criteria have been developed further to allow assessment at regional, national, and/or local levels (IUCN 2003). The regional process involves two steps that take into account breeding and non-breeding populations: Step 1 involves an initial assessment using the Red List Criteria Step 2 involves investigation of the existence and status of any conspecifics outside the region. If endemic, then the Red List Categories are used, but if not and populations outside could affect the regional extinction risk, then criterion E (IUCN 2001) is used to redefine the category as appropriate.

Further steps are described for dealing with population projections and distinguishing real population changes from ones that, for example, occur with fluctuations in non-breeding populations (IUCN 2003). Protocols are set for documentation and publication of regional listings. The regional level is considered useful by Gärdenfors et al. (2001), who note that application of the criteria is possible once there is some experience of the use of the assessment system by experts. Despite the existence of some subjectivity in the evaluation, these authors believe that the framework is well defined and enables regional listings (as used in Cavanagh et al. 2003).

Notes specific to evaluation of fish species that are managed as fishstocks are given in Standards and Petitions Subcommittee of the IUCN SSC Red List Programme Committee (2003). This states that “fisheries managed sustainably should be listed under A1, where higher thresholds of 90% [Critically Endangered], 70% [Endangered], and 50% [Vulnerable] make it less likely to be classified as threatened”.

2.2 CITES The CITES listing of species at risk of extinction was developed originally for land-based species. The aquatic species development of CITES is restricted to those species that are commercially exploited. CITES criteria for aquatic commercially-exploited species were evaluated in several sessions (FAO 2000a, 2001, Mace et al. 2002) and note the important distinction between target species (in Trade) and species taken as bycatch. The latter are only covered under CITES if, once taken, they are marketed. Further, CITES listing should not be used for non-threatened target species, the exploitation of which endangers other species. A description of the categories is discussed in FAO (2001), but is not given here because this listing process is not relevant to all the marine species in New Zealand waters that could be assessed. However, discussion of some of the issues from the technical consultation for CITES aquatic commercially-exploited species is included in the discussion section, as they are pertinent to the IUCN and “family” classification systems. A full review is given in FAO (2000b).

2.3 COSEWIC This Canadian system, adapted from the IUCN criteria base, incorporates the best available information on the biological status of a species, including scientific knowledge, community knowledge, and Aboriginal traditional knowledge. Species are classified as: • Extinct X a species that no longer exists • Extirpated X a species that no longer exists in the wild in Canada, but occurs elsewhere • Endangered X a species facing imminent extirpation or extinction • Threatened X a species that is likely to become endangered if limiting factors are not reversed • Special concern X a species of special concern because of characteristics that make it particularly sensitive to human activities or natural events • Not at Risk X a species that has been evaluated and found not to be at risk • Data Deficient X a species for which there is insufficient scientific information to support status designation.

This system also considers the need to account for life-history variation among taxa by considering factors such as fecundity, Allee density-dependent effect, specific life-history strategies, and age-at- maturity. The criteria are based on the IUCN (2001) and are summarised as:

• Declining total population as measured by specified rate of decline in 10 years of over 3 generations • Small distribution and decline or fluctuation within specified bounds • Small total population size and decline within specified bounds • Very small population or restricted distribution • Quantitative analysis to indicate probability of extinction in the wild by a specified percentage in a number of years or generations.

2.4 DOC Threat Classification System The DOC system was developed to provide categories that describe the level of threat of extinction that taxa face, under the following criteria: Marine, freshwater, or terrestrial taxa Sensitive to changes in population status Separate naturally uncommon taxa from those threatened with extinction Separate taxa according to management response required Use of any relevant data for evaluation of taxon for listing Category titles easily understood Objective so can be audited Allow numerical limits for criteria to account for population attributes

This system would then satisfy: Requirements for DOC resource allocation decisions Environmental monitoring (‘environmental indicators’) ‘use/take’ decisions Research priorities for other agencies/organisations Biodiversity protection Biological evaluation of site managed by other organisations Advocacy for species conservation International reporting and advocacy

As such, the DOC system complements the IUCN global view. With the focus on the national level and, with the capacity to take into account the time over which recent declines have occurred, the DOC system allows for a measure of sensitivity for those taxa that are habitat size restricted and/or have small population numbers.

The DOC system is designed to cover both native and exotic species and provides 7 “threatened” categories and 1 “non-threatened” category. For each listing under a “threatened” category, there are 11 possible qualifiers to further define the classification. Threat categories Nationally Critical Nationally Endangered Nationally Vulnerable Serious Decline Gradual Decline Range Restricted Sparse Qualifiers Extinct in wild Conservation dependent Data poor Recovering Stable

Secure overseas Threatened overseas Human induced Recruitment failure Extreme fluctuations One location

Listing is separate for taxa that are ‘distinct’ (i.e., are published and generally accepted as distinct by experts) and for taxa that are ‘indeterminate’ (i.e., are either published, but not generally accepted as distinct, or yet to be published). The IUCN listing, where provided, is used for those introduced and naturalised taxa (including vagrant, coloniser, and migrant groups).

For each listing under the Acutely Threatened and Critically Threatened (the first 5 categories listed above), the assessment is required to be based on both population status criteria (total population size, number of sub-populations, or area of occupancy) and trend criteria (measured decline in population or habitat area, or predicted decline forecast). These are based on decreasing scales from Nationally Critical to Gradual Decline and are more specific in the actual population numbers required to fit the category than is the IUCN system.

2.5 AFS The American Fisheries Society has developed a specific set of criteria to evaluate the extinction risk of both commercial and non-commercial marine fishes. This was developed to provide a system that was more applicable to marine fishes than the IUCN system and that would better address a major concern that the IUCN population decline criteria grossly overestimate the risk of extinction for many marine fish species such that many managed fisheries (species) may be classed as at risk at or about their Maximum Sustainable Yield (MSY).

Musick (1999) argues that the main reason for the misfit of marine fishes with the IUCN system is that most species are r-selected, with high natural productivity rates and large interannual variation in recruitment. After reviewing various studies on fish stock collapses, Musick (1999) states the following as the most pressing problems in assessing risk extinction of marine fishes: the lack of knowledge of critical minimum population size and any Allee effect, and the problematic nature of assessing variability of estimating population parameters necessary for input into an assessment process.

The AFS criteria were developed (based on a precautionary approach) from these concerns, to: “identify [distinct population segments 2] at risk at a sufficiently early stage of decline to avoid listing as threatened or endangered minimise the probability of under- or over-estimating the risk of extinction use the best existing knowledge of stock dynamics at low population levels and allow experts on [distinct population segments] to” categorise the extinction risk (Musick 1999).

The criteria look at rarity, specialisation of habitat requirements, endemicity or small range, and population decline for these distinct population segments. For the measure of decline, these distinct population segments can be assigned into one of four categories of resilience or productivity using available knowledge on the intrinsic rate of increase, von Bertalanffy growth coefficient, fecundity, age at maturity, and maximum age. Suggested values are given in Musick (1999, 2000) on the understanding that other more appropriate values may be necessary for some fishes. The level of decline (in terms of mature individuals) is then measured against a decline threshold (measured over 10 years or 3

2 “Distinct population segments” are defined by the U.S. Fish and Wildlife Service and National Marine Fisheries Service as “populations that are separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioural factors and that are significant to the species to which it belongs” (see Musick 2000).

generations) to give the final listing of endangered , threatened , vulnerable , and conservation dependent . The biology of those species that are rare (about which there is little information), that suffer from significant habitat loss, or that require specialised habitats should be considered in the risk assessment.

2.6 Comparison of systems All these systems are designed to use best available information as well as inference and projection to test taxon against criteria, and all are based on population numbers, distribution, population decline, and use the precautionary approach. The data used in the assessment is for mature individuals. Generally, the processes involved in the assessments • identify that the species (or stock) chosen is taxonomically valid, native/non-resident/migratory and dependent on local waters for key parts of life cycle • develop list of candidate species based on factors such as population size and distribution, geographic range, sensitivity to human activities, and threats • commission preparation of status reports on species, following precise guidelines specifying types of information needed to be included for assessment • hold workshop to assess species, and • report on findings and associated rationale.

All definitions used need to be clear and concise to enable optimal interpretation and applicability of the criteria. We note also the importance to the end-user of being able to define the rationale behind the listing given.

Some of the concerns expressed with these systems, especially related to explicit quantification of population numbers or extent of area of occupancy or area of occurrence generally include: difficulties in estimating population sizes, “misses” may occur because for those with widespread populations the density may be low even though numbers are high, problems with those species with discontinuous distributions (the probability of detecting a species), a population may experience a decline but still have large numbers, and the reason for the decline may be unknown (natural fluctuation?) ― difficulty in measuring this against survivorship and potential fecundity. Further, a literature review shows that the extinctions, extirpations, and current listings of fish species suggest that of greater threat (than commercial harvest) is habitat loss and degradation (FAO 2001). management of commercial fish species is based on stocks, not populations.

The COSEWIC, CITES, and DOC systems draw their principles heavily from the IUCN system. CITES is concerned with commercially-exploited species only. We offer no further consideration of COSEWIC, given that it is almost like the Canadian version of the DOC system, though COSEWIC includes traditional aboriginal input.

There is a high level of complementarity between the DOC and IUCN systems, with many of the descriptors used referred to by their IUCN definitions. The DOC system is more definitive in the confines it places on the measurement parameters, whereas the IUCN system provides a wider variety of measures for each category. The use of the DOC system could be difficult in the marine system, with the strict definitions of population numbers and small area definitions. However, experts have used this system to list marine fish and invertebrate taxa (Hitchmough 2002). Several of the experts who took part in that process did suggest that there were difficulties with the actual approach for the marine environment, wanting a more ecosystem approach rather than a species approach. Many of the fish taxa listed so far under the DOC system are sharks and rays – species perhaps more amenable to the taxon by taxon approach than, for example, (imaginary) small cryptic fishes confined to black coral holdfasts for which an ecosystem approach might be better. A comparison is given below in Table 1 for sharks that have both DOC and IUCN (regional) listings.

The processes involved in gaining background information and general assessment material for the DOC system is less comprehensive than that for IUCN because of the larger variety of ‘choices’ in each criterion under the IUCN system and the stricter criteria in the DOC system. For example, major threats are not described in the DOC questionnaire. However, where a taxon is being re-evaluated, the DOC system allows for immediate action if a listing change is necessary, rather than the 5-year wait as required by the IUCN system.

Table 1: Comparison of DOC (Rod Hitchmough pers comm.) and IUCN (Cavanagh et al. 2003) species classification listings for some sharks*.

Common name Scientific name DOC IUCN Dark ghost shark Hydrolagus novaezealandiae NT LC Pale ghost shark Hydrolagus sp. B2 NT LC Spiny dogfish Squalus acanthias NT NT Shovelnose spiny dogfish Deania calcea NT LC Baxter’s lantern dogfish Etmopterus baxteri NT LC Longnose velvet dogfish Centroscymnus crepidater NT LC Elephant fish Callorhinchus milii NT LC Whitetailed dogfish Scymnodalatias albicauda S DD Great white shark Carcharodon carcharias GD VU

* For DOC notation: NT is Not Threatened; S is Sparse; GD is Gradual Decline. For IUCN notation, LC is Least Concern; NT is Near Threatened; DD is Data Deficient; and VU is Vulnerable (the only IUCN “threatened” listing).

The AFS system differs from all the above in that there are no specified thresholds for population size and distribution. Rather, limits are suggested for the productivity index parameters, in recognition of the wide variation in life history parameters. The population decline thresholds are a measure of resilience and are similar to those in the other systems; the decline is measured over the longer of 10 years or 3 generations.

However, in an evaluation of the CITES classification, NMFS note concern with regard to the use of “decline” (historical versus recent) and suggest that the “historical extent of decline should be as long as possible to enable a meaningful baseline to be chosen” (Mace et al. 2002). These authors suggest that declines down to 5% (for high productivity species) to 30% (for low productivity species) of historical or potential levels would work reasonably well for exploited marine species. We believe this is an important point and suggest, that if the Ministry of Fisheries agrees to use the AFS system, the 3 generation or 10 years provision be extended to a baseline appropriate for the species based on the available knowledge. Mace et al. (2002) suggest the recent rates of decline be considered in combination with historical rates to give a threshold equal to the cumulative annual rate that would drive a population down from current level to the threshold extent of decline in the near future. These authors suggest that the extent of decline must be viewed as specific to the taxonomic group.

2.7 Summary Most of the above systems first investigate those species suspected of being at risk of becoming endangered ― the highest risk group. The Ministry of Fisheries has agreed, however, that for the marine fishes and invertebrates, we should first assess 15 main commercial fish species and 10 fish and 25 invertebrate species taken as bycatch. We envisage that the chosen risk classification system will be initially tested with the 50 species and that there may need to be some further refinements to suit some species, stocks, or taxonomic

groups. At a later stage, it will be possible to draw up a “candidate list” to set priorities for the assessment of other species.

It is important in the assessment of relative risk that any threat of extinction classification system has threatened taxa spread over the categories, rather than grouped at either extreme (Keith et al. 2000). We provide a concise summary of the main points pertinent to a discussion of the classification systems presented here in Table 2.

We note that the CITES system deals only with commercially-exploited aquatic species, and the IUCN and its main derivatives do not deal particularly well with marine taxa in general. These systems have been used to assess marine organisms (Hitchmough 2002, Cavanagh et al. 2003), sometimes with agreed modifications pertinent to the taxonomic group (Hallingbäck et al. 1998), but mainly solitary K-selected species and not the highly productive r-selected ones. We believe that the most appropriate system for New Zealand marine species is that of the AFS because it was developed with marine taxa as the focus, and it deals better with harvested populations, and it also deals well with those that are not exploited. We acknowledge that some modifications to this system may be necessary to ensure the best possible outcome, and that the first assessment exercise may be an evolving process.

We also acknowledge that the DOC system has been developed with New Zealand conditions in mind – yet is still tied securely into the IUCN principles. But there are some potential issues. The system seems best to fit the terrestrial environment, where parameters such as population size and range are likely to be much better known and more easily understood. Discussion with DOC and experts involved in the assessment of marine species using the DOC system has not allayed our concerns about the applicability of this system to marine fishes and invertebrates.

With the concerns of some fish experts in mind, we note the major dichotomy of a taxon vs community approach. This is where it is the rarity or threat towards the community that is the issue – for example, the (imaginary) black coral community with its cryptic blennies and its array of encrusting and dependent invertebrates. It seems to us that such a community approach is not possible under any of the classification systems considered here. Therefore we cannot consider the matter further because our contract does not allow it. We see the way forward as prioritising consideration of taxa that form part of these vulnerable communities.

Lastly, we acknowledge that consistency of approach is important to consider when assessing relative risk of extinction within a region (and the DOC system has been set up with New Zealand species in mind), but meaningful assessments are based on scales appropriate to species, stocks, or taxonomic groups, and the best system used must allow that flexibility. We are concerned that the DOC system will not handle well the range of marine species (commercial and non-commercial) in our waters.

Table 2: Main characteristics of the threat of extinction classification systems pertinent to the discussion of relevance to the assessment of threat for New Zealand marine species.

IUCN Probably the most widely used globally Has been used for New Zealand sharks Deals well with non-harvested populations Not as effective in dealing with harvested populations CITES Widely applied Deals solely with traded species COSEWIC Designed for use in Canada only Considers aboriginal traditional knowledge DOC An established, New Zealand-specific classification Works well with terrestrial species Doubtful use in many marine species, particularly harvested ones AFS Developed particularly for marine species Handles well both commercial and non-commercial species Handles well “distinct population segments” Has been applied in many different areas

3. Development of an invertebrate species list

3.1 Introduction

The purpose of this section is to come up with a list of invertebrate species to be assessed for threat status that might be acceptable to the Ministry of Fisheries managers. There are a vast number of associated or dependent invertebrates that could be considered, from the tiny and obscure to the large and obvious. Similarly, there are innumerable ways that a species list might be developed. The overall criteria we have used are summarised as follows. • The species are components of communities within recognisable and significant ecosystems [best bang for bucks ] • The ecosystems are deep to moderately deep [ where long term effects are probably most severe ] • The communities are benthic or near benthic, rather than pelagic [ which in NZ are less impacted by fishing ] • The communities are ones that have been and/or are being moderately or heavily impacted by fishing [ hence there are associated/dependent species ] • The communities are at least reasonably well studied and known • The species are reasonably well known macrofaunal species [ smaller ones generally being too poorly known ] • The species are not ones already on the IUCN red list • Our tender was based on 25 invertebrate species

3.2 The Benthic Community

A benthic invertebrate community includes the demersal species, the epibenthos, and the infauna. It does not include those species that spend most of their time higher in the water column – which, at least in New Zealand waters, are much less impacted by trawling.

As elsewhere, there is less known of invertebrate community structure in the deeper waters around New Zealand compared with those shallow. Invertebrate bycatch, other than for commercially important, or obvious, species such as arrow squid, octopus, and prawn killers, has rarely been reported in detail by commercial fishers, by scientific observers, nor, until recently, by researchers. This complicates any comprehensive temporal analysis of the invertebrate bycatch (Grove & Probert 1998). Best data come from dedicated sampling. But such benthic studies in NZ’s bathyal zone have mainly concerned the structure of benthic communities, with emphasis on the composition and distribution of the larger epifauna and their biomass, rather than the functional role of the benthos in these bathyal systems (Probert et al. 1996).

Nevertheless, some generalisations are possible. Deep-sea communities are characterised by life-history adaptations such as slow growth, extreme longevity, delayed age at maturation, and low natural adult mortality (Dayton et al. 1995). They are also often characterised by fragile structures that have important community roles. Such adaptations are characteristic of systems with low productivity and turnover; they are extremely vulnerable to human intervention such as fishing. As a consequence there has been frequent reduction in invertebrate fauna in trawled deepwater habitats (Jones 1992, Cryer et al. 1999, 2002).

Much of the deep sea is soft sediment and more or less featureless. In terms of numerical abundance and energy flow in the macrobenthos, polychaetes are usually by far the most important group in this soft- bottom community (Knox 1977). But other taxa, including those vulnerable to trawling such as echinoderms, also have important influences on benthic community structure (Probert et al. 1997). These include holothurians, important deposit feeders in many deep-sea communities and commonly dominating the invertebrate epifauna. Rarer – but very significant – are exposed rock surfaces such as those on hills or small seamounts (Probert et al. 1997). By contributing to the structural dimension, macrofauna on these structures provide opportunities for many associated species, thereby creating

patches of enhanced biodiversity. This in turn feeds into the well known productivity and fisheries associated with seamounts.

3.3 The Chatham Rise

3.3.1 Benthic and epibenthic structure and communities of the Chatham Rise

This section summarises the principal ecosystems and benthic invertebrate communities of the Chatham Rise. The Chatham Rise is a broad ridge about 1400 km long, extending east from central New Zealand to about 168 W, east of the Chatham Islands. To the west of the Chathams the rise is generally flat- topped at depths of 200-400 m, but to the east the depth gradually increases to about 3000 m. At the western end is the Mernoo Gap, a narrow depression that separates the rise from the New Zealand continental shelf. On the rise are four banks with depths less than 250 m: Mernoo, Veryan, and Reserve Banks toward the western margin and the smaller Matheson Bank nearer the Chathams. The STC, where subtropical and subantarctic waters meet, is zonally orientated over the rise. The Chatham Rise supports major trawl fisheries. Surface sediments ore predominantly fine-grained (0.5-0.063 mm; Probert & McKnight 1993), with terrigenous sediments giving way to pelagic sediments at about 179 E. Probert & McKnight (1993) reported the infaunal macrobenthos biomass at 244–1394 m at 23 anchor- box dredge positions, along three north-south transects. On the north side biomass showed a logarithmic decline with water depth comparable to other bathyal regions, but there was no such relationship on the south side where it was higher than expected. This may be related to enhanced primary productivity at the Subtropical Convergence. The fauna was dominated numerically by polychaetes and peracarid crustaceans. Faunal density and biomass were significantly correlated. For the polychaetes (Probert et al. 1996), two main assemblages were identified: at 244-663 m, mainly on the crest of the rise, and at 802- 1394 m on the slopes of the rise. Community composition however varied between the northern and southern slopes: the southern slope supporting higher faunal densities and a greater proportion of surface deposit feeders, again probably reflecting variability in organic flux across the STC, but possibly also higher disturbance (as represented by increased numbers of colonisers of disturbed deep-sea sites such as spionid worms).

McKnight & Probert (1997) examined the epibenthic macrofauna at 237–2039 m at 40 sledge trawl stations. A total of 218 taxa were collected, predominantly echinoderms, crustaceans, and molluscs. Multivariate analysis based on 85 species indicated three epibenthic communities, the shallowest characterised mainly by crustaceans and the two deeper by echinoderms: • A community on predominantly sandy sediments on the crest and shallower flanks of the rise at 237–602 m that included as characteristic species the crustaceans Munida gracilis , Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalves Cuspidaria fairchildi and Euciroa galatheae . This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m. • A community associated with muddy sediments at 462–1693 m that included the holothurians Ypsilothuria bitentaculata and Pentadactyla longidentis , the echinoid Brissopsis oldhami , and the ophiuroid Amphiophiura ornata . • A community on muddy sediments at 799–2039 m that included the ophiuroid Ophiomusium lymani , the asteroid Porcellanaster cerulleus , the echinoid Gracilechinus multidentatus , and the gastropod Aenator recens .

There was a marked submergence on the north side similar to the vertical displacement of the core of the Antarctic Intermediate Water.

Probert et al. (1997) reported benthic invertebrate bycatch collected during trawling for orange roughy at 662–1524 m on the northern and eastern Chatham Rise in July 1994. This included both ‘flat’ areas and ‘hills' (small seamounts). Although orange roughy trawling is likely to produce a very incomplete picture of the benthic community because the trawl rolls over and smashes material and species most likely retained are large upright ones such as black corals, spiny ones that snag easily in trawl mesh, and large

soft species that become pinched in the angle of the trawl mesh, there were patterns in the invertebrates. The bycatch from the two areas differed significantly, but it also differed between groups of hills. Dominant taxa from the flats were Holothuroidea, Asteroidea, and Natantia; on the hills it was Gorgonacea and Antipatharia. These latter corals are long-lived and require at least 100 years to recover from trawling. Squires (1965) described the coral structures on the south flank of the rise to be composed primarily of Goniocorella dumosa and Desmophyllum cristagalli . These, together with the large gorgonian Paragorgia aborea , the sea pens Funiculina quadrangularis and Virgularia mirabilis , and the sponges Axinella polypoides , Geodia , and Chondrocladia , may be exterminated by the single passage of a trawl (Probert et al. 1997).

Grove & Probert (1998) reported the megabenthic invertebrate bycatch in abyssal areas (300–1500 m) off southern and eastern New Zealand, including the Chatham Rise, but the groups were not partitioned by taxa. Asteroids, anemones and echinoids, and particularly, holothurians and sponges, were the taxa most commonly recorded and generally with the highest biomass. In the deeper trawls, there was higher biomass of holothurians, sponges, and echinoids on the south side of the Chatham Rise than to the north. Shallower and deeper trawls differed significantly in their bycatch.

Livingston et al. (2003) reported that benthic invertebrate records from commercial vessels increased between 1989–90 and 1998–99, but this was thought to have been due to increased requirements for observers to identify such species, rather than any increase in their abundance on the seabed.

3.3.2 Why choose the Chatham Rise?

• A major fishery area, fished commercially and extensively since 1978 • Spatially very large and significant • Benthic invertebrates have been reasonably well studied • Deep to very deep, and includes seamounts • Important from commercial, biological and oceanographic perspectives so is always going to be studied – and so provide for continuity in monitoring

3.3.3 The Chatham Rise species chosen

• Species that characterise the two main shallower communities, including representative infaunal ones (but not spionid polychaetes) • The hard-bottom (hill/seamount) species that in themselves provide crucial refuge for other invertebrates

3.3.3.1 Species characterising the two main shallower communities a) The crustaceans Munida gracilis , Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalves Cuspidaria fairchildi and Euciroa galatheae . b) The holothurians Ypsilothuria bitentaculata and Pentadactyla longidentis , the echinoid Brissopsis oldhami , and the ophiuroid Amphiophiura ornata .

3.3.3.2 Hard-bottom species

The corals Goniocorella dumosa and Desmophyllum cristagalli , the gorgonian Paragorgia aborea , the sea pens Funiculina quadrangularis and Virgularia mirabilis , and the sponges Axinella polypoides , Geodia , and Chondrocladia . (The antipatharian Antipathes fiordensis is already on the range restricted classification.)

3.4 Bay of Plenty

3.4.1 Benthic and epibenthic structure and communities of the Bay of Plenty

This section summarises the ecosystem and benthic invertebrate communities of the Bay of Plenty. The area of interest is the continental slope between 200 and 600 m, from Mercury islands to White Island. From the 1980s there was a large increase in trawling in this region, particularly for gemfish, hoki, and most recently scampi (Cryer et al. 2002). The fishing grounds are ribbon-shaped and parallel to the depth contours; ribbons tens of kilometres long are obstructed by canyons and rocky grounds.

Detailed taxonomic analysis of the invertebrate bycatch of three research voyages in 1996 and 1997 (Cryer et al. 1999, 2002) showed a relationship between benthic community structure and fishing history which could be explained by three broad types of hypothesis. • Benthic community had been modified by fishing, or • Scampi fishing had been conducted preferentially (especially in the early years of the fishery) in areas of particular community structure and consequent bycatch composition, or • Scampi, being a vigorous burrowing species as well as the target of the fishery, dominated and modified the benthic environment and community in a manner similar to other disturbances.

There were significant negative relationships between the indices of fishing pressure and invertebrate richness and diversity, the abundance of a variety of invertebrate taxa, and the average size of some invertebrate taxa. These relationships between fishing pressure and benthic community structure are consistent with the predicted and estimated effects of fishing worldwide. However, given that scampi trawl gear probably samples only large epifauna reasonably well, the clarity of the relationship between fishing history and density of a wide variety of invertebrate species was surprising. Of particular concern was the negative association with fishing activity of large, fragile, or surface-dwelling species such as the urchins Ogmocidaris benhami and Phormosoma bursarium , the basket star Gorgonocephalus dolichodactylus , the gastropods Penion dilatatus and Alcithoe lutea , and the hermit crabs Diacanthurus rubricatus and Paguristes barbatus .

3.4.2 Why choose the Bay of Plenty?

• A major fishery area, fished commercially and extensively since early 1980s • Spatially large and significant • Benthic invertebrates have been reasonably well studied • Moderate to deep • Important from commercial (particularly scampi) and biological perspectives so is always going to be studied – and so provide for continuity in monitoring

3.4.3 Bay of Plenty species chosen

The approach is slightly different to that taken for the Chatham Rise. The infaunal species have not been described in detail. The work of Cryer et al. (1999, 2002) provides a list of species that are negatively associated with fishing activity, and it was thought that these should be the invertebrates investigated, particularly the large, fragile, and surface-dwelling listed above.

The echinoderms Ogmocidaris benhami , Phormosoma bursarium , Gorgonocephalus dolichodactylus , Psilaster acuminatus , and Laetmogone sp., the gastropods Penion dilatatus , Alcithoe lutea, Iredalina mirabilis , Calliostoma turnerarum , and the crustaceans Campylonotus rathbunae , Diacanthurus rubricatus , Paguristes barbatus , Paramola petterdi , Trichopeltarion fantasticum , and Ibacus alticrenatus . Note that Alcithoe lutea , Calliostoma turnerarum , and Gorgonocephalus dolichodactylus are listed as being in Gradual decline.

4. Development of a fish species list

Initially we looked at developing a species list in a similar way to that described above. Then we noted the paucity of published material on those taxa that constitute the smaller proportions of catch (for example, in data from the Chatham Rise trawl surveys). McClatchie et al (1997) and Bull et al. (2001) identified differences in community structure and species associations across the Chatham Rise, but for the top 30 catch species, and the threat status of the chondrichthyans fishes in this list have been assessed either under IUCN or the DOC Threat Classification (R. Hitchmough pers comm.). [At present the documentation for non-threatened species is not published, and therefore the spreadsheet held at DOC, which includes listings of both threatened and non-threatened species, was used to determine which species had been classified.]

We considered that as a first pitch it would be valuable to have a variety of species such that we may be able to “test” the classification system along the length of the threatened to non-threatened continuum. Thus, in accordance with the opinions expressed in our discussion with the Ministry of Fisheries on 17 February, we have suggested the following species, which include inshore and continental shelf species caught by trawling or longlining, in shallow and deep waters:

Target species Bycatch species arrow squid ( Nototodarus sloanii ) frostfish ( Lepidotus caudatus ) barracouta ( Thyrsites atun ) John dory ( Zeus faber ) black oreo ( Allocyttus niger ) moonfish ( Lampris guttatus ) bluenose ( Hyperglyphe antarctica ), oilfish ( Ruvettus pretiosus ) butterfish ( Odax pullus ) Ray’s bream ( Brama brama ) gemfish (Rexea solandri ) red gurnard ( Chelidonichthys kumu ) hake ( Merluccius australis ) ribaldo ( Mora mora) hoki (M acruronus novaezelandiae ), stargazer ( Kathetostoma giganteum ) ling (G enypterus blacodes ) trumpeter ( Latris lineata ) orange roughy ( Hoplostethus atlanticus ), white warehou ( Seriolella caerulea ) silver warehou ( Seriolella punctata ) smooth oreo ( Neocyttus rhomboidalis ) snapper ( Pagrus auratus ) southern blue whiting ( Micromesistius australis ) tarakihi ( Nemadactylus macropterus )

5. References

Bull, B.; Livingston, M.E.; Hurst, R.; Bagley, N. (2001). Upper-slope fish communities on the Chatham Rise, New Zealand, 1992–99. New Zealand Journal of Marine and Freshwater Research 35 : 795– 815. Cavanagh, R.D.; Kyne, P.M.; Fowler, S.L.; Musick, J.A.; Bennett, M.B. (2003). The Conservation Status of Australasian Chondrichthyans. Report of the IUCN Shark Specialist Group Australia and Oceania Regional Red List Workshop . The University of Queensland, School of Biological Sciences, Brisbane, Australia. 170 p. COSEWIC (2003). COSEWIC’s Assessment Process and Criteria (15 April 2003) available at http://www.COSEWIC.gc.ca 18 p. Cryer, M.; Coburn, R.; Hartill, B.; O’Shea, S.; Kendrick, T.; Doonan, I. (1999). Scampi stock assessment for 1998 and an analysis of the fish and invertebrate bycatch of scampi trawlers. New Zealand Fisheries Assessment Research Document 99/4 . 75 p. Cryer, M.; Hartill, B.; O’Shea, S. (2002). Modification of marine benthos by trawling: toward a generalization for the deep ocean? Ecological applications 12(6) : 1824–1839. Dayton, P.K.; Thrush, S.F.; Agardy, M.T.; Hofman, R.J. (1995). Environmental effects of fishing. Aquatic conservation: marine and freshwater ecosystems 5 : 205–232.

