New Zealand Fisheries Assessment Report 2006/45 November 2006 ISSN 1175-1584

Trawl survey of middle depth species in the Southland and Sub-Antarctic areas, November–December 2005 (TAN0515)

R. L. O’Driscoll N. W. Bagley Trawl survey of middle depth species in the Southland and Sub-Antarctic areas, November-December 2005 (TAN0515)

R. L. O'Driscoll N. W. Bagley

NIWA Private Bag 14901 Wellington

New Zealand Fisheries Assessment Report 2006/45 November 2006 Published by Ministry of Fisheries Wellington 2006

ISSN 1175-1584

© Ministry of Fisheries 2006

Citation: O'Driscoll, R.L.; Bagley, N.W. (2006). Trawl survey of middle depth species in the Southland and Sub-Antarctic areas, November-December 200S (TANOSlS). New Zealand Fisheries Assessment Report 2006145. 64 p.

This series continues the infonnal New Zealand Fisheries Assessment Research Document series which ceased at the end of 1999. EXECUTIVE SUMMARY

O'Driscoll, R.L.; Bagley, N.W. (2006). Trawl survey of middle depth species in the Southland and Sub-Antarctic areas, November-December 2005 (TAN0515).

New Zealand Fisheries Assessment Report 2006145. 64 p.

This report presents results from the summer 2005 trawl survey of the Southland and Sub-Antarctic areas. The trawl survey, the ninth in the summer time series, was carried out from 24 November to 21 December 2005. A total of96 trawls was successfully completed in 21 strata.

Biomass estimates (and c.v.s) for all strata were 20 679 t (12.7%) for hoki, 19755 t (8.5%) for ling, and 1624 t (17.3%) for hake. The biomass estimate for hoki in 2005 was 14% higher than in 2004, but remains low: less than 25% of the hoki biomass observed in the early 1990s. Biomass estimates for hake and ling have declined since the resumption of the summer trawl surveys in 2000, and estimates for both species in 2005 were the lowest in either the summer or autumn trawl time series. The biomass of ling in 2005 was 17% lower than in 2004 and the biomass of hake decreased by 9%.

A significant proportion of the hoki catch was small (35--65 cm) fish from the 2002--04 year-classes. Age 1+ hoki (2004 year-class) were concentrated in the shallow stratum at Puysegur, but age 2+ (2003 year-class) and 3+ (2002 year-class) were more widely distributed over the western part of the survey area .. Hoki from the strong 1991-94 year-classes continue to be an important part of the adult population. The age distributions for hake and ling were broad, with most fish aged between 4 and 14.

Acoustic data were also collected during the trawl survey. Excellent weather during the survey meant that the quality of acoustic recordings was very good. There was a weak positive correlation between acoustic density close to the bottom and trawl catch rates. A short acoustic survey with 9 transects was carried out on 17 December in an area of rough ground on the Stewart-Snares shelf where commercial fishing vessels reported an aggregation of spawning hake. Dense marks were observed close to the bottom. The acoustic estimate of hake biomass from the surveyed area was 945 t (c.v. 23%).

3 1. INTRODUCTION

Trawl surveys of the Southland and Sub-Antarctic region (collectively referred to as the "Southern Plateau") provide fishery independent abundance indices for hoki, hake, and ling. Although the T ACC for hoki was reduced by 80 000 t to 100000 t in 2004-05, hoki is still New Zealand's largest fishery. The Southland and Sub-Antarctic region is believed to be the principal residence area for the hoki that spawn off the west coast of the South Island (WCSI) in winter ("western" stock). Annual catches ofhoki from the Southern Plateau (including Puysegur) peaked between 35000 and 36500 t from 1999--00 to 2001--02, declining to 12000 t in 2004-05 (Ballara et al. in press). Hoki are managed as a single stock throughout the EEZ, but there is an agreement to split the catch between western and eastern areas. The catch limit for hoki from western areas (including the Southern Plateau) in 2004-05 and 2005--06 was 40 000 t. Hake and ling are also important commercial species in Southland and the Sub-Antarctic. The catches of hake and ling in the southern areas in 2004-05 were 4795 t (HAK 1, includes the western Chatham Rise), 3584 t (LIN 5, Southland), and 5506 t (LIN 6, Sub-Antarctic).

Two time series of trawl surveys have been carried out from Tangaroa in the Southland and Sub­ Antarctic region: a summer series in November-December 1991, 1992, 1993,2000,2001,2002,2003, and 2004; and an autumn series in March-June 1992, 1993, 1996 and 1998 (reviewed by O'Driscoll & Bagley (2001)). The main focus of the early surveys (1991-93) was to estimate the abundance ofhoki. The surveys in 1996 and 1998 were developed primarily for hake and ling. Autumn was chosen for these species as the biomass estimates were generally higher and more precise at this time of year. Autumn surveys also allowed the proportion of hoki maturing to spawn to be estimated (Livingston et al. 1997, Livingston & Bull 2000). However, interpretation of trends in the autumn trawl survey series was complicated by the possibility that different proportions of the hoki adult biomass may have already left the survey area to spawn. The timing of the trawl survey was moved back to November-December in 2000 to obtain an estimate of total adult hoki biomass at a time when abundance should be maximal in Southland and the Sub-Antarctic.

The hoki biomass estimate from the two most recent Southern Plateau surveys in 2003 and 2004 were the lowest observed in either the summer or autumn Sub-Antarctic trawl time-series and less than 25% of the hoki biomass in the early 1990s (O'Driscoll & Bagley 2004,2006). The stock status for "western" hoki stock from the 2005 assessment suggested that current biomass was 18-23% Bo and that there was an extended period of poor recruitment from 1995 to 2001 (Sullivan et al. 2005). The 2005 survey, carried out from 24 November to 21 December 2005 (TAN0515) provides a ninth summer estimate of western hoki biomass in time for the 2006 assessment. With the discontinuation of the WCSI acoustic surveys, this is the only abundance index available for western hoki.

2. METHODS

2.1 Survey design

As in previous years, the survey was a two-phase stratified random design (after Francis 1984). The survey area was divided into 21 strata by depth (300--600,600-800, and 800-1000 m) and area (Figure 1). There are 15 core 300-800 m strata (Strata 1 to 15) which have been surveyed in all previous summer and autumn surveys (Table 1). Strata 3 and 5 were subdivided in 2000 to increase the coverage in the region where hake and ling aggregations were thought to occur (Bull et al. 2000). Deeper 800-1000 m strata (Strata 25-28) have been surveyed since 1996. There is no 800-1000 m stratum along the eastern side of the survey area as catches of hake, hoki, and ling from adjacent strata are small. Known areas of foul ground were excluded from the survey.

The allocation of stations in phase 1 was based on a statistical analysis of catch rate data from the five most recent surveys (2000--04) using the 'allocate' procedure of Bull et al. (2000) as modified by

4 Francis (2006). A minimum of three stations per stratum was used. Conservative target coefficients of variation (c.v.s) of 17% for hake and 12% for hoki and ling were used in the statistical analysis to increase the chance that the usual Ministry of Fisheries target c.v.s of 20% for hake and 15% for hoki and ling would be met. Additional stations were added to some strata outside the statistical framework because of the need to focus effort on covering the full distributional range of hake age classes. A total of 82 stations was originally planned for phase 1 (Table 1), with phase 2 stations to be allocated at sea to improve c.v.s for hoki, hake, and ling, and to increase the number of hake sampled.

2.2 Vessel and gear specifications

R.V. Tangaroa is a purpose-built research stern trawler of 70 m overall length, a beam of 14 m, 3000 kW (4000 hp) of power, and a gross tonnage of2282 t.

The trawl was the same as that used on previous surveys of middle depth species by Tangaroa. The net is an eight-seam hoki bottom trawl with 100 m sweeps, 50 m bridles, 12 m backstrops, 58.8 m groundrope, 45 m headline, and 60 mm codend mesh (see Chatterton & Hanchet (1994) for net plan and rigging details). The trawl doors were Super Vee type with an area of6.1 m2•

2.3 Trawling procedure

Trawling followed the standardised procedures described by Hurst et al. (1992). Station positions were selected randomly before the voyage using the Random Stations Generation Program (Version 1.6) developed at NIWA, Wellington. A minimum distance between stations of 3 n. miles was used. If a station was found to be on foul ground, a search was made for suitable ground within 3 n. miles of the station position. If no suitable ground could be found, the station was abandoned and another random position was substituted. Tows were carried out during daylight hours (as defined by Hurst et al. 1992), with all trawling between 0447 hand 2002 h NZST. At each station the trawl was towed for 3 n. miles at a speed over the ground of 3.5 knots. If foul ground was encountered, or the tow hauled early due to reducing daylight, the tow was included as valid only if at least 2 n. miles had been covered. If time ran short at the end of the day and it was not possible to reach the last station, the vessel headed towards the next station and the trawl was shot on that course before 1900 h NZST, if at least 50% of the steaming distance to the next station was covered.

Towing speed and gear configuration were maintained as constant as possible during the survey, following the guidelines given by Hurst et al. (1992). Measurements of doorspread (from a Scanmar 400 system), headline height (from a Furuno net monitor), and vessel speed were recorded every 5 min during each tow and average values calculated.

2.4 Acoustic data collection

Acoustic data were collected during trawling and while steaming between trawl stations (both day and night) using a custom-built CREST system (Coombs et al. 2003) with hull-mounted Simrad single-beam 12 kHz and 38 kHz transducers. CREST is a computer-based "software echo-sounder" which supports multiple channels. The transmitter was a switching type with a nominal power output of 2 kW rms. Transmitted pulse length was 1 ms with 3 s between transmit pulses. The CREST receiver has broadband, wide dynamic range pre-amplifier and serial analog-to-digital converters (ADCs), which feed a digital signal processor (DSP56002). Data from the ADCs were complex demodulated, filtered, and a 20 log R time-varied gain was applied. The results were then shifted to give 16-bit resolution in both real and imaginary terms and the complex data stored for later processing. The 38 kHz transducer has been calibrated following standard procedures (Foote et al. 1987). The 12 kHz transducer was not

5 calibrated. Data collected on 12 kHz were used only to make visual comparisons with 38 kHz data and were not analysed quantitatively.