FAO (2000a). Technical consultation on the suitability of the CITES Criteria for listing commercially- exploited aquatic species. Report from Rome, Italy, 28–30 June 2000. The key points from an appraisal of the suitability of the CITES criteria for listing commercially-exploited aquatic species (available at http://www.fao.org/DOCREP/MEETING/X4894E.HTM). 21 p. FAO (2000b). An appraisal of the suitability of the CITES criteria for listing commercially-exploited aquatic species. Fisheries Circular 954 . FAO, Rome. 66 p. FAO (2001). Second technical consultation on the suitability of the CITES Criteria for listing commercially- exploited aquatic species. Report from Windhoek, Namibia, 22–25 October 2001 CITES criteria for amendment of Appendices I and II. Conf. 9.24 available at http://www.fao.org/DOCREP/MEETING/003/Y1626E.HTM . 22 p. Gärdenfors, U.; Hilton-Taylor, C.; Mace, G; Rodríguez, J.P. (2001). The Application of IUCN Red List Criteria at regional levels. Conservation Biology 15(5) : 1206–1212. Grove, S.L.; Probert, P.K. (1998). Bycatch of megabenthic invertebrates from bathyal trawl fisheries off southern and eastern New Zealand. NIWA Technical Report 13 . Hallingbäck, T.; Hodgetts, N.; Raeymaekers, G.; Schumacker, R.; Sérgio, C.; Söderström, L. Stewart, N.; Vána, J. (1998). Guidelines for application of the revised IUCN threat categories to bryophytes. Lindbergia 23 : 6–12. Hitchmough, R.A. (Comp.)(2002). New Zealand Threat Classification System lists, 2002. Threatened Species Occasional Publication 23. Department of Conservation. 210 p. Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233. IUCN (2003). Guidelines for application of IUCN Red list Criteria at Regional Levels: Version 3.0. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, UK. ii + 26 pp. IUCN (2001 ). IUCN Red List Categories and Criteria Version: 3.1.IUCN Species Survival commission. IUCN, Gland, Switzerland and Cambridge, UK. ii + 30 pp. Jones, J.B. (1992). Environmental impact of trawling on the seabed: a review. New Zealand Journal of Marine and Freshwater Research 26 : 59–67. Keith, D.A.; Auld, T.D.; Ooi, M.K.J.; Mackenzie, B.D.E. (2000). Sensitivity analyses of decision rules in World Conservation Union (IUCN) red List criteria using Australian plants. Biological Conservation 94 : 311–319. Knox, G.A. (1977). The role of polychaetes in benthic soft-bottom communities. In Essays on polychaetous annelids in memory of Dr Olga Hartman. Reish, D.J.; Fauchald, K. (Eds). pp 547-604. Allan Hancock Foundation, University of Southern California, Los Angeles. Livingston, M.E.; Clark, M.R.; Baird, S.-J. (2003). Trends in incidental catch of major fisheries on the Chatham Rise for fishing years 1989-90 to 1998-99. New Zealand Fisheries Assessment Report 2003/52 . 74 p. Mace, P.M.; Bruckner, A.W.; Daves, N.K.; field, J.D.; Hunter, J.R.; Kohler, N.E.; Kope, R.G.; Lieberman, S.S.; Miller, M.W.; Orr, J.W.; Otto, R.S.; Smith, T.D.; Thompson, N.B.; Lyke, J.; Blundell, A.G. (2002). NMFS/Interagency Working Group Evaluation of CITES criteria and guidelines. U.S. Department of commerce, NOAA Technical Memorandum NMFS-F/SPO-58. 70 p. McClatchie, S.; Millar, R. B.; Webster, F.; Lester, P. J.; Hurst, R.; Bagley, N. 1997: Demersal fish community diversity off New Zealand: is it related to depth, latitude and regional surface phytoplankton? Deep-Sea Research 144: 647–667. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. Molloy, J.; Bell, B.; Clout, M.; de Lange, P.; Gibbs, G.; Given, D.; Norton, D.; Smith, N.; Stephens, T. (2002). Classifying species according to threat of extinction. A system for New Zealand. Threatened Species Occasional Publication 22 . 26 p.

Musick, J.A. (1999). Criteria to define extinction risk in marine fishes. Fisheries 24(12) : 6–14. Musick, J.A.; Harbin, M.M.; Berkeley, S.A.; Burgess, G.H.; Eklund, A. M.; Findley, L.; Gilmore, R.G.; Golden, J.T.; Ha, D.S.; Huntsman, G.R.; McGovern, J.C.; Parker, S. J.; Poss, S.G.; Sala, E.; Schmidt, T.W.; Sedberry, G.R.; Weeks, H.; Wright, S.G. (2000). Marine, estuarine, and diadromous fish stocks at risk of extinction in North America (exclusive of Pacific salmonids). Fisheries 25(11) : 6–30. Probert, P.K.; McKnight, D.G. (1993). Biomass of bathyal macrobenthos in the region of the Subtropical Convergence, Chatham Rise, New Zealand. Deep-sea Research 40 : 1003–1007. Probert, P.K.; Grove, S.L.; McKnight, D.G.; Read, G.G. (1996). Polychaete distribution on the Chatham Rise, Southwest Pacific. Int. Revue ges. Hydrobiol. 81 : 577–588. Probert, P.K.; McKnight, D.G.; Grove, S.L. (1997). Benthic invertebrate bycatch from a deep-water trawl fishery, Chatham Rise, New Zealand. Aquatic conservation: marine and freshwater ecosystems 7: 27-40. Squires, D.F. (1965). Deep-water coral structure on the Campbell Plateau, New Zealand. Deep-sea research 12 : 785–788. Standards and Petitions Subcommittee of the IUCN SSC Red List Programme Committee (2003). Guidelines for using the IUCN Red List Categories and Criteria (May 2003). Available from: http://www.iucn.org/themes/ssc/redlists/Redlistguidelines2003.pdf

APPENDIX 4: INVERTEBRATE SPECIES SUMMARIES FOR THE COMMUNITY-BASED APPROACH DESCRIBED IN APPENDIX 3

The following pages contain the draft summaries for the invertebrate species, based on the Appendix 3 approach, listed alphabetically by Order. These species are a subset of the suggested species given in the Appendix 3 review paper and were collated in 2004. Where a threat status is mentioned (for example, “Gradual Decline”) the reference is to the DOC Threat Classification System (Hitchmouth 2002) current in 2003–04.

Order Family Common name Species Choristida Geodiidae Geodia spp. Cidaroida Cidaridae Ogmocidaris benhami Mortensen, 1921 Decapoda Campylonotidae Sabre prawn Campylonotus rathbunae Schmitt, 1926 Decapoda Homolidae Antlered crab Dagnaudus petterdi (Grant, 1905) Decapoda Paguridae Diacanthurus (previously Pagurus) rubricatus Decapoda Paguridae Paguristes subpilosus Decapoda Crangonidae Philoceras ( previously Pontophilus ) acutirostratus Decapoda Scyllaridae Prawn killer Ibacus alticrenatus Bate, 1888 Decapoda Atelecyclidae frilled crab Trichopeltarion fantasticum Richardson & Dell, 1964 Euryalida Gorgonocephalidae Basket starfish Gorgonocephalus dolichodactylus Döderlein, 1911 Gorgonacea Paragorgiidae Bubblegum Paragorgia arborea (Linnaeus, 1758) coral Halichondrida Axinellidae Axinella dissimilis (formerly polypoides ) Bowerbank, 1866 Neogastropoda Volutidae Alcithoe larochei Marwick, 1926 Neogastropoda Buccinulidae Penion cuvierianus cuvierianus (Powell, 1927) (formerly Penion dilatatus) Neogastropoda Volutidae golden volute Provocator mirabilis (Finlay, 1926) (formerly Iredalina mirabilis) Paxillosida Astropectinidae geometric star Psilaster acuminatus Sladen, 1889 Anomalodesmata Cuspidariidae Cuspidaria fairchildi Suter, 1908 Anomalodesmata Euciroidae Euciroa galatheae (Dell, 1956) Reptantia Galatheidae squat lobster Munida gracilis Henderson, 1885 Reptantia Galatheidae little craylet Phylladiorhynchus pusilla (Henderson, 1885) Scleractinia Caryophylliidae Desmophyllum dianthus (formerly cristagalli) (Esper, 1794) Scleractinia Caryophylliidae Bushy hard Goniocorella dumosa (Alcock, 1902) coral Spatangoida Brissidae Brissopsis oldhami Alcock, 1893 Vetigastropoda Calliostomidae Calliostoma (Maurea) turnerarum (Powell, 1964)

Hitchmough, R.A. (Comp.)(2002). New Zealand Threat Classification System lists, 2002. Threatened Species Occasional Publication 23. Department of Conservation. 210 p.

Order Choristida: Family Geodiidae

Geodia spp.

Overview This cosmopolitan group of large, encrusting sponges is probably common and widespread in New Zealand waters. However, the taxonomy of this family is difficult and species identifications may not always be sure. Little is known of its biology. Its greatest threat is through being trawled as bycatch.

Distribution and relative abundance This probably common, cosmopolitan group of sponges appears to be widespread in New Zealand waters; the family has world-wide distribution and ranges from the intertidal to at least 2840 m (Hooper & Wiedenmayer 1994; Hooper & Van Soest 2002). The identification to only genus for the Chatham Rise material (Probert et al. 1997) indicates that diagnoses may be difficult and so conclusions – including those regarding vulnerability of species - may be difficult. Probert et al. (1997) considered it to be among the vulnerable taxa on the Chatham Rise – species fragile, long-lived, and nearly exterminated by a single passage of a trawl. The genus was not listed by Cryer et al. (1999) as being significant in the Bay of Plenty, nor by Probert et al. (1997) off Otago.

Reproduction and life history There appears to be nothing known specifically for this sponge concerning reproduction, and there is no information on age or growth.

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This family of sponge is characterised by having thickly encrusting, massive to bowl-shaped growth forms (Hooper & Wiedenmayer 1994) and is found associated with both hard and firm substrates. Presumably where it is common it forms hollow spaces, and niches, and shelter for other organisms.

Commercial catches There are no commercial landings of these sponges.

Threats Sponges such as Geodia are an unavoidable bycatch in some bottom trawl fisheries, including those on the Chatham Rise.

Conservation and management There are no conservation or management measures in place for these probably widespread and fairly common sponges. Because of their fragility and form, they are prone to being damaged by trawling.

Order Cidaroida: Family Cidaridae

Ogmocidaris benhami

Overview This endemic echinoid, which reaches at least 25 mm in test diameter, is found on the shelf and slope, particularly off northern New Zealand. Very little is known of its biology. Its greatest threat is through being trawled as bycatch.

Distribution and relative abundance This echinoid is relatively common in shelf and slope waters off northern New Zealand (200–800 m) (O’Shea et al. 1999) and is taken in the Bay of Plenty scampi trawls. It has also been recorded from the Chatham Rise (99–720 m) (Pawson 1968), but was not reported from there by McKnight & Probert (1997) or Probert et al. (1997).

Reproduction and life history There appears to be nothing known specifically for this echinoid concerning reproduction, and there is no information on age or growth.

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This grazing echinoid probably lives mainly on soft – mud and sand – substrates.

Commercial catches There are no commercial landings of this echinoid.

Threats Echinoids such as O. benhami are an unavoidable bycatch in some bottom trawl fisheries, particularly for scampi on the east coast of Northland and in the Bay of Plenty.

Conservation and management This echinoderm is probably widespread throughout its range, but seldom particularly abundant. Being relatively large and complex in form, it is prone to being damaged by trawl gear.

References McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505-513. O’Shea, S.; McKnight, D.; Clark, M. (1999). Bycatch – the common, unique, and bizarre. Seafood New Zealand June: 45-51 Pawson, D.L. (1968). The echinozoan fauna of the New Zealand subantarctic islands, Macquarie Island, and the Chatham Rise. New Zealand Oceanographic Institute Memoir 42 . Probert, P.K.; McKnight, D.G.; Grove, S.L. (1997). Benthic invertebrate bycatch from a deep-water trawl fishery, Chatham Rise, New Zealand. Aquatic conservation: marine and freshwater ecosystems 7: 27–40.

Order Decapoda: Family Campylonotidae

Sabre prawn Campylonotus rathbunae Schmitt, 1926

Overview This carid prawn is the only member of the family in New Zealand waters and there is very limited biological or other information concerning it. It was the subject (together with other deepwater prawns) of trial trawl fisheries in the 1980s but no fishery was established. It was one of the focus ‘coldwater’ prawn species of an exploratory fishing endeavour in 2002 (Thomas 2002), but no information on any fishing outcomes is publicly available.

Distribution and relative abundance The sabre prawn C. rathbunae is endemic to Australasia, having been reported from on and near muddy substrates around much of New Zealand and off eastern and southern Australia (Yaldwyn 1960, Webber et al. 1990, 2003, Anon 2002, Davie 2002, Webber 2002a, O’Driscoll et al. 2003). Because specimens are often covered in mud, this prawn probably spends time in the surface of muddy seafloors (Yaldwyn 1960).

Webber et al. (1990) and Webber (2002a) reported it to occur in waters 270–800 m deep, from Northland to Campbell Island and off the east and west coasts of both main islands, along the Chatham Rise, and on the Campbell Plateau and Bounty Platform. It may be especially abundant in Bay of Plenty, but has not been recorded from the Kermadecs. Records from the Ministry of Fisheries trawl and obs databases (in mid 2002 — O’Driscoll et al. 2003) showed a similar distribution, but the prawn may also occur deeper, to at least 800 m (Davie 2002). The northern-most record for this species on the Ministry of Fisheries trawl and obs databases (mid 2002) is 36º S, the southernmost 51º S, but Museum of New Zealand Te Papa Tongarewa has records of it from 35º S to 52º S. There is no information relevant to the recognition of any separate stocks around New Zealand or between New Zealand and Australia.

Reproduction and life history Nothing is known of the breeding and early life history of this prawn in New Zealand waters except that it is a protandric hermaphrodite, starting life as male and later becoming female (Yaldwyn 1960, Webber 2002a). However, deepwater carid prawns typically have a single brood per year and abbreviated larval development, incubating large (>1 mm) embryos that have a short planktonic period (Bauer 2004).

There is no information on age and growth of this prawn in New Zealand waters, although deep-sea carideans typically have slow growth imposed by the cold waters and perhaps low or restricted food supply (Bauer 2004). Males have been found ranging from 50–95 mm (including the straight rostrum which makes up about 20%) total length (TL), females up to 140 mm TL (including the strongly upward- curving rostrum), with the transition taking place between 80 and 100 mm TL (Webber 2002a).

Habitat and ecology Most deepwater prawn species are largely bottom-dwelling, but some also have a diurnal cycle of movement, rising from the bottom at night (Richardson & Yaldwyn 1958). It is unclear how much C. rathbunae migrates vertically, but while in the water column they would be trawlable, and they could possibly be trapped, dredged, or trawled while on the bottom.

Deepwater prawns are thought to feed mainly on detritus on the seafloor, but any diurnal migration into the water column at night may also involve predation of other animals (R. Webber, Museum of New Zealand Te Papa Tongarewa, pers. comm.). Sabre prawns are prey at various stages of their life to fishes such as orange roughy near the bottom and mesopelagic fishes higher in the water column.

On the Chatham Rise, where sabre prawns are often taken, there are two relevant benthic communities with which they are associated. The first is on predominantly sandy sediments on the crest and shallower

flanks of the rise at 237–602 m and includes as characteristic species the crustaceans Munida gracilis , Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalves Cuspidaria fairchildi and Euciroa galatheae (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana - Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403– 604 m. The second community is associated with muddy sediments at 462–1693 m that includes the holothurians Ypsilothuria bitentaculata and Pentadactyla longidentis , the echinoid Brissopsis oldhami , and the ophiuroid Amphiophiura ornata .

Parasitism of this species by a bopyrid isopod has been noted (Yaldwyn 1960).

Exploitation Sabre prawns are not routinely taken commercially in New Zealand waters, but they do have commercial potential (Thomas 2002, Webber 2002a). Exploratory fishing for prawns in the 1980s did not lead to any significant reported landings of this species. There are trivial (a few kg) estimated catches and reported landings of this species in the Ministry of Fisheries databases (at 9 December 2003).

There have been no assessments of the potential yield of sabre prawns. Many existing prawn fisheries rely on several species contributing to commercial-sized catches, the prawns often being sold mixed. A mix of species is likely in the New Zealand catches (e.g., Thomas 2002, Webber 2002a, b). This, together with problems of identification of species from a prawn fauna that is not particularly well known, means that mixed-catch TACs are recommended.

Threats and conservation and management Sabre prawns will remain an unavoidable bycatch in some deepwater trawl fisheries but levels of bycatch are believed to be small compared with what could occur through targeted fishing with appropriate gear. This prawn, along with others, is due to become part of the QMS in October 2004. The manner and areas for management have not yet been made clear.

References Anon (2002). Tasmanian seamounts marine reserve management plan. www.deh.gov.au/coasts/mpa/semaounts/plan/attachment2.html Bauer, R.T. (2004). Remarkable shrimps. University of Oklahoma Press, Norman. Davie, P.J.F. (2002). Crustacea: Malacostraca: Phyllocarida, Hoplocarida, Eucarida (Part 1). In Wells, A; Houston, W.W.K. (eds) Zoological catalogue of Australia. Vol. 19.3A. Melbourne: CSIRO Publishing, Australia. Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–223. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. O’Driscoll, R.L.; Booth, J.D.; Bagley, N.W.; Anderson, O.F.; Griggs, L.H.; Stevenson, M.L.; Francis, M.P. (2003). Areas of importance for spawning, pupping or egg-laying, and juveniles of New Zealand deepwater fish, pelagic fish, and invertebrates. NIWA Technical Report 119 . Richardson, L.R.; Yaldwyn, J.C. (1958). A guide to the natant decapod crustacea (shrimps and prawns) of New Zealand. Tuatara 7 : 17–41. Thomas, L. (2002). Vela explores coldwater prawns. Seafood New Zealand 10(7) : 30–32. Webber, W.R. (2002a). Prawns coming in from the cold. Seafood New Zealand 10(9) : 75–78. Webber, W.R. (2002b). Prawns coming in from the cold. Seafood New Zealand 10(10) : 70–71. Webber, W.R.; Fenaughty, C.M.; Clark, M.R. (1990). A guide to some common offshore shrimp and prawn species of New Zealand. New Zealand Fisheries Occasional Publication No. 6 . Webber, W.R.; Yaldwyn, J.C.; Dawson, E.W. (unpubl.). An annotated checklist of New Zealand decapod crustacea. Te Papa report. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53.

Order Decapoda: Family Homolidae

Antlered crab Dagnaudus petterdi (Grant, 1905)

The species was formerly placed in Latreillopsis and Paramola .

Overview This crab, which reaches at least 69 mm carapace width (CW) in males and 73 mm CW in females, is found on the shelf edge and slope around much of New Zealand.

Distribution and relative abundance This crab is found from Northland to The Snares at 180–540 m, and also off western, southern, and eastern Australia (91–920 m) and New Caledonia (McLay 1988, Poore 2004, Webber et al. unpubl.). It is found on soft substrates, where it is taken in trawls and pots, and is locally common (e.g., off Banks Peninsula). It is described as common in deep-water dredge samples off southern Australia (Poore 2004).

Reproduction and life history There is virtually no information on reproduction, age or growth. Davie & Short (1989) reported all (of the few) females to be ovigerous (44-49 mm CW) in collections off southern Queensland; the crabs came from collections in March, August and November, pointing to an extensive breeding period. There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology This crab lives on soft grey mud, probably using its long legs to hold itself above (Dell 1963). It is sometimes seen with tube worms and ‘soft-shelled oysters’ attached (Takeda & Miyake 1969).

This crab is prey to various demersal fishes, including red cod to a small extent (McLay 1988).

In the Bay of Plenty, where D. petterdi are often taken, the other species that are negatively associated with fishing activity, particularly the large, fragile, and surface-dwelling ones are the echinoderms Ogmocidaris benhami , Phormosoma bursarium , Gorgonocephalus dolichodactylus , Psilaster acuminatus , and Laetmogone sp., the gastropods Penion dilatatus , Alcithoe lutea, Iredalina mirabilis , Calliostoma turnerarum , and the crustaceans Campylonotus rathbunae , Diacanthurus rubricatus , P. subpilosus, Trichopeltarion fantasticum , and Ibacus alticrenatus (Cryer et al. 1999, 2002).

Commercial catches There are no commercial landings of this crab.

Threats Antlered crabs are an unavoidable bycatch in some bottom trawl fisheries.

Conservation and management There is no conservation or management practice in place for this crustacean.

Davie, P.J.F.; Short, J.W. (1989). Deepwater Brachyura (Crustacea: Decapoda) from southern Queensland, Australia with descriptions of four new species. Memoirs of the Queensland Museum 27: 157-187. Dell, R.K. (1963). Native crabs. A.H. & A.W. Reed, Auckland. McLay, C.L. (1988). Crabs of New Zealand. Leigh Laboratory Bulletin 22 . Poore, G.C.B. (2004). Marine decapod Crustacea of southern Australia: a guide to identification. CSIRO Publishing, Collingwood. Takeda, M. & Miyake, S (1969). A small collection of crabs from New Zealand. Ohmu Occasional Papers of Zoological Laboratory Faculty of Agriculture Kyushu University 2: 158–193. Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document.

Order Decapoda: Family Paguridae

Hermit crab Diacanthurus (previously Pagurus) rubricatus

Overview This widespread, endemic hermit crab is taken around much of the New Zealand shelf and slope.

Distribution and relative abundance This hermit crab is found only in New Zealand waters, mainly on soft to light shingle sediments at depths of 15–2134 m (mainly 180–300 m): northern and southern New Zealand, Stewart Island, and the Chatham Islands (Probert et al. 1979; Forest et al. 2000, Webber et al. unpubl.).

Only one report was found that gave relative abundance figures. In the Otago region, this species was common (0.1–1.0 individuals per m 2) or rare (0.01–0.1) on the inner shelf, and rare, very rare, or absent deeper and shallower (Schembri 1988) on soft to gravely substrates (Probert et al. 1979). In contrast, Paguristes barbatus was common or abundant (>1) on the inner, mid and outer shelf, but rare or absent elsewhere (Schembri 1988).

Reproduction and life history Females with shield lengths of 7–16.4 mm were found carrying eggs, and the reproductive season is thought to be from September to March with a peak in January (Forest et al. 2000). There is no information on age and growth.

There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology These hermit crabs have been found occupying a variety of gastropod shells which are frequently covered with the hydrozoan Hydractinia rubricata . The crab may also carry anemones (Schembri & McLay 1983; Forest et al. 2000). They will be prey to various demersal fishes. This crab is a predator, deposit-feeder, scavenger, and to a small extent a suspension-feeder, excavating trenches in the sediment and digging pits in search of prey (Schembri 1982).

In the Bay of Plenty, where D. rubricatus are often taken, the other species that are negatively associated with fishing activity, particularly the large, fragile, and surface-dwelling ones are the echinoderms Ogmocidaris benhami , Phormosoma bursarium , Gorgonocephalus dolichodactylus , Psilaster acuminatus , and Laetmogone sp., the gastropods Penion dilatatus , Alcithoe lutea, Iredalina mirabilis , Calliostoma turnerarum , and the crustaceans Campylonotus rathbunae , Diacanthurus rubricatus , Paguristes barbatus , Paramola petterdi , Trichopeltarion fantasticum , and Ibacus alticrenatus (Cryer et al. 1999, 2002).

Commercial catches There are no commercial landings of this hermit crab.

Threats Hermit crabs are an unavoidable bycatch in some bottom trawl fisheries.

Conservation and management There is no conservation or management practice in place for this crustacean. A considerable issue is that of differentiation between species, there being several other Diacanthurus spp.

References Cryer, M.; Coburn, R.; Hartill, B.; O’Shea, S.; Kendrick, T.; Doonan, I. (1999). Scampi stock assessment for 1998 and an analysis of the fish and invertebrate bycatch of scampi trawlers. New Zealand Fisheries Assessment Research Document 99/4 . 75 p. Cryer, M.; Hartill, B.; O’Shea, S. (2002). Modification of marine benthos by trawling: toward a generalization for the deep ocean? Ecological applications 12(6) : 1824–1839. Forest, J.; de Saint Laurnet, M.; McLaughlin, P.A.; Lemaitre, R. (2000). The marine fauna of New Zealand: Paguridea (Decapoda: Anomura). NIWA Biodiversity Memoir 114 . Probert, P.K.; Batham, E.J.; Wilson, J.B. (1979). Epibenthic macrofauna off southeastern New Zealand and mid-shelf bryozoan dominance. New Zealand Journal of Marine and Freshwater Research 13 : 379–392. Schembri, P.J. (1982). Feeding behaviour of fifteen species of hermit crabs (Crustacea: Decapoda: Anomura) from the Otago region, southeastern New Zealand. Journal of Natural History 16 : 859– 878. Schembri, P.J. (1988). Bathymetric distribution of hermit crabs (Crustacea: Decapoda: Anomura) from the Otago region, southeastern New Zealand. Journal of the Royal Society of New Zealand 18 : 91– 102. Schembri, P.J.; McLay, C.L. (1983). An annotated key to the hermit crabs (Crustacea: Decapoda: Anomura) of the Otago region (southeastern New Zealand). New Zealand Journal of Marine and Freshwater Research 17 : 27–35. Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document.

Order Decapoda: Family Paguridae

Hermit crab Paguristes subpilosus

[The species listed by Cryer et al. (1999) was P. barbatus , but we believe that the crabs were misidentified P. subpilosus . P. barbatus , which is frequently confused with the more common and widespread P. subpilosus , has been taken only in the far north, at depths of 20–37 m and is quite rare (Forest et al. 2000).]

Overview This endemic hermit crab, which reaches about 30 mm carapace length, is found in inshore waters around much of the New Zealand shelf and slope. (Schembri 1988; mean shield length 7 mm – tip of rostrum to the cervical suture).

Distribution and relative abundance This hermit crab is found only in New Zealand waters, on a range of mainly soft to light shingle sediments (but possibly preferring the less coarse substrates) at depths of 18–27 and 350–400 m: North and South Islands, Stewart Island, and the Chatham Islands (Probert et al. 1979; Forest et al. 2000, Webber et al. unpubl.). Only one report was found that gave relative abundance figures. In the Otago

region, this species (as P. barbatus ) was common or abundant (>1 individual per m2) on the inner, mid and outer shelf (Schembri 1988) on soft to gravely substrates (Probert et al. 1979), but rare or absent elsewhere. In contrast, Diacanthurus rubricatus was common (0.1–1.0) or rare (0.01–0.1) on the inner shelf, and rare, very rare, or absent deeper and shallower (Schembri 1988).

Reproduction and life history Females with carapace lengths of 7–22 mm were found carrying eggs, the reproductive season appearing to be from August to February (Forest et al. 2000). There is no information on age and growth. There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology These hermit crabs have been found occupying a variety of gastropod shells including Ancilla pyramidalis (Schembri & McLay 1983; Forest et al. 2000). The crab may also carry anemones on the shell (Schembri & McLay 1983). The preponderance of females in some samples during the egg-bearing season (Forest et al. 2000) may indicate some ecological demarcation at breeding. This crab is primarily a deposit-feeder, scraping detritus from the surface of objects with its pincers, but it also browses and scavenges (Schembri 1982). It is prey to various demersal fishes.

In the Bay of Plenty, where P. subpilosus are often taken, the other species that are negatively associated with fishing activity, particularly the large, fragile, and surface-dwelling ones are the echinoderms Ogmocidaris benhami , Phormosoma bursarium , Gorgonocephalus dolichodactylus , Psilaster acuminatus , and Laetmogone sp., the gastropods Penion dilatatus , Alcithoe lutea, Iredalina mirabilis , Calliostoma turnerarum , and the crustaceans Campylonotus rathbunae , Diacanthurus rubricatus , Paramola petterdi , Trichopeltarion fantasticum , and Ibacus alticrenatus (Cryer et al. 1999, 2002).

Commercial catches There are no commercial landings of this hermit crab.

Threats and Conservation and management

Hermit crabs are an unavoidable bycatch in some bottom trawl fisheries. There is no conservation or management practice in place for this crustacean. A considerable issue is that of differentiation between species, there being several other Paguristes spp.

Order Decapoda: Family Crangonidae

Philoceras ( previously Pontophilus ) acutirostratus

Overview This widespread, endemic, benthic crangonid shrimp is taken around much of the New Zealand shelf and upper slope, its main source of threat being trawled as bycatch.

Distribution and relative abundance This benthic shrimp is found only around New Zealand, at depths of 90–730 m (Richardson & Yaldwyn 1958; Yaldwyn 1960; Webber et al. unpubl.).

Reproduction and life history Females appear to reach maturity at about 4 mm carapace length, with ovigerous specimens present at least during February and August (Yaldwyn 1960). Deepwater carid prawns typically have a single brood per year and abbreviated larval development, incubating large (>1 mm) embryos that have a short planktonic period (Bauer 2004).

There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology These shrimps are highly benthic, living on mainly soft mud/sand bottoms, but sometimes gravel, in which they dig for cover (Bauer 2004). They emerge from the substrate and become active only at night. They prey on such invertebrates as small crustaceans and polychaetes, using their chelae.They will be prey to various, mainly the smaller, demersal fishes.

On the Chatham Rise, where P. acutirostris are often taken, the main benthic community with which they are associated is the predominantly sandy sediments on the crest and shallower flanks of the rise at 237–602 m and includes as characteristic species the crustaceans, Campylonotus rathbunae , Phylladiorhynchus pusillus , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalves Cuspidaria fairchildi and Euciroa galatheae (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m.

Commercial catches There are no known commercial landings.

Threats Crangonid shrimp are an unavoidable bycatch in some bottom trawl fisheries, but their small size presumably means that many escape through the mesh.

Conservation and management There is no conservation or management practice in place for this crustacean; crangonid shrimps are not part of the QMS. A considerable issue is that of differentiation between species, there being at least six other Philoceras spp.

References Bauer, R.T. ( 2004). Remarkable shrimps. University of Oklahoma Press, Norman. Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233.

McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. Richardson, L.R.; Yaldwyn, J.C. (1958). A guide to the natant decapod crustacea (shrimps and prawns) of New Zealand. Tuatara 7 : 17-41. Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53.

Order Decapoda: Family Scyllaridae

Prawn killer Ibacus alticrenatus Bate, 1888

Overview

This scyllarid lobster is widespread, sometimes common, on soft substrates around New Zealand and off southern Australia. Whereas its larval stages are quite well known, there is little information on the juveniles and adults. Interest is shown from time to time in its commercial potential, but the adult rarely grows large enough to sustain a fishery. Although trawled as bycatch from time to time, it is not thought that this species is under any particular threat of extinction. However, there are no firm data one way or the other.

Distribution This scyllarid is endemic to Australasia, living on soft mud/sand bottoms. It is widespread in New Zealand waters at depths to 500 m (and occasionally to 700 m), being found probably more or less continuously around the North Island, northern South Island as far south as Oamaru, on the Chatham Rise, and near the Chatham Islands (Dell 1955, O’Driscoll et al. 2003; Webber et al. unpubl.). It possibly also occurs on the Campbell Plateau. It is also found in southern Australia, from north Queensland to south of North West Cape in Western Australia (Griffin & Stoddart 1995; Brown & Holthuis 1998; Davie 2002; Poore 2004). It is not known from the Tasman Sea, but its presence on seamounts and rises there cannot be ruled out. In the meantime, the New Zealand and Australian populations are considered separate and discrete.

Habitat This lobster lives on soft bottoms (soft mud, blue mud, ooze, and sand, shells and mud – Holthuis 1985) in which it digs and covers itself (Coleman 1977; Holthuis 1991; Davie 2002). Substrates such as these are widespread around New Zealand, and there is no suggestion that this lobster is associated more with one type than any other.

Biological characteristics Sexes are separate but co-occur. Examination of material held at Museum of New Zealand showed that females reach maturity at a carapace length (CL) of about 25 mm, based on the development of pleopodal setae. Holthuis (1991) reported ovigerous females from May to October, but a more extensive breeding season can be derived from Dell (1955), Lesser (1974), and Atkinson & Boustead (1982). The phyllosoma larval stage (Atkinson & Boustead 1982) lasts about 4 months and so there is opportunity for wide dispersal, but most specimens, particularly the later stages, have been taken over the continental shelf, and all nistos (postlarvae) have been taken within the area of the adults (NIWA unpublished data). Thus, although the juvenile/adult is presumably capable of walking some distance (as I. chacei do – Stewart & Kennelly 1998), there is no evidence for the breeding or juvenile areas being discrete.

There is no information on age and growth. There is no information relevant to the recognition of any separate stocks around New Zealand or between New Zealand and Australia.

This lobster is nocturnally active (Yearsley & Last 1999). Like many other scyllarids, this species is capable of propelling itself backwards – probably mainly in escape. Population densities are moderately high in places; single trawls can take tens to hundreds of individuals (NIWA unpublished data).

Morphological characteristics These characteristics include: dorso-ventrally flattened; second antenna modified to a closely hinged series of five, flat plates; carapace covered by short, velvety pubescence; lateral carapace spines and pleural spines tipped with yellow brown; 6th abdominal segment and uropods and telson yellow-brown; cervical incision of carapace very wide, behind which the lateral margin of carapace bears 7–11 sharp, posterolateral teeth that get smaller the further posterior; elongate pleura; anterior margin of 6th antennal segment has 5–8 quite large teeth; dorsal surface of carapace and antennae red-orange to brown, with darker red spots in the middle of the carapace.

Ibacus brucei is more flattened and appears to lack hair on the carapace. Arctides antipodarum is larger, and the outer margin of the distal antennal lamellae has numerous insignificant teeth.

Role of the species in the ecosystem This is unknown, apart from the species presumably being one of the larger predatory crustaceans.

On the Chatham Rise, where prawn killers are taken, the main benthic community with which they are associated is the predominantly sandy sediments on the crest and shallower flanks of the rise at 237– 602 m and includes characteristic species such as the crustaceans Munida gracilis , Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana ; the ophiuroid Amphiura lanceolata ; and the bivalves Cuspidaria fairchildi and Euciroa galatheae (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m.

Prawn killers are prey at various stages of their lives to fishes such as tunas (phyllosoma and nisto) and sharks and fishes such as John dory (juveniles and adults) (Chilton 1911; Atkinson & Boustead 1982; NIWA unpublished data). The precise diet of this lobster is unknown (it has not been reported taken in pots), but its mouthparts are like that of a rock lobster and so it is likely to consume a wide range of foods, probably with particular focus on other invertebrates.

Status and trends

Habitat trends Bottom trawling modifies the soft-sediment habitat of this species, but the effects are unknown. Data for this species in the Ministry of Fisheries trawl and obs databases (in mid 2002, O’Driscoll et al. 2003) show a geographic range of 36º–51º S (O’Driscoll et al. 2003), and Museum of New Zealand Te Papa Tongarewa has records that show a range of 35º–52º S. It is most frequently taken in northern waters from Bay of Plenty to Chatham Rise and on the southern part of the Challenger Plateau at 200–400 m. [The southern and deepwater occurrences (900–1200 m) may be an undescribed deepwater scyllarid lobster.] Few I. alticrenatus were measured, and of those, few were smaller than 25 mm CL.

Population dynamics There are no estimates of population size and there is no information on population structure or trends.

Threats Prawn killer lobsters will remain an unavoidable bycatch in some trawl fisheries, but bycatch levels are believed to be small compared with potential catches through targeted fishing with appropriate gear. The impact of habitat loss/change through bottom trawling is unknown. Other threats to the status of this lobster are unknown.

Utilisation and trade Species management Prawn killers are not routinely taken during commercial fishing in New Zealand waters, but they have been viewed as having commercial potential (Webber, pers. comm.). Records of very small estimated

catches and reported landings of this species exist in the Ministry of Fisheries databases (at 9 December 2003). However, Coleman (1977 in Holthuis 1991) reported commercial quantities from trawlers working off the continental shelf, and the speices is an important commercial bycatch of prawn or scallop fisheries in Australian waters (Brown & Holthuis 1998).

Habitat conservation There are no protected areas for this species, except that associated with closures to trawling (e.g., certain seamounts, which may or may not contain this species).

Information on similar species New Zealand has only one other Ibacus species, I. chacei at the Kermadecs; it is uncommon and certainly not commercial. Other scyllarids are Antipodarctus aoteanus (very small and seldom encountered as an adult) and the Spanish lobster Arctides antipodarum (taken by divers, and occasionally in pots, in northern New Zealand). These are readily distinguished morphologically from I. alticrenatus.

References Atkinson, J.M. & Boustead, N.C. (1982). The complete larval development of the scyllarid lobster Ibacus alticrenatus Bate, 1888 in New Zealand waters. Crustaceana 42: 275–287. Brown, D.E.; Holthuis, L.B. (1998). The Australian species of the genus Ibacus (Crustacea: Decapoda: Scyllaridae), with the description of a new species and addition of new records. Zoologische Mededelingen 72: 113–141. Chilton, C. (1911). Crustacea, Scientific Research New Zealand Government Trawling Expedition. Records of the Canterbury Museum 1 : 285–312. Coleman, N. (1977). A field guide to Australian marine life. Rigby Limited, Sydney. Davie, P.J.F. (2002). Crustacea: Malacostraca: Phyllocarida, Hoplocarida, Eucarida (Part 1). In Wells, A; Houston, W.W.K. (eds) Zoological catalogue of Australia. Vol. 19.3A. Melbourne: CSIRO Publishing, Australia. Dell, R.K. (1955). A record of Latreillopsis petterdi Grant ( Crustacea, Brachyura ) from New Zealand, with notes on some other species of Crustacea. Records of the Dominion Museum 2(3): 147–149. Griffin, D.J.G.; Stoddart, H.E. (1995). Deep-water decapod Crustacea from eastern Australia: lobsters of the families Nephropidae, Palinuridae, Polychelidae and Scyllaridae. Records of the Australian Museum 47 : 231–263. Holthuis, L.B. (1985). A revision of the family Scyllaridae (Crustacea: Decapoda: Macrura). I. Subfamily Ibacinae. Zoölogische Verhandelingen, Leiden, 218:1–130. Holthuis L.B. (1991). Marine lobsters of the world. FAO Fisheries Synopsis 125 . Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233. Lesser, J.H.R. (1974). Identification of early larvae of New Zealand spiny and shovel-nosed lobsters (Decapoda, Palinuridae and Scyllaridae). Crustaceana 27 : 259–277. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. O’Driscoll, R.L.; Booth, J.D.; Bagley, N.W.; Anderson, O.F.; Griggs, L.H.; Stevenson, M.L.; Francis, M.P. (2003). Areas of importance for spawning, pupping or egg-laying, and juveniles of New Zealand deepwater fish, pelagic fish, and invertebrates. NIWA Technical Report 119 . 377 p. Poore, G.C.B. (2004). Marine decapod Crustacea of southern Australia: a guide to identification. CSIRO Publishing, Collingwood. Stewart, J.; Kennelly, S.J. (1998). Contrasting movements of two exploited scyllarid lobsters of the genus Ibacus off the east coast of Australia. Fisheries Research 36 : 127–132. Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53. Yearsley, G.K.; Last, P.R. (1999). Crustaceans. In: Australian seafood handbook – an identification guide to domestic species. Eds Yearsley, G.K.; Last, P.R.; Ward, R.D. CSIRO Marine Research.

Order Decapoda: Family Atelecyclidae

Frilled crab Trichopeltarion fantasticum Richardson & Dell, 1964

Overview This endemic crab, which reaches at least 86 mm carapace width (CW) in both males and females, is found on the shelf and slope around much of New Zealand and on the Chatham Rise.

Distribution and relative abundance This crab has been reported from fine, soft substrates from the Bay of Plenty to Foveaux Strait on the east coast, on the Chatham Rise, and from Kaipara to Fiordland on the west coast at 15–720 m (McLay 1988, Webber et al. unpubl.).

In the Bay of Plenty, it has been collected from 300–400 fathoms (550–730 m); in the region of Cook Strait and on the Chatham Rise 40–330 fathoms (70–600 m); in southern New Zealand 8–160 fathoms (15–290 m) (Richardson & Dell 1964).

Reproduction and life history There is little information on reproduction, age or growth. Ovigerous females have been collected in June and October (McLay 1988), one of which was 25 mm carapace width (excluding spines) (Takeda & Miyake, 1969). There is probably only one short-lived zoeal stage that remains at or near the bottom (Wear & Fielder 1985, McLay 1988). There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology This crab is prey to various demersal fishes, including dogfish, rig and red cod (McLay 1988). Its food is unknown.

In the Bay of Plenty, where T. fantasticum are often taken, the other species that are negatively associated with fishing activity, particularly the large, fragile, and surface-dwelling ones are the echinoderms Ogmocidaris benhami , Phormosoma bursarium , Gorgonocephalus dolichodactylus , Psilaster acuminatus , and Laetmogone sp., the gastropods Penion dilatatus , Alcithoe lutea, Iredalina mirabilis , Calliostoma turnerarum , and the crustaceans Campylonotus rathbunae , Diacanthurus rubricatus , P. subpilosus, Dagnaudus petterdi , and Ibacus alticrenatus (Cryer et al. 1999, 2002).

Commercial catches There are no commercial landings of this crab.

Threats These crabs are an unavoidable bycatch in some bottom trawl fisheries.

Conservation and management There is no conservation or management practice in place for this crustacean.

Wear, R.G.; Fielder, D.R. (1985). The marine fauna of New Zealand: larvae of the Brachyura (Crustacea, Decapoda). New Zealand Oceanographic Institute Memoir 92 . Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document.

Order Euryalinida: Family Gorgonocephalidae

Basket starfish Gorgonocephalus dolichodactylus Döderlein, 1911

Overview This endemic but widespread ophiuroid, which reaches at least 58 mm disc diameter, is found on the shelf and slope around much of New Zealand. Very little is known of its biology. Its greatest threat is through being trawled as bycatch, and it is listed as being in Gradual Decline.

Distribution and relative abundance This ophiuroid is widespread from off the Bay of Islands to the Bounty Plateau, and is also on the Lord Howe Rise, but most material has come from the Bay of Plenty (McKnight 2000). Gorgonocephalus spp. are found at depths of 150–897 m (NIWA Species Database).

Reproduction and life history There appears to be nothing known specifically for this ophiuroid concerning reproduction, and there is no information on age or growth.

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This ophiuroid lives in substrates that include the soft, grey mud of the Bay of Plenty scampi grounds. Small specimens are sometimes found on pennatulids (sea pens) (McKnight 2000). The food of ophiuroids is small molluscs and other animals, hard and soft, or sometimes fine organic particles (Morton & Miller 1968).

Commercial catches There are no commercial landings of this ophiuroid.

Threats Ophiuroids such as G. dolichodactylus are an unavoidable bycatch in some bottom trawl fisheries, particularly the east coast Northland/Bay of Plenty scampi fishery.

Conservation and management This ophiuroids is listed as being in Gradual Decline by the Department of Conservation. Although probably widespread throughout its range, it is probably not present in high numbers anywhere. Being often large and complex in form, it is prone to being trawled.

References McKnight, D.G. (2000). The marine fauna of New Zealand: Basket-stars and snake-stars (Echinodermata: Ophiuroidea: Euryalinida). NIWA Biodiversity Memoir 115 . Morton, J.; Miller, M. (1968). The New Zealand sea shore. Collins, Auckland. 638 p.

Order Gorgonacea: Family Paraforgiidae

Bubblegum coral Paragorgia arborea (Linnaeus, 1758)

Overview This horny coral, colonies of which can reach several metres in height, is found on sea mounts and banks on the Chatham Rise and on hard ground elsewhere. It is thought that beds of this species are important refuges, and harbour food, for various invertebrates and fishes, particularly their juveniles. Colonies are destroyed by trawling and are thought to take centuries– if ever - to recover. It is unclear how widespread this coral now is in New Zealand waters.

Distribution and relative abundance This coral, which is widespread in temperate waters and cooler waters of the Northern and Southern Hemispheres (Grasshoff 1979), was a significant by catch in the orange roughy fishery on the Chatham Rise at depths of 662–1524 m (Probert et al. 1997). It is thought to have been common on most seamounts in the New Zealand region, but being prone to trawling has probably disappeared from many; it is unclear how widespread and abundant this coral now is in our waters. Its depth range is in the order of 200-2000 m or more (NIWA Species Database, www.afsc.noaa.gov/groundfish/ HAPC/HornyCorals_synopsis.htm).

Reproduction and life history Fertilised eggs develop within the female polyps into planula larvae – which are usually not dispersed very far from the parent colonies. In colonial species such as this, asexual reproduction also occurs through budding of the primary polyp.

Growth is slow, and some colonies may be several centuries old (Cimberg et al. 1981, Tracey 2004).

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This coral lives mainly on firm substrates, particularly those associated with seamounts and banks. It is likely that these and other corals play an important role as cover and food source for various deepwater fishes, particularly juveniles (e.g., Husebo et al. 2002), and various invertebrates. Horny corals are suspension feeders, taking their food from the water column. Predators of horny corals include snails, fish, polychaetes, sea stars and nudibranchs (Cimberg et al. 1981).

Commercial catches There are no commercial landings of this coral.

Threats Corals such as P. arborea are a bycatch in bottom trawl fisheries, particularly on seamounts and banks.

Conservation and management There are no conservation or management measures in place for this coral. Being relatively large and complex in form, it is prone to being trawled. Colonies may be centuries old and beds are thought to take hundreds of years to recover after being destroyed by trawling (Probert et al. 1997). There does not appear to be any information on whether trawl-damaged colonies recover. It is unclear how widespread this coral now is in New Zealand waters.

Grasshoff, M. (1979). Zur bipolaren verbreitung der Oktokoralle Paragorgia arborea (Cnidaria: Anthozoa: Scleraxonia). Senckenbergiana Maritima 11 : 115–137. Husebo, A.; Nottestad, L.; Fossa, J.H.; Furevik, D.M.; Jorgensen, S.B. (2002). Distribution and abundance of fish in deep-sea coral habitats. Hydrobiologia 471 : 91–99. Probert, P.K.; McKnight, D.G.; Grove, S.L. (1997). Benthic invertebrate bycatch from a deep-water trawl fishery, Chatham Rise, New Zealand. Aquatic conservation: marine and freshwater ecosystems 7: 27–40.

Order Halichondrida: Family Axinellidae

Axinella dissimilis (formerly polypoides ) Bowerbank, 1866

Overview This cosmopolitan sponge that grows to about 15 cm in height is probably common and widespread in New Zealand waters. However, the taxonomy of this family is difficult and species identifications may not always be sure. Little is known of its biology. Its greatest threat is through being trawled as bycatch.

Distribution and relative abundance This probably common, cosmopolitan sponge appears to be widespread in New Zealand waters but no published geographic or depth ranges were found. The great morphological plasticity exhibited by species in this genus means that it is one of the most difficult genera in the Axinellidae to diagnose (Alvarez de Glasby 1996), and so conclusions – including those regarding vulnerability of this species - may be difficult. This sponge was reported from the Chatham Rise, where Probert et al. (1997) considered it to be among the vulnerable taxa – species fragile, long-lived, and nearly exterminated by a single passage of a trawl. However, it was not listed by Cryer et al. (1999) as being significant in the Bay of Plenty, nor by Probert et al. (1997) off Otago.

Reproduction and life history The Axinellida are oviparous, producing small eggs which, after fertilisation, develop to free-swimming larvae outside the parent body (Bergquist 1970). There is no information on age or growth of this sponge.

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This family of sponge has a massive, branching, fan-shaped and tubular growth form (Hooper & Wiedenmayer 1994) and is found associated with both hard and firm substrates. Presumably where it is common it forms hollow spaces, and niches, and shelter for other organisms.

Commercial catches There are no commercial landings of this sponge.

Threats Sponges such as A.dissimilis are an unavoidable bycatch in some bottom trawl fisheries, including on the Chatham Rise, because of their form.

Conservation and management There are no conservation or management measures in place for this probably widespread sponge. Because of its fragility and form, it is prone to being damaged by trawling.

References Alvarez de Glasby, B. (1996). The phylogenetic relationships of the family Axinellidae (Porifera: Demospongiae). Unpublished PhD thesis, The Australian National University.

Bergquist, P.R. (1970). The marine fauna of New Zealand: Porifera, Demospongiae, Part 2 (Axinellida and Halichondrida). New Zealand Oceanographic Institute Memoir 51 . Cryer, M.; Coburn, R.; Hartill, B.; O’Shea, S.; Kendrick, T.; Doonan, I. (1999). Scampi stock assessment for 1998 and an analysis of the fish and invertebrate bycatch of scampi trawlers. New Zealand Fisheries Assessment Research Document 99/4 . 75 p. Hooper, N.A.; Wiedenmayer, F. (1994). Porifera. Zoological Catalogue of Australia 12. Probert, P.K.; McKnight, D.G.; Grove, S.L. (1997). Benthic invertebrate bycatch from a deep-water trawl fishery, Chatham Rise, New Zealand. Aquatic Conservation: Marine and Freshwater Ecosystems 7: 27–40.

Order Neogastropoda: Family Volutidae

Alcithoe larochei Marwick, 1926

(Note that Alcithoe lutea is reported only from the Cookian Province (Spencer et al. 2002), the most likely deepwater species from Bay of Plenty (Powell 1979) being A. larochei )

Overview This endemic volute (gastropod), which reaches at least 114 mm in height, is found near the coast and on the shelf around much of the northern half of New Zealand. It is possibly in Gradual decline through being sought by shell collectors.

Distribution and relative abundance This volute is found in soft substrates in the Aupourian and Cookian Provinces (North Island and northern South Island), at depths of 30–340 fathoms (55–622 m) (Powell 1979).

Reproduction and life history Little is known about the reproduction of this volute and there is no information on age or growth. There appears to be no information relevant to the recognition of any separate stocks in New Zealand.

Alcithoe species enclose their often large eggs in clusters in spherical calcareous secretions of the gland in the foot and affix them to empty shells or stones (Morton & Miller 1968, Powell 1979). In A. arabica and A. swainsoni , up to three embryos may develop from an egg, but if fewer than this survive then a larger protoconch results.

Habitat and ecology This volute lives in soft substrates including the soft, grey mud of scampi grounds. Intertidal species are found burrowing or half buried in sand or mud (Powell 1979), and presumably this species behaves similarly. Volutes are carnivores that feed mainly on bivalves (Morton & Miller 1968, Powell 1979), and so are found associated with such prey. A. larochei is probably prey to various crabs and demersal fishes.

Commercial catches No commercial landings specifically of this gastropod have been reported to the Ministry of Fisheries. However, under the label VOL (for volute), there have been fishing year landings of up to 14 t in recent times – but almost all from statistical areas 38 (Tasman and Golden Bays) and 34 (central west coast of South Island), almost certainly mostly A. arabica for meat, and as bycatch in other fisheries (mainly scallop and dredge oyster) (NIWA unpubl. data).

Threats Gastropods such as A. larochei are an unavoidable bycatch in some bottom trawl fisheries, particularly the east coast Northland/Bay of Plenty scampi fishery and to a lesser extent shallower dredging and flatfish trawling.

Conservation and management There is no conservation or management practice in place for this volute. It is probably widespread in its range, but is unlikely to be present in high numbers anywhere. However, A. lutea is listed by Department of Conservation as being in Gradual decline (Hitchmough 2002), and it is possible that the species meant is A. larochei. The main reason for such a classification among the deeper water Alcithoe spp. is probably that they are sought by shell collectors.

References Hitchmough, R. (2002). New Zealand threat classification system lists. Threatened Species Occasional Publication 23 . Morton, J.; Miller, M. (1968). The New Zealand sea shore. Collins, Auckland. 638 p. Powell, A.W.B. (1979). New Zealand Mollusca. Marine, land and freshwater shells. Collins, Auckland. 500 p. Spencer, H.G.; Willan, R.C.; Marshall, B.A.; Murray, T.J. (2002). Checklist of the Recent Mollusca described from the New Zealand Exclusive Economic Zone. http://toroa.otago.ac.nz/pubs/spencer/Molluscs/index.html

Order Neogastropoda: Family Buccinulidae

Penion cuvierianus cuvierianus (Powell, 1927) (formerly Penion dilatatus)

Overview This endemic gastropod, which reaches at least 235 mm in height, is found near the coast and on the shelf around much of the northern half of New Zealand.

Distribution and relative abundance This gastropod is found in soft substrates in the Aupourian and Cookian Provinces (North Island and northern South Island), at depths of 20–100 fathoms (37–183 m) (Powell 1979).

Reproduction and life history No information was located on reproduction, age or growth. There appears to be no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This gastropod lives in substrates including the soft, grey mud of scampi grounds. It is carnivorous, and is probably prey to various crabs and demersal fishes.

Commercial catches There have no commercial landings of this gastropod reported to the Ministry of Fisheries.

Threats Gastropods such as P. cuvierianus cuvierianus are an unavoidable bycatch in some bottom trawl fisheries.

Conservation and management There is no conservation or management practice in place for this gastropod.

References Powell, A.W.B. (1979). New Zealand Mollusca. Marine, land and freshwater shells. Collins, Auckland. 500 p.

Order Neogastropoda: Family Volutidae

Golden volute Provocator mirabilis (Finlay, 1926) (formerly Iredalina mirabilis)

Overview This endemic volute (gastropod), which reaches at least 140 mm in height, is found in outer shelf and slope waters around much of New Zealand. It is considered by Department of Conservation to be in Gradual Decline, probably mainly through it being often taken as bycatch in trawling/dredging and because it is of interest to shell collectors.

Distribution and relative abundance This volute is widespread from the north of the North Island to the subantarctic, and near the Chatham Islands, at depths of 100–400 fathoms (183–732 m), although dead shells, presumably brought up by hermit crabs, can be found in shallower waters (Powell 1979, Spencer et al. 2002).

The Research bottom trawl and Scientific observer records ( trawl and obs databases of the Ministry of Fisheries) show relatively high catches of VOL (volutes) at 400-500 m depth east and southeast of Auckland Island (O’Driscoll et al. 2003). Although these volutes could also be Alcithoe flemingi (or possibly Zygomelon zodion , which is known from the Bounty Plateau and Bounty Trough – Harasewych & Marshall 1995), there is a good chance that they are mostly P. mirabilis .

Reproduction and life history Volutes enclose their often large eggs clusters in spherical, usually calcareous, secretions of the gland in the foot and affix them to empty shells or stones (Morton & Miller 1968, Powell 1979, Harasewych & Marshall 1995). No information was located on age or growth of this species. There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology Volutes are carnivores that feed mainly on bivalves (Morton & Miller 1968, Powell 1979), and so are found associated with such prey. Intertidal species are found burrowing or half buried in sand or mud (Powell 1979), and presumably this deeper species behaves similarly. This volute lives in at least the soft, grey mud substrates of scampi grounds. It is probably prey to various crabs and demersal fishes.

Commercial catches There have no commercial landings specifically of this gastropod reported to the Ministry of Fisheries. However, under the label VOL (for volute), there have been fishing year landings of up to 14 t in recent times – but almost all from statistical areas 38 (Tasman and Golden Bays) and 34 (central west coast of South Island), almost certainly mostly Alcithoe arabica for meat, and as bycatch in other fishers (mainly scallop and dredge oyster) (NIWA unpubl. data).

Threats Gastropods such as P. mirabilis are an unavoidable bycatch in some bottom trawl fisheries. They are also sought by shell collectors, particularly as live shells.

Conservation and management There is no conservation or management practice specifically in place for this volute. It is probably widespread over its wide range, but it is unlikely to be present in high numbers anywhere. However, it is listed by Department of Conservation as being in Gradual decline (Hitchmough 2002) . The main reason for this classification is probably that they are a robust component of the bycatch and are sought by shell collectors.

References Harasewych, M.G.; Marshall, B.A. (1995). Zygomelon zodion , a new genus and species of bathyal volute from New Zealand. The Veliger 38(2) : 145–151.

Hitchmough, R. (2002). New Zealand threat classification system lists. Threatened Species Occasional Publication 23 . Morton, J.; Miller, M. (1968). The New Zealand sea shore. Collins, Auckland. 638 p. Powell, A.W.B. (1979). New Zealand Mollusca. Marine, land and freshwater shells. Collins, Auckland. 500 p. Spencer, H.G.; Willan, R.C.; Marshall, B.A.; Murray, T.J. (2002). Checklist of the Recent Mollusca described from the New Zealand Exclusive Economic Zone. http://toroa.otago.ac.nz/pubs/spencer/Molluscs/index.html

Order Paxillosida: Family Astropectinidae

Geometric star Psilaster acuminatus Sladen, 1889

Overview This widespread seastar, which reaches at least 121 mm in radial length, is found on the shelf and slope around much of New Zealand. Its greatest threat is through being trawled as bycatch.

Distribution and relative abundance This seastar is one of New Zealand’s commonest. It is widespread from Lord Howe Island, and the Three Kings Islands/North Cape area in the north, to The Snares, Bounty, Antipodes and Auckland Islands in the south, and east to the Chathams. It is not known from Foveaux Strait or Stewart Island. Most specimens have been collected between 200 and 600 m, but the full range is 0–2460/2519 m (Clark & McKnight 2000). The species occurs in Australian and South African waters (Clark & McKnight 2000).

Reproduction and life history There appears to be nothing known specifically for this seastar concerning reproduction, and there is no information on age or growth.

There is no information relevant to the recognition of any separate stocks in New Zealand. Although there are two distinct forms of P. acuminatus (in one, the arms are long, slender, and rapidly and evenly tapering; in the other, the arms are short and broad basally and the animal is ‘thick’ dorso-laterally), it does not appear to be a geographic variation (Clark & McKnight 2000).