A short (4 hour) acoustic survey was also carried out on 17 December in an area of rough ground on the Stewart-Snares shelf (boundary between Strata 3B and 5A in Figure 1) where commercial fishing vessels reported an aggregation of spawning hake. The survey boundary was defined as approximately 490 05'S to 490 09' Sand 1660 39' E to 1660 44'E, based on coordinates provided by one of the vessels fishing in this area. Nine north-south transects were run over this area at a speed of 10 knots. One mark identification tow was carried out with the bottom trawl in support of the acoustic survey.

2.5 Hydrology

Temperature and salinity data were collected using a calibrated Seabird SM-37 Microcat CTD datalogger (serial number 2416) mounted on the headline of the trawl. Data were collected at 5 s intervals throughout the trawl, providing vertical profiles. Surface values were read off the vertical profile at the beginning of each tow at a depth of about 5 m, which corresponded to the depth of the hull temperature sensor used in previous surveys. Bottom values were about 7.0 m above the sea-bed (i.e., the height of the headline).

2.6 Catch and biological sampling

At each station all items in the catch were sorted into species and weighed on Seaway motion­ compensating electronic scales accurate to about 0.3 kg. Where possible, finfish, squid, and crustaceans were identified to species and other benthic fauna were identified to species, genera, or family. Unidentified organisms were collected and frozen at sea. Specimens are being stored at NIWA for subsequent identification.

An approximately random sample of up to 200 individuals of each commercial, and some common non­ commercial, species from every successful tow was measured and sex determined. More detailed biological data were also collected on a subset of species and included fish weight, sex, gonad stage, gonad weight, and occasional observations on stomach fullness, contents, and prey condition. Otoliths were taken from hake, hoki, and ling for age determination. A description of the macroscopic gonad stages used for the three main species is given in Appendix 1.

Liver and gutted weights were recorded from up to 20 hoki per station to determine condition indices. Female gonads from the subset ofhoki with recorded organ weights were preserved in formalin and are available for histological examination to estimate proportion spawning (Grimes 2005).

2.7 Estimation of biomass and length frequencies

Doorspread biomass was estimated by the swept area method of Francis (1981, 1989) using the formulae ofVignaux (1994). Total survey biomass was estimated for the top 20 species in the catch by weight. Biomass and c.v. were also calculated by stratum for major species. The group of 12 major species was defined by O'Driscoll & Bagley (2001), and includes the three target species (hoki, hake, ling), eight other commercial species (black oreo, dark ghost shark, lookdown dory, pale ghost shark, ribaldo, southern blue whiting, spiny dogfish, white warehou), and one non-commercial species Gavelinfish).

The catchability coefficient (an estimate of the proportion of fish in the path of the net which is caught) is the product of vulnerability, vertical availability, and areal availability. These factors were set at 1 for

6 the analysis, the assumptions being that fish were randomly distributed over the bottom, that no fish were present above the height of the headline, and that all fish within the path of the doors were caught.

Scaled length frequencies were calculated for the major species with the Trawlsurvey Analysis Program, version 3.2 (Vignaux 1994), using length-weight data from this survey.

Only data from stations where the gear performance was satisfactory (codes 1 or 2) were included for estimating biomass and calculating length frequencies.

2.8 Estimation of numbers at age

Hoki, hake, and ling otoliths were prepared and aged using validated ageing methods (hoki, Hom & Sullivan (1996) as modified by Cordue et al. (2000); hake, Hom (1997); ling, Hom (1993».

Subsamples of 745 hoki otoliths and 576 ling otoliths were selected from those collected during the trawl survey. Subsamples were obtained by randomly selecting otoliths from 5 cm length bins covering the bulk of the catch and then systematically selecting additional otoliths to ensure the tails of the length distributions were represented. The numbers aged approximated the sample size necessary to produce mean weighted c.v.s ofless than 20% across all age classes. All 424 hake otoliths collected were read.

Numbers at age were calculated from observed length frequencies and age-length keys using customised NIWA catch-at-age software (Bull & Dunn 2002). For hoki, this software also applied the "consistency scoring" method of Francis (2001), which uses otolith ring radii measurents to improve the consistency of age estimation.

2.9 Acoustic data analysis

Acoustic recordings made during the trawl survey (both during trawls and while steaming between stations) were visually examined. Marks were classified on the relative depth of the mark in the water column, mark orientation (surface- or bottom-referenced), mark structure (layers, schools, or single targets), and the relative strength of the mark on 38 kHz and 12 kHz (see O'Driscoll (2001) for details). Descriptive statistics were produced on the frequency of occurrence of different mark types. As part of the qualitative description, the quality of acoustic data recordings was subj ectively classified as 'good', 'marginal', or 'poor' (see appendix 2 of O'Driscoll & Bagley (2004) for examples). Only good or marginal quality recordings were considered suitable for quantitative analysis.

A quantitative analysis was carried out to compare acoustic backscatter from bottom-referenced marks with previous surveys. Acoustic data collected on 38 kHz during each trawl were integrated using custom Echo Sounder Package (ESP2) software (McNeill 2001) to calculate the mean acoustic backscatter per square kilometre from bottom-referenced marks. Two values of acoustic backscatter were calculated for each trawl. The first estimate was based on an integration height of 10m above the acoustic bottom, which was similar to the measured headline height of the trawl (average 7.0 m). The second acoustic estimate integrated all backscatter from the bottom up to the maximum height of the bottom referenced mark or 100 ill, but excluded all other mark types.

An acoustic estimate of hake biomass was determined from the acoustic survey of the Stewart-Snares shelf using standard echo integration methods (Simmonds & MacLennan 2005), as implemented in ESP2 (McNeill 2001). Echograms from the nine transects were visually examined, and the bottom determined by a combination of an in-built bottom tracking algorithm and manual editing. Regions corresponding to hake marks were then identified subjectively based on their appearance on the echogram (shape, structure, depth, strength, etc), incorporating information from the skipper of a

7 commercial vessel fishing in the area. Backscatter from regions identified as hake was then integrated to produce an estimate of acoustic density (m-2). Transect acoustic density estimates were converted to hake biomass using a ratio, r, of mean weight to mean backscattering cross section (linear equivalent of target strength) for hake. The ratio, r was calculated from:

1. the length frequency distribution of hake from the single mark identification trawl carried out by Tangaroa (note that at least one of the commercial vessels fishing in the surveyed area carried observers, so more extensive length frequency data should be available at a later date);

2. the best available target strength-length relationship for hake (Macaulay & Grimes 2000),

TS= 27.110glO(L) - 83 .5

where TS is in decibels and L is total fish length in centimetres;

3. the length-weight relationship for hake calculated from the trawl survey.

The abundance estimate and variance for the survey area were obtained from transect estimates using the formulae of Jolly & Hampton (1990).

3. RESULTS

3.1 Survey coverage

The trawl survey and acoustic work contracted for this voyage were successfully completed. Due to extraordinarily good weather, no survey time was lost, and an extensive phase 2 component was possible.

A total of 96 successful trawl survey stations was completed in 21 strata (Figure 2, Table 1). All but one of the 82 phase 1 stations originally proposed for the survey were successfully completed (Table 1). One phase 1 station in stratum 26 was dropped after a tow in this stratum came fast (i.e., got stuck on the bottom). The substitute station required a very long steam, and only one hoki and no hake or ling were caught at the other two stations in this stratum. An additional phase 1 station was carried out in stratum 12. Fourteen phase 2 stations were completed (Table 1). Most phase 2 effort was directed at reducing the c.v. for hake and increasing the number of hake sampled in strata 5A, 4, 8, 25, and 27. Phase 2 stations were also carried out in strata 1 and 2 (Puysegur area) for ling and hoki.

Three further stations were considered unsuitable for biomass estimation: station 20 had poor gear performance (a trawl door fell over), station 30 came fast, and station 94 was a non-random tow in support of the acoustic work on hake (see Section 3.9).

3.2 Gear performance

Gear parameters by depth and for all observations are summarised in Table 2. The headline height was obtained for all 96 successful tows, but doorspread readings were not available for five tows. Missing doorspread values were calculated from data collected in the same depth range on this voyage. Measured gear parameters in 2005 were similar to those obtained on other voyages of Tangaroa in this area when the same gear was used (Table 3). The slightly lower average doorspread and slightly higher average headline height in 2005 was probably due to the very good weather for much of the survey. Warp-to-depth ratios were the same as in previous years, following the recommendations of Hurst et al. (1992).

8 3.3 Catch

A total catch of 39.2 t was recorded from all successful trawl stations. From the 194 species or species groups caught, 100 were teleosts, 26 elasmobranchs, 13 squids or octopuses, 18 crustaceans, and 23 echinoderms (Appendix 2). Hoki accounted for 17.8%, ling 12.9%, and hake 3.7% of the total catch.

3.4 Biomass estimates

Total survey biomass estimates for the 20 species with highest catch weights are given in Table 4. Biomass estimates are presented by stratum for the 12 major species (as defined by O'Driscoll & Bagley (2001» in Table 5. Subtotals for these species are given for the core 300--800 m depth range (Strata 1- 15) and core + Puysegur 800--1000 m (Strata 1-25) in Table 5 to allow comparison with results of previous surveys where not all deep (800--1000 m) strata were surveyed. The time series of core estimates for the 12 major species are plotted in Figure 3

The biomass estimate for hoki in 2005 was 14% higher than in 2004, but remains low: less than 25% of the hoki biomass observed in the early 1990s (Table 6, Figure 3). The biomass estimates for length ranges corresponding to 1+ « 45 cm) and 2+ (46-60 cm) hoki were 370 t (c.v. 49%) and 1679 t (c.v. 25%) respectively.

Biomass estimates for hake and ling have declined since the resumption of the summer trawl surveys in 2000, and estimates for both species in 2005 were the lowest in either the summer or autumn trawl time series (Table 6, Figure 3). The biomass of ling in 2005 was 17% lower than in 2004 and the biomass of hake decreased by 9%.

There was no evidence for a change in trawl catchability in 2005 that would bias trawl survey results. Biomass estimates in core strata for five of the nine other major species increased from 2004 to 2005 (Figure 3). The biomass of black oreo was particularly high in 2005, which was driven by a single large catch (3.4 t) in stratum 11. Consequently the c.v. on the estimate of black oreo biomass was also very high (98%) in 2005 (see Table 5).