Habitat and ecology This seastar lives in substrates that include the soft, grey mud of the Bay of Plenty scampi grounds. Seastar are primarily carnivores that feed particularly on bivalves, and so are found associated with such prey. P. acuminatus is probably prey to various crabs and demersal fishes.

Commercial catches There are no commercial landings of this seastar.

Threats Seastars such as P. acuminatus are an unavoidable bycatch in some bottom trawl fisheries, particularly the east coast Northland/Bay of Plenty scampi fishery and to a lesser extent shallower dredging and flatfish trawling.

Conservation and management There is no conservation or management practice in place for this seastar. It is probably widespread thorugout its range, and in places probably present in high numbers.

References Clark, H.E.S.; McKnight, D.G. (2000). The marine fauna of New Zealand: Echinodermata: Asteroidea (sea-stars). Order Paxillosida. NIWA Biodiversity Memoir 116 . 196 p.

Order Pholodomyoida: Family Cuspidariidae

Cuspidaria fairchildi Suter, 1908

Overview This endemic bivalve, which reaches at least 59 mm in length, is found on the shelf and slope around much of New Zealand.

Distribution and relative abundance This bivalve is found in soft substrates around the North, South, and Chatham Islands at depths of 75– 350 fathoms (140–640 m) (Powell 1979). Dell (1956) says that although occurring sparingly on the shelf, it is much more common in deeper waters, those in the deeper water growing largest (Dell 1963).

Reproduction and life history

There is no information on reproduction, age or growth. There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology This bivalve lives in the substrate, but there was no published information on the nature of the substrate.

This bivalve is probably prey to various crabs and demersal fishes.

On the Chatham Rise, where C. fairchildi is often taken, there is one relevant benthic community with which it is associated: predominantly sandy sediments on the crest and shallower flanks of the rise at 237–602 m and includes as characteristic species the crustaceans Munida gracilis , Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalve Euciroa galatheae (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m.

Commercial catches There are no commercial landings of this bivalve.

Threats Bivalves such as C. fairchildi are an unavoidable bycatch in some bottom trawl fisheries, but probably many more are damaged or become prone to predation after disturbance by the trawl than are actually found in the trawl contents on the deck.

Conservation and management There is no conservation or management practice in place for this bivalve.

References Dell, R.K. (1956). The archibenthal Mollusca of New Zealand. Dominion Museum Bulletin 18 . Dell, R.K. (1963). Archibenthal Mollusca from northern New Zealand. Transactions of the Royal Society of New Zealand. Zoology 3: 205-216. Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. Powell, A.W.B. (1979). New Zealand Mollusca. Marine, land and freshwater shells. Collins, Auckland. 500 p. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53.

Order Pholodomyoida: Family Euciroidae

Euciroa galatheae (Dell, 1956)

Overview This endemic bivalve, which reaches at least 45 mm in length, is found on the slope around much of New Zealand.

Distribution and relative abundance This bivalve is found in soft substrates around the North and South Islands, Chatham Islands, and Auckland Islands, and on the Chatham Rise, at depths of 260–340 fathoms (480–620 m) (Powell 1979; NIWA unpubl. data).

Reproduction and life history There is no information on reproduction, age or growth. There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology This bivalve lives in the substrate but nothing published was found regarding the exact nature of such substrates.

This bivalve is probably prey to various crabs and demersal fishes.

On the Chatham Rise, where E. galatheae is often taken, there is one relevant benthic community with which it is associated: predominantly sandy sediments on the crest and shallower flanks of the rise at 237–602 m and includes as characteristic species the crustaceans Munida gracilis , Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalve Cuspidaria fairchildi (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m.

Commercial catches There are no commercial landings of this bivalve.

Threats Bivalves such as E. galatheae are an unavoidable bycatch in some bottom trawl fisheries, but probably many more are damaged or become prone to predation after disturbance by the trawl than are actually found in the trawl contents on the deck.

Conservation and management There is no conservation or management practice in place for this bivalve.

References Dell, R.K. (1956). The archibenthal Mollusca of New Zealand. Dominion Museum Bulletin 18 . Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. Powell, A.W.B. (1979). New Zealand Mollusca. Marine, land and freshwater shells. Collins, Auckland. 500 p. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53.

Order Reptantia: Family Galatheidae

Squat lobster Munida gracilis Henderson, 1885

Overview This endemic Munida is widespread on sedimentary bottoms, particularly over parts of the continental shelf and slope. The biology of M. gracilis is poorly known. Munida spp., in both their pelagic and benthic forms, have been viewed as a commercial resource, particularly for their chitin and carotenoid pigment.

Distribution and relative abundance Together with M. gregaria , this species is one of the most common galatheids in New Zealand waters (O’Shea et al. 1999). M. gracilis is reported from various parts of the New Zealand slope, and particularly on the Challenger Plateau (Webber et al. unpubl.).

Reproduction and life history There is no information on reproduction, age or growth. The larvae presumably swarm in mainly surface waters from time to time. There is no information relevant to the recognition of any separate stocks around New Zealand.

Habitat and ecology Galatheid lobsters live on rough sedimentary seafloors (Poore 2004) in which they may dig for cover. Population densities are moderate to high in places, with single trawls taking hundreds of individuals.

Munida are prey at various stages of their life to fishes such as tunas (pelagic phases) and sharks and gropers (juveniles and adults). The diet of this lobster is unknown.

On the Chatham Rise, where Munida are often taken, the main benthic community with which they are associated is the predominantly sandy sediments on the crest and shallower flanks of the rise at 237– 602 m and includes as characteristic species the crustaceans, Phylladiorhynchus pusillus , Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalves Cuspidaria fairchildi and Euciroa galatheae (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m.

Commercial catches Munida have from time to time been viewed as having commercial potential and small landings have been made (Webber, pers. comm.). There are trivial (a few kilograms) estimated catches and reported landings of this species in the Ministry of Fisheries databases (at 9 December 2003).

Threats Munida lobsters will remain an unavoidable bycatch in some trawl fisheries but levels of bycatch are believed to be small compared with what could occur through targeted fishing with appropriate gear.

Conservation and management There is no conservation or management practice in place for this crustacean; Munida are not part of the QMS, but M. gregaria (MUN) is likely to be considered for QMS introduction in 2005 or soon after www.tokm.co.nz). A considerable issue is that of differentiation between Munida species, many being undescribed and difficult to distinguish (O’Shea et al. 1999), requiring careful attention to spines on the carapace and antennules, so there is every likelihood that there will be blanket Munida grouping.

References Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233. O’Shea, S.; McKnight, D.; Clark, M. (1999). Bycatch – the common, unique, and bizarre. Seafood New Zealand June : 45-51. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. Poore, G.C.B. (2004). Marine decapod crustacea of southern Australia: a guide to identification. Collingwood: CSIRO Publishing. Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53.

Order Reptantia: Family Galatheidae

Little craylet Phylladiorhynchus pusilla (Henderson, 1885)

Overview This widespread galatheid, which reaches at least 8 mm carapace length (CL, including rostrum) in males and 5 mm in females (but possibly much more because these measurements were based on Japanese material, for which the maximum size is quite a lot smaller than that from New Zealand – Baba 1991), is taken around much of the New Zealand shelf and upper slope.

Distribution and relative abundance This crustacean is found on soft mud/sand bottoms in New Zealand, Indian Ocean, Chinese and Japanese waters, eastern Australia from northern Queensland south and west to southern Western Australia, and New Caledonia (and possibly Juan Fernandez) (Baba 1991; Davie 2002; Poore 2004; Webber et al. unpubl.). It is a bathyal benthic species that lives on the shelf and upper slope from the intertidal to 310 m, but overall is more common at the greater depths (Haig 1973, although Baba 1991 gives the depth range of the New Zealand material to be 15–46 m).

Reproduction and life history There is very little information on reproduction, age, or growth. Ovigerous females in Japan were >4 mm CL (Baba 1969) and in New Caledonia >3 mm (Baba 1991, but note the above comment about sizes of the New Zealand versus Japanese specimens). There is no information relevant to the recognition of any separate stocks around New Zealand.

The presence of rhizocephalan parasites has been reported (see Haig 1973).

Habitat and ecology This lobster lives on soft mud/sand bottoms in which it may dig for cover. Galatheids are prey at various stages of their life to demersal fishes such as sharks and gropers. The diet of this lobster is unknown.

On the Chatham Rise, where P. pusilla are often taken, the main benthic community with which they are associated is the predominantly sandy sediments on the crest and shallower flanks of the rise at 237– 602 m and includes as characteristic species the crustaceans, Campylonotus rathbunae , Pontophilus acutirostris , and Acutiserolis bromleyana , the ophiuroid Amphiura lanceolata , and the bivalves Cuspidaria fairchildi and Euciroa galatheae (Yaldwyn 1960, McKnight & Probert 1997). This is essentially the Serolis bromleyana -Spatangus multispinus community described by Hurley (1961) from the Chatham Rise at depths of 403–604 m.

Commercial catches There are no commercial landings.

Threats and Conservation and management Galatheid lobsters are an unavoidable bycatch in some bottom trawl fisheries. There is no conservation or management practice in place for this crustacean; Galatheids are not part of the QMS, but M. gregaria (MUN) is likely to be considered for QMS introduction in 2005 or soon after. A considerable issue is that of differentiation between species, so there is every likelihood that there will be blanket Munida of galatheid grouping.

References Baba, K. (1969). Four new genera with their representatives and size new species of the Galatheidae in the collection of the Zoological Laboratory, Kyushu University, with redefinition of the genus Galathea . Ohmu Occasional Papers of Zoological Laboratory Faculty of Agriculture Kyushu University 2: 1–32. Baba, K. (1991). Crustacea Decapoda: Alainius gen. nov., Leiogalathea Baba, 1969, and Phylladiorhynchus Baba, 1969 (Galatheidae) from New Caledonia. Memoires du Museum National d’Histoire Naturelle, Paris 152 : 479–491. Davie, P.J.F. (2002). Crustacea: Malacostraca: Eucarida (Part 2). Decapoda-Anomura, Brachyura. In Wells, A; Houston, W.W.K. (eds) Zoological catalogue of Australia. Vol. 19.3B. Melbourne: CSIRO Publishing, Australia. Haig, J. (1973). Galatheidea (Crustacea, Decapoda, Anomura) collected by the F.I.S. Endeavour. Records of the Australian Museum 28 : 269–289. Hurley, D.E. (1961). The distribution of the isopod crustacean Seriolis bromleyana Suhn with a discussion of an associated deepwater community. New Zealand DSIR Bulletin 139 : 225–233. McKnight, D.G.; Probert, P.K. (1997). Epibenthic communities on the Chatham Rise, New Zealand. New Zealand Journal of Marine and Freshwater Research 31 : 505–513. Poore, G.C.B. (2004). Marine decapod crustacea of southern Australia: a guide to identification. Collingwood: CSIRO Publishing. Webber, R.W.; Yaldwyn, J.C.; Dawson, E.W. (unpublished). Annotated checklist of New Zealand decapod Crustacea. Te Papa document. Yaldwyn, J.C. (1960). Crustacea Decapoda Natantia from the Chatham Rise: a deep water bottom fauna from New Zealand. New Zealand DSIR Bulletin 139(1) : 13–53.

Order Scleractinia: Family Caryophylliidae

Desmophyllum dianthus (formerly cristagalli) (Esper, 1794)

Overview This cosmopolitan cnidarian is widespread in New Zealand waters where it reaches at least 55 mm in calicular diameter and 190 mm in length. Little is known of its biology. Its greatest threat is through being trawled as bycatch.

Distribution and relative abundance This common, cosmopolitan cnidarian is found in New Zealand waters at depths of 25–1750 m, the shallowest records from the fiords (Cairns 1995). New Zealand records extend from 26–56° S, from off both coasts, and along the Chatham Rise, often in deep-water bank environments. It was not, however, listed by Cryer et al. (1999) as being significant in the Bay of Plenty, nor by Probert et al. (1997) off Otago.

Reproduction and life history There appears to be nothing known specifically for this cnidarian concerning reproduction, and there is no information on age or growth.

There is no information relevant to the recognition of any separate stocks in New Zealand, even though the Fiordland specimens tend to have broader pedicels than the deeper-water populations (Cairns 1995).

Habitat and ecology Because this cnidarian is most often found in deep-water bank environments, it is probably often associated with firm substrates. Individual coralla are sometimes grouped into quasicolonies. This coral is also often found attached to other corals (e.g., Goniocorella dumosa and Madrepora oculata ), stylasterids, and isidid gorgonians; dead specimens often provide a substrate for Stenocyathus vermiformis. Where it is associated with G. dumosa , the coral colonies can form ‘coppices’ of a bushy interlocking network of branches, the hollow spaces formed within the colony provide numerous niches for a diverse assemblage of attached organisms (Squires 1965, Cairns 1995). These include other corals, sponges, bryozoans, polychaetes, ophiuroids, asteroids, gastropods, bivalves, anemones, and foramifera. It is likely that these and other corals also play an important role as cover and food source for various deepwater fishes, particularly juveniles.

Commercial catches There are no commercial landings of this cnidarian.

Threats Cnidarians such as D. dianthus are an unavoidable bycatch in some bottom trawl fisheries, including on the Chatham Rise.

Conservation and management There are no conservation or management measures in place for this widespread and common cnidarian. Being relatively large and complex in form, it is prone to being trawled.

Order Scleractinia: Family Caryophylliidae

Bushy hard coral Goniocorella dumosa (Alcock 1902)

Overview This scleractinian coral, the bushy colonies of which reach up to 40 cm across, is widespread in the New Zealand region and particularly on the Chatham Rise. Beds of this species are important refuges, and harbour food, for various invertebrates in particular. Colonies are destroyed by trawling and may take decades to recover. Nevertheless, it seems likely that this coral is still widespread in New Zealand waters.

Distribution and relative abundance This coral, which is also reported from off South Africa, Indonesia, and Japan, is widespread in the New Zealand region and particularly on the Chatham Rise, at depths of 88–1488 m (Cairns 1995). It was a significant bycatch in the orange roughy fishery on hill stations on the Chatham Rise at depths of 662– 1524 m (Probert et al. 1997). It is unclear how widespread and abundant this coral now is in our waters: being prone to trawling, its abundance has probably been greatly reduced.

Growth is probably slow, and colonies may be decades or centuries old.

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology Although this coral was most often taken on hill stations of the Chatham Rise (Probert et al. 1997), it is also thought to form, together with other corals such as Desmophyllum dianthus , large coppices up to at least 40 m high and 700 m wide, on sedimentary substrates (Squires 1965).

Because the colonies of G. dumosa form a bushy interlocking network of branches, the hollow spaces formed within the colony provide numerous niches for a diverse assemblage of attached organism, including other corals, sponges, bryozoans, polychaetes, ophiuroids, asteroids, gastropods, bivalves, anemones, and foramifera (Cairns 1995). It is likely that these and other corals play an important role as cover and food source for various deepwater fishes, particularly juveniles (e.g., Husebo et al. 2002).

These corals are suspension feeders, taking their food from the water column. Predators of such corals include snails, fish, polychaetes, sea stars and nudibranchs (Cimberg et al. 1981).

Commercial catches There are no commercial landings of this coral.

Threats Corals such as G. dumosa are a bycatch in bottom trawl fisheries, particularly on seamounts and banks, but also on more open seafloor.

Conservation and management There are no conservation or management measures in place for this coral. Being relatively large and complex in form, it is prone to being trawled. Colonies may be decades or centuries old; there does not appear to be any information on whether trawl-damaged colonies ever recover. It is unclear how widespread this coral now is in New Zealand waters, but because it seems to be so widespread, there are probably still many untrawled populations.

References Cimberg, R. L., T. Gerrodette, and K. Muzik. 1981. Habitat requirements and expected distribution of Alaska coral, p. 207-308. In: Outer Continental Shelf Environmental Assessment Program (OCSEAP), Final Reports of Principal Investigators: 54. RU 0601. U.S. Department of Commerce, NOAA. Cairns, S.D. (1995). The marine fauna of New Zealand: Scleractinia (Cnidaria: Anthozoa). New Zealand Oceanographic Institute Memoir 103 . Husebo, A.; Nottestad, L.; Fossa, J.H.; Furevik, D.M.; Jorgensen, S.B. (2002). Distribution and abundance of fish in deep-sea coral habitats. Hydrobiologia 471 : 91–99. Probert, P.K.; McKnight, D.G.; Grove, S.L. (1997). Benthic invertebrate bycatch from a deep-water trawl fishery, Chatham Rise, New Zealand. Aquatic conservation: marine and freshwater ecosystems 7: 27–40. Squires, D.F. (1965). Deep-sea coral structure on the Campbell Plateau, New Zealand. Deep-Sea Research 12 : 785–788.

Order Spatangoida: Family Brissopsidae

Brissopsis oldhami Alcock 1893

Overview This infaunal echinoid, with an average test length of 40–50 mm, is found on the Chatham Rise but probably elsewhere too. Very little is known of its biology. Its greatest threat is through being trawled as bycatch.

Distribution and relative abundance This echinoid was recorded in all three community categories (A–C) on the Chatham Rise (237–2039 m) (McKnight & Probert 1997), so it clearly has a wide depth range, and it may or may not be common in places. It is unclear how widespread it is in New Zealand waters; it is not listed by Cryer et al. (1999) for the Bay of Plenty nor by Probert et al. (1997) off Otago. The species is reported from the Indian Ocean (www.nhm.ac.uk/palaeontology/echinoids).

Reproduction and life history There appears to be nothing known specifically for this echinoid concerning reproduction, and there is no information on age or growth.

There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology This grazing echinoid probably lives mainly on soft – mud and sand – substrates.

Commercial catches There are no commercial landings of this echinoid.

Threats Echinoids such as B. oldhami are an unavoidable bycatch in some bottom trawl fisheries, particularly on the Chatham Rise.

Conservation and management There are no conservation or management measures in place for this echinoid. Being relatively large and complex in form, it is prone to being trawled. It is unclear how widespread this echinoderm is in New Zealand waters.

Order Vetigastropoda: Family Calliostomidae

Calliostoma (Maurea) turnerarum (Powell 1964)

Overview This endemic trochid (gastropod), which reaches at least 42 mm in height and 56 mm in width, is found in deep waters, mainly near the shelf edge in northern New Zealand. It is possibly in Gradual Decline, being a bycatch in trawling and at the same time sought by shell collectors.

Distribution and relative abundance This trochid is found in the Aupourian Province, from the Three Kings islands and Ninety Mile Beach to Cape Runaway. Live specimens have been taken at depths of 312–529 m (dead shells 186–805 m) (Powell 1979, Marshall 1995, Spencer et al. 2002).

Reproduction and life history There seems to be no information on reproduction, age or growth, although it can be noted that shallow- water trochids such as Melagraphia aethiops do not have egg capsules but are broadcast spawners (Morton & Miller 1968). There is no information relevant to the recognition of any separate stocks in New Zealand.

Habitat and ecology Calliostomids live mostly on rocky grounds (Marshall 1995), yet surprisingly this species is also taken in the predominantly soft substrates of the scampi grounds. All known species are carnivores, most feeding on Cnidaria, and sometimes carrion, though a few feed exclusively on sponges; intestinal tracts of this species have been found to contain numerous fragments of thecate hydroids (Marshall 1995). Suitable firm surfaces are probably not particularly abundant and so this species, although possibly reasonably widespread, may not be anywhere common. It is probably prey to various crabs and demersal fishes.

Commercial catches There have no commercial landings specifically of this gastropod reported to the Ministry of Fisheries.

Threats Gastropods such as C. (Maurea ) turnerarum are an unavoidable bycatch in some bottom trawl fisheries, particularly the east coast Northland/Bay of Plenty scampi fishery and, perhaps to a lesser extent, shallower dredging and flatfish trawling.

Conservation and management There is no conservation or management practice in place for this trochid. It is probably widespread in its range, but is unlikely to be present in high numbers anywhere. However, C. (Maurea ) turnerarum is listed by Department of Conservation (as C. turnerarum ) as being in Gradual Decline (Hitchmough 2002) . The main reason for this classification is probably that this trochid is easily collected in trawl gear and may be sought by shell collectors.

References Hitchmough, R. (2002). New Zealand threat classification system lists. Threatened Species Occasional Publication 23 . Marshall, B.A. (1995). A revision of the Recent Calliostoma species of New Zealand (Mollusca: Gastropoda: Trochoidea). The Nautilus 108 : 83-127. Morton, J.; Miller, M. (1968). The New Zealand sea shore. Collins, Auckland. 638 p. Powell, A.W.B. (1979). New Zealand Mollusca. Marine, land and freshwater shells. Collins, Auckland. 500 p. Spencer, H.G.; Willan, R.C.; Marshall, B.A.; Murray, T.J. (2002). Checklist of the Recent Mollusca described from the New Zealand Exclusive Economic Zone. Available at http://toroa.otago.ac.nz/pubs/spencer/Molluscs/index.html.

APPENDIX 5: FISH SPECIES SUMMARIES FOR THE APPENDIX 3 COMMUNITY -BASED APPROACH

The following pages contain the draft summaries for 12 fish species, based on the Appendix 3 approach and were collated in 2006–07. They are presented alphabetically by Order.

Order Family Common name Species name Beryciformes Trachichthyidae orange roughy Hoplostethus atlanticus Collett, 1889 Gadiformes Merlucciidae hake Merluccius australis (Hutton, 1872) Gadiformes Merlucciidae hoki Macruronus novaezelandiae (Hector, 1871) Gadiformes Gadidae southern blue Micromesistius australis Norman, 1937 whiting Ophidiiformes Ophidiidae ling Genypterus blacodes (Forster, 1801) Perciformes Gempylidae barracouta Thyrsites atun (Euphrasen, 1791) Perciformes Centrolophidae bluenose Hyperoglyphe antarctica (Carmichael, 1812) Perciformes Centrolophidae silver warehou Seriolella punctata (Forster, 1801) Perciformes Odacidae butterfish Odax pullus (Forster, 1801) Perciformes Gempylidae gemfish Rexea solandri (Cuvier, 1832) Perciformes Sparidae snapper Pagrus auratus (Forster, 1801) Zeiformes Oreosomatidae black oreo Allocyttus niger James, Inada & Nakamura, 1988 Zeiformes Zeidae John dory Zeus faber Linnaeus, 1758

Order Beryciformes: Family Trachichthyidae

Orange roughy Hoplostethus atlanticus (Collett, 1889)

Overview Orange roughy inhabit depths between 600 m and at least 1500 m within the New Zealand EEZ, but are most common between 800 m and 1200 m. In winter, orange roughy form dense spawning aggregations in a number of consistent areas that are often associated with bottom features such as pinnacles and canyons. Throughout the rest of the year they are more widespread across the continental slope. Some orange roughy spawning sites were overfished in the 1980s and 1990s. Orange roughy are a very slow- growing, long-lived fish, and may live up to 120–130 years, with a mean age for the onset of maturity between 23 and 31.5 years. Orange roughy is a highly valuable commercial species with exports earning between $70 and $130 million annually, from total catches from 4 000 t to 9 000 t over the past six years.

Distribution Orange roughy are widely distributed throughout temperate waters of the Southern Hemisphere and the North Atlantic Ocean. Orange roughy occur throughout New Zealand’s EEZ; the main area of uncertainty is on the Kermadec and Colville ridges where little fishing or research in deeper waters has been carried out. Its distribution extends along ridges into the Tasman Sea, along the Lord Howe Rise, West Norfolk Ridge, and Puysegur Ridge, and into the Pacific Ocean along the Louisville Ridge east of New Zealand. Orange roughy cover a wide depth range from 600 m to 1500 m.

In winter, orange roughy form dense spawning aggregations in a number of consistent areas. The main areas are north of the Chatham Islands (the ‘Spawning Box’), on the northeastern and northwestern Chatham Rise, Ritchie Banks off Hawke Bay, East Cape, several areas of the Bay of Plenty, and off the Auckland Island shelf. Spawning is often associated with bottom features such as pinnacles and canyons. Spawning fisheries also used to occur on the Challenger Plateau, Cook Canyon, and Puysegur Bank, but stocks on these grounds were overfished in the 1980s and early 1990s. Seasonal distribution is thought to be generally similar in spring, summer and autumn, with a more widespread distribution on the continental slope than in winter. However, aggregations do occur for feeding, primarily on seamounts of the eastern and southern Chatham Rise. In several areas, catches in spring–summer–autumn were large during the early development of the fishery, but over time these have decreased, presumably as resident fish decline, and the fishery focuses more on migratory spawning fish. Outside of the spawning season important fisheries occur on the east coast of the North Island, off Wairarapa and Kaikoura coasts, the western end of the northern Chatham Rise, and on seamount features on the eastern and southern Chatham Rise.

Juveniles have been located in only one area, at a depth of 800–900 m about 80 nm east of the main spawning ground on the north Chatham Rise.

Reproduction and life history Orange roughy are a very slow-growing, long-lived fish, and may live up to 120–130 years. The mean age at the onset of maturity ranges from 23 to 31.5 years and around 30.5 cm. Orange roughy in New Zealand waters reach a maximum size of about 50 cm standard length (SL), and 3.6 kg in weight. Their average size is around 35 cm SL, although there is some variation between areas.

Spawning occurs once each year in winter, between June and early August, in dense aggregations at depths of 700–1000 m and is often associated with bottom features such as pinnacles and canyons. Spawning fish are also found outside the EEZ on the Challenger Plateau, Lord Howe Rise, and Norfolk Ridge to the west, and the Louisville Ridge to the east. It is likely that individual orange roughy do not spawn every year.

Fecundity is relatively low, with females carrying on average about 40 000 and 60 000 eggs. Details of larval biology are poorly known.

Natural mortality ( M) is estimated at 0.045 yr -1. This was based on otolith age data from a 1984 research survey of the Chatham Rise.

Orange roughy have very low resilience, with a minimum population doubling time of more than 14 years ( K=0.04-0.06; tmat =5-32; tma x=130; Fec=10 000).

Habitat and ecology Orange roughy inhabit water from 600–1500 m deep around New Zealand, most abundant on the Chatham Rise, from the Bay of Plenty to Kaikoura, at selected spots on the Challenger and Campbell Plateaus, and off Fiordland. During the winter spawning season they form dense spawning aggregations near bottom features such as pinnacles and canyons, usually at depths of 750 −950 m. Seasonal distribution is thought to be generally similar in spring, summer and autumn, with a more widespread distribution on the continental slope. Orange roughy can also form aggregations outside the spawning period, presumably for feeding. The main prey species include mesopelagic and benthopelagic organisms such as prawns, fish and squid, with other organisms such as mysids, amphipods and euphausiids occasionally being important. When the fish grow in length, there is a transition in the diet from prawns, mysids, and fish, to prawns, fish and squid. Squid have not been found in the stomach contents of fish smaller than 20 cm.

There does not seem to be sex specific schooling of orange roughy (landings show ~ 50:50 sex ratio).

Commercial catches Prior to 1993–94 there was no established ORH 1 fishery, until aggregations were fished on two hill complexes in the western Bay of Plenty during winter, in 1996 catches were also taken off the west coast of Northland. From 1995–96, ORH 1 was subject to an Adaptive Management Programme (AMP), and the TACC was increased to 1190 t. In 1994, 1995, 1996–07 research and exploratory fishing was carried out under Special Permit, which allowed an additional 800 t (not included in the TACC) to be taken. An evaluation of the results from the AMP, resulted in the TACC reduced to 800 t for the 2000–01 fishing year. Catch limits of 200 t were established in each of four areas in ORH 1, with an individual seamount feature limit of 100 t. In 2001–02, ORH 1 was reintroduced into the AMP and the TACC was increased from 800 to 1400 t. In recent years the fishery has also developed off the west coast and sizeable catches have been taken off the Tauroa Knoll and West Norfolk Ridge. Landings of orange roughy were less than 200 t until 1994–95 when landings leapt to 1000 t only to drop back to 500 t during 1997–98 from where they have followed an increasing trend to be well below the TACC at 1200 t in 2004–05.

The first reported landings of orange roughy in ORH 2, were in 1981–82 with the development of the Wairarapa fishery. The ORH 2 fishery had landings between 9 000–10 000 t for eight years from the late 1980s. Since then landings have decreased with a declining TACC until 2004–05 with landings of 1700 t. There was a major change in the ORH 2A fishery in 1993–94 with a shift of effort from the main spawning hill on Ritchie Bank to hills off East Cape, and management of the area was split into two areas (2A North and 2A South). For the 2000–01 fishing year the TACC for ORH 2A was reduced to 1 100 t, for ORH 2B to 185 t, and for ORH 3A to 415 t. Within the TACC for ORH 2A, the catch limits for 2A North and 2A South were reduced to 200 t and 900 t respectively. This gave a catch limit for the Mid-East Coast (MEC) stock of 1500 t. The catch limit for MEC was reduced to 800 t (and ORH 2A South to 480 t) for the 2002–03 and 2003–04 fishing years, then raised to 1 500 t from 2004–05, though 2A North retained a separate TACC of 200 t.