3.5 Species distribution

The distribution and catch rates at each station for hoki, hake, and ling are given in Figures 4-6. Hoki were widespread throughout the core survey area, occurring in 88 of the 96 successful trawl stations. As in previous surveys (review by O'Driscoll & Bagley 2001), hoki catch rates were generally higher in the west, on the Stewart-Snares shelf, on the western side of the Campbell Rise, and at Puysegur (Figure 4a). Large catches of small (1 and 2 year-old) hoki were made in Stratum 1 (300-600 m) at Puysegur (Figures 4b and 4c), but 2 year-old hoki were also caught on the Stewart-Snares shelf (Figure 4c). Hake were concentrated in deeper water (more than 600 m) at Puysegur, on the northwestern part of the Campbell Rise, and on the Stewart-Snares shelf (Figure 5). About 30% of the hake biomass was from the 800--1000 m depth range (see Table 5). Ling were widely distributed over most of the survey area between 300--800 m, with the largest catch taken at Puysegur (Figure 6). Both hoki and ling were seldom caught deeper than 800 ill.

3.6 Biological data

The numbers of fish of each species measured or selected for biological analysis are shown in Table 7. Pairs of otoliths were removed from 1212 hoki, 1069 ling, and 424 hake. Length-weight relationships used to scale length frequency data are given in Table 8. Length frequency histograms by sex for hoki,

9 hake, and ling are compared to those observed in previous surveys in Figures 7-9. Length frequencies for the other major species are shown in Figure 10.

Hoki length frequencies in 2005 had four clear modes (Figure 7). The adult mode was centred on about 91 cm for males and about 96 cm for females. Ageing shows that these were mostly fish from the strong year classes in 1991-94 seen in 2005 as 11-14 year olds, with ages 5 (2000 year-class) and 7-9 (1996- 98 year-class) also contributing to the adult mode (Figure 11). There were juvenile modes at 30--43 cm and 46-59 cm and 60-70 cm (Figure 7), corresponding to ages 1+,2+, and 3+ hoki from the 2002-04 year-classes (Figure 11). Although these juvenile year-classes were abundant by number in the 2005 survey (Figure 11) they contributed relatively little to the biomass (see Section 3.4).

The length frequency distribution of hake showed no clear modes (see Figure 8). There was a lower catch of male hake than in previous surveys and few small (50-70 cm) hake were caught in 2005. In some previous surveys small hake were captured in quite high numbers at 800-1000 m depth at Puysegur (Stratum 25). Since 1998 there has been a lower proportion of old hake (older than age 12) than were observed in surveys in the early 1990s (Figure 12). The modal age in 2005 was 8 for males and 8-9 for females (Figure 12).

The length frequency distribution of ling was broad and similar to that observed in 2004 (see Figure 9). The age frequency for ling showed most fish were between 4 and 13 years old (Figure 13).

The length frequency distribution of southern blue whiting caught in 2005 had modes at 36 cm and 45 cm for males and 36 cm and 47 cm for females (see Figure 10). This bimodal distribution was similar to that observed in the commercial fishery for southern blue whiting on the Campbell Island Rise in September 2005 (Hanchet et al. unpublished results). The smaller length mode probably consisted of 3 year-old fish from the 2001 year class, whilst the mode of larger fish probably comprised fish aged 6 and older. The size of black oreo was similar to that observed in the five previous surveys, with modal lengths of 29 cm for males and 30 cm for females (see Figure 10). Other points of interest in Figure 10 included: the biomodallength distribution of javelinfish, which was also observed in 2004 (O'Driscoll & Bagley 2006); the high proportion of female ribaldo (scaled sex ratio of 7.4 females for every male); and the large difference in the length frequencies of male and female spiny dogfish.

Gonad stages for hoki, hake, and ling are summarised in Table 9. Immature hoki made up about 55% of fish examined, and these were typically fish smaller than 70 cm. Most adult hoki were in the resting phase. About 8% of female hoki were macroscopically staged as spent, and 8% of male hoki still exuded milt and were classified as partially spent. The proportion of spent females and partially spent males in 2005 was higher than in the 2004 survey, when only 2% of females and 3% of males were spent and partially spent respectively (O'Driscoll & Bagley 2006). Ling of all gonad stages were recorded, with 38% of males and 16% of females in spawning condition (ripe and running ripe), indicating that some spawning was occurring at the time of the trawl survey. About half (47%) of male hake were ripe or running ripe, but most female hake were immature (35%), resting (35%), or ripening (22%). The acoustic survey (see Section 3.9) showed that spawning aggregations of hake were present in the survey area in early December.

3.7 Hoki condition indices

Liver and gutted weights were recorded from 1106 hoki. Mean hoki liver condition index (LCI = liver weight divided by gutted weight) and somatic condition factor (CF = gutted weight divided by length cubed) are given in Table 10. Somatic condition for both male and female hoki was high in 2005. Examination of relationships between fish weight and length indicated that a 90 cm hoki was, on average, 20-30 g (1.0-1.7%) heavier in 2005 than in 2001-04. Average liver condition for male hoki in 2005 was also the highest since liver data were first collected in 2001 (Table 10)

10 As in 2001--04 (O'Driscoll & Bagley 2003a, 2003b, 2004, 2006), female hoki that were macroscopically staged as spent (stage 7) tended to have lower LeI (average LeI = 2.75%, n = 151) than resting (stage 2) females (average LeI = 3.20%, n = 357), suggesting that fish that have recently spawned may have lower condition than fish that either spawned earlier or did not spawn. A similar pattern was observed for male hoki in 2005, with fish that were partially spent or spent (stages 6-7) having lower LeI (average LeI = 2.34%, n = 86) than resting (stage 2) males (average LeI = 2.81%, n = 121). Immature (stage 1) hoki of both sexes typically had higher LeI than mature fish (average LeI for immature females = 3.36%, n = 206; average LeI for immature males = 3.47%, n = 179).

Gonad samples were taken from 570 female hoki and preserved in 10% buffered formalin. These are available for histological examination to estimate proportion spawning (Grimes 2005).

3.8 Acoustic results

A total of 197 acoustic data files (99 trawl files and 98 steam files) was recorded during the trawl survey. Excellent weather during the survey meant that the quality of acoustic recordings was very good, with only 9% of the files considered too poor to be analysed quantitatively (Table 11).

Mark types were similar to those described for previous surveys (O'DriscoIl2001, O'Driscoll & Bagley 2003a, 2003b, 2004, 2006). The frequency of occurrence in 2005 of each of the eight mark categories described by O'Driscoll (2001) is given in Table 12. Surface layers (shallower than 100 m) were observed in most (87%) daytime echograms and all night echograms in 2005 (Table 12). The identity of organisms in these surface layers is unknown because no tows were targeted at the surface. Acoustic scattering is probably contributed by a number of pelagic zooplankton (including gelatinous organisms such as salps) and fish. The occurrence of pelagic schools and layers in daytime recordings in 2005 was higher than in 2003 and 2004, and similar to 2000--02. Pelagic schools and layers also occurred in a relatively high proportion of overnight recordings in 2005, but were usually observed at dawn and dusk, dispersing at night or moving to the surface. Pelagic schools and layers probably contain mesopelagic fish species such as pearlsides (Maurolicus australis) and myctophids, which are important prey ofhoki. Bottom layers were observed in 67% of day steam files, 57% of overnight steams, and 38% of trawl files in 2005. Bottom layers were usually associated with a mix of demersal fish species, but may also contain mesopelagic species when these occur close to the bottom (O'Driscoll 2003). Strong bottom layers were associated with the aggregation of spawning hake in the acoustic survey area (see Section 3.9). Pelagic and bottom layers tend to disperse at night, to form pelagic and bottom clouds respectively. However, a noticeable change in 2005 was the higher occurrence of cloud-type marks during the daytime (day steam and trawl) recordings. This may have been related to the very good weather, which allowed lower density marks to be readily detected. Most bottom-referenced schools were observed during the day in 300-600 m water depth. As in previous years (O'DriscoIl2001), bottom schools were sometimes associated with catches of southern blue whiting in the bottom trawl (e.g., station 37).

Acoustic data from 87 trawl files were integrated. Data from the other 12 trawl recordings were not included in the quantitative analysis because the acoustic data were too noisy (9 files) or because the accompanying bottom trawl was not considered suitable for biomass estimation (3 files). Average acoustic backscatter from bottom-referenced regions in 2005 was in the range of previous surveys and higher than in 2004 (Table 13).

There was a weak positive correlation between acoustic backscatter and trawl catch rates (Figure 14). Trawl catch rates were more strongly correlated with total acoustic backscatter from bottom-referenced marks than with backscatter from the bottom 10 m only (Figure 14). This suggests that the trawl may be vertically herding fish from more than 10 m above the bottom. Significant positive correlations were also observed between trawl and acoustic data in 2000,2001, and 2003 (O'DriscoIl2002, O'Driscoll & Bagley 2004), but not in 2002 (O'Driscoll & Bagley 2003b) or 2004 (O'Driscoll & Bagley 2006). In

11 2002, O'Driscoll & Bagley (2003b) hypothesised that there may have been an increased proportion of mesopelagic species close to the bottom. In 2004, there were several instances where large catches of ling or juvenile hoki were taken but relatively little was detected acoustically, especially in the bottom 10 m (O'Driscoll & Bagley 2006).

Acoustic methods are unlikely to provide alternative abundance estimates for demersal species in the Sub-Antarctic because of the relatively low fish densities and mixed species composition. However, we believe it is useful to continue to collect acoustic data to monitor other components of the ecosystem (especially mesopelagic fish) and to aid in the interpretation of trawl survey results.

3.9 Acoustic survey

Relatively dense bottom layers were detected in the area where commercial vessels were targeting hake. The marks were over very rough bottom and were typically about 5 m high, but extending up to 20 m off the bottom in places (Figure 15). The vessels were fishing on these marks using a bottom trawl 'flown' above the bottom (i.e., close to the bottom with no bottom contact), with high catch rates of spawning hake.

The nine acoustic transects encompassed an area of 48.5 km2 (Figure 16). The densest marks were observed in the central and southern parts of this region (Figure 16). Although hake densities were lower on the outer transects it was clear that the spawning aggregation extended beyond the survey boundaries, particularly to the northwest and southeast. There was insufficient time available to carry out a more extensive acoustic survey to determine the full extent of the aggregation.

One bottom trawl (station 94) was carried out in the acoustic survey area for mark identification and to obtain a sample of hake. The location of the tow was determined by the suitability of the bottom for trawling, and it did not pass through the densest marks. This trawl came fast after only 0.8 n. miles but caught 320 kg of hake (69% of the total catch by weight). The other major species caught were ling (14% of catch) and hoki (12% of catch). The mean length of hake caught in this tow was 86 cm. Most of the hake (84%) was running ripe (stage 5) males, with the remainder made up of maturing (stages 3 and 4) females. Mean weight and mean backscattering cross-section (obtained by transforming the length frequency distribution and then calculating the means of the transformed distributions) were 4.85 kg and 0.000797 m2 (equivalent to -31.0 dB) respectively, giving a ratio, r, of 6082 kg m-2•

The uncorrected acoustic biomass estimate from the survey area was 878 t. Because the hake marks were very close to the bottom, the acoustic biomass estimate was corrected for the effect of shadowing using the full formula of Barr given by Doonan et al. (1999). This method assumes that acoustic backscatter in the shadow zone is equivalent to backscatter in the region (10 m) immediately above the detected bottom. The corrected biomass estimate for hake was 945 t with a c.v. of 23%. Both acoustic estimates assume that all backscatter from marks classified as hake was from hake (i.e., no species decomposition). Although hoki and ling were caught in the single research trawl in the survey area, reports from commercial vessels indicated they were making relatively 'clean' catches of hake.

3.10 Hydrological data

Temperature profiles were available from 97 CTD casts. Surface (5 m depth) temperatures ranged between 7.6 and 14.9 °C (Figure 17), while bottom temperatures were between 4.0 and 10.6 °C (Figure 18). Bottom temperature decreased with depth, with lowest bottom temperatures recorded from water deeper than 900 m on the margins of the Campbell Plateau. Highest surface and bottom temperatures were at Puysegur. As in previous years, there was a general trend of increasing water temperatures towards the north and west (Figures 17-18).

12 The average surface temperature in 2005 of 10.5 °C was higher than that observed in 2002-04 (8.8- 10.3 0C). Vertical profiles of temperature (e.g., Figure 19) indicated that the surface mixed layer in 2005 was usually deeper than in 2002, when there was a thin layer of warm surface water in some areas, but shallower than in 2003-04. The depth of the mixed layer is probably related to the amount of surface mixing and extent of thermal stratification, with shallower mixed layers in those years with warmer, more settled weather conditions. Average bottom temperatures were similar in 2005 (6.8 0C), 2004 (7.0 0C), 2003 (6.9 0C), and 2002 (6.7 °C). It is difficult to compare temperatures with previous summer Sub-Antarctic surveys because temperature sensors were uncalibrated before 2002.

4. CONCLUSIONS

The 2005 survey met target c.v.s for hoki, hake, and ling. The biomass estimate for hoki in 2005 was 14% higher than in 2004, but was still less than 25% of the hoki biomass observed in the early 1990s. A significant proportion of the hoki catch was small fish from the 2002-04 year-classes. Biomass estimates for hake and ling from all strata in 2005 were the lowest in the time-series.

Aggregations of spawning hake were present in an untrawlable area during the survey. The summer Sub-Antarctic trawl survey probably does not adequately sample hake.

5. ACKNOWLEDGMENTS

Thanks to the scientific staff who participated in this voyage, and the master, officers, and crew of Tangaroa. Jennifer Devine provided helpful comments on a draft of this report. This work was carried out by NIWA under contract to the Ministry of Fisheries (Contract No. MDT2005/01).

6. REFERENCES

Ballara, S.L.; O'Driscoll, RL.; Fu, D. (in press). Catches, size, and age structure of the 2004-05 hoki fishery, and a summary of input data used for the 2006 stock assessment. New Zealand Fisheries Assessment Report. Bull, B.; Bagley, N.W.; Hurst, RJ. (2000). Proposed survey design for the Southern Plateau trawl survey ofhoki, hake and ling in November-December 2000. Final Research Report to the Ministry of Fisheries for Project MDT1999101 Objective 1. 31 p. (Unpublished report held by Ministry of Fisheries, Wellington.) Bull, B.; Dunn, A. (2002). Catch-at-age user manual v1.06.2002/09/12. NIWA Internal Report 114. 23 p. (Unpublished report held in NIWA library, Wellington.) Chatterton, T.D.; Hanchet, S.M. (1994). Trawl survey of hoki and associated species in the Southland and Sub-Antarctic areas, November-December 1991 (TAN9105). New Zealand Fisheries Data Report 41.55 p. Coombs, RF.; Macaulay, G.J.; Knol, W.; Porritt, G. (2003). Configurations and calibrations of 38 kHz fishery acoustic survey systems, 1991-2000. New Zealand Fisheries Assessment Report 2003149. 24p. Cordue, P.L.; Ballara, S.L.; Hom, P.L. (2000). Hoki ageing: recommendation of which data to routinely record for hoki otoliths. Final Research Report to the Ministry of Fisheries for Project MOF1999101 (Hoki ageing). 24 p. (Unpublished report held by Ministry of Fisheries, Wellington.) Doonan, I.; Coombs, R; Barr, R; McClatchie, S.; Grimes, P.; Hart, A.; Tracey, D.; McMillan, P. (1999). Estimation of the absolute abundance of orange roughy on the Chatham Rise. Final Research Report for Ministry of Fisheries Project ORH9701. 68 p. (Unpublished report held by Ministry of Fisheries, Wellington.)

13 Foote, K.G.; Knudsen, H.P.; Vestnes, G.; MacLennan, D.N.; Simmonds, E.J. (1987). Calibration of acoustic instruments for fish density estimation: a practical guide. ICES Cooperative Research Report 144. 68 p. Francis, RI.C.C. (1981) Stratified random trawl surveys of deep-water demersal fish stocks around New Zealand. Fisheries Research Division Occasional Publication 32.28 p. Francis, RI.C.C. (1984) An adaptive strategy for stratified random trawl surveys. New Zealand Journal ofMarine and Freshwater Research 18: 59-71. Francis, RI.C.C. (1989). A standard approach to biomass estimation from bottom trawl surveys. New Zealand Fisheries Assessment Research Document 89/3. 3 p. (Unpublished report held in NIWA library, Wellington.) Francis, RI.C.C. (2001). Improving the consistency of hoki age estimation. New Zealand Fisheries Assessment Report 2001112. 18 p. Francis, RI.C.C. (2006). Optimum allocation of stations to strata in trawl surveys. New Zealand Fisheries Assessment Report 2006123.50 p. Grimes, P. (2005). Estimating the proportion of female hoki on the Southern Plateau which spawn each year by microscopic examination of gonad samples. Research Progress Report for Ministry of Fisheries Research Project MDT2003/01 Objective 6. 14 p. (Unpublished report held by Ministry of Fisheries, Wellington.) Hom, P.L. (1993). Growth, age structure, and productivity of ling, Genypterus blacodes (Ophidiidae), in New Zealand waters. New Zealand Journal ofMarine and Freshwater Research 27: 385- 397. Hom, 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. Hom, 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 ofMarine and Freshwater Research 30: 161-174. Hurst, R.J.; Bagley, N.; Chatterton, T.; Hanchet, S.; Schofield, K.; Vignaux, M. (1992). Standardisation ofhoki/middle depth time series trawl surveys. MAP Fisheries Greta Point Internal Report 194. 89 p. (Unpublished report held in NIWA library, Wellington.) Jolly, G.M.; Hampton, I. (1990). A stratified random transect design for acoustic surveys offish stocks. Canadian Journal ofFisheries and Aquatic Sciences 47: 1282-1291. Livingston, M.E.; Bull, B. (2000). The proportion of western stock hoki developing to spawn in April 1998. New Zealand Fisheries Assessment Report 2000113. 20 p. Livingston, M.E.; Vignaux, M.; Schofield, K.A. (1997). Estimating the annual proportion of nonspawning adults in New Zealand hoki, Macruronus novaezelandiae. Fishery Bulletin 95: 99-113. Macaulay, G.J.; Grimes, P. (2000). Estimates of target strength of hake (Merluccius australis). Final Research Report for Ministry of Fisheries Research Project HAK9801 Objective 2. 16 p. (Unpublished report held by Ministry of Fisheries, Wellington.) McNeill, E. (2001). ESP2 phase 4 user documentation. NIWA Internal Report 105. 31 p. (Unpublished report held in NIWA library, Wellington.) O'Driscoll, RL. (2001). Classification of acoustic mark types observed during the 2000 Sub-Antarctic trawl survey (TAN0012). Final Research Report for Ministry of Fisheries Research Project MDT2000101 Objective 3. 28 p. (Unpublished report held by Ministry of Fisheries, Wellington.)

14 O'Driscoll, RL. (2002). Estimates of acoustic:trawl vulnerability ratios from the Chatham Rise and Sub-Antarctic. Final Research Report for Ministry of Fisheries Research Projects H0K2001102 Objective 3 & MDT2001101 Objective 4. 46 p. (Unpublished report held by Ministry of Fisheries, Wellington. ) O'Driscoll, RL. (2003). Determining species composition in mixed species marks: an example from the New Zealand hoki (Macruronus novaezelandiae) fishery. ICES Journal of Marine Science 60: 609- 616. O'Driscoll, RL.; Bagley, N.W. (2001). Review of summer and autumn trawl survey time series from the Southland and Sub-Antarctic area 1991-1998. NIWA Technical Report 102. 115 p. o 'Driscoll, RL.; Bagley, N.W. (2003a). Trawl survey of middle depth species in the Southland and Sub-Antarctic areas, November-December 2001 (TAN0118). New Zealand Fisheries Assessment Report 200311. 53 p. O'Driscoll, RL.; Bagley, N.W. (2003b). Trawl survey of middle depth species in the Southland and Sub-Antarctic areas, November-December 2002 (TAN0219). New Zealand Fisheries Assessment Report 2003146. 57 p. O'Driscoll, RL.; Bagley (2004). Trawl survey of hoki, hake, and ling in the Southland and Sub­ Antarctic areas, November-December 2003 (TAN0317). New Zealand Fisheries Assessment Report 2004149. 58 p. O'Driscoll, RL.; Bagley (2006). Trawl survey of hoki, hake, and ling in the Southland and Sub­ Antarctic areas, November-December 2004 (TAN0414). New Zealand Fisheries Assessment Report 2006/2.60 p. Simmonds, E.J.; MacLennan, D.N. (2005). Fisheries acoustics: theory and practice. 2nd edition. Blackwell Science, Oxford. 437 p. Sullivan, K.J.; Mace, P.M.; Smith, N.W.McL.; Griffiths, M.H.; Todd, P.R; Livingston, M.E.; Harley, S.J.; Key, J.M.; Connell, A.M. (comps.) (2005). Report from the Fishery Assessment Plenary, May 2005: stock assessments and yield estimates. 792 p. (Unpublished report held in NIWA library, Wellington.) Vignaux, M. (1994). Documentation of Trawlsurvey Analysis Program. MAF Fisheries Greta Point Internal Report 225.44 p. (Unpublished report held in NIWA library, Wellington.)