The orange roughy fishery in ORH 3B has historically been concentrated on the Chatham Rise. Annual orange roughy catches in ORH 3B were 30 000 t for most of the 1980s, catches then declined steadily to 9000 t by 1996–97 (following declines in the TACC), and since then has slowly risen to around 12 000 t, just below the 2004–05 TACC. There have been major changes in the distribution of catch and effort over the history of this fishery. Initially, that effort was confined to areas on the northern slopes of the Chatham Rise with relatively flat seafloor (in the Spawning Box), during winter. During the mid 1980s

about one third of the catch was taken on and around, small seamount features. The early 1990s saw effort within the Chatham Rise further shifted from the Spawning Box to eastern and northwestern parts of the Rise. The Spawning Box was closed to fishing from 1992–93 to 1994–95. In recent years, the main fishing grounds on the Chatham Rise have yielded relatively constant catches of 3000 t to 4000 t. The Puysegur fishery was developed in the early 1990s, followed by other fishing grounds near the Auckland Islands and on the Pukaki Rise. Outside the Spawning Box catches increased in the 1990s and catch rates have been highly variable, sustained largely by the discovery of new fishing areas. However, during the 1990s more than half of the Chatham Rise catch came from four hill complexes, all of which have shown a decline in catch rate since the early years of the fishery, though in recent years catch rates have been relatively stable.

The orange roughy fishery on the Challenger Plateau (ORH 7A) occurs in the southwestern region, both inside and outside the EEZ. Fish are caught throughout the year, with most effort in winter. Reported commercial catches show two peak catching years when landings were over 12 000 t, the first in 1982– 83 with the majority of the catch coming from Outside the EEZ, then again in 1987–88 when the majority of the catch came from Inside the EEZ. Catches declined rapidly after this, with the TACC reduced to 1 t (effectively closing the fishery) in 2000–01.

The West Coast South Island (ORH 7B) fishery centres on an area near the Cook Canyon in fishery statistical areas 033, 034 and 705, where most of the catch is taken in winter. Catches from 1992–93 to 1994–95 were well below the TACC. The TACC was reduced to 430 t for the 1995–96 fishing year, and then reduced further to 110 t for 2001–02; reported landings for 2004–05 were 106 t.

Fisheries outside the EEZ in the New Zealand region occur on ridge systems and seamount chains in the Tasman Sea and southwest Pacific Ocean. There are five main fishing areas, Lord Howe Rise, Northwest Challenger Plateau, West Norfolk Ridge, South Tasman Rise, and Louisville Ridge. These fisheries have been unregulated, with the exception of the South Tasman Rise area, where catches by Australian and New Zealand vessels have at times been restricted by a TAC imposed under a Memorandum of Understanding between the two countries. Fisheries for orange roughy outside the EEZ have followed a common path, with initial effort focused on the flat ground of the broad platforms during the 1980s, before shifting effort to rough ground and small hill features with shorter tow lengths. Within a decade of targeting spawning aggregations the stock declines and effort is transferred to another feature, or fishstock, where the pattern is repeated.

No information on Maori customary fishing for orange roughy is available. There is no known recreational fishery for orange roughy.

There may be some overrun of reported catch because of fish loss via trawl gear damage and ripped nets. A level of 5% is estimated in some orange roughy fisheries.

Conservation and management Methods used to manage orange roughy both inside and outside the New Zealand EEZ have included, TACCs, Fishstocks, exploratory quotas, research trawling, Special Permits, AMPs, and one Memorandum of Understanding. The main orange roughy fisheries have been managed under the QMS as five separate FMAs, each consisting of one or more fishstock. In addition there are five unmanaged fisheries for orange roughy outside New Zealand’s EEZ. 1. Northern North Island (ORH 1): Mercury-Colville stock 2. Cape Runaway to Banks Peninsula (ORH 2A, 2B, & 3A): East Cape stock, Mid-East Coast stock 3. Chatham Rise and Puysegur (ORH 3B): Northwest Chatham Rise stock, East Chatham Rise stock, Spawning Box, Northeast Flats subarea, Northeast Hills subarea, Andes subarea, South Chatham Rise stock, Puysegur stock 4. Challenger Plateau (ORH 7A) 5. West coast South Island (ORH 7B) 6. Outside the EEZ: Lord Howe, Northwest Challenger, Louisville, West Norfolk, South Tasman

Population trends Fishery-area summaries are presented in Table A. Within ORH 1 it is clear that, for whatever reason, fish abundance in the Mercury-Colville box has been considerably reduced and is now at low levels. A catch limit of 30 t has been set for the box. The assessment indicates that a catch level of about 100 t will probably maintain the stock at its current size (assuming deterministic recruitment), and levels between 16 t and 35 t are consistent with MCY or CAY strategies, which may allow the stock to rebuild slowly. In other areas, the level of catch and effort has varied. In some areas, stocks have been lightly exploited and the fishery is thought to still be in the fishing down phase. Therefore, the current stock size is probably above that which will support the maximum sustainable yield. From 2001–02, the TACC for ORH 1 was increased to 1400 t within the AMP. However, it is not known if recent catch levels and the current TACC are sustainable in the long term.

The stock assessment for the East Cape (2A North) was last updated in 2003. The current surplus production in the year 2003 (550 t) was greater than both the current catch limit of 200 t and the catches in the two most recent years included in the assessment (302 t in 2000–01, and 186 t in 2001–02). The best estimates of CAY and MAY were greater than both the catch limit and catches for the two most recent years in the assessment. This suggests that the current catch limit should allow the stock to rebuild.

Biomass was estimated for MEC to have reached a minimum in the mid 1990s and to have been slowly increasing since. When the relationship between CPUE and biomass is assumed to be linear ( β=1), the current stock is estimated to be below Bmsy (18% B0). When β is estimated, or the CPUE data are excluded, the current stock size is estimated to be near Bmsy . Recent model projections indicate that the current catch limit (1500 t) is sustainable, and that stock size will increase at any catch level less than 3000 t. These projections are uncertain because the magnitude and rates of future increases in stock size are driven by the assumption that future recruitment will be constant at the virgin level. However, this assumption is not currently supported by any direct observations or data.

Within ORH 3B the northwest Chatham Rise 2006 assessment is uncertain because the estimated current status of the stock is strongly dependent on the CPUE data for the flat areas and the extent to which these data index the entire stock is unknown. Survey biomass indices provided only limited information on stock status because there are so few of them and they are restricted to the end of the time series when there is relatively little contrast in biomass. There is also conflict amongst the survey estimates in that no model run provided satisfactory fits to all of them.

It was not possible to carry out an overall assessment for the whole East Chatham Rise area due to pronounced differences in CPUE trends for different subareas.

If the usual productivity assumptions are correct for the Spawning Box and Northeast Flats, then the increase in biomass, modelled for 1990–91 or 1991–02, has been substantial. Recent exploitation rates are estimated to be less than that associated with a CAY policy, ECAY (0.064 for Chatham Rise orange roughy). If the actual productivity of orange roughy in this subarea is lower than is usually assumed, the increase in biomass will be less and the estimated yields will be lower. Recent exploitation rates are estimated to have exceeded ECAY.

The assessment of the Northeast Hills indicates that the biomass has been fished down to a level of about 14% B0, but has increased slightly in the last two years in response to reductions in catches. However, the current exploitation rate is about three times ECAY, and yield estimates (CAY and MAY) are both lower than the 2004–05 catch.

The assessment of the Andes indicates that the biomass has been fished down and is currently estimated to be about 29% B0. The current exploitation rate is about double ECAY and yield estimates (both CAY and MAY) are both about half the 2004–05 catch.

The status of the South Chatham Rise stock is uncertain because of the limited information available. Changes over the history of the fishery necessitated the production of separate CPUE indices for each of

three sectors of the fishery (two hill areas and fishing on the flat), but no information is available about the movement of fish between these sectors. The simplest assumption, of no movement, produces estimates of virgin biomass (B0) of around 100 000 t. Assessment results that indicate rebuilding over the past 15 years to levels of either 29% B0 or 41% B0 (depending on assumptions) are not supported by the CPUE data. This inconsistency also undermines confidence in the yield estimates and forward projections. Initial attempts to model migration between the sectors showed some promise but were not comprehensive enough to be conclusive.

The assessment for the Puysegur (Southern ORH 3) stock has remained unchanged from those presented in the 1998. It is uncertain because the three time series of biomass indices on which it is based are all very short. All three series (two of trawl surveys and one of CPUE) suggest that the biomass has been reduced substantially. The point estimate of biomass from this assessment is probably below Bmsy , but it is uncertain. The fishery has been voluntarily closed since 1997 −98 and zero catch should allow the stock to move towards Bmsy .

The 2000 assessment of the Challenger Plateau (ORH 7A) stock indicated that it was about one tenth of Bmsy . The TACC was reduced to 1 t (effectively closing the fishery) in 2000–01 to promote the rebuilding of the stock towards Bmsy . The extent to which the stock has rebuilt since the closure of the fishery cannot be determined without the collection of additional data.

The estimated status of the West Coast South Island (ORH 7B) stock depends strongly on which alternative assessment is used. If CPUE is assumed to be directly proportional to biomass (Beta1) then the current biomass is estimated to be 17% B0. When this assumption is relaxed (EstBeta) the current biomass is much higher. Both assessments indicate that recent catches are allowing the stock to rebuild. One concern is that the model results indicate that the stock has been slowly rebuilding since the mid 1990s, whereas trends in catch rates and tow duration are not consistent with this conclusion.

Most fisheries outside the New Zealand EEZ (ORH ET) continue to have variable levels of catch and effort between years. Catch levels have decreased for all fisheries since they began, but in recent years the total catch by New Zealand vessels has been consistent at 2000–2500 t. Trends in catch and effort have been difficult to interpret, given changes in the vessel composition over time and the areas fished between years. Mean catch rates for the Lord Howe Rise have increased in recent years, and the fishery appears more stable now following a period of low catch and effort in the mid 1990s. The orange roughy catch in the Northwest Challenger Plateau fishery has declined substantially in the last few years. Unstandardised CPUE has been at relatively low levels since 2000–01, and associated with a shift towards long tows on the flat, the winter fishery on the hills declined considerably in 2004–05. The Louisville Ridge fishery has been the largest of those in the New Zealand region, and catch and effort levels are broadly similar to those in recent years, although the patterns on individual seamounts differ, with some appearing stable, while others have declined. The fishery on the South Tasman Rise has decreased to very low levels, and New Zealand vessels have not fished the Rise since 2001. The West Norfolk Ridge fishery developed rapidly in 2001 −02, and after an initial decrease in catch and effort, these increased in 2004–05 as new sites were fished.

List of information sources Anderson, O.F. (2006). A summary of biological information on the New Zealand fisheries for orange roughy (Hoplostethus atlanticus) for the 2004–05 fishing year. New Zealand Fisheries Assessment Report 2006/47. 25p. Andrews, A.H. & Tracey D.M. (2003). Age validation of orange roughy, oreos, and black cardinalfish. Final Research Report for Ministry of Fisheries Research Project DEE2000/02. NIWA. 25 p. Clark, M.R.; Fincham, D.J.; Tracey, D.M. (1994). Fecundity of orange roughy (Hoplostethus atlanticus) in New Zealand waters. New Zealand Journal of Marine and Freshwater Research 28 : 193–200. FishBase (2007). http://www.fishbase.org/Summary/speciesSummary.php?ID=334& genusname=Hoplostethus&speciesname=atlanticus Accessed 30 January 2007. Horn, P.L.; Tracey, D.M.; Clark, M.R. (1998). Between-area differences in age and length at first maturity of orange roughy ( Hoplostethus atlanticus ). Marine Biology 132 (2 ): 187–194.

Ministry of Fisheries (2007) http://www.fish.govt.nz/en-nz/SOF/Species.htm?code=ORH&list=name Accessed 01 February 2007. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz Accessed 30 January 2007. Rossechi, E.: Tracey, D.M.; Weber, W.R. (1988). Diet of orange roughy, Hoplosthethus atlanticus (Pisces: Trachichthyidae), on the Challenger Plateau, New Zealand. Marine Biology 99 : 293–306. Zeldis, J.R.; Francis, R.I.C.C.; Field, K.D.; Clark, M.R.; Grimes, P.J. (1997). Description and analyses of the 1995 orange roughy egg surveys at East Cape and Ritchie Bank (TAN9507), and reanalyses of the 1993 Ritchie Bank egg survey. N.Z. Fisheries Assessment Research Document 97/28. 34 p. [Unpublished report held in NIWA library, Wellington.] Zeldis, J.R.; Grimes, P.J.; Ingerson, J.K.V. (1994). Ascent rates, vertical distribution, and a thermal history model of development of orange roughy ( Hoplostethus atlanticus ) eggs in the water column. Fishery Bulletin (U.S.) 93 : 373–385.

Table A: Summary of ORH population trend analysis: stock assessment, biomass estimates, and projections. Uncertainties and assumptions are defined in Table B. Note that the Puysegur fishery has been voluntarily closed since 1997 −−−98 and the Challenger fishery has been effectively closed (with a TACC of 1 t) since 2000–01.

Assessed Uncertainty Annual Most Biomass Best estimate Data 5-year projection Uncertainties Assumptions recent ORH 1 Mercury- Y Uncertain 2001 Below Bmsy CAY 35t Research, 1 Colville box MCY 16t CPUE White Is. N Tauroa Knoll N ORH 2 2A North Y 2003 24% of B0 CAY 370t (20–32% B0) MAY 410t 2A South, Y Uncertain 2004 Below Bmsy (18% 1 2 2B, ORH 3A B0) ORH 3B NW Uncertain 2006 CPUE, egg 2, 3 Chatham survey, Rise research, L/F Spawn. Box, Y 2006 51–61% B0 CAY MAY lower Continued fishing at 2004– 3 NE Flats than 2004–05 catch 05 level will allow further small increase NE Hills Y 2006 14% of B0 (7– CAY MAY lower Biomass increase further if 32% B0) than 2004–05 catch catch remains at 2004–05 level Andes Y 2006 29% of B0 (14– CAY MAY are half Biomass decrease further 74% B0) the 2004–05 catch if catch remains at 2004– 05 level S Chatham Y Uncertain 4 Rise Puysegur Y Uncertain 1998 Below Bmsy MCY CAY < 420t 3 trawl survey 5 1 CPUE ORH 7A Challenger Y 2000 10% of Bmsy (7– 14% Bmsy ) ORH 7B WCSI 2002 17% of B0 (14– All yield > TACC CPUE 6 4 23% B0) & recent catches (Beta1) 2002 45% of B0 (18– All yield > TACC CPUE 6 69% B0) & recent catches (EstBeta) ORH ET N

68 Table B: Definitions of Uncertainties and assumptions used in Table A.

Uncertainties 1 Magnitude and rates of future increases in stock size are driven by assumption 2 2 Estimated current stock status is dependent on CPUE for flat areas 3 No model run provided satisfactory fits to survey estimates 4 Limited information available 5 Biomass indices very short 6 Model results not equal to catch rates and tow duration

Assumptions 1 Env. factors influenced availability or catchability of fish 2 Future recruitment will be constant at virgin level 3 Usual productivity assumptions 4 CPUE is assumed to be directly proportional to biomass

Order Gadiformes: Family Merlucciidae

Hake Merluccius australis (Hutton, 1872)

Overview In New Zealand, hake are mostly caught around the South Island in waters associated with the Subtropical Front and Sub-Antarctic water. Hake are mainly caught by bottom trawlers in the West Coast South Island, Sub-Antarctic, and Chatham Rise areas. Good catch rates arise when the fish are densely aggregated during spawning (spring and summer), particularly off Westland, west of the Chatham Islands, on the Stewart-Snares shelf, and Puysegur Bank.

Distribution Hake occur in New Zealand and South America. In New Zealand EEZ hake are widely distributed throughout the middle depths, typically south of 40º S. There are hotspots within this distribution that relate largely to seasonal spawning aggregations, such as the West Coast of the South Island from June to October, Chatham Rise from September to January, Kaikoura coast, and in the Sub-Antarctic from September to February. The known depth range of hake is 10–1 500 m, and can be associated with hills or seamounts that are 900 m or deeper. Juveniles occur in shallow water around the South Island.

Reproduction and life history There are at least three main spawning areas for hake; off the west coast of the South Island from June to October, to the west of the Chatham Islands from September to January, and to the north-east of the Auckland Islands, from September to February. Juvenile hake have been taken in coastal waters on both sides of the South Island and on the Campbell Plateau. They reach a length of about 15–20 cm total length at one year old and about 35 cm total length at 2 years. Hake reach a maximum age of at least 25 years. Males rarely exceed 100 cm total length (TL), females, to 120 cm TL or more. Both sexes reach sexual maturity between 6 and 10 years of age, at lengths of about 67–75 cm TL (males) and 75–85 cm TL (females). Hake reached 50% maturity at between 6–8 years in HAK 1, and 7–8 years in HAK 4.

Estimates of natural mortality (M) and the associated methodology are given in Dunn et al. (2000); M is estimated as 0.18 yr -1 for females and 0.20 y -1 for males. Colman et al. (1991) previously estimated M as 0.20 yr -1 for females and 0.22 yr -1 for males using the maximum age method of Hoenig (1983). Horn (1997) determined the age of hake by counting zones in sectioned otoliths and concluded that M was likely to be in the range of 0.20–0.25 yr -1.

Hake has a low resilience, with a minimum population doubling time of 4.5–14 years ( K=0.07–0.19; tm=6–10; tmax =30)

Habitat and ecology Adults are mainly distributed from 250–800 m, though some have been found as deep as 1200 m, while juveniles (0+) are found in shallower inshore regions less than 250 m. There is a winter spawning ground on the west coast of the South Island, and two summer spawning grounds, west of the Chatham Islands and near the Auckland Islands. It is likely adults migrate to these spawning areas. The New Zealand population feeds mainly on fishes (especially gadoids), squids, euphausiids and benthic organisms.

Commercial catches The largest hake fishery has been off the west coast of the South Island (HAK 7) with a catch of 17 000 t in 1977. The west coast South Island hake fishery has generally consisted of bycatch in the much larger hoki fishery, but has undergone a number of changes during the last 15 years. These include changes to the TACCs of both hake and hoki, changes in fishing practices to limit hake bycatch, such as gear used, tow duration, and fishing strategies. In some years, most notably in 1992 and 1993, there was a hake target fishery in September after the peak of the hoki fishery had ended, with more than 2 000 t of hake taken in this target fishery during September 1993. Bycatch levels of hake early in the fishing season in the years 1994–95, 1995–96, and 1997–89 to 2000–01 were relatively high. In HAK 1 (where most of the catch is taken from the Sub-Antarctic) and HAK 4 (Chatham Rise), hake have also been caught mainly as bycatch by trawlers targeting hoki. However, in both areas some targeting for hake occurs, particularly in Statistical Area 404 in HAK 4, which is a known spawning area for hake north-west of the Chatham Islands.

Landings in HAK 1 have been steady from the late 1990s with average annual landings of 3800 t. In 2000–01 landings dropped to 2800 t but have since increased to historic peak for HAK 1 of 4800 t in 2004–05. An increase in TAC occurred in the early 1990s of almost 1000 t from 2600 t to 3600 t, the TAC for 2004–05 was 3700 t.

In HAK 4 during the 1990s landings sharply increased from 500 t to a peak of around 3500 t where landings remained for 4 years before sharply declining to early 1990 levels around 750 t in 2002–03. Landings then spiked in 2003–04 up to 2 200 t, but dropped back down to 1200 t the following year. In the early 1990s the TAC for HAK 4 was increased by 2500 t from 1000 t to 3500 t where it remained for 12 years. In the last year the TAC had been almost halved to 1 800 t.

The highest landings of hake have always come from HAK 7 where landings have been stable for the past five years at around 7500 t, slightly higher than the TACC. In the 10 years prior to this stability, landings have oscillated as high as 8 900 t and as low as 3000 t. HAK 7 had a TAC increase in the early 1990s, this increase of around 3500 t was from a TAC of 3300 t to 6800 t where it has remained unchanged for 13 years.

The recreational fishery for hake is negligible. The amount of hake caught by Maori is not known but is believed to be negligible.

Conservation and management The QMS manages the hake fishery in three Fishstocks, Challenger (HAK 7), Chatham Rise (HAK 4), and the remainder of the EEZ comprising the Auckland, Central, Southeast (Coast), Southland and Sub- Antarctic (HAK 1). The recent high catches of hake on the western Chatham Rise have raised concerns that the Chatham Rise stock may consist of two stocks.

Population trends Model estimates of the state of the sub-Antarctic stock (HAK 1) suggest that there has been only small reduction in the available biomass since the mid-1990s. Although estimates of current and reference spawning stock biomass may not be reliable, it is likely that the current TACC is sustainable, as current catches do not appear to be having a measurable impact on biomass levels.

The 2004 model results suggested a decline in biomass within the Chatham Rise stock (HAK 4 and western Chatham Rise HAK 1), with biomass in 2004 at about 35% B0. Year class strengths from 1995 to 2000 are estimated to be weaker than average. In the projections, the model assumes average year class strength since 2001, although more small hake have been caught in the most recent trawl surveys, suggesting that the 2002 year class may be above average. Projections for the Chatham Rise stock estimated the risk of reducing the stock below 20% B0 in 2009 to be 88% with catches of 3616 t, and 28% with catches of 1800 t. The higher assumed catch of 3616 t represents the current HAK 4 TACC plus half the HAK 1 TACC, while the lower catch level of 1800 t represents the HAK 4 TACC only.

The model for the west coast South Island stock (HAK 7) was fitted to catch at age data from the commercial fishery with the catch history and biological parameters (including M) assumed to be known without error. Selectivity assumptions were varied to determine the sensitivity of the model results to the catch at age data. In the initial case the logistic assumption for the selectivity ogives is considered a conservative assumption. This run suggested current biomass was between 30% and 70% B0. The other runs gave similar estimates of biomass and stock status. All the model results indicated that current catches appear to be sustainable in the short term.

List of information sources Colman, J.A.; Stocker, M.; Pikitch, E. (1991). Assessment of hake ( Merluccius australis ) stocks for the 1991–92 fishing year. New Zealand Fisheries Assessment Research Document 91/14. 29 p. [Unpublished report held in NIWA library, Wellington.] Colman, J.A. (1998). Spawning areas and size and age at maturity of hake (Merluccius australis) in the New Zealand Exclusive Economic Zone. New Zealand Fisheries Assessment Research Document 98/2. 17 p. [Unpublished report held in NIWA library, Wellington.] Dunn, A.; Horn, P.L.; Cordue, P.L.; Kendrick, T.H. (2000). Stock assessment of hake (Merluccius australis) for the 1999–2000 fishing year. New Zealand Fisheries Assessment Report 2000/50 . 50 p. FishBase (2007). http://www.fishbase.org/Summary/SpeciesSummary.php?id=322 Accessed 29 January 2007 Horn, P.L. (1997). An ageing methodology, growth parameters, and estimates of mortality for hake (Merluccius australis ) from around the South Island, New Zealand. Marine and Freshwater Research 48 : 201–209. Hoenig, J.M. (1983). Empirical use of longevity data to estimate mortality rates. Fisheries Bulletin 81 : 899–903. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz. Accessed 29 January 2007. Paul, L.J. (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p.

Order Gadiformes: Family Merlucciidae

Hoki Macruronus novaezelandiae (Hector, 1871)

Overview Hoki are widely distributed throughout New Zealand waters from 34° S to 54° S, at depths from 10 m to over 900 m, but are most abundant at depths between 200 and 600 m. Historically, the main fishery for hoki has operated from mid-July to late August on the west coast of the South Island (WCSI) where hoki aggregate to spawn. Since 1988 a major fishery has developed in Cook Strait from late June to mid September, where separate spawning aggregations of hoki occur. Where hoki disperse to their feeding grounds, substantial fisheries have developed on the Chatham Rise, and Sub-Antarctic. The commercial hoki fishery was developed by Japanese and Soviet vessels during the early 1970s, more recently, in 1997–98, landings reached a peak of 269 000 t (TACC 250 000 t), which by 2004–05 had decreased to 106 000 t (TACC 100 000).

Distribution Hoki occur around New Zealand and southern Australia, south of 30° S, and at depths from 10 m to over 900 m. In New Zealand, hoki are mostly caught around the South Island in waters associated with the Subtropical Front and Subantarctic water. Tuna vessels have caught hoki in midwater over very deep water associated with the Bounty Trough and offshore from Fiordland. They are also associated with hills or seamounts that may be 900 m or deeper. Although hoki are caught around much of the North Island, the commercial catch is relatively small, and catch rates tend to be low. It is likely that hoki occur in small numbers in oceanic waters south of 30° S.

During the main spawning season, from mid-July to late August on the west coast of the South Island, and from late June to mid September in Cook Strait hoki will aggregate to spawn in midwater. Throughout the rest of the year the adults are dispersed around the edge of the Stewart-Snares shelf, over large areas of the Sub-Antarctic and Chatham Rise, and to a lesser extent around the North Island.

Juvenile fish (2–4 yrs) are found on the Chatham Rise in depths of 200 m to 600 m throughout the year.

Reproduction and life history Historically, the main spawning season for hoki has been from mid-July to late August on the west coast of the South Island. Spawning aggregations begin to concentrate in depths of 300–700 m around the Hokitika Canyon from late June, and further north off Westport later in the season. Another spawning site for hoki is in Cook Strait from late June to mid September, peaking in July and August. Other known spawning grounds include the Puysegur Bank, western Challenger Plateau, Pegasus Canyon, Conway Trough, and White Island. Throughout the rest of the year the adults are dispersed around the edge of the Stewart-Snares shelf, over large areas of the Sub-Antarctic and Chatham Rise, and to a lesser extent around the North Island. Juvenile fish (2–4 yrs) are found on the Chatham Rise in depths of 200 m to 600 m throughout the year.

Hoki spawn from late June to mid-September, releasing multiple batches of eggs. They have moderately high fecundity with an average sized female of 90 cm TL spawning over 1 million eggs in a season. Not all hoki within the adult size range spawn in a given year. Winter surveys in the early 1990s of both Chatham Rise and Sub-Antarctic have shown that not all mature hoki spawn every season, only 67% to 82% of large hoki aged 7 years and older spawn each year. A more recent study of female hoki from the Sub-Antarctic in November–December of 2002 to 2004 estimated that 77% of hoki age 4 and older had spawned in the previous season.

A study of the observed sex ratios of hoki in the two spawning and two non-spawning fisheries found that in all areas, the proportion of male hoki declines with age.

Growth is fairly rapid with juveniles reaching about 27–30 cm TL at the end of the first year. There is some variability in growth rates, but hoki reach about 40–45, 50–55 and 60–65 cm TL respectively in the following three years. Males appear to mature at 60–65 cm TL at 4–5 years, while females mature at 65– 70 cm TL. From the age of maturity the growth of males and females differs. Males grow up to about 115 cm TL, while females grow to a maximum of 130 cm TL and up to 7 kg weight. Fish from the eastern stock sampled in Cook Strait are smaller on average at all ages than fish from the WCSI.

Maximum age is from 20–25 years, and the instantaneous rate of natural mortality ( M) in adults is about 0.25 to 0.3 per year. There has been an increasing trend in size at age in data from both the trawl surveys and the commercial catch; length at age has increased by about 10% since 1983.

Habitat and ecology Throughout most of the year adult hoki are dispersed around the edge of the Stewart-Snares shelf, over large areas of the Sub-Antarctic and Chatham Rise, and to a lesser extent around the North Island. In the winter months hoki migrate to spawning grounds in Cook Strait, WCSI, Puysegur, and ECSI areas. Not all mature hoki spawn every season, only 67% to 82% of fish aged 7 years and older spawn annually.

Large adult fish are generally found beyond the shelf edge and are most abundant in water deeper than 400 m, while juveniles are more abundant in shallower water on the Chatham Rise throughout the year, moving into deeper water as the fish get larger. Hoki are midwater feeders, on planktonic crustaceans, mesopelagic fishes, squid, and salps.

Commercial catches Historically, the main fishery for hoki has operated from mid-July to late August on the west coast of the South Island (WCSI) where hoki aggregate to spawn. Since 1988, another major fishery has developed in Cook Strait, where separate spawning aggregations of hoki occur. Outside the spawning season, when hoki disperse to their feeding grounds, substantial fisheries have developed since the early 1990s on the Chatham Rise and in the Sub-Antarctic, operating in depths of 400–800 m. The Chatham Rise fishery generally has similar catches over all months except in July-September, when catches are lower due to the fishery moving to the spawning grounds. In the Sub-Antarctic, catches typically peak in April-June.

The hoki fishery was developed by Japanese and Soviet vessels in the early 1970s, peaking in 1977 when 100 000 t were caught before dropping to less than 20 000 t in 1978 when the EEZ was declared and quota limits were introduced. From 1979 on, the hoki catch increased to about 50 000 t until an increase in the TACC from 1986 to 1990 saw the fishery expand to a catch of about 255 000 t. Annual catches ranged between 175 000 and 215 000 t from 1988–89 to 1995–96, increasing to 246 000 t in 1996–97, and peaking at 269 000 t in 1997–98, when the TACC was over-caught by 19 000 t. Catches have since declined, and the TACC was reduced from 250 000 t to 200 000 t in the 2001–02 fishing year, then to 180 000 t in 2003–04, and further to 100 000 t in 2004–05.

The pattern of fishing has changed markedly since 1988–89 when over 90% of the total catch was taken in the WCSI spawning fishery. Landings from the WCSI declined steadily from 1988–89 to 1995–96, increased again to between 90 000 and 110 000 t from 1996–97 until 2001–02, then dropped over the last three years to 34 000 t in 2004–05. In Cook Strait, catches increased from 1988–89 to 1995–96, declined to a low of 22 000 t in 2001–02, peaked again at 41 000 t in 2003–04, before dropping to 25 000 t in 2004–05. Non-spawning catches on the Chatham Rise increased from 1993–94, peaked at over 70 000 t in 1997–98 and 1998–99, then decreased over the last five years to 30 500 t in 2004–05. Catches from the Sub-Antarctic peaked at over 30 000 t in 1999–2000 to 2001–02, and then declined to 6500 t in 2004–05. Catches from other areas have remained at relatively low levels, with 5500 t taken from Puysegur and 4000 t from the ECSI spawning fishery in 2004–05.