15 Table 1: Stratum areas, depths, and number of successful biomass stations from the November-December 2005 Southland and Sub-Antarctic trawl survey. Stratum boundaries are shown in Figure 1, and station positions are plotted in Figure 2.

Stratum Name Depth Area Proposed Completed Completed (m) (km2) phase 1 phase 1 phase 2 stations stations stations 1 Puysegur Bank 300-600 2 150 4 4 1 2 Puysegur Bank 600-800 1 318 4 4 3a Stewart-Snares 300-600 4548 3 3 3b Stewart-Snares 300 -600 1556 4 4 4 Stewart-Snares 600-800 21018 4 4 1 5a Snares-Auckland 600-800 2981 4 4 3 5b Snares-Auckland 600-800 3281 4 4 6 Auckland Is. 300-600 16682 4 4 7 South Auckland 600-800 8497 3 3 8 N.E. Auckland 600-800 17294 4 4 2 9 N. Campbell Is. 300-600 27 398 8 8 10 S. Campbell Is. 600-800 11288 3 3 11 N.E. Pukaki Rise 600-800 23008 3 3 12 Pukaki 300-600 45259 6 7 13 N.E. Camp. Plateau 300-600 36051 4 4 14 E. Camp. Plateau 300-600 27 659 3 3 15 E. Camp. Plateau 600-800 15 179 3 3 25 Puysegur Bank 800-1000 1928 4 4 3 26 S.W. Campbell Is. 800-1000 31 778 3 2 27 N.E. Pukaki Rise 800-1000 12986 3 3 3 28 E. Stewart Is. 800-1000 8336 4 4

Total 320195 82 82 14

16 Table 2: Survey tow and gear parameters (recorded values only). Values are number of tows (n), and the mean, standard deviation (s.d.), and range of observations for each parameter.

n Mean s.d Range Tow parameters Tow length (n.miles) 96 2.95 0.10 2.30--3.04 Tow speed (knots) 96 3.5 0.05 3.4-3.8

Gear parameters (m) 300--600 m Headline height 38 7.2 0.20 6.9-7.7 Doorspread 37 116.4 6.42 104.8-129.4 600--800 m Headline height 39 7.1 0.16 6.8-7.4 Doorspread 36 118.5 6.81 104.7-134.4 800--1000 m Headline height 19 7.4 0.29 6.9-7.9 Doorspread 18 115.9 6.06 104.0--129.0 All stations 300--1000 m Headline height 96 7.2 0.22 6.8-7.9 Doorspread 91 117.1 6.53 104.0--134.4

Table 3: Comparison of doorspread and headline measurements from all surveys in the summer Tangaroa time-series. Values are the mean and standard deviation (s.d.). The number of tows with measurements (n) and range of observations is also given for doorspread.

DoorsI2read {m} Headline height {m} Survey n mean s.d. mm max mean s.d. 1991 152 126.5 7.05 106.5 145.5 6.6 0.31 1992 127 121.4 6.03 105.0 138.4 7.4 0.38 1993 138 120.7 7.14 99.9 133.9 7.1 0.33 2000 68 121.4 5.22 106.0 132.4 7.0 0.20 2001 95 117.5 5.19 103.5 127.6 7.1 0.25 2002 97 120.3 5.92 107.0 134.5 6.8 0.14 2003 13 123.1 3.80 117.3 129.7 7.0 0.22 2004 85 120.0 6.11 105.0 131.8 7.1 0.28 2005 91 117.1 6.53 104.0 134.4 7.2 0.22

17 Table 4: Biomass estimates, coefficients of variation, and catch of the 20 species with highest catch weights in the 2005 Sub-Antarctic trawl survey. Estimates are from successful biomass stations for all strata combined. Biomass estimates from 2004 (from O'Driscoll & Bagley 2006) are shown for comparison.

2005 {T AN05152 2004 {TAN04142 Species Catch Biomass c.v. Catch Biomass c.v. Commercial species code (kg) (t) (%) (kg) (t) (%) Hoki HOK 6997 20679 12.7 12805 18 114 11.6 Ling LIN 5048 19755 8.5 16174 23794 12.2 Javelinfish JAV 3861 14390 9.7 3409 17415 22.4 Blackoreo BOE 3707 42887 97.9 160 867 66.0 Spiny dogfish SPD 1842 4344 18.9 1824 3376 27.3 Longnose velvet dogfish CYP 1816 2260 21.2 966 2241 37.8 Pale ghost shark GSP 1558 9416 10.2 1326 8549 10.3 Hake HAK 1443 1624 17.4 1341 1774 20.0 Arrow squid NOS 1 129 995 35.3 309 233 28.4 Shovelnosed dogfish SND I 107 583 21.2 1262 738 17.4 Silver dory SDO 1056 1229 58.7 232 108 63.4 Ridge-scaled rattail MCA 1042 12377 59.0 220 888 28.5 Deepwater spiny dogfish CSQ 647 594 27.2 385 404 45.6 Ribaldo RIB 530 833 13.4 444 1053 15.4 Oliver's rattail COL 529 2302 23.2 458 1824 31.2 Giant stargazer STA 487 352 32.1 503 298 12.6 Southern blue whiting SBW 478 4146 38.0 349 3346 36.0 Baxter's lantern dogfish ETB 430 2144 22.0 339 1628 21.0 Small-scaled slickbead SSM 420 2012 18.0 241 581 81.0 Four-rayed rattail CSU 305 894 50.0 115 359 55 .0

Total catch (all species) 39220 50949

18 Table 5: Estimated biomass (t) and coefficients of variation (%, below in parentheses) of the twelve major species by stratum. Species codes are given in Appendix 2. Sub-totals are provided for core strata (1-15) and core + Puysegur 800-1000 m (Strata 1-25).

Stratum HOK LIN HAK BOE GSH GSP 1 1 198 1060 72 0 90 3 (22) (37) (70) (100) (73) 2 412 86 35 0 0 8 (29) (29) (50) (31) 3a 506 826 0 0 0 253 (90) (45) (33) 3b 164 71 0 0 70 0 (59) (48) (58) 4 1 196 898 216 0 0 836 (46) (25) (42) (38) 5a 336 271 191 0 1 78 (40) (27) (35) (100) (51) 5b 509 208 79 0 0 246 (40) (15) (21) (17) 6 1 707 1273 35 0 342 202 (49) (58) (100) (53) (59) 7 641 852 48 0 0 43 (33) (66) (100) (50) 8 5543 1418 290 0 0 692 (37) (26) (51) (29) 9 1999 2787 104 0 13 894 (19) (22) (74) (100) (18) 10 402 328 64 0 0 173 (38) (31) (100) (39) 11 790 713 0 41986 0 351 (47) (50) (100) (51) 12 2688 4219 0 0 0 2777 (27) (15) (23) 13 833 2209 0 0 0 1 760 (37) (14) (23) 14 895 1895 0 0 0 633 (46) (36) (48) 15 624 569 0 0 0 121 (34) (38) (32) Subtotal (stra(a 1-15) 20440 19685 1133 41986 517 9069 (9) (20) (100) (40) (11)

25 77 26 325 0 0 9 (41) (53) (30) (39) Subtotal (strata 1-25) 20517 19712 1459 41986 517 9078 (13) (9) (17) (100) (40) (11)

26 62 0 0 10 0 151 (100) (100) (64) 27 75 44 149 81 0 62 (68) (66) (92) (39) (27) 28 26 0 17 811 0 125 (85) (100) (76) (19) Total (All strata) 20679 19755 1624 42887 517 9416 (13) (9) (17) (98) (40) (10)

19 Table 5 (cont): Estimated biomass (t) and coefficients of variation (%, below in parentheses) of the twelve major species by stratum. Species codes are given in Appendix 2. Sub-totals are provided for core strata (1-15) and core + Puysegur 800-1000 m (Strata 1-25).

Stratum JAV LDO RIB SBW SPD WWA I 35 17 9 0 375 56 (41) (44) (100) (69) (75) 2 176 8 61 0 0 0 (25) (26) (11) 3a 133 8 20 0 845 16 (26) (100) (93) (56) (61) 3b 1 11 0 0 250 84 (100) (87) (44) (73) 4 1 310 0 133 0 521 13 (28) (23) (57) (100) 5a 120 8 69 0 71 0 (21) (33) (40) (90) 5b 338 0 8 0 113 13 (35) (66) (38) (37) 6 102 67 0 1507 18 23 (33) (58) (100) (100) (100) 7 632 11 114 0 0 0 (54) (100) (36) 8 3100 0 69 0 298 75 (27) (38) (54) (100) 9 417 41 18 165 811 9 (27) (55) (100) (68) (54) (100) 10 876 0 80 0 0 0 (32) (52) 11 2671 37 67 0 0 25 (12) (59) (53) (100) 12 832 188 20 1 109 414 224 (40) (43) (100) (18) (30) (78) 13 247 148 0 622 391 0 (46) (42) (44) (40) 14 895 118 0 402 226 0 (56) (~3) (46) (50) 15 908 43 54 340 11 0 (27) (64) (100) (62) (100) Subtotal (stra~a 1-15) 12793 703 721 4146 4344 538 (10) (19) (15) (38) (19) (39)

25 348 4 69 0 0 0 (38) CWO) (34) Subtotal (strata 1-25) 13141 707 789 4146 4344 538 (10) (19) (14) (38) (19) (39)

26 0 0 0 0 0 0

27 1 170 0 44 0 0 0 (48) (66) 28 79 0 0 0 0 0 (56) Total (All strata) 14390 707 833 4146 4344 538 (10) (19) (13) (38) (19) (39)

20 Table 6: Time series of biomass estimates of hoki, hake, and ling for core 300-800 m strata and for all surveyed strata from Sub-Antarctic trawl surveys.