Recreational fishing for hoki is negligible. The level of Maori customary fishing is believed to be negligible.

Conservation and management Hoki is managed within the QMS, but also uses closed areas and vessel length limits in its management. Hoki is managed as only one Fishstock (HOK 1), although it is assessed and managed as two separate stock units, the west coast of the North and South Islands and the area south of New Zealand including Puysegur, Snares and the Southern Plateau has been taken as one stock unit (the "western stock"), and the area of the ECSI, Mernoo Bank, Chatham Rise, Cook Strait and the ECNI up to North Cape has been taken as the other stock unit (the "eastern stock").

Hoki occur in New Zealand, South Australia and South America. New Zealand hoki and Tasmanian hoki (blue grenadier) are the same species, Macruronus novaezelandiae, though genetically distinct. The South American hoki is currently described as a separate species, Macruronus magellanicus, but recent genetic studies have indicated that it is probably the same species as in New Zealand (P. Smith, NIWA, unpublished data). Morphometric and ageing studies have found consistent differences between adult hoki taken from the two main dispersed areas (Chatham Rise and Southern Plateau), and from the two main spawning grounds in Cook Strait and WCSI. These differences clearly demonstrate that there are two sub-populations of hoki. Whether or not they reflect genetic differences between the two sub- populations, or they are just the result of environmental differences between the Chatham Rise and Sub- Antarctic, is not known.

From 1999–00 to 2001–02, there was a redistribution in catch from ‘eastern stock’ areas to ‘western stock’ areas, initially because of industry initiatives to reduce the catch of small fish in the area of the Mernoo Bank, but from 2001–02 was part of an informal agreement with the Minister of Fisheries that 65% of the catch should be taken from the western fisheries to reduce pressure on the eastern stock. This agreement was removed following the 2003 hoki assessment which indicated that the eastern hoki stock was less depleted than the western stock and effort was shifted back into eastern areas, particularly Cook Strait. In 2004–05 and 2005–06 there was a further agreement with the Minister that only 40% of the catch should be taken from western fisheries. About 43% of the catch was taken from western areas in 2004–05.

Population trends Bmsy has not been defined for hoki; however, it is likely to be in the range 30–40% B0.

The hoki stock assessment was updated in 2006. Three final runs are reported for each stock. For the western stock, median estimates of current biomass are between 20 and 24 % B0. This stock experienced an extended period of poor recruitment from 1995 to 2001 but there is some evidence of improvement in more recent years. For the eastern stock, current biomass was estimated to be between 33 and 49 % B0. Recent recruitment is estimated to be close to the long term average. For both stocks, the model projections suggest that continued fishing at the current TACC (with the agreed 60:40 catch splits) is likely to be sustainable and to allow biomass to increase unless future recruitment is poor.

List of information sources Clark, M.R. (1985). Feeding relationships of seven fish species from the Campbell Plateau, New Zealand. New Zealand Journal of Marine and Freshwater Research 19(3 ):365–374. FishBase (2007). http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=1825 Accessed 30 January 2007. Horn, P.L.; Sullivan, K.J. (1996). Validated aging methodology using otoliths, and growth parameters for hoki ( Macruronus novaezelandiae ) in New Zealand waters. New Zealand Journal of Marine and Freshwater Research 30 : 161–174. Livingston, M.E. (1990). Spawning hoki ( Macruronus novaezelandiae Hector) concentrations in Cook Strait and off the east coast of the South Island, New Zealand, August-September 1987. New Zealand Journal of Marine and Freshwater Research 24 : 503-517. Livingston, M.E.; Schofield, K.A. (1996). Stock discrimination of hoki ( Macruronus novaezelandiae Merlucciidae) in New Zealand waters, using morphometrics. New Zealand Journal of Marine and Freshwater Research 30 : 197–208. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz. Accessed 30 January 2007. O’Driscoll, R.L.; Phillips, N.L.; Livingston, M.E.; Hicks, A.C.; Ballara, S.L. (2002). Catches, size, and age structure of the 2000–01 hoki fishery, and a summary of biological research for the 2002 stock assessment. New Zealand Fisheries Assessment Report 2002/39 . 70 p. Paul, L.J. (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p. Smith, P.J.; McVeagh, S.M.; Ede, A. (1996). Genetically isolated stocks of orange roughy ( Hoplostethus atlanticus ), but not of hoki ( Macruronus novaezelandiae ), in the Tasman sea and southwest Pacific ocean around New Zealand. Marine Biology 125: 783–793.

Order Gadiformes: Family Gadidae

Southern blue whiting Micromesistius australis (Norman, 1937)

Overview Southern blue whiting is found globally throughout the Southern Ocean, in New Zealand it is almost exclusively in subantarctic waters in 200–600 m depth, and are most abundant during winter on their spawning grounds, the Campbell Rise, Auckland Island rise, Pukaki Rise, and Bounty Plateau. Commercial catches peaked in 1992 with a catch in excess of 75 000 t. Catch limits are now in place limiting the catch of southern blue whiting to 35 650 t annually, landings for 2005–06 were 30 260 t.

Distribution Southern blue whiting is found around South America, New Zealand, and in the Bellingshausen Sea. They extend north from Cape Horn to about 46 °S off the coast of Chile and to about 37 ° S off the coast of Argentina, and east across the Patagonian shelf to the Falkland Islands. However, the Falkland Islands and New Zealand populations of Micromesistius australis are reproductively isolated conspecific populations, with Micromesistius australis australis found around the Falkland Islands and Argentine Patagonia, off Chile, South Georgia, South Shetland and South Orkney island’s and Micromesistius australis pallidus which occurs around the South Island of New Zealand. During summer Micromesistius australis australis migrate south and have been reported as far south as 60–65 ° S. They have also been caught in this area feeding on krill in surface waters over bottom depths exceeding 4 000 m. They have also been reported from the South Pacific mid-ocean ridge at about 130 °E and 55 °S. Within New Zealand southern blue whiting are found almost exclusively in subantarctic waters in 200–600 m depth, they occur on the Chatham Rise, Campbell Plateau, and Bounty Plateau, but are most abundant during winter on their spawning grounds, on the Campbell Rise, Auckland Island rise, Pukaki Rise, and Bounty Plateau. During the rest of the year the fish disperse for feeding, and may be found throughout the Southern Plateau. It is not known whether they occur on the Macquarie Ridge, or pelagically south of the Campbell Plateau and Bounty Plateau over deep water.

Reproduction and life history Four spawning areas have been identified for southern blue whiting, on the Bounty Platform, Pukaki Rise, Auckland Islands Shelf, and Campbell Island Rise. The Campbell Island Rise has two separate spawning grounds to the north and south. Fish appear to recruit first to the southern ground but thereafter spawn on the northern ground. Spawning on Bounty Platform begins in mid August and finishes by mid September. Spawning begins 3–4 weeks later on the Pukaki Rise and Auckland Islands Shelf, finishing in late September-early October. Southern blue whiting are highly synchronised batch spawners; spawning occurs at night, in midwater, over depths of 400–500 m on Campbell Island Rise but shallower elsewhere.

Young fish reach a length of about 20 cm FL after one year and 30 cm FL after two years, growth slows down after five years, and virtually ceases after ten years. Ages have been validated up to at least 15 years by following strong year classes, but ring counts from otoliths suggest individual fish may reach 25 years. In some years a small proportion of males mature at age 2, but the majority do not mature until age 3 or 4, usually at a length of 33–40 cm FL. The majority of females also mature at age 3 or 4 at a length of 35–42 cm FL.

Natural mortality ( M) was estimated using the equation loge(100)/maximum age, where maximum age is the age to which 1% of the population survives in an unexploited stock. Using a maximum age of 22 years, M was estimated to equal 0.21. The value of 0.2 is assumed to reflect the imprecision of this value. Recent Campbell Island stock assessments have estimated M within the model, using an informed prior with a mean of 0.2.

Habitat and ecology Southern blue whiting are almost entirely restricted to subantarctic waters, and comprise four distinct stocks, the Campbell Island Rise (SBW 6I), Bounty Platform (SBW 6B), Pukaki Rise (SBW 6R), and Auckland Islands Shelf (SBW 6A). For most of the year southern blue whiting are dispersed across the continental slope over much of the Campbell Plateau and Bounty Platform. However, in August and September fish aggregate in shelf waters to spawn on distinct spawning grounds on the Campbell Island Rise, Bounty Platform, Pukaki Rise, and Auckland Islands Shelf. Spawning appears to occur at night, in midwater, over depths of 400–500 m on Campbell Island Rise, but shallower elsewhere.

Adult southern blue whiting principally feed on amphipods, crustaceans, and euphausiids. The young feed on euphausiids and amphipods and occasionally on copepods, cephalopods and small fish.

Commercial catches The Southern blue whiting fishery was developed by Soviet vessels during the early 1970s when total landings exceeding 40 000 t. From 1978 to 1984, the entire Campbell Plateau was fished throughout the year, but highest catches were usually made in September on the Pukaki Rise and the northern Campbell Island Rise while the fish were spawning. As a result of the increase in hoki quota in 1985 and 1986, the Japanese surimi fleet increased its presence in New Zealand waters and some vessels stayed on after the hoki fishery to fish for Southern blue whiting. Since then many of the Soviet and Japanese vessels which fish for hoki on the west coast of the South Island during July and August each year move in mid to late August to the Southern blue whiting spawning grounds.

Between 1986 and 1989, fishing was confined to the spawning grounds on the northern Campbell Island Rise. From 1990 onwards, vessels also started fishing spawning aggregations on the Bounty Platform, the Pukaki Rise, and the southern Campbell Island Rise. Fishing effort increased markedly between 1990 and 1992, culminating in a peak catch of over 75 000 t in 1992. The increased catch came mainly from the Bounty Platform. In 1993, a fishery developed for the first time on the Auckland Islands spawning grounds and fishing has continued there at a low level sporadically since then. Because of the differences in timing of spawning on each ground, vessels typically start fishing on the Bounty Platform before moving on to the Campbell Island Rise, the Pukaki Rise, and the Auckland Islands Shelf.

A catch limit of 32 000 t for all areas was introduced for the 1992–93 fishing year (1993 season). This was increased to 58 000 t in 1997, lowered to 35 140 t in 2001, increased to 45 140 t in 2002, and lowered to 35 650 t for the last two fishing seasons. Annual landings since the peak of 76 000 t in the early 1990s have always been below the TACC, around 25 000 t during the mid 1990s, then two peak catches of 40 000 t in 1998 and 2002 seasons. The current catch is 30 200 t, 85% (26 200 t) of which has been taken from the Campbell Island Rise. The fleet has comprised mainly Japanese surimi vessels, and Russian, Ukrainian, and Polish “dressed-product” vessels.

There is no recreational fishery for southern blue whiting.

Quantitative estimates of the level of Maori customary take are not available.

Operators of one vessel have recently been convicted for area misreporting. However, the level of illegal and unreported catch is thought to be low.

Conservation and management Southern blue whiting are managed within the Quota Management System using four Southern Ocean Fisheries Management Areas (FMA), with commercial catch limits for each FMA.

Population trends The 2005 Campbell Island stock assessment was updated by including an additional year of proportion- at-age data. For the base case, B2005 was estimated to be 68 000 t (90% credible interval 46 000– 105 000 t), corresponding to 28% B0 (90% credible interval 19–41%). Estimates of B2005 were very sensitive to the choice of series of acoustic survey estimates but only slightly sensitive to the prior used for the adult acoustic q.

The Bounty Platform stock model indicates that the median estimate of B2003 is 30% of B0. At catches at the level of the current TACC (3500 t) the biomass is projected to increase slightly. Higher yields will only be available when there is good recruitment – which occurs only sporadically in this stock

Based on the flat trajectory of the abundance indices over the period modelled in the assessment, recent catch levels do not appear to have had any impact on the biomass of the Pukaki Rise stock. Greater catches would be required to provide any contrast in the abundance indices, and therefore enable better estimates of stock size. This stock has been only lightly exploited since 1993, and is likely to be above the level that will support the MAY.

No estimates of current biomass or yield are available for the Auckland Island stock. It is unknown if recent catches are sustainable or if they will allow the stock to move towards a size that will support the MSY. The only information available on stock size is from an acoustic survey in 1995.

List of information sources Clark, M.R. (1985). Feeding relationships of seven fish species from the Campbell Plateau, New Zealand. New Zealand Journal of Marine and Freshwater Research 19 : 365–374. FishBase (2007) http://www.fishbase.org/Summary/SpeciesSummary.php?id=320 Accessed 12 February 2007. Hanchet, S.M. (1991). Southern blue whiting fishery assessment for the 1991–92 fishing year. New Zealand Fisheries Assessment Research Document 91/7. 48 p. Hanchet, S.M.; Blackwell, R.G. (2005). Development and evaluation of catch-per-unit-effort indices for southern blue whiting ( Micromesistius australis ) on the Campbell Island Rise (1986–2002) and the Bounty Platform (1990–2002). New Zealand Fisheries Assessment Report 2005/55 . 60 p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 12 February 2007. PáJARO, M.; MACCHI, G.J. (2001). Spawning pattern, length at maturity, and fecundity of the southern blue whiting ( Micromesistius australis ) in the south-west Atlantic Ocean. New Zealand Journal of Marine and Freshwater Research 35(2) . 375–385. Ryan, A.W.; Smith, P.J.; Mork, J. (2002). Genetic differentiation between the New Zealand and Falkland Islands populations of southern blue whiting Micromesistius australis . New Zealand Journal of Marine and Freshwater Research 36(3 ): 637–643.

Order Ophidiiformes: Family Ophidiidae

Ling Genypterus blacodes (Forster, 1801)

Overview Ling are widely distributed throughout the Southern Oceans, from Brazil and Chile, South Australia, and New Zealand. Within New Zealand ling occur throughout the middle depths (200–800 m) of the New Zealand EEZ, particularly to the south of latitude 40° S. From the early 1990s total ling landings have increased, from 9000 t to a maximum of 23 000 t landed in 1997–98, since then landings have gradually declined to 17 000 t in 2004–05. The increased ling landings were caused by additional effort being put into the fishery from the addition of several larger domestic longliners fitted with autoline equipment.

Distribution Ling occur throughout the southern ocean; in the south Pacific, around New Zealand, southern Australia, and Chile, and the southwest Atlantic around Brazil.

Within New Zealand ling occur throughout the continental shelf waters from the Three Kings Islands to the southern edge of the Campbell Plateau, including the Challenger Plateau, Chatham Rise, and Bounty

Plateau. It is also present on the Kermadec Ridge. It occurs from shallow depths (~10 m) to at least 1200 m. Hotspots for ling occur further north during winter, off Cape Kidnappers, and further south during summer, with a hotspot occurring southeast of the Auckland islands.

Ling spawn in a number of localities throughout the EEZ. Time of spawning appears to vary between areas, July to November on the Chatham Rise, September to December on Campbell Plateau and Puysegur Bank, September to February on the Bounty Plateau, July to September off west coast South Island and in Cook Strait, with additional spawning sites known to occur off Northland, Cape Kidnappers, and in the Bay of Plenty.

Reproduction and life history Ling live to a maximum age of about 30 years, with females growing significantly faster and reaching a greater size than males. Growth rates are significantly different between areas, with ling growing fastest in Cook Strait and slowest on the Campbell Plateau.

M was estimated from the equation M = loge100/maximum age, where maximum age is the age to which 1% of the population survives in an unexploited stock. The mean M calculated from 5 samples of age data was 0.18 (range = 0.17–0.20). A likely minimum value of M = 0.15 was calculated using a maximum age of 30 years. Less than 0.2% of successfully aged ling have been older than 30 years. The oldest ling aged was from the Chatham Rise and was 46 years old.

Ling in spawning condition have been reported in a number of localities all around New Zealand. Time of spawning appears to vary between areas, on the Chatham Rise spawning occurs between July and November, on the Campbell Plateau and Puysegur Bank from September to December, on the Bounty Plateau from September to February, the west coast South Island from July to September, and in Cook Strait from June to September, in Northland from July to October, Northern Wairarapa from May to October, and in the Bay of Plenty from July to October.

Little is known about the distribution of juveniles until they are about 40 cm total length, when they begin to appear in trawl samples over most of the adult range.

Ling has a low resilience, with a minimum population doubling time of 4.5–14 years ( K=0.1–0.23; tmax =30).

Habitat and ecology Ling appear to be mainly bottom dwellers ranging from coastal waters close to deep reefs or canyons, down to 800 m over rough ground and open muddy seafloor. Ling can are found in midwater when feeding on hoki during the hoki spawning season, but mostly feed on fish such as hoki and conger eels, benthic crustaceans, and squid.

Juveniles seem to have a similar distribution to adults.

Commercial catches From 1975 to 1980 there was a substantial longline fishery on the Chatham Rise carried out by Japanese and Korean longliners. Since 1980 ling have been caught by large trawlers, both domestic and foreign owned, and by small domestic longliners and trawlers. In the early 1990s the domestic fleet was increased by the addition of several larger longliners fitted with autoline equipment, which caused a large increase in the catches of ling off the east and south of the South Island (LIN 3, 4, 5 and 6). Since about 2000, there has been a declining trend in catches taken by line vessels in most areas.

The principal fishing grounds for smaller domestic vessels are the west coast of the South Island (WCSI) and the east coast of both main islands south of East Cape. For the large trawlers the main sources of ling are Puysegur Bank and the slope of the Stewart-Snares shelf and waters in the Auckland Islands area. Longliners fish mainly in east and south coasts of South Island, Chatham Rise and Southern Ocean (LIN 3, 4, 5 and 6). Landings in 2004–05 were close to the TACCs in Fishstocks LIN 2 and LIN 5, above the

TACC in LIN 7, but under-caught in LIN 1, LIN 3, LIN 4, and LIN 6. The significant TACC overrun (13%) in LIN 7 continues a trend apparent since 1988–89.

In LIN 1 the TACC has been at 265 tonnes since 1989–90, landings in LIN 1 increased slowly, not passing the TACC until 1996–97. Since this time landings have oscillated above and below the unchanging TACC. In 2002–03 the TACC was increased from 265 t to 400 t under an AMP, and at the same time landings dropped to 250 t, where they have remained well under the TACC at less than 300 t. The LIN 2 TACC has only increased 72 t since 1986–87, from 910 t to 982 t. During this time landings have steadily increased to 1200 t during 1996–97, and from that time remained roughly within 100 t of the TACC, only slipping below it by 50 t in 2004–05.

The LIN 3 TACC and LIN 3 landings have matched each other, both slowly rising from the late 1980s to a maximum, under an AMP, during the late 1990s of almost 3 000 t. This was followed by a downward trend to 2004–05 where landings were 1600 t and the TACC was 2 100 t. Landings in LIN 4 were up and down between 4000 t and 5000 t during the 1990s, but have had a steady decline since 1997–98 to 2600 t in 2003–04, with a slight increase in landings for 2004–05. The TACC is now 1500 tonnes more than landings at 4200 t. Only once have landings been higher than the TACC in 1991–92, by 7%.

LIN 5 landings have been above the TACC for 7 years since the mid 1980s, and have oscillated between a 1991–92 high of 3800 t and a 1993–94 low of 2500 t. For the last ten years landings have remained roughly between 3000 t and 3500 t, with a TACC during that time remaining at 3 000 t. 2004–05 saw the LIN 5 TACC increase by 600 t along with landings, both are now at 3600 t. LIN 6 has had an oscillating increase in landings since mid 1980s with landings stabilising between 6000 and 7000 t for the six years of 1998–99 and 2003–04, landings dropped in 2004–05 to 5500 t at the same time the TACC was put up to 8500 t. Landings have surpassed the TACC for two years, in the late 1990s. The TACC for LIN 7 increased only slightly between the mid 1980s (2 000 t) and mid 1990s, where it reached 2225 t and remained unchanged for 10 years. Since the TACC was introduced landings have only been less than the TACC for 3 years, and only once in the last 16 years. Over the past decade landings reached a maximum of 3500 t in 2000–01 and have followed a downward trend since then to be 2500 t in 2004–05.

A 1993–94 Northern region recreational fishing survey estimated the annual recreational catch from LIN 1 as 10 000 fish (c.v. 23%) which equates to a recreational harvest between 15 t and 40 t. Recreational catch was recorded from LIN 1, 5, and 7 in the 1996 national diary survey, but the estimated harvests were too low to provide reliable estimates.

Quantitative information on the level of Maori customary take is not available. However, ling bones have been recovered from archaic middens throughout the South Island and southern North Island, and on Chatham Island. In South and Chatham Islands, ling comprised about 4% of recovered fish remains.

Conservation and management Ling are managed within the QMS in eight Fishstocks, although five of these (LIN 3, LIN 4, LIN 5, LIN 6, LIN 7) account for 95% of ling landings. Studies of morphometrics, genetics, growth, population age structures, and reproductive biology, and behavior have indicated that there are at least five ling stocks, west coast South Island, Chatham Rise, Cook Strait, Bounty Plateau, and the Southern Plateau (including the Stewart-Snares shelf and Puysegur Bank). Stock affinities of ling north of Cook Strait are unknown.

Many of the TACC increases since 1986–87 in all ling Fishstocks are the result of quota appeals.

Population trends In LIN 1 the current stock size is considered to be above Bmsy based on an analysis of CPUE from the longline fisheries. For LIN 2 it is not known if recent landings and the current TACC is sustainable in the long term, or is at a level which will allow the stock to move towards a size that will support the MSY. In 2004 the stock size was estimated to be above BMAY and building for LIN 3 and LIN 4. Catches at the level of the current TACC are likely to be sustainable.

Ling stocks (LIN 5 and LIN 6, but excluding fish on the Bounty Plateau) have not been updated since 2003. These Fishstocks are probably only lightly fished and current stock sizes are estimated to be well above BMAY . Estimates of absolute current and reference biomass are unreliable. It is likely that the current TACC is sustainable, as current catches do not appear to be having a measurable impact on biomass levels. The assessment is indicative of surplus ling production being available, at least in the short to medium term. The ling stock on the Bounty Plateau (part of the LIN 6 Fishstock) is estimated to be above BMAY. There is no separate TACC for this stock.

The current assessment does not include ling from the Cook Strait section of QMA 7. The status of the LIN 7WC stock was updated in 2006 and is highly uncertain. It is not known if recent landings are sustainable in the long term, or are at levels which will allow the stocks to move towards a size that will support the MSY. The stock assessment model results do not provide reliable estimates of current biomass as a percentage of B0. The relatively constant catch history since 1989 and the relatively flat CPUE indices suggest that future catches at the current level are probably sustainable, at least in the short term.

List of information sources FishBase (2007). http://www.fishbase.org/Summary/speciesSummary.php?ID=482&genusname=Genypterus&speciesn ame=blacodes Accessed 30 January 2007. Horn, P.L. (1993). Growth, age structure, and productivity of ling, Genypterus blacodes (Ophidiidae), in New Zealand waters. New Zealand Journal of Marine and Freshwater Research 27 : 385–397. Horn, P.L. (2005). A review of the stock structure of ling ( Genypterus blacodes ) in New Zealand waters. New Zealand Fisheries Assessment Report 2005/59 . 41 p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 30 January 2007. Paul, L.J. (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p. Smith, P.J.; Paulin, C.D. (2003). Genetic and morphological evidence for a single species of pink ling Genypterus blacodes (Forster) in New Zealand waters. New Zealand Journal of Marine and Freshwater Research 37 : 183–194.

Order Perciformes: Family Gempylidae

Barracouta Thyrsites atun (Euphrasen, 1791)

Overview Barracouta are widespread throughout New Zealand waters from the Three Kings Islands to the Auckland Islands and the Chatham Islands. This species is mostly caught in water down to 400 m. Barracouta are targeted during spring spawning, and summer feeding aggregations, and as bycatch comprise a significant proportion of the west coast North Island jack mackerel and The Snares squid fisheries. Commercial catches increased during the late 1960s to reach a peak of 47 000 t in 1977. Since the mid 1980s commercial catches have fluctuated between 18 000 and 28 000 t per annum, with an annual average about 24 000 t. Total landings for 2004–05 were 27 000 t, the highest for 7 years.

Distribution Barracouta occur in coastal and continental temperate waters of the Southern Hemisphere, including New Zealand, southern Australia, South Africa, and southern South America. In New Zealand, barracouta occur throughout mainland waters from the Three Kings Islands to the Auckland Islands, and around the Chatham Islands. The known depth range of barracouta is 0–670 m.

Barracouta aggregate during winter and spring for spawning, and during summer and autumn for feeding. Spring is the peak spawning period with high densities off Southland and the Chatham Islands. Summer hotspots in South Taranaki Bight, Canterbury Bight, on the Stewart–Snares shelf, and west of the Chatham Islands are likely feeding aggregations. Juvenile barracouta have been recorded from inshore areas (< 100 m) all around New Zealand and the Chatham Islands, although they appear to be less common on the west coast of the South Island.

Barracouta are migratory, and apart from aggregations at certain spawning areas, and feeding concentrations elsewhere, their movements remain largely unknown. Tagged barracouta have travelled considerable distances, up to 500 nautical miles to spawn.

Reproduction and life history Sexual maturity is reached at about 50–60 cm fork length (FL) at about 2–3 years of age. Spawning occurs from July to September on the east coast of the North Island and northern South Island in 100– 150 m, the west coast of the South Island in 350 m, and from October to December on the Chatham Islands and coastal Southland.

Juvenile barracouta have been recorded from inshore areas, in water less than 100 m, all around the mainland and Chatham Islands, although they appear to be less common on the west coast of the South Island. Nursery grounds are known in the Hauraki Gulf, Tasman Bay, and Canterbury Bight where schools of uniformly sized fish between 10 and 40 cm are found. Tagged barracouta have moved considerable distances to spawn (up to 500 nautical miles).

Ageing studies carried out in the mid 1970s showed that the maximum age rarely exceeded 10 years. Ages have been validated for fish up to 3 years old by following length frequency modes over time. M was estimated using the equation M = loge100/maximum age, where maximum age is the age to which 1% of the population survives in an unexploited stock. Using 10 years for the maximum age suggests an M of up to 0.46. The maximum size is recorded at 120 cm.

Barracouta have a medium resilience, with a minimum population doubling time 1.4– 4.4 years ( tm=2–4; tmax =10).

Habitat and ecology Adult barracouta have a wide depth range, from close inshore out to about the continental shelf edge at 200 m, and in some areas extending down the slope to 670 m. Water temperatures within the range of 13–18 °C are preferred, where they form schools or small groups on the bottom and in midwater, and sometimes at the surface, to feed on items such as pelagic crustaceans such as Munida gregaria & Nyctiphanes australis , cephalopods ( Nototodarus sloani ) and fishes.

Barracouta migrate to spawning and feeding areas where they aggregate, during winter and spring for spawning, and during summer and autumn for feeding.

Commercial catches Over 99% of the recorded catch is taken by trawlers. Major target fisheries have been developed on spring spawning aggregations (Chatham Islands, Stewart Island, west coast South Island and northern and central east coast South Island) as well as on summer feeding aggregations, particularly around The Snares and on the east coast of the South Island. Barracouta also comprise a significant proportion of the bycatch in the west coast North Island jack mackerel, the South Island east coast red cod fishery, and The Snares squid fisheries.

Catches increased significantly in the late 1960s and peaked at about 47 000 t in 1977. Since 1983–84, catches appear to have fluctuated between 18 000 and 28 000 t per annum (annual average about 24 000 t). Total landings in for 2004–05 were 26 919 t (the highest for 7 years), the TACC was 32 672 t. From 1994–95 to 1997–98 the catches exceeded the TACC in BAR 1; however, in the last 5 years catches have been well below the TACC of 11 000 t. Catches in BAR 4 have fluctuated at levels well

below the TACC but declined to only 98 t in 2004–05. In both BAR 5 and 7 the catch limits were exceeded in 2004–05.

A 1999–00 recreational survey estimated catches for the east coast stock (BAR 1) of 182–377 t (C.V. 35%), the southern stock (BAR 5) of 2–7 t (C.V. 51%), and for the northwest stock (BAR 7) the estimated recreational catch was 68–120 t (C.V. 28%)

Quantitative information on the current level of Maori customary take is not available.

Conservation and management Barracouta in New Zealand are managed in five separate Fisheries Management Areas, but the stock boundaries are not well understood. The Chatham Islands stock is probably separate, and it appears that there is considerable overlap of Southland fish with other areas, probably the west coast of the South Island and possibly the east coast as well. However, there is not enough data at this stage to alter the existing stock boundaries. If fish from the southern area stock (BAR 5) overlap significantly with other South Island stocks, then the MCYs for all Fishstocks on the South Island may need adjusting downward.

There are recreational fishing limits for barracouta around most of the South Island. In the Southern Region, including Fiordland, there is a maximum daily limit per person that is currently set at 30 barracouta.

Throughout New Zealand, barracouta stock structure has been assessed as recently as 2000, and biomass estimates have been made for barracouta recruits from inshore trawl surveys.

Barracouta are part of the shelf (30–300 m) mixed fishery and are usually the dominant species in these depths around the South Island. Any increase or decrease in barracouta quotas will have overflow effects onto bycatch species. The economics of targeting on barracouta is probably affected by its availability relative to other more preferred species and this will, in turn, affect fishing patterns.

Current estimates of yield are based on commercial landings data only, and have not changed since 1992.

Population trends In the last five years, catches have been below the estimated MCY in BAR 1, which suggests that the current catch levels are sustainable. However, it is not known if catches at the level of the current TACC (11 000 t) will allow the stock to move towards a size that will support the maximum sustainable yield.The most recent assessment was in 1992 and the best estimate of yield is 8050 t.

Catches in BAR 5 and 7 were above the TACCs in 2004–05. It is not known if current TACCs and recent catches in these areas are sustainable or whether they are at levels which will allow the stock to move towards a size that will support the maximum sustainable yield.

List of information sources FishBase (2007). http://www.fishbase.org/Summary/speciesSummary.php?ID=489& genusname=Thyrsites&speciesname= atun Accessed 24 January 2007. Harley, S.J.; Horn, P.L.; Hurst, R.J.; Bagley, N.W. (1999). Analysis of commercial catch and effort data and age determination and catch-at-age of barracouta in BAR 5. New Zealand Fisheries Assessment Research Document 1999/39. 39p. Hurst, R.J.; Bagley, N.W. (1989). Movements and possible stock relationships of the New Zealand barracouta, ( Thyrsites atun ), from tag returns. New Zealand Journal of Marine and Freshwater Research 23(1) : 105–111. Langley, A.D.; Walker, N.A. (2002). Characterisation of the barracouta ( Thyrsites atun ) fishery in BAR 1. New Zealand Fisheries Assessment Report 2002/44 . 37p.

Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 24 January 2007. Nakamura, I.; Parin, N.V. (1993). FAO species catalogue. Vol. 15. Snake mackerels and cutlassfishes of the world (families Gempylidae and Trichiuridae). An annotated and illustrated catalogue of the snake mackerels, snoeks, escolars, gemfishes, sackfishes, domine, oilfish, cutlassfishes, scabbardfishes, hairtails, and frostfishes known to date. FAO Fish. Synop. 125(15) . 136 p. O'Driscoll, R.L., (1998). Feeding and schooling behaviour of barracouta ( Thyrsites atun ) off Otago, New Zealand. Marine and Freshwater Research 49 :19–24. Paul, L.J. (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p.

Order Perciformes: Family Centrolophidae

Bluenose Hyperoglyphe antarctica (Carmichael, 1819)

Overview Bluenose are found throughout New Zealand’s EEZ in water from 100 m to 1000 m deep, most commonly off the north and east coasts of the North Island, the West Coast, and the Chatham Rise. Important domestic trawl fisheries occur off the Wairarapa Coast, where bluenose is a major bycatch in the alfonsino and gemfish target trawl fisheries. There is a substantial target line fishery for bluenose in the Bay of Plenty and off Northland. Fisheries for bluenose also exist north and east of East Cape and to the west of Cook Strait, where about half of the catch is taken by longline and the remainder with bottom trawl. There is a developing fishery for bluenose on the Chatham Rise using both trawl and line gear. About two thirds of bluenose landings from the South Islands East and South Coasts, and the Southern Ocean are taken as a bycatch of the hoki bottom trawl and ling longline fisheries.

Distribution Bluenose are widely distributed in temperate waters including New Zealand, southern Africa, the southern Indian Ocean, New Caledonia, and off southeast Australia. Bluenose are distributed throughout New Zealand’s EEZ near rough ground on the outer shelf and upper slope, from the Kermadec Ridge to the Campbell Rise, from the Challenger Plateau to the Chatham Rise and the southern Louisville Ridge. Bluenose are most commonly found off the north and east coasts of the North Island, the Chatham Rise, Karitane Canyon shelf, Puysegur Bank, and the west coast South Island. The known depth range is 100 m to 1 112 m. Juveniles are probably pelagic above the shelf edge.

Reproduction and life history Bluenose grow quickly for the first two years, to average sizes of 31 and 45 cm fork length (FL) in the first and second year, respectively. At around 47 cm (FL) juvenile fish recruit to a demersal lifestyle from a presumed pelagic one. Females grow faster than males, and fish first spawn at about 62 cm FL at age 4–5 years. Radiocarbon dating was used on bluenose otoliths, and showed that bluenose live to at least 25 years old.

Little is known about the reproductive biology of bluenose. Spawning probably begins in late summer and may span several months. In the East Cape region, bluenose probably spawn from January to April. No distinct spawning grounds are known.

It is likely that estimates of natural mortality are influenced both by size specific variation in vulnerability to fishing gear, and by age specific migration to areas that are not currently fished. A maximum age of 25 years in a lightly exploited population implies an estimate of 0.18 for natural mortality ( M), using the method of Hoenig (1983). However, the estimate of M=0.18 should be considered preliminary as work on bluenose age and growth is still progressing. F0.1 was estimated to equal 0.36 for BNS 2, assuming an M of 0.3.

Bluenose has a low resilience with a minimum population doubling time of 4.5 – 14 years ( K=0.03–0.3; tm=5–7; tmax =15).

Habitat and ecology Juvenile bluenose inhabit surface waters, sometimes in association with floating debris, and consume small planktonic and sedentary organisms. Adults are found over rough ground on the outer shelf and upper slope in water between 100 m and 1112 m deep. Australian reports note that adults feed primarily on the pelagic tunicate Pyrosoma atlantica which is found near the sea bed during the day but dispersed throughout the water column at night, suggesting midwater or above-bottom feeding. They also feed on squid, molluscs, crustaceans, and fish ranging from small lanternfish (Myctophidae) to large fish such as gemfish (Rexea solandri ).

A tagging survey from BNS 2 indicated that bluenose may be generally sedentary in the short term (6– 8 months), although age specific migration may occur.

Commercial catches Total annual bluenose landings were relatively constant at a level of about 1 400 t from 1984 to 1989–90, then rose to approximately 2300 t from 1992–93 to 1995–96. Total landings since 2002–03 have exceeded 3 000 t. Landings in BNS 1 have followed an increasing trend from when readings began in the early 1980s. Currently landings are between 900 t and 1000 t, and have been for the last 9 years. The BNS 2 TACC was increased from 900 t to 1050 t under an AMP in 2004–05. Bluenose landings have been above the TACC the past 14 years, averaging 1000 t.

The TACC for BNS 3, south and eastern South Island, Chatham’s and Sub-Antarctic, was increased under the adaptive management programme (AMP) from 175 t to 350 t for the 1992–93 fishing year. This TACC was exceeded from 1994–95 to 2000–01, leading to an increased TACC of 925 t implemented on 1 October 2001 within the provisions of the AMP. The rise in landings was caused by the development of a bottom trawl fishery targeting alfonsino (and bluenose in 2001–02) on the Chatham Rise, to an increase in bluenose bycatch in target ling line fishing near the Chatham Islands and to the development of a target dahn line fishery for bluenose in the south-western part of the South Island. Landings have shown an increasing trend since the 1980s when less than 100 t were landed annually, in 2004–05 850 t were landed.

The TACCs for BNS 7 and 8 were increased to 150 t and 100 t respectively for the 1994–95 fishing year under the adaptive management programme. Landings since this time have approached the new TACCs, in the late 1990s but have been considerably under-fished since that time. In 2004–05 landings in both fisheries were below 100 t

The annual recreational catch in the north of the North Island (BNS 1) was estimated, from face-to-face interviews in 1999–2000, to be 11 000 fish. No quantitative information on the level of Maori customary take is available.

Conservation and management Bluenose in New Zealand is managed in five separate Fisheries Management Areas, all of which have an annual TACC. Adaptive Management Plans have been used in some management areas.

Bluenose may be resilient to fishing pressure due to widespread distribution, occurrence in untrawlable areas, and juvenile pelagic life-style. However, the longevity and apparent sedentary nature of adults probably permits localised depletion.

Population trends The TACC for BNS 1 was increased from 705 t to 1000 t for the 1996–97 fishing year under the adaptive management programme. Commercial CPUE from 1998–90 to 2004–05 shows no trend, but owing to changes in marketing and gear, the standardised CPUE may be affected by factors other than bluenose abundance.

BNS 1 was believed to be above Bmsy when it was introduced into the AMP in 1996–97. Based on the size of the area currently fished in relation to the total area of BNS 1, the lack of a consistent trend in the standardised CPUE analysis and the fact that catches of 850 to 1050 t have been sustained for almost 10 years, BNS 1 is most likely above Bmsy . It cannot, however, be determined if the new TACC of 1000 t is sustainable or will allow the stock to move towards the size that will support the maximum sustainable yield.

Catch levels in BNS 2, between 919 t and 1288 t, have been sustained in this fishery since the early 1990s (under TACCs ranging from 833 to 873 t). The BNS 2 TACC was increased from 873 t to 1048 t under an AMP on 1 October 2004. It is not known if recent catch levels or the current TACC are sustainable or if they are at levels that will allow the stock to move towards the size that will support the maximum sustainable yield.

The TACC for BNS 3 was increased to 925 t for the 2001 –02 fishing year (plus an additional 250 t of ACE for two years) under the AMP. It is not known if recent catch levels or the current TACC are sustainable or if they are at levels that will allow the stock to move towards a size that will support the maximum sustainable yield. However, as BNS 3 is a large area and some FMAs (for example the Chatham Rise) have been lightly fished; the increased TACC, if appropriately apportioned across areas, is likely to be sustainable.

The TACC for BNS 7 was increased from 97 t to 150 t under the AMP. Recent catch levels and the current TACC are having no apparent effect on stock size and are probably sustainable in the short-term. The stock is likely to be above Bmsy and may be near its virgin size. It is not known if recent catch levels or the current TACC are at levels that will allow the stock to move towards a size that will support the maximum sustainable yield.

The TACC for BNS 8 was increased from 22 t to 100 t under the AMP. Recent catch levels and the current TACC are having no apparent effect on stock size and are probably sustainable in the short-term. The stock is likely to be above Bmsy and may be near its virgin size. It is not known if recent catch levels or the current TACC are at levels that will allow the stock to move towards a size that will support the maximum sustainable yield.

List of information sources Boyd, R.O., Reilly, J.L. (2005). 1999/2000 national marine recreational fishing survey: harvest estimates. Draft New Zealand Fisheries Assessment Report. FishBase (2007). http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=496 Accessed 24 January 2007. Hoenig, J.M. (1983). Empirical use of longevity data to estimate mortality rates. Fisheries Bulletin 81 : 899–903. Kailola, P.J.; Williams, M.J.; Stewart, P.C.; Reichelt, R.E.; McNee, A.; Grieve, C. (1993). Australian fisheries resources. Bureau of Resource Sciences, Canberra, Australia. 422 p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz Accessed 24 January 2007. Paul, L.J., (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p. Paul, L.J.; Sparks, R.J.; Neil, H.J.; Horn, P.L. (2004). Maximum ages for bluenose ( Hypoglyphe antarctica ) and rubyfish ( Plagiogeneion rubiginosum ) determined by the bomb chronometer method of radiocarbon ageing, and comments on the inferred life history of these species. Final Research Report for Ministry of Fisheries Project INS2000/02.

Order Perciformes: Family Centrolophidae

Silver warehou Seriolella punctata (Forster, 1801)

Overview Silver warehou is a schooling species, aggregating to both feed, and spawn which happens in late winter- spring-early summer. Silver warehou are found in water 50–1000 m deep, but are more common between 200 m and 800 m. In recent years, most of the silver warehou catch has been taken as a by-catch of the hoki, squid, barracouta and jack mackerel trawl fisheries. Commercial landings of silver warehou over the last three years have been around 10 000 t, with a TACC of 10 400 t

Distribution Silver warehou occurs in New Zealand, southern Australia and southern South America. In New Zealand silver warehou occur between 50–1000 m, but are more common in depths of 200–800 m in waters associated with the Subtropical Front around the South Island and the Chatham Rise. The majority of the commercial catch is taken from the Chatham Rise, Canterbury Bight, southeast of Stewart Island and the west coast of the South Island.

Silver warehou aggregate to spawn from September to December along the edge of the Stewart and Snares Island shelf, the west coast of the South Island, and the western end of Chatham Rise. However they will form dense feeding aggregations at other times of year.

The winter distribution of silver warehou has hotspots on the west coast spawning grounds, at Mernoo Gap, and the gap at Puysegur Bank. During spring additional hotspots occur at Canterbury Bight, the southern and eastern edges of the Stewart-Snares shelf to spawn, and still some silver warehou remaining from the late winter spawning on the west coast. The summer distribution of silver warehou is similar to spring, except that fewer fish occur off the west coast spawning grounds, more are found on the southern Campbell Plateau, and less at the Mernoo Gap. The autumn distribution of silver warehou has hotspots at Mernoo and Canterbury Bight and along the south and east edges of the Stewart-Snares shelf. Fewer fish are caught around the North Island during summer.

Juvenile silver warehou inhabit shallow water at depths of 150–200 m and remain apart from sexually mature fish. Juveniles have been caught in Tasman Bay, on the east coast of the South Island, and around the Chatham Islands.

Reproduction and life history Spawning occurs on the Chatham Rise (Mernoo), east coast North Island, Stewart-Snares shelf, and west coast South Island in late winter, and at the Chatham Islands in late spring-early summer. It is uncertain whether the same stock migrates from one area to another, spawning whenever conditions are appropriate, or if there are several separate stocks.

Silver warehou is a schooling species, aggregating to both feed and spawn. During spring-summer, both adult and juvenile silver warehou migrate to feed along the continental slope off the east and southeast coast of the South Island.

Late-stage silver warehou eggs and larvae have been identified in plankton samples. Juvenile silver warehou inhabit shallow water, and remain apart from sexually mature fish.

Silver warehou reach a length of about 17–23 cm fork length (FL) at 0.5 years, 25–35 cm (FL) at 1.5 years, 35–42 cm (FL) at 2.5 years, and 43–47 after 3.5 years. Silver warehou reach sexual maturity at 4– 6 years. Initial growth is rapid and fish reach sexual maturity at around 45 cm fork length in 4 years. Maximum age is 23 years for females and 19 years for males. An estimate of instantaneous natural mortality ( M) was derived by using the equation M = log e100/ Amax , where Amax is the age reached by 1% of the virgin population. From their study, Amax of 19 years for female silver warehou and 17 years for

males produced estimates of M of 0.24 and 0.27 respectively. Whilst M is likely to fall within the range 0.2–0.3, 0.25 is probably a satisfactory estimate at this stage.

Silver warehou have a medium resilience, with a minimum population doubling time of 1.4 – 4.4 years (K=0.36; tm=3-4; tmax =15).

Habitat and ecology Silver warehou are present around most of New Zealand, but are more abundant around the South Island where they are found on the shelf edge and upper slope in water 200–800 m deep. Juveniles are found all around New Zealand throughout the year in water from 0–200 m; as the fish get larger they move into the deeper water along the shelf edge.

Silver warehou feed mainly on planktonic jellyfish.

Commercial catches The estimated catches of silver warehou before the declaration of the EEZ were particularly high, 13 000 t for the years 1976, 1977 and 1978, which led to concern about overfishing, so an initial TAC of 18 000 t set in 1979–80 was halved.

In recent years, most of the silver warehou catch has been taken as a by-catch of the hoki, squid, barracouta and jack mackerel trawl fisheries. Catches from the North Island and west coast of the South Island (SWA 1) have increased substantially since 1985–86 following the development of the west coast South Island hoki fishery. Overruns of the TAC are probably partly related to the hoki fleet fishing in relatively shallow water (northern grounds) in the later part of the season, but could also reflect changes in abundance. Some target fishing for silver warehou does still occur, predominantly on the Mernoo Bank and along the Stewart-Snares shelf.

In SWA 1 landings have followed a rapid increase one year followed by a substantial decrease the next year, oscillating above and below the TACC, with peaks reaching 3 000 t and troughs at 1000 t to 1200t from the late 1980s onwards. In the last three years landings have remained below the TACC varying only 500 t between 1 000 t and 1 500 t.

In SWA 3 landings were below the TACC for 9 out of 10 years from the mid 1980s to 1996–97. Since that time landings have oscillated above and below the TACC with average landings of 3500 t and a TACC unchanged at 3300 t.

SWA 4 landings peaked in 1984–85 at 4500 t, only to decrease the next year to 2700 t, where landings remained around 3000 t until another peak on 1996–97 of 5300 t, with in annual landings to 4000 t the next year. Landings increased steady from the late 1990s to a peak of 5500 t in 2003–04, after which landings dropped to 4300 t in 2004–05, still 200 t above the unchanged TACC.

There are no current recreational fisheries for silver warehou, and quantitative information on the current level of Maori customary take is not available.

Conservation and management Silver warehou is managed within the QMS using 3 Fishstocks, and tools such as TACCs, and Adaptive Management Programmes (AMPs).

In recent years, most of the silver warehou catch has been taken as by-catch of the hoki, squid, barracouta and jack mackerel trawl fisheries. Although targeting of silver warehou still takes place.

Population trends There are no new data that would alter the yield estimates given in the 1997, No estimates of reference current absolute biomass are available, a 1991 biomass assessment was uncertain. Landings of silver warehou have declined since 1996–97, when the landings were the highest ever reported. Annual catches of silver warehou are largely dependent on the main target fisheries within each area. The annual

distribution of fishing effort has been variable, and no conclusions regarding the level of exploitation can be made from the catch histories. The sustainability of current TACCs and recent catch levels for all Fishstocks is not known, and it is not known if they will allow the stocks to move towards a size that will support the maximum sustainable yield.

List of information sources FishBase (2007). http://fishbase.org/Summary/SpeciesSummary.php?id=12922 Accessed 09 February 2007 Horn, P.H.; Bagley, N.W.; Sutton, C.P. (2001). Stock structure of silver warehou ( Seriolella punctata ) in New Zealand waters, based on growth and reproductive data. New Zealand Fisheries Assessment Report 2001/13 . 29 p. Horn, P.H.; Sutton, C.P. (1995). An ageing methodology, and growth parameters for silver warehou (Seriolella punctata ) from off the southeast coast of the South Island, New Zealand. N.Z. Fisheries Assessment Research Document 95/15. 16 p. Livingston, M.E. (1988). Silver warehou. New Zealand Fisheries Assessment Research Document 88/36. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock Assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 30 January 2007. Paul, L.J., (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p.

Order Perciformes: Family Odacidae

Butterfish Odax pullus (Forster, 1801)

Overview Butterfish are endemic to New Zealand and occur around most of the coastline, as well as the Chatham, Snares, Bounty and Antipodes Islands. Butterfish are targeted with commercial setnets in shallow coastal waters principally around kelp-beds. The main fishery is centred on Cook Strait, between Tasman Bay, Castlepoint, and Kaikoura. There is also a smaller fishery around Stewart Island. Butterfish are also popular with recreational fishers, and are taken mainly by setnet and spear. 35% of the TAC is for recreational fishers (184 t), 35% for Maori customary fishing (184 t) and 30% for commercial fishers (162 t).

Distribution Butterfish are endemic to New Zealand. They do not occur at Tasman Sea islands, and are replaced at the Three Kings Islands by the related species Odax cyanoallix. They occur around most of the New Zealand coast from North Cape to the Snares Islands, and at the Chatham Islands. Their presence on the high energy mid-Westland coastline is probable but not confirmed, and they might be present in small numbers at isolated rocky coast localities along the west Auckland and west Northland coast, where the habitat is predominantly sandy shores. The main depth range of butterfish is 0–20 m; they occur shallower, to 10 m in the north, 20 m in Cook Strait, and in southern waters they can be found as deep as 40 m.

Reproduction and life history Adult butterfish average 30–50 cm in length, maximum size is approximately 70 cm. Unvalidated ageing research suggests that butterfish grow moderately fast, and the maximum recorded age is 11 years, though longevity is likely to be older, possibly 15 years. The most likely range of natural mortality ( M) is 0.30 to 0.45.

Some butterfish undergo sex reversal at about 40 cm; an estimated 50% of mature females transform into males. The depth distribution of butterfish differs by size and sex. Juveniles (to 30 cm) occur in the shallow weed beds, and (outside the breeding season) males occur in deeper waters than females.

Consequently, sex ratios vary with locality, but females often outnumber males. The spawning season extends from July to March in Cook Strait, peaking in September-October. The spawning season in southern New Zealand appears to be shorter, likely August to January, peaking in October-January. Postlarvae quickly settle out from the plankton.

Butterfish have a low resilience, with a minimum population doubling time of 4.5 – 14 years ( tmax =11; K=0.23)

Habitat and ecology Butterfish are almost exclusively herbivorous, feeding on several of the larger seaweeds. The diet of butterfish varies regionally, largely determined by the species composition of the local seaweed beds. Gut fullness is lowest in winter. Feeding activity is greatest early in the day, and the tidal state controls the accessibility of intertidal seaweeds.

The main depth range of butterfish is 0–20 m; they occur shallower, to 10 m in the north, 20 m in Cook Strait, and in southern waters they can be found as deep as 40 m. Larval and early juvenile butterfish inhabit the shallowest and most turbulent areas of kelp beds, presumably where there are lower levels of predation, and move into deeper parts of the weed beds as they grow larger.

Commercial catches From 1982 −83 to 2000 −01 total reported landings of butterfish ranged between 105 t and 193 t. Butterfish was introduced into the QMS in 2001–02, since this time the TACC has remained at 162 t, and total reported landings have oscillated between 121 t and 129 t.

Butterfish is targeted by setnets in shallow coastal waters principally around kelp-beds. The main fishery is centred on Cook Strait, between Tasman Bay, Castlepoint, and Kaikoura. There is also a smaller fishery around Stewart Island. A setnet mesh size of 108 mm and a minimum fish size of 35 cm applies to commercial and recreational fishers; additional regional netting restrictions may also apply. There is also a competitive quota of 30 t in FMA 5 (Southland).

Butterfish is popular with recreational fishers, and taken mainly by setnet and spear. Recreational daily bag limits were set at 30 fish in 1986, but subsequently reduced to 20 for Northern, Central and Challenger (1995), and 15 for South (1993). A national face-to-face recreational survey in 1999–2000 had very high c.v.’s but still showed that recreational catches of butterfish are highest on the South Islands east coast, between 27 and 76 t (c.v. 47%), followed by the North Island south-east coast at 16– 36 t (c.v. 39%), and the south of the South Island with 11– 27 t (c.v. 42%).

There is no quantitative information on the current level of Maori customary take.

Conservation and management Butterfish was introduced into the QMS in 2002–03 and is managed with TAC’s, competitive quotas, minimum mesh sizes, and recreational controls such as minimum fish sizes, and catch limits.

There is no clear information on whether biologically distinct stocks occur, although there is some evidence of regional variation in meristic characters which suggests some separation of populations. There is no information on movement or migration along the coastline within a weed-bed habitat. Butterfish populations at offshore islands (Chatham, Antipodes, Bounties, and Snares), have not been studied but may be distinct from the mainland population(s) simply because of their isolation.

Population trends Landings from this fishery have been reasonably stable for the last 15 years and appear to be sustainable, but measures of effort are not available. It is not known whether recent catch levels will allow the stock to move towards a size that will support the maximum sustainable yield. Butterfish populations are almost certainly susceptible to localised depletion.

List of information sources Boyd, R.O., Reilly, J.L. (2005). 1999/2000 national marine recreational fishing survey: harvest estimates. Draft New Zealand Fisheries Assessment Report FishBase (2007). http://www.fishbase.org/Summary/speciesSummary.php?ID=12838&genus name=Odax&speciesname=cyanoallix Accessed 26 January 2007. Francis, M.P. (1996). Geographic distribution of marine reef fishes in the New Zealand region. New Zealand Journal of Marine and Freshwater Research 30 : 35–55. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 24 January 2007. Paul, L.J. (2000). New Zealand Fishes. Identification, natural history and fisheries. Reed Books, Auckland. 253 p. Paul, L. J., Ó Maolagáin, C., Francis, M. P., Dunn, A., Francis, R. I. C. C. (2000). Age, growth, mortality, and yield per recruit for butterfish ( Odax pullus ) in Cook Strait, New Zealand. New Zealand Fisheries Assessment Report 2000/6. 30 p.

Order Perciformes: Family Gempylidae

Gemfish Rexea solandri (Cuvier, 1832)

Overview Gemfish occur throughout mainland New Zealand’s continental shelf and slope at depths down to 1100 m. Most gemfish are caught by trawl nets in water down to 550 m off the west coast of both North and South Islands. Gemfish aggregate on the outer shelf during spawning and post-spawning migrations, which results in a more northern distribution for the northern stock in autumn–winter, and a more northern distribution for the southern stock in winter–early spring. These aggregations disappear in summer.

Distribution Gemfish occur in southern Australia and New Zealand. In New Zealand they occur throughout mainland waters from the Three Kings Islands to the southern edge of the Snares shelf. There are also a few verified records from Wanganella Bank, the northern Challenger Plateau, the Chatham Islands, and the Auckland Islands. Hotspots for this species occur around the north and east coasts of the North Island, north-west of the South Island, off Banks Peninsula and the Snares shelf. The known depth range for gemfish is 0–1100 m.

Gemfish spawning occurs near North Cape around July, and on the west coast of the South Island in late August/September.

Reproduction and life history Gemfish occur on the continental shelf and slope, and probably undertake spawning migrations and pre- spawning runs. Peak spawning probably takes place in June/July near North Cape and late August/September on the west coast of the South Island.

Ageing of southern gemfish indicate that fish attain about 30 cm at the end of the first year, 45 cm at the end of the second year, 53 cm at the end of the third year, and 63 cm at the end of the fourth year. Both sexes display similar growth rates until age 5 when females grow larger. The maximum ages recorded for gemfish between 1989 and 1994 are 17 years for both sexes. In the northern fishery (SKI 1, SKI 2), males and females appear to recruit into the fishery from age 3 but are probably not fully recruited until about age 5 for the south-east coast North Island (SKI 2), and age 7 or 8 for the north of North Island (SKI 1). In the southern fishery gemfish start to recruit into spawning and non-spawning fisheries at age 2, however, age at full recruitment was difficult to determine.

Recruitment variability in the southern stock (SKI 3, SKI 7) has been correlated to wind and sea surface temperature patterns during the spawning season. No significant correlations were found between SKI 1 and SKI 2 recruitment indices and a range of ocean climate variables.

M = 0.25 y-1 is considered the best estimate for all areas for both sexes.

Gemfish have a low resilience, with a minimum population doubling time of 4.5–14 years ( K=0.15–0.21; tm=3–6; tmax =16; Fec =500 000).

Habitat and ecology Gemfish aggregate on the outer shelf during spawning and post-spawning migrations, this results in the northern stock having a more northern distribution (east and west coast of North Island) in autumn– winter, and the southern stock having a more northern distribution (west coast South Island) in late autumn to early spring. These aggregations disappear in summer and fish are more abundant off Southland and off the east coast of the South Island and southern North Island.

Gemfish are normally caught close to the sea bed but move into midwater at times where they feed primarily on fish, squid, and crustaceans; the juveniles are pelagic.

Commercial catches Gemfish are caught in coastal waters around mainland New Zealand down to about 550 m. Most of the recorded catch is taken by trawlers. Target fisheries have continued off the eastern and northern coasts of the North Island. There has also been a major shift in effort from east of North Cape to the west, and over 50% of the SKI 1 catch is now taken from the west coast of the northern North Island. Catches off the west and southern coasts of the South Island are primarily bycatch of hoki and squid target fisheries. Annual landings increased significantly in the early 1980s and peaked at over 8 000 t in 1985–86. In the late 1980s annual landings generally ranged from about 4 200 to 4 800 t per annum, but since then have steadily declined, with landings of less than 1 100 t reported in the last five years. TACCs were reduced for the southern stock (SKI 3, SKI 7) for the 1996–97 fishing year and have been progressively reduced for the northern stock (SKI 1, SKI 2) since 1997–98.

In SKI 1 landings rose to a broad peak around 1 100 t during the late 1980s and early 1990s, then followed a downward trend to 200 t in 2000–01 where landings have remained for the past 3 years.

In SKI 2 landings rose to a broad peak around 1 100 t during the late 1980s and early 1990s, then followed a downward trend to 300 t in 2000–01 where landings have remained for the past 4 years.

Landings in SKI 3 in 1985–86 were 4–5 times larger than the other areas, reaching a peak of 5500 t, only to drop to 2000 t the next fishing year, and then continue a steady decline to 50 t in 1995–96. Landings have remained under 100 t for 8 of the last 9 years.

Landings in SKI 7 have declined from a high of 1 700 t in the early 1980s to around 100 t during the mid to late 1990s and have begun to increase steadily from 250 t in 2002–03 to 600 t in 2004–05.

There was no recreational catch reported in marine recreational fishing catch and effort surveys of the South and Central regions during the early 1990s, however, there is a target recreational fishery in the Bay of Plenty.

Quantitative information on the current level of Maori customary take is not available and assumed negligible.

Conservation and management Gemfish are managed within the QMS in four fisheries management areas using TACs. A northern population is managed in SKI 1 and SKI 2, and a southern population managed in SKI 3 and SKI 7.

Weak year classes in SKI 3 and SKI 7 appear to be correlated with cold meteorological anomalies and El Nino events between 1989 and 1994, which may be responsible for the weak recruitment observed. In Australia, the eastern gemfish stock has been subjected to a prolonged period of poor recruitment which started in 1989, this event resulted in a very significant decline in the gemfish resource, and efforts are now being channelled towards the recovery of the fishery.

Population trends The assessment of the southern gemfish stock has not been updated since 2003. Virgin and current biomass for the northern gemfish stock were estimated assuming one stock (SKI 1, SKI 2). Year class strengths from 1989 to 1997 appear to have been low, except for one strong cohort in 1991. Under the assumption that the commercial CPUE data are relative abundance indices, the base case model results suggest that the stock is at about 23% of virgin biomass, which is less than BMAY . Projections at current catch levels suggest the stock may increase with average recruitment (1978 to 1997 period) but is likely to decline if recruitment remains at the levels seen in more recent years (1992 to 1997 period).