Core strata {300-800 m} All strata {300-1000 m} HOKI Biomass c.v. (%) Biomass c.v. (%) Summer series 1991 80285 7 1992 87359 6 1993 99695 9 2000 55663 13 56407 13 2001 38145 16 39396 15 2002 39890 14 40503 14 2003 14318 13 14724 13 2004 17593 11 18 114 12 2005 20440 13 20679 13

Autumn series 1992 67831 8 1993 53466 10 1996 89029 9 92650 9 1998 67709 11 71 738 10

HAKE Summer series 1991 5553 44 1992 1822 12 1993 2286 12 2000 2194 17 3103 14 2001 1 831 24 2360 19 2002 1293 20 2037 16 2003 1335 24 1898 21 2004 1250 27 1774 20 2005 1 133 20 1624 17

Autumn series 1992 5028 15 1993 3221 13 1996 2026 12 2825 12 1998 2506 18 3898 16

LING Summer series 1991 24085 7 1992 21368 6 1993 29747 12 2000 33023 7 33033 7 2001 25059 7 25167 6 2002 25628 10 25635 10 2003 22174 10 22192 10 2004 23744 12 23794 12 2005 19685 9 19755 9

Autumn series 1992 42334 6 1993 33553 5 1996 32133 8 32363 8 1998 30776 9 30893 9

21 Table 7: Numbers offish for which length, sex, and biological data were collected; - no data.

Leng!h freguenc~ data Leng!h-weight data No. offish measured No. of No. of No. of Species Total t Male Female samples fish samples

Alfonsino 0 1 1 Arrow squid 1 143 791 348 42 582 31 Banded bellowsfish I 0 0 I I I Banded rattail 1884 0 3 59 549 27 Banded stargazer 1 0 0 1 1 Basketwork eel 143 36 54 14 139 13 Baxter's lantern dogfish 341 172 168 39 287 32 Bigeye cardinalfish 20 0 0 4 11 3 Black cardinalfish 35 I 4 5 27 4 Black javelinfish 13 5 6 2 13 2 Black oreo 863 509 352 12 331 II Blackspot rattail 7 0 0 3 7 3 Bluenose 1 1 0 1 1 1 Bollons's rattail 141 0 12 13 140 13 Brown chimaera 1 0 1 1 1 Carpet shark 1 0 1 1 1 Catshark 6 2 3 4 6 4 Dark ghost shark 327 150 177 10 287 10 Dawson's catshark 5 4 1 4 5 4 Deepwater spiny dogfish 79 34 43 19 68 18 Finless flounder 1 0 0 1 1 Four-rayed rattail 1013 0 5 11 270 4 Gernfish 4 2 2 3 4 3 Giant chimaera 1 0 1 1 1 1 Giant stargazer 138 29 109 20 138 20 Hairy conger 37 1 4 17 34 16 Hake 424 146 278 43 424 43 Hapuku 3 3 0 2 3 2 Hoki 4907 1996 2911 88 1416 78 1avelinfish 7236 0 7 86 820 21 10hnson's cod 56 3 7 7 54 6 Kaiyomaru rattail 47 0 0 3 47 3 Lighthouse fish 1 0 0 1 Ling 2084 1095 989 83 1 351 72 Longn()se velvet dogfish 511 117 394 23 296 15 Longnosed chimaera 66 29 37 37 64 35 Lookdown dory 142 64 77 39 125 37 Lucifer dogfi$h 399 225 171 41 234 33 Mahia rattail 3 0 0 2 2 1 Notable rattail 119 0 0 7 55 5 Oblique panded rattail 533 0 0 27 304 18 Oliver's rattail 2649 0 I 42 391 14 Orange roughy 374 190 184 16 372 16 Owston's dogfish 99 37 61 6 56 4 Pale ghost shark 980 518 460 83 818 74 Plunket's shark 7 5 2 5 7 5 Prickly dogfish 3 2 1 2 3 2 Ray's bream 51 22 29 8 51 8 Red cod 161 104 57 7 119 7 Ribaldo 308 87 220 45 281 42 Ridge-scaled rattail 733 346 178 26 418 15

22 Table 7 cont: Numbers of fish for which length, sex, and biological data were collected.

Leng!h fre9uenc~ data Leng!h-weight data No. offish measured No. of No. of No. of Species Total t Male Female samples fish samples

Robust cardinalfish 1 0 0 1 1 1 Rough skate 8 2 6 6 8 6 Rudderfish 9 1 8 6 9 6 Scampi 9 9 0 1 9 1 Sea perch 22 13 9 3 20 2 Seal shark 24 6 18 9 21 8 Serrulate rattail 29 0 0 3 27 2 Shovelnosed dogfish 395 150 244 14 227 9 Silver dory 491 0 0 5 393 5 Silver warehou 77 30 47 6 29 6 Silverside 654 0 0 30 370 22 Slender rattail 3 0 0 3 3 3 Slender smooth-hound 2 2 0 1 2 Small banded rattail 12 0 0 1 12 1 Small headed cod 23 0 0 5 23 5 Small-scaled slickhead 400 130 141 14 159 8 Smooth oreo 557 295 262 15 533 14 Smooth skate 4 0 4 4 4 4 Southern blue whiting 766 352 414 23 536 23 Spiky oreo 5 3 2 2 4 2 Spineback 166 0 14 25 150 22 Spiny dogfish 796 303 493 45 378 33 Swollenhead conger 37 5 4 18 31 15 Violet cod 25 0 0 3 25 3 White rattail 73 20 12 8 57 7 White warehou 154 109 45 18 112 17 Widenosed chimaera 27 16 11 11 27 11 tTotal is sometimes greater than the sum of male and female fish because the sex of some fish was not recorded.

23 Table 8: Length-weight regression parameters* used to scale length frequencies for the twelve major species.

Regression Qarameters Length Species a b ? n range (cm) Data source Blackoreo 0.044545 2.776595 .80 326 23.1 - 40.8 TAN0515 Dark ghost shark 0.002153 3.267209 .97 287 28.0-74.2 TAN0515 lavelinfish 0.000670 3.329332 .96 784 21.9 - 56.2 TAN0515 Hake 0.002997 3.202775 .97 423 47.9-121.5 TAN0515 Hoki 0.005824 2.840234 .98 1412 33.2 - 112.6 TAN0515 Ling 0.002042 3.186303 .97 1345 42.0-137.0 TAN0515 Lookdown dory 0.026807 2.974310 .98 125 16.8 - 53.5 TAN0515 Pale ghost shark 0.011441 2.840570 .97 817 24.3 - 84.8 TAN0515 Ribaldo 0.004319 3.231992 .98 278 21.7 -72.1 TAN0515 Southern blue whiting 0.001706 3.360020 .97 534 25.0- 59.7 TAN0515 Spiny dogfish 0.001378 3.271252 .93 376 52.6 -100.5 TAN0515 White warehou 0.028007 2.918178 .98 112 31.4-59.7 TAN0515

* W = aLb where W is weight (g) and L is length (cm); ? is the correlation coefficient, n is the number of samples.

Table 9: Numbers ofhoki, hake, and ling at each reproductive stage*.

Hoki Hake Ling Reproductive stage Male Female Male Female Male Female 1 1246 1446 34 97 146 202 2 539 1209 35 97 262 551 3 0 8 2 62 188 60 4 1 0 8 2 346 146 5 1 1 60 1 67 14 6 156 2 6 3 72 11 7 52 242 1 16 13 3 Total staged 1995 2908 146 278 1094 987

*See Appendix 1 for description of gonad stages.

Table 10: Average liver condition index (LCI) and somatic condition factor (CF) for hoki sampled during Sub-Antarctic trawl surveys 2001-05.

LCI CF Year Male Female Male Female 2001 2.58 3.12 2.61 2.57 2002 2.37 2.74 2.63 2.60 2003 2.36 2.93 2.62 2.60 2004 2.71 3.25 2.63 2.59 2005 3.01 3.15 2.75 2.68

LCI = liver weight (g) / gutted weight (g) x 100 CF = gutted weight (g) / (length (cm))3 x 1000

24 Table 11. Quality of acoustic data collected during trawl surveys in the Sub-Antarctic between 2000 and 2005. The quality of each recording was subjectively categorised as "good", "marginal" or "poor" based on the appearance of the 38 kHz echograms (see appendix 2 of O'Driscoll & Bagley (2004) for examples).

Survey Number of % of recordings recordings Good Marginal Poor

2000 (TANOOI2) 234 57 21 22 2001 (TANOI18) 221 65 20 15 2002 (TAN0219) 202 78 12 10 2003 (TAN0317) 169 37 25 38 2004 (TAN0414) 163 61 25 14 2005 (T AN0515) 197 75 16 9

25 Table 12: Percentage occurrence of the eight acoustic mark types classified by O'Driscoli (2001) in trawl surveys of the Sub-Antarctic between 2000 and 2005. Several mark types were usually present in the same echogram. n is the number of acoustic files examined.

Pelagic marks Bottom marks Acoustic file Survey n Surface layer School Layer Cloud Layer Cloud School Single target

Day steam 2000 (TANOOI2) 90 93 71 63 6 58 17 11 96 2001 (TANOl18) 85 91 71 72 41 54 26 12 91 2002 (TAN0219) 72 92 72 75 19 79 19 14 94 2003 (TAN0317) 64 94 56 53 47 67 30 l3 77 2004 (T AN0414) 49 82 63 55 43 69 31 12 73 2005 (T AN0515) 75 91 77 73 63 67 59 16 95

Night steam 2000 (TANOOI2) 36 97 22 14 33 17 67 3 92 2001 (TAN01l8) 26 100 23 19 85 38 85 8 88 2002 (T AN0219) 23 100 l3 13 96 39 91 0 87 2003 (TAN0317) 22 95 14 14 86 32 73 0 55 2004 (TAN0414) 22 95 14 23 68 36 95 0 91 2005 (TAN0515) 23 100 61 44 100 57 91 4 100

Trawl 2000 (T ANOO 12) 108 90 50 52 23 37 20 10 91 2001 (TAN0118) 110 81 60 62 32 35 26 15 89 2002 (T AN0219) 108 91 60 59 32 41 31 15 56 2003 (T AN0317) 83 86 37 53 28 46 25 4 65 2004 (TAN0414) 92 63 47 48 29 38 33 10 61 2005 (TAN0515) 99 85 65 60 55 38 52 6 91

26 Table 13. Average trawl catch and acoustic backscatter from bottom-referenced marks during tows where acoustic data quality was suitable for echo integration for Sub-Antarctic surveys between 2000 and 2005. All tows were conducted during daylight. Data for 2000-04 are from O'Driscoll & Bagley (2003b, 2004, 2006).

Survey Number of Trawl catch {kg km-2} Average acoustic backscatter {m2 km-2} recordings Mean Median Bottom 10m Entire layer

2000 (TANOOI2) 100 697 590 0.502 3.37 2001 (TANOIl8) 101 779 567 0.506 2.90 2002 (TAN0219) 96 726 443 0.6S7 4.08 2003 (T AN0317) 48 568 3S1 0.622 2.50 2004 (TAN0414) 80 1031 393 0.484 1.77 200S (T ANOS1S) 87 691 457 0.623 2.40

27 ~ Foul ground

47"

25 Stewart 48" Snares shelf 300

49"

50"

51 "S

52'

53"

54"

Figure 1: Stratum boundaries for the November-I)ecember 2005 Southland and Sub-Antarctic trawl survey.

28 ~ Foul ground

47"

48° .<

49°

50°

51"8

52°

53°

54°

Figure 2: Map showing start positions of all bottom trawls (including unsuccessful stations) from the November-December 2005 Southland and Sub-Antarctic trawl survey_

29 120 -r--~------, 2 ,------, Ribaldo '0 100 o eo 80 ~ 60 ro E 40 o iii 20

o -'-----,---,--,---.--.--.---r-~0~

60 ,------, 6-,------,------~ White warehou o e 40 4 en en ro E 20 o iii

10 ,-r------, 50 ,------,--, Hake Black oreo o 8 40 o e 6 30 en ~ 4 20 E ffi 2 10

O~--.-__,_--__._--,______r--___._--_.___--I o ~~~~~~~_r_~~~~.-~

80 ,------, 4,------Southern blue whiting Lookdown dory o 60 3 eo ~ 40 2 ro E o 20 iii O-'------.---,---r-----,--,------,--,---

30 -,------, 20 -,------, Pale ghost shark o 15 e 20 en en 10 ~ 10 o 5 iii

6 ,--,------, 30 ,------, Dark ghost shark Javelinfish o e 4 20 en en ~ 2 10 o iii

93 95 97 99 01 03 05 07 93 95 97 99 01 03 05 07

Year Year

Figure 3: Trends in biomass (± 2 standard errors) of major species in the core 300-800 m strata in aU Sub­ Antarctic trawl surveys from Tangaroa. Solid circles show the summer time series and solid triangles the autumn time series. The open circle shows biomass from a survey of the same area in September-October 1992.

30 TAN0515 hoki

Max. catch -2 = 872 kg.km

o Zero catch .'

50'

51 'S

52'

53'

54'

Figure 4a: Distribution and ~atch rate~ of all hoki in the summer 2005 trawl survey. <:;ircIe area is proportional to ~atch rate.

31 TAN0515 1+ hoki

47" Max. catch -2 • = 306 kg.km o Zero catch

48"

49"

50"

51"S

52"

53"

54" o

Figure 4b: Distribution and catch rates of 1+ «45 cm) hoki in the summer 2005 trawl survey. Circle area is proportional to catch rate.

32 T AN0515 2+ hoki

47" Max. catch -2 = 663 kg.km

o Zero catch

48· -'

49·

50·

51·S

52·

53·

54·

Figure 4c: Distributiou and catch rates of 2+ (46-60 cm) hold in the summer 2005 trawl survey. Circle area is proportional to catch rate.

33 T AN0515 hake

4T Max. catch ·2 = 362 kg.km

o Zero catch

48'

49'

50"

51'S

52'

53"

54'

Figure 5: Distribution and catch rates of hake in the summer 2005 trawl survey, Circle area is proportional to catch rate,

34 TAN0515 ling

47' Max. catch -2 = 1198 kg.km

o Zero catch 48· .'

Figure 6: Distribution and catch rates of ling in the summer 2005 trawl survey. Circle area is proportional to catch rate.

35 2 November/December 1991 2 November/December 2000 m=29093 754 (12%) m = 12810216 (15%) m=29 080 534(12%) 1 m= 12 m 972 (15%) o +---.-""""''''-r......

2 April/May 1992 2 November/December 2001 m=18471246(10%) m=9655589 (19%) m= 9 557 068 (19%)

2 November/December 1992 2 November/December 2002 m = 25 079 858 ( 9%) m = 9 287109 (22%) m=25 054574(9%) 1 m = 9 244 242 (22%) .- en c .Q ·E 2 May/June 1993 2 November/December 2003 '-" m= 14910167 (21%) m = 8 723 067 (24%) .c en m= 8 716892 (24%) l+= '5 o ~ Q) .0 2 November/December 1993 2 November/December 2004 E ::J m= 30 518 858 (15%) m= 10 137028 (36%) Z m=30491506(15%) 1 m= 10 127 933 (36%)

March/April 1996 2 m = 40 731 596 (16%) 2 November/December 2005 m=40 184024(16%) m= 5 740871 (15%) m= 5 723 400 (15%)

20 30 40 50 60 70 80 90 100 110 120 2 April/May 1998 m=21894594(10%) m=21102508(1001o)

0+-...,.....-..-...,...... 20 30 40 50 60 70 80 90 100 110 120

Totallength (an)

Figure 7a: Scaled length frequency for male hoki from all Sub-Antarctic Tangaroa trawl surveys. Population numbers for core strata are presented as black bars and for all stra~a as white bars. Numbers (m values) above are for all strata and below (in bold) for core strata with c.v.s in parentheses.

36 Novermer/December 1991 November/Decermer 2000 2 2 .f=38540 056 (9%) f= 22 937 372 (12%) 1 1~ f= 38 511588 (9%) f= 22 596 402 (12%)

o I...f' I : i I I

2 April/May 1992 2 Novermer/Decermer 2001 f=26811646(9%) f= 15720532 (14%) f= 15205687 (15%)

2 November/Decermer 1992 2 NovermerlDecember2002 f= 34 909 584 (7%) f= 17092 600 (15%) f= 34 841 368 (7%) 1 f= 16 839 920 (15%)

2 May/June 1993 2 Novermer/December 2003 f= 10209 969 (13%) .c f=22286606(16%) 1 en f= 10057 274 (13%) ;;:: 15 ....en a.> .n Novermer/Decermer 1993 E 2 f =39 230 688 (11 %) 2 November/December 2004 ::J f= 39140 924 (12%) 1 f= 13186 656 (25%) Z f= 12 984 706 (25%) O+----,--J-...... --,...-..-.

2 March/April 1996 f =43 061 620 (11 %) 2 November/Decermer 2005 f= 41421 568 (11%) f= 9 600 143 (13%) f= 9 498 761 (13%)

O+-~~~"~~~~"~~ 20 30 40 50 60 70 80 90 100 110 120 2 April/May 1998 f= 30 258 390 (11%) f=28164834(11%)

20 30 40 50 60 70 80 90 100 110 120

Total length (an)

Figure 7b: Scaled length frequency for female hoki from all Sub-Antarctic Tangaroa trawl surveys. Population numbers for core strata are presented as black bars and for all strata as white bars. Numbers if values) above are for all strata and below (in bold) for core strata with c.v.s in parentheses.

37 November/December 1991 November/December 2000 m = 594 652 (85%) m = 269 042 (28%) 40 m = 575 548 (88%) =0 j m = 99 978 (30".. ) 20

0 ~ _QLl~ n,

April/May 1992 November/December 2001 40 m= 196 524 (21%) 40 m =146 593 (14%) 20 20 m= 48 602 (31%)

0

November/December 1992 November/December 2002 40 40 m=43520 (31%) m =175288 (20%) 20 m= 22 577 (32%) m = 64 332 (39%) .- en "0 0 c: co en ::J May/June 1993 40 November/December 2003 0 40 .c m = 90 275 (25%) m = 159262 (28%) '-" 20 m= 87673(42%) .c- 20 en ....~ 0 0 ....en Q) November/December 1993 November/December 2004 .0 40 40 E m= 125819 (22%) m = 193 277 (20%) ::J m= 87015 (24%) m= 117379 (28%) Z 20 20 0

40 March/April 1996 40 November/December 2005 m = 247 797 (20%) m = 72 806 (25%) m= 118151 (23%) 20 20 m = 23 784 (40%)

40 50 60 70 80 90 100 110 120 130 40 AprillMay 1998 m = 259 990 (27%) m= 85 883 (41%) 20

40 50 60 70 80 90 100 110 120 130

Total length (an)

Figure 8a: Scaled length frequency for male hake from all Sub-Antarctic Tangaroa trawl surveys. Population numbers for core strata are presented as black bars and for all strata as white bars. Numbers (m values) above are for all strata and below (in bold) for core strata with c.v.s in parentheses.

38 November/December 1991 r~~ 40 j__ f= 395 219 (15%) 40 f = 551 657 (14%) f= 365 495 (16%) 20 20 A f=341436(17"/~ 0 o .~ ...~~II ~ I April/May 1992 November/December 2001 f= 418 3n (16%) 40 40 f=408174 (15%) 20 20 f= 268 900 (20%)

0 0

November/December 1992 November/December 2002 40 40 f= 253 317( 12%) f= 362 732 (16%) 20 f=226271 (12%) 20 f= 197952 (21%)

C/) ----"0 0 0 C ctI C/) ::::l May/June 1993 November/December 2003 o 40 f= 349 210 (1&'10) 40 ..c f= 321 010 (21%) ~ 20 ..c 20 f= 219 542 (25%) C/) i+= 0 0 '0 ~ (J) November/December 1993 November/December 2004 .0 40 E f= 342 531 (16%) 40 f= 232 418 (19%) ::::l 20 f= 273 010 (15%) 20 f= 130 318 (29%) Z

MarchlApril1996 November/December 2005 40 f= 350 295 (14%) 40 f= 256 482 (16%) f= 242 232 (1&'/0) 20 20 f= 163 324 (19%)

0 0 40 50 60 70 80 90 100 110 120 130 April/May 1998 f= 259 990 (27%) 40 f= 85 883 (41%) 20

40 50 60 70 80 90 100 110 120 130

Totallength (em)

Figure 8b: Scaled length frequency for female hake from all Sub-Antarctic Tangaroa trawl surveys. Population numbers for core strata are presented as black bars and for all strata as white bars. Numbers if values) above are for all strata and below (in bold) for core strata with c.v.s in parentheses.