The assessment of the southern gemfish stock has not been updated since 1997. Landings from SKI 7 have increased in recent years and were over twice the TACC in 2004–05. Reported catches in SKI 3 & 7 have increased in the last year with SKI 7 now at 90% of the TACC. It is not known if recent catches and the current TACC are sustainable or whether they will allow the stock to move towards the size that will support the MSY.

List of information sources FishBase (2007). http://64.95.130.5/Summary/SpeciesSummary.php?id=8490 Accessed 29 January 2007. Horn, P.L.; Hurst, R.J. (1999). Stock structure and age of gemfish (Rexea solandri ) in New Zealand waters. Marine and Freshwater Research 50: 103115. Hurst, R.J.; Bagley, N.W. (1998). A summary of the biology and commercial landings, and a stock assessment of southern (SKI 3 and SKI 7) gemfish Rexea solandri (Gempylidae) in New Zealand waters. New Zealand Fisheries Assessment Research Document 98/3. 51 p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz Accessed 29 January 2007. Nakamura, I.; Parin, N.V. (1993). FAO species catalogue. Vol. 15. Snake mackerels and cutlassfishes of the world (families Gempylidae and Trichiuridae). An annotated and illustrated catalogue of the snake mackerels, snoeks, escolars, gemfishes, sackfishes, domine, oilfish, cutlassfishes, scabbardfishes, hairtails, and frostfishes known to date. FAO Fish. Synop. 125(15). 136 p. Paul, L.J., (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p. Renwick, J.A.; Hurst, R.J.; Kidson, J.W. (1998). Climatic influences on the recruitment of southern gemfish (Rexea solandri , Gempylidae) in New Zealand waters. International Journal of Climatology 18(15) : 1655–1667.

Order Perciformes: Family Sparidae

Snapper Pagrus auratus (Bloch & Schneider, 1801)

Overview Snapper are possibly New Zealand’s most popular marine fish. Found throughout the New Zealand region in waters from 0 m to 280 m, snapper are most abundant around the North Island and the northern South Island in waters 15 m to 60 m. Snapper first reach maturity at 3–4 years of age, may live up to 60 years, and have a very low rate of natural mortality ( M = 0.075 yr -1). The commercial fishery reached a peak of 18 000 t in 1978 as the fishery expanded with increased catches by pair trawl and Danish seine. Total snapper landings during 2004–05 were 6900 t, slightly above a TACC of 6500 t.

Distribution Snapper are found in New Zealand, Australia, and the islands and reefs of the northern Tasman Sea. A closely-related sub-species, red sea bream, occurs in the western and north-western Pacific Ocean, in the Philippines, Indonesia, China, Taiwan, and Japan. In the New Zealand region, snapper occurs at Lord Howe and Norfolk islands and throughout mainland New Zealand waters from the Three Kings Islands to Otago, and at the Chatham Islands. They are most abundant around North Island and the northern South Island. They are only occasionally found south of Banks Peninsula, although stragglers may extend as far south as Southland and Stewart Island (a diary survey of recreational fishers reported snapper from Southland/South Otago). Snapper have not been reported from the Kermadec Islands, but may occur there given the islands’ similar latitude and habitat to Norfolk Island. The known depth range of snapper is 0–280 m.

Snapper are not known to make significant seasonal migrations; however records from around southern South Island and the west coast South Island occur mainly during summer–autumn, suggesting that a small part of the population drifts south as the water temperature rises. The southern limits of the snapper population probably extend further south in summer–autumn than in winter–spring, but there are insufficient data to adequately describe their seasonal locations.

Reproduction and life history Snapper are demersal fish found down to depths of about 200 m, but are most abundant in 15–60 m. They are the dominant fish in northern inshore communities and occupy a wide range of habitats, including rocky reefs and areas of sand and mud bottom. They are widely distributed in the warmer waters of New Zealand.

Snapper are serial spawners, releasing many batches of eggs over an extended season during spring and summer. The larvae have a relatively short planktonic phase which results in the spawning grounds corresponding fairly closely with the nursery grounds of young snapper. Young fish school in shallow water and sheltered areas and move out to deeper water in winter. The fish disperse more widely as they grow older. They first reach maturity from 20 to 28 cm fork length at 3–4 years of age. Large schools of snapper congregate before spawning and move on to the spawning grounds, usually in November- December. The spawning season may extend to January-March in some areas and years before the fish disperse, often inshore to feeding grounds. The winter grounds are thought to be in deeper waters where the fish are more widespread.

Water temperature appears to play an important part in the success of recruitment. Generally strong year classes in the population correspond to warm years, weak year classes correspond to cold years.

Growth rate varies geographically and from year to year. Snapper from Tasman Bay/Golden Bay and the west coast of the North Island grow faster and reach a larger average size than elsewhere. Snapper have a strong seasonal growth pattern, with rapid growth from November to May, and then a slowing down or cessation of growth from June to September. They may live up to 60 years or more and have very low rates of natural mortality. An estimate of M = 0.06 yr -1 was made from catch curves of commercial

catches from the west coast North Island pair trawl fishery in the mid-1970s. These data were re- analysed in 1997 and the resulting estimate of 0.075 yr -1 has been used in the base case assessments for SNA 1, 2, and 7 (and SNA 8 up to 2004).

Snapper have a low resilience with a minimum population doubling time of 4.5 – 14 years ( tmax =11).

Habitat and ecology Adult snapper occur in water out to 200 m depth during winter, although they are most common in less than 100 m. Snapper follow an inshore offshore local migration pattern, moving into deeper offshore waters in winter and returning to shallow coastal waters for summer. Although individual fish have recorded some long-distance movements, tagging studies show that generally movement is localised.

Juvenile occur over large areas from 5 m to 50 m depth in the Hauraki Gulf, in shallow bays and estuaries along the north-east coastline, and in or near north-western harbours, and with less regularity further south. Snapper eat a wide range of foods, juveniles feed on small invertebrates and fishes, adults feed on what is most plentiful locally or seasonally, including salps, echinoderms, crustaceans and molluscs.

Commercial catches The snapper fishery is one of the largest and most valuable coastal fisheries in New Zealand. The commercial fishery, which developed last century, expanded in the 1970s with increased catches by pair trawl and Danish seine, with landings reaching a peak of 18 000 t in 1978. In the 1980s an increasing proportion of the SNA 1 catch was taken by longlining as the Japanese "iki jime" market was developed. By the mid 1980s catches had declined to 8500 t–9000 t, and some stocks showed signs of overfishing. The fisheries had become more dependent on the recruiting year classes as stock size decreased. With the introduction of the QMS in 1986, TACCs in all Fishstocks were set at levels intended to allow for some stock rebuilding.

Since records began SNA 1 has had the highest landings, the highest were in the 1970s with two annual peaks in excess of 10 000 t, this was due to an expansion of the SNA 1 fishery with the introduction of Danish seine and pair trawling leading to increased ladings. Landings have steadily decreased, and from 1986–87 have matched any changes in TACC. The most recent 7 years have seen landings and the TACC stable at 4500 t.

SNA 8 has the next highest snapper landings after SNA 1. Landings in SNA 8 over the past 12 years have been stable around 1600 t, slightly above the TACC which has remained at 1500 t for the same period.

Snapper landings in SNA 2 reached 800 t during the late 1960s and early 1970s but since then have remained below 500 t, with an average of 330 t landed annually over the past 15 years. During this time the TACC has risen from 150 t, to 250 t, to 315 t; the bycatch of snapper in the tarakihi, gurnard and other fisheries has resulted in snapper landings being above the TACCs since 1986–87.

There have been three peaks in snapper landings in SNA 7, during the late 1950s of over 1000 t, then over 1500 t in the 1960s and 2700 t in the late 1970s. Landings for the last 14 years have been relatively stable around 150 t –200 t, and in 2004–05 were below the TACC of 200 t.

There has been very little snapper landed from SNA 3.

The snapper fishery is the largest recreational fishery in New Zealand; it is the major target species on both coasts of the North Island. In SNA 1 there is a non-commercial allowance (recreational and customary) of 2600 t, in SNA 8 there is an annual recreational catch of 312 t, and in both SNA 2 and SNA 7 recreational fishers are allocated 90 t annually. A national snapper minimum legal size, and per person bag limit for recreational fishers was introduced in 1985, there are now individual limits for each recreational fishing area such as Auckland & Kermadec Islands, Central, Southern, Fiordland, and Challenger.

Snapper form important fisheries for Maori. The annual catch is not known, but a customary and recreational allowance of 2600 t exists for SNA 1, in SNA 8 there is 43 t allocated for customary take, 16 t in SNA 7, and 14 t in SNA 2.

Illegal catch of snapper was assumed to be 20% of reported domestic commercial catch prior to 1986 and 10% of reported domestic commercial catch since the QMS was introduced.

Conservation and management The Quota Management System (QMS) was introduced in 1986 and commercial catches have been constrained by TACCs since. Snapper are managed in 6 Fishstocks; however, SNA 10 (Kermadec) and SNA 3 (East coast South Island, and Southern ocean) have very little or zero commercial catch of snapper. Separation of stocks has previously been on the basis of genetic studies and other biological information; the location of spawning grounds, differences in growth rates between areas, and the results of tagging studies suggest that 6 or 7 stock units may exist. Although individual fish have recorded some long-distance movements, tagging studies show that generally movement is localised, so a heavily fished site will take time to recover.

Snapper in SNA2 are mainly taken as bycatch of autumn-winter inshore trawling for tarakihi, gemfish, trevally, flatfish, and gurnard along the Wairarapa coast, Hawke Bay, and east coast. Snapper are also taken as bycatch of longlining for hapuku/bass and bluenose, line fishing of school shark, and set netting of rig and blue moki.

Most snapper in SNA 7 are now taken as bycatch around the northern tip of the South Island (Tasman/Golden Bay) by trawling during late summer, particularly for gurnard and flatfish. Snapper are also taken as bycatch of set netting for rig, warehou, and school shark and line fishing for school shark during the summer. A small target fishery now occurs on the spawning stock during spring-summer, with landings by longline, single trawlers, and pair trawlers.

Population trends The stocks in SNA 1 were last assessed in 2000. The status of the two sub-stocks differs. The base case East Northland stock assessment indicates that the current recruited biomass is at about the Bmsy reference point and is expected to exceed Bmsy at the end of the twenty-year projection period (with 67% probability). This conclusion is robust to all sensitivities investigated, except when a low natural mortality was investigated. Even in this sensitivity, the stock is expected to increase to near Bmsy at the end of the projection period.

The base case Hauraki Gulf/Bay of Plenty stock assessment indicates that the current recruited biomass is less than the Bmsy reference point but is expected to increase over the next twenty years under the current TACC and estimated levels of recreational and unreported catch. It is expected to exceed the Bmsy reference point at the end of the projection period (with 100% probability). This conclusion is robust to all sensitivities investigated.

For SNA 1 as a whole, catches at the level of the TAC will allow the stock to increase over the next 20 years.

An assessment model was fitted to four years of proportions at age data for SNA 2 in 2002. As there are no indices of biomass available, model estimates must be treated with caution. For almost all runs, the current biomass was estimated to be near to or somewhat below Bmsy but was projected to increase towards Bmsy by 2006 at the current catch level of 436 t.

An assessment was completed in 2002 for the SNA 7 stock. Model results indicated that the stock should have rebuilt substantially since the low levels of the early 1980s. However, there are no current indices of abundance for this stock to verify the results from the assessment model; only catch at age data is available for recent years.

The MLEs for B2001 for the base case and all of the sensitivity runs are well above Bmsy . The large reduction in catches from the mid-1980’s and the long period that cohorts persist in the recent catch at age data are reflected in model estimates of a rebuilding stock. The results indicate the stock would continue to increase even if future catches were substantially larger than those currently being taken.

The 2005 stock assessment of SNA 8 indicated that current biomass (start of year 2004–05) was between 8% and 12% B0 and the biomass was predicted to slowly increase at the TACC level of 1500 t. However, from 2005–06 the TACC was reduced to 1 300 t to ensure a faster rebuild of the stock. At this TACC level the rebuild to Bmsy (20% B0) occurred after 2018 in all cases assuming either constant recreational effort, or capped recreational catch at the alternative levels of 300 t or 600 t per year. Rebuilding tended to be slower for runs that allowed the recreational catch to rise with increasing biomass.

List of information sources Blackwell, R.G.; Gilbert, D.J.; Davies, N.M. (1999). Age composition of commercial snapper landings in SNA 2 and Tasman Bay/Golden Bay, 1997–98. New Zealand Fisheries Assessment Research Document 99/17. 23 p. Blackwell, R.G.; Gilbert, D.J.; Davies, N.M. (2000). Age composition of commercial snapper landings in SNA2 and Tasman Bay/Golden Bay (SNA7), 1998-99 . New Zealand Fisheries Assessment Report 2000/12 . 22 p. Davies, N.M.; Gilbert, D.J.; McKenzie, J.R. (1999). Assessment of the SNA 1 and 8 stocks for the 1998– 99 fishing year. New Zealand Fisheries Assessment Research Document 99/28. 82 p. FishBase (2007). http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=6426 Accessed 12 February 2007. Gilbert, D.J.; Taylor, P.R. (2001). The relationships between snapper (Pagrus auratus) year class strength and temperature for SNA 2 and SNA 7. New Zealand Fisheries Assessment Report 2001/64 . 33 p. Godfriaux, B.L. (1974). Food of snapper in Western Bay of Plenty, New Zealand. New Zealand Journal of Marine and Freshwater Research 8(3) . 473–504. Harley, S.J.; Gilbert, D.J. (2000). Assessment of the Tasman and Golden Bays snapper fishery for the 1999-2000 fishing year. New Zealand Fisheries Assessment Report 2000/28 . 42 p. Hartill, B. (2001). Recreational catch and effort in the Ministry of Fisheries north region. NIWA Technical Report 101 . 64p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz. Accessed 12 February 2007. Paul, L.J. (1976). A study on age, growth, and population structure of the snapper, Chrysophrys auratus (Forster), in the Hauraki Gulf. New Zealand Fisheries Research Division, 13. 62p Paulin, C.D. 1990. Pagrus auratus , a new combination for the species known as "snapper" in Australasian waters (Pisces: Sparidae ). New Zealand Journal of Marine and Freshwater Research 24(2). 259–265.

Order Zeiformes: Family Oreosomatidae

Black oreo Allocyttus niger (James, Inada & Nakamura, 1988)

Overview Black oreo have been commercially fished in New Zealand waters since 1972, making oreos the longest established New Zealand deepwater fishery. The commercial catch peaked in 1981–82 with over 21 000 t of black oreo caught, over the last five years the total catch has levelled out at 4500 t. The largest oreo fishery is on the south Chatham Rise, where black oreo appear to settle over a wide depth range, but appear to prefer the depth interval 600–800 m, that is often dominated by individuals with a modal size of 28 cm TL.

Distribution Black oreo is known from New Zealand, Tasmania, and south Australia. In New Zealand it is mainly found in central and southern waters. It favours the south slope of Chatham Rise, seamounts of the south, east and north Chatham Rise, off the Otago-Southland coast, north and east slope of Pukaki Rise, Bounty Plateau, and the Puysegur and Solander Trough slopes. The known depth range is 550–1200 m.

Found close to the sea bed in deep water, black oreo can form large shoals over rough ground near pinnacles and canyons. The juveniles are pelagic and inhabit oceanic waters.

Reproduction and life history Spawning occurs from late October to at least December and is widespread on the south Chatham Rise. Mean length at maturity for females, estimated from Chatham Rise trawl surveys (1986–87, 1990, 1991– 93) using macroscopic gonad staging, is 34 cm TL. They appear to have a pelagic juvenile phase, but little is known about this phase because very few fish less than 21 cm TL have been caught. The pelagic phase may last for 4–5 years to lengths of 21–26 cm TL.

Unvalidated age estimates were obtained for Chatham Rise and Puysegur-Snares fish in 1995 and 1997 respectively using counts of the zones (assumed to be annual) observed in thin sections of otoliths. These estimates indicate that black oreo is slow growing and long lived. Maximum estimated age was 153 years (45.5 cm TL fish). Australian workers used the same methods, i.e., sections of otoliths, and reported similar results.

A von Bertalanffy growth curve was fitted to black oreo from Puysegur, and an age at maturity for females was estimated at 27 years. A first estimate of natural mortality (M), 0.044 (yr -1), was made in 1997 using the Puysegur growth data only. This estimate is uncertain because it appeared that the otolith samples were taken from a well fished part of the Puysegur area.

Black oreo have a very low resistance, with a minimum population doubling time of more than 14 years (tmax =100; Fec >5 000).

Habitat and ecology Juveniles look very different to adults, with large bony tubercles on the back and belly. Juveniles are pelagic for the first 4–5 years. Adults can be found in feeding or spawning schools above or near pinnacles and canyons at depths between 550–1200 m. Black oreos feed on benthic crustaceans (Acanthephyra pelagica ), salps ( Salpa thompsoni ), fish and squids.

Commercial catches Black oreos were first taken mainly as bycatch to orange roughy target fishing. Most direct targeting of oreos (smooth and black) did not begin until the mid 1990s or later in some fishstocks. Following a peak in 1981–82 for all fishstocks of over 21 000 t the estimated total commercial catch of black oreo has oscillated between 3000 and 9000 t, with an average of 6000 t, levelling out at 4500 t over the last five years.

The estimated catch of black oreos in OEO 1 did not peak during the early 1980s as the other fishstocks did, it reached a peak over a decade later in 1992–93 when the catch reached 3700 t. The catch in OEO 1 has been below 1000 t for the past 8 years. Oreos were fished under the adaptive management programme up to the end of 1997–98. The OEO 1 TAC reverted back to pre-adaptive management levels from 1998–99.

OEO 3A (South Island east coast and inner Chatham Rise) since the late 1970s has always had the highest commercial catch, however, that importance has diminished consistently since the 1980’s and now has a similar sized catch to OEO 6 (Southern Ocean). From a peak of 11 500 t in 1981, the estimated catch of black oreo declined rapidly to oscillate between 2000 t and 4000 t for the next 17 years, the last 3 years has seen estimated catch drop below 2000 t in OEO 3A.

Following a peak of 5500 t in 1981, estimated catch of black oreo in OEO 4 declined rapidly, then remained less than 2000 t for the next 20 years.

Estimated black oreo catch from the Subantarctic area (OEO 6) decreased from a 1981 peak of 4300 t to oscillate between no catch and 2000 t until 1998–99. For the past 6 years estimated catch has levelled out between 1000 t and 1600 t. There was a voluntary agreement not to fish for oreos in the Puysegur area which started in 1998–99.

There is no known Maori customary, or recreational fishing for black oreo.

Conservation and management The three species of oreos, black oreo, smooth oreo and spiky oreo are managed as if they were one stock. Each species could be managed separately because they have different depth and geographical distributions, different stock sizes, rates of growth, and productivity. Adaptive Management Plans (AMP) have been used in some FMAs.

A New Zealand study examined stock relationships using samples from the main four management areas (OEO 1, OEO 3A, OEO 4 & OEO 6) within the New Zealand EEZ. Techniques used included genetic (nuclear and mitochondrial DNA), lateral line scale counts, settlement zone counts, parasites, otolith microchemistry, and otolith shape. Lateral line scale and pyloric caeca counts were different between samples from OEO 6 and the other three areas. The relative abundance of three parasites differed significantly between all areas. Otolith shape from OEO 3A samples was different to that from OEO 1 and OEO 4, but OEO 1, OEO 4 and OEO 6 otolith samples were not morphologically different. Genetic, otolith microchemistry, and settlement zone analyses showed no regional differences. This suggested that the current stock boundaries should remain until more definitive evidence for stock relationships is obtained.

The stock structure of Australian and New Zealand samples was examined using genetic (allozyme and mitochondrial DNA) and morphological counts (fin rays, etc.). It was concluded that the New Zealand samples constituted a stock distinct from the Australian sample.

Population trends This was the first stock assessment for OEO 4 that included the results from the 1998 acoustic survey, and was updated by NIWA in 2000.

The black oreo stock assessment of OEO 4 was considered unreliable and was not accepted. However, abundance indices from standardised CPUE analysis suggest that there has been a decline in the stock over time. It is not known if recent catch levels or the current TACC are sustainable or if they are at levels that will allow the stock to move towards a size that will support the maximum sustainable yield.

In the OEO 1 black oreo and smooth oreo fishery the TACC was increased from 5033 t to 6044 t in 1992–93 under the adaptive management programme but reverted to 5033 t in 1998–99. It is not known if recent catch levels or the current TACC are sustainable or will allow the stock to move towards a size that will support the maximum sustainable yield.

In the OEO 6 black oreo and smooth oreo fishery the current TACC increased from 3000 to 6000 t in 1996–97 and is not based on historical catch levels or on estimates of biomass and productivity. It is not known if recent catch levels or the current TACC are sustainable or if they are at levels that will allow this stock to move towards a size that will support the maximum sustainable yield.

The assessment has been unchanged from 2004. That assessment used an acoustic absolute abundance estimate (and associated length and biological data) made from a survey carried out in 2002.

List of information sources Clark, M.R.; King, K.J.; McMillan, P.J. (1989). The food and feeding relationships of black oreo, Allocyttus niger, smooth oreo, Pseudocyttus maculatus, and eight other fish species from the continental slope of the south-west Chatham Rise, New Zealand.. Journal of Fish Biology 35 : 465– 484. Coburn, R.P.; Doonan, L.J.; McMillan, P.J. (2005). Descriptions of the black oreo and smooth oreo fisheries in OEO 1, OEO 3A, OEO 4, and OEO 6 from the 1977–78 to the 2002–03 fishing years. New Zealand Fisheries Assessment Report 2005/48. 63 p. Coburn, R.P.; McMillan, P.J. (2006). Description of the black oreo and smooth oreo fisheries in OEO 1, OEO 3A, OEO 4, OEO 6, from the 1977–78 to the 2004–05 fishing years. New Zealand Fisheries Assessment Report 2006/60 . 70p. FishBase (2007). http://filaman.ifm-geomar.de/Summary/SpeciesSummary.php?id=12962 Accessed 24 January 2007. McMillan, P.J.; Doonan, I.J.; Hart, A.C. (1997). Revision of black oreo life history parameters. New Zealand Fisheries Assessment Research Document 97/8. 13 p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 24 January 2007. Paul, L.J., (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p. Smith, M.H.; Doonan, I.J.; McMillan, P.J.; Hart, A.C. (2006). Black oreo abundance estimates from the September - October 2002 acoustic survey of the south Chatham Rise (OEO 3A). New Zealand Fisheries Assessment Report 2006/33 . 20p.

Order Zeiformes: Family Zeidae

John dory Zeus faber (Linnaeus, 1758)

Overview John dory are found from the Three Kings Islands to Stewart Island, in harbours and estuaries as well as over the continental shelf to 300 m. John dory is taken mainly as a bycatch of trawl and Danish seine fisheries targeting snapper, trevally and jack mackerel. Since the early 1990s annual landings have been between 800 t and 900 t. John dory are serial spawners with a spawning season extending from October to May and a peak between December and February.

Distribution John dory have a worldwide distribution, in the eastern Atlantic from Norway to South Africa, also the Mediterranean and Black Sea, the Western Pacific from Japan, Korea, Australia and New Zealand. They are also found in the Indian Ocean. John dory are most common in the North Island but range from the Three Kings Islands to Stewart Island and shallow parts of the Chatham Rise. They have also been found on the West Norfolk Ridge, Norfolk Island shelf, and the Capel Bank. John dory are found in harbours and estuaries as well as over the continental shelf to a maximum depth of about 300 m. In New Zealand hot spots of John dory are located off Wairarapa, Poverty Bay, Coromandel to Hauraki Gulf, east Northland, and from Kawhia Harbour to Tasman and Golden Bays.

Reproduction and life history John dory grow rapidly to about 12 cm to 18 cm by age 1 and about 30 cm by age 2. Male growth slows considerably after age 2 and fish reach a maximum estimated age of 9 with and an estimated length of about 40 cm. Females grow slightly larger than males, reaching an estimated length of about 46 cm at a maximum estimated age of 9.

Females mature at a size of 29 cm to 35 cm SL at an age of 3+ years, males mature at 23 cm to 28 cm SL at about 2+ years. John dory are serial spawners and have a long spawning season extending from

October to May with a peak between December and February. The eggs are large and pelagic and take 12–14 days to hatch.

Uncertainties about the degree of exploitation, and the true maximum age of John dory, make it impossible to estimate M precisely; the most plausible range is 0.35-0.5.

John dory have a low resilience, with a minimum population doubling time 4.5–14 years ( K=0.15; tm=3– 4; tmax =12).

Habitat and ecology John dory are common in the inshore coastal waters of northern New Zealand and to a lesser extent in Tasman Bay, to depths of 50 m. In the Hauraki Gulf, adults move to deeper waters during summer, and occasional feeding aggregations occur during winter, where they feed mainly on small pelagic fishes, and occasionally on cephalopods and crustaceans.

Commercial catches John dory is taken mainly as a bycatch of trawl and Danish seine fisheries. Since the early 1990s total landings have been between 800 t and 900 t. About 80% of the national landings are from JDO 1. Total annual landings have been less than the TACC since their implementation in 1986–87. Reported landings were generally less than 100 t annually until the 1950s when they increased rapidly, and then more gradually, to 800 t by 1981. In the 1980s and 90s, landings ranged between 700 t and 900 t, and were always within the total TAC, which increased from 860 t in 1986–87 to about 1100 t from 1989–90 onwards.

Landings from JDO 1 account for over half the total annual John dory landings, but have been as high as 80% in the early 1980s and 1990s when JDO 1 landings peaked at around 700 t. Landings have only been higher than the TACC once since they were implemented in 1986–87. Current landings are on the increase and were 560 t in 2004–05. It is estimated that during the 1990s about 10–20% of the annual JDO 1 landings were taken in QMA 9, mainly as bycatch in fisheries targeting snapper and trevally. Landings from the eastern part of JDO 1 (QMA 1) are taken primarily in target fisheries for John dory and snapper. However, since 1990 there has been a steady trend of increased target fishing directed at John dory and decreased landings of this species from the snapper fishery.

Landings in JDO 2 currently account for 20% to 30% (180 t to 240 t) of total annual landings and have never exceeded the TACC. Substantial proportions of John dory landings are taken as bycatch in target trawl fisheries for jack mackerels in QMA 8, and as tarakihi and red gurnard bycatch in QMA 2.

JDO 7 accounts for the remaining John dory catch, most of which is from Tasman and Golden Bays, with landings increasing from 70 t in 1999–00 to current landings of 130 t. In JDO 7 the TACC has been over fished by 15% to 70% since 2000–01. This substantial increases in landings can be attributed to increased abundance in response to environmental influences on recruitment and stock displacement, and an increase in the TACC for JDO 7. There are negligible landings from JDO 3. John dory is an important recreational fish. Annual recreational take estimated from diary surveys conducted in 1999–2000 shows that over 200 t (c.v. 23%) of John dory are caught annually in the north of the North Island, and 16 t (c.v. 41%) from the south of the North Island.

John dory was certainly taken by early Maori, but currently there is no quantitative information available on the current level of Maori customary take

Conservation and management Management areas JDO 1 and JDO 2 each have east coast and west coast components, and it is not known whether John dory populations on each coast constitute separate stocks. However, coastal stock separation in John dory is a reasonable assumption given that the adults are weak swimmers and the North Island coastal hydrology is not conducive to bulk inter-coastal larval transport. For recent stock assessment they have been treated as different stocks: JDO lE, JDO 1 W, JDO 2E, and JDO 2W.

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Research trawl surveys have been undertaken to calculate John dory abundance indices for the North Island. However, for each time series there was a change in the configuration of the trawl gear following the 1988 trawl survey and comparisons are therefore uncertain.

John dory is principally a by-catch species and, and so estimates of MCY based on catch statistics are uncertain. Under such conditions it is difficult to determine whether changes in the reported catches indicate actual changes in the stocks or simply changes in the catches of the target species.

Population trends Estimates of absolute current and reference biomass are not available.

For JDO 1 recent catch levels and the current TACC are likely to be sustainable at least in the short term. It is not known if recent catch levels and the current TACC are sustainable in the long term. For all other Fishstocks it is not known if the recent catch levels and current TACCs are sustainable. For all Fishstocks it is unknown if recent catches or the current TACCs are at levels that will allow the stocks to move towards a size that will support the MSY.

List of information sources FishBase (2007). http://www.fishbase.org/Summary/SpeciesSummary.php?id=1370 Accessed 22 February 2007. Hanchet, S.M.; Francis, M.P.; Horn, P.L. (2001). Age and growth of John dory ( Zeus faber ). New Zealand Fisheries Assessment Report 2001/10 . 25 p. Hore, A.J. (1982). Age, growth and reproduction of the John Dory, Zeus faber (Linnaeus). (Unpublished MSc thesis, University of Auckland.). 95p. Horn, P.L.; Hanchet, S.M.; Stevenson, M.J.; Kendrick, T.H.; Paul, J.J. (1999). Catch history, CPUE analysis, and stock assessment of John dory (Zeus faber) around the North Island (Fishstocks JDO 1 and JDO 2). New Zealand Fisheries Assessment Research Document 99/33. 58p. Ministry of Fisheries, Science Group (Comps.) (2006). Report from the Fishery Assessment Plenary, May 2006: stock assessments and yield estimates. 875p. [Unpublished report held in NIWA library.] NABIS (2007). www.nabis.govt.nz . Accessed 22 February 2007. Paul, L.J. (2000). New Zealand fishes: identification, natural history & fisheries. Reed Books, Auckland. 253 p. Russell, B.C. (1983). The food and feeding habits of rocky reef fish of north-eastern New Zealand. New Zealand Journal of Marine and Freshwater Research 17 : 121–145.

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