39 400 November/December 1991 400 November/December 2000 m= 3 478 726 (6%) m = 6 960 578 ( 9%) 200 m= 3 474 679 ( 6%) 200 m= 6 959 707 (9%)

0 0

400 April/May 1992 400 November/December 2001 m= 6 970937 (6%) m= 5 541474 (7%) 200 200 m= 5 512 967 (7%)

0 0

400 November/December 1992 400 November/December 2002 m=3827741 (7%) m=4682928 (11%) 200 m= 3 783 672 (7«'/0) 200 m=4681 006(11%) .- en "0 0 0 C co ~400 May/June 1993 400 November/December 2003 0 ..c m= 5 558 013 (7«'10) m=4341717(12%) :::::.. 200 200 m=4341152(12%) ..c en ;;::::: 0 0 '+- 0 en '- (]) 400 November/December 1993 400 November/December 2004 .0 E m=4 745116 (16%) m=4830901 (17%) :::J 200 200 Z m=4734 096(16%) m= 4 823 008 (17«'/0) 0 0

400 400 m= 6123 598 (8%) November/December 2005 m= 6 075 699 (8%) m = 3 850 706 (9%) 200 200 m= 3 842162 (9%)

0 0 20 30 40 50 60 70 80 90 100 110 120 130 400 April/May 1998 m= 5 994140 (8%) 200 m= 5 978 688 ( 8%)

20 30 40 50 60 70 80 90 100 110 120 130

Total length (an)

Figure 9a: Scaled length frequency for male ling from all Sub-Antarctic Tangaroa trawl surveys. Population numbers for core strata are presented as black bars and for all strata as white bars. Numbers (m values) above are for all strata and below (in bold) for core strata with c.v.s in parentheses.

40 400 November/December 1991 400 November/December 2000 f= 5328206 ( 8%) f= 8 931456 (8%) 200 f= 5 327 265 ( 8%) 200 f= 8 929 737 (8%)

0 0

400 April/May 1992 400 f= 7053 206 (T»Io) November/December 2001 f= 6414 929 (8%) 200 200 f= 6 396 967 (8%)

0 0

400 November/December 1992 400 November/December 2002 f=4483895(7%) f= 6376829 (10%) 200 f=4441594{7%) 200 f= 6 376 670 (10%) ..-.. en "'0 0 0 c:: co ~400 May/June 1993 400 November/December 2003 0 ..c:: f= 5 743 077 ( T»/o) f= 5 571690 (11%) ~ 200 200 ..c:: f= 5 566 904 (11%) en .;::::: 0 0 '+- 0 ....en Q) 400 November/December 1993 400 November/December 2004 .0 E f= 6161622 (8%) f= 5 974 062 (9%) z:::l 200 f= 6151 385 ( 8%) 200 f= 5 963104 (9%) 0 0

400 March/April 1996 f=5757568(11%) 400 November/Decermer 2005 f=5737290{11%) 200 f= 5 070 772 (9%) 200 f= 5 058 518 (9%)

0 0 20 30 40 50 60 70 80 90 100 110 120 130 400 April/May 1998 f= 6 2:37 624 (13%) 200 f= 6 221 070 (13%)

0 20 30 40 50 60 70 80 90 100 110 120 130

Total length (an)

Figure 9b: Scaled length frequency for female ling from all Sub-Antarctic Tangaroa trawl surveys. Population numbers for core strata are presented as black bars and for all strata as white bars. Numbers if values) above are for all strata and below (in bold) for core strata with c.v.s in parentheses.

41 8 Black area - Males 8 Black area - Females en scaled total = 31 965 424 scaled total = 45 736 348 .=§ c.v. = 96 % c.v. = 99 % n = 509 n = 352 I 6 6 ~ -=CIl b 4 4 ~ Q) .0 E 2 2 z~

10 20 30 40 50 10 20 30 40 50 Total length (em)

Dark ghost shark - Males Dark ghost shark - Females 60 scaled total = 313 436 60 scaled total = 554 287 c.v. = 44 % c.v. = 45 % n = 150 n = 177

40 40 ~ -=CIl b

Q)~ 20 20 .0 E z~

o 20 40 60 80 o 20 40 60 80 Chimaera length (em)

10 Javelinfish - unsexed scaled total = 102031 992 c.v. = 13% n = 7 230

b 4

o 10 20 30 40 50 60 Total length (em)

Figure 10: Length frequency distributions by sex of other major species in the November-December 2005 survey. Scaled total is the estimated total number of fish in the surveyed area, c.v. is the coefficient of variation, n is the number of fish measured.

42 100 Lookdown dory - Males 100 Lookdown dory - Females scaled total =200 261 scaled total =377 347 c.v. =26 % c.v. =22 % 80 n =64 80 n= 75

60 60

40 40

20

10 20 30 40 50 60 10 20 30 40 50 60 Total length (em)

Pale ghost shark - Males 300 Pale ghost shark - Females Ul 300 scaled total 2 697 687 "0 scaled total =2 863 583 = C c.v.=11% ro c.v. = 12 % CIl n = 511 n =454 ::::lo §. 200 200 ..c:: CIl .;:::: '0 ~ 100 100 Q) .D E ::::l Z O~~~--~~llW~WW~~~~~~~ 20 30 40 50 60 70 80 90 20 30 40 50 60 70 80 90 Chimaera length (em)

Ribaldo - Males Ribaldo - Females 50 50 scaled males =52 245 scaled total =384 631 c.v. =22 % c.v. = 14 % 40 n =87 40 n =220

30 30

20 20

10

20 30 40 50 60 70 80 20 30 40 50 60 70 80 Total length (em)

Figure 10 cont: Length frequency distributions by sex of other major species in the November-December 2005 survey. Scaled total is the estimated total number of fish in the surveyed area, c.v. is the coefficient of variation, n is the number of fish measured.

43 Southern blue whiting - Males Southern blue whiting - Females scaled total = 4 423 636 scaled total = 4 936 307 c.v.=37% c.v. = 30 % 900 n= 350 900 n = 411

600 600

300 300

o~-=~~~~wu~~~~wu~w=~~ 20 30 40 50 60 20 30 40 50 60 Fork length (em)

en 150 Spiny dogfish - Males Spiny dogfish - Females "0 scaled total = 1 125 381 150 scaled total = 1 568 709 c C1l c.v. = 26 % c.v. = 20 % CIJ n= 303 n =492 o:J §. 100 100 ..c -=CIJ '5

Q)~ 50 50 .0 E :J Z

O~--T--',m~illW~~~--.--.--~ O~ __.-~~~illW~illW~Will~~ __-, 30 40 50 60 70 80 90 100 110 30 40 50 60 70 80 90 100 110 Total length (em)

White warehou - Females 100 White warehou - Males 100 scaled male total = 244 315 scaled total = 118 690 c.v. =43% c.v. = 49 % 80 n = 109 80 n =49

60 60

40 40

20 o 10 20 30 40 50 60 70 10 20 30 40 50 60 70 Fork length (em)

Figure 10 cont: Length frequency distributions by sex of other major species in the November-December 2005 survey. Scaled total is the estimated total number of fish in the surveyed area, c.v. is the coefficient of variation, n is the number of fish measured.

44 15 15 Nove~rlDece~1991 Nove~r/December 2000 10 m= 311 (23%) 10 m= 238 (26%) 5 5

O~~~Ll~,L~~~--.-.-~ 0+-~~~~r-9--r-'--.-.-~ 15 Nove~r/Dece~r 2001 April/May 1992 :: 1 m=222(25%) 10 m= 350 (29%) 5

O_CJI~ O+=~~~~~~.-o-.--,-. 15 Nove~r/Dece~r 1992 15 Noven1berlDece~r2002 10 m=334(19%) 10 m=297 (36%) 5 5

CJ) O+-~~~~,L~=o-.--.-.-~ -c: .Q 15 15 May/June 1993 Nove~rl~r2003 E 10 m= 323 (21%) 10 '-"' m= 319 (29%) ~ 5 5 '+= o O~~~~~~~~~~.-.-~ O~Lr=O-.r-~'--r-.--.-.-~ i!? Q) 15 .0 Nov~/~r 1993 15 November/December 2004 E 10 10 :J m= 294 (32%) Z m=342 (41%) 5 5

0~~=T~r-.-~~-.--.-.-~

15 November/December 2005 m=313 (28%) 10 m=341 (28%) :~l£~ 5 O~~~~r-~~=o-.--.-.-~ o 2 4 6 8 10 12 14 16 18 20 15 April/May 1998 10 m=300(20%) 5

0+=~~L4k2~~-r~--.-.-~ o 2 4 6 8 10 12 14 16 18 20

Age

Figure 11a: Scaled age frequency for male hoki from all Sub-Antarctic Tangaroa trawl surveys for the core 300--800 m survey area. Number offish aged (m values) are given with c.v.s in parentheses.

45 15 j November/Decermer 1991 15 Novermer/Decermer 2000 1: j f= 407 (21%) ':_D'~ (=449(19"10) 0 ,~, 15 April/May 1992 15 November/Decermer 2001 10 f=56O (17%)

15 Novermer/DecerriJer 1992 10 f=399 (21%) 5 .-... en c .Q 15 May/June 1993 ·E-- 10 f= 1136 (13%) ~ 5 ;;:::: o 0+L~~L4~~~=r~--.-.-~ ~ Q) 15 ..0 Novermer/DecerriJer 1993 E 10 :::J f= 370 (28%) Z 5

o~~~~r=~~~~~r-.-~

15 j March/April 1996 ': ~ (=411 (25%)

o 2 4 6 8 10 12 14 16 18 20 15 April/May 1998 10 f=897 (17%)

5

o+-~~~~~~~~--.-.-~ o 2 4 6 8 10 12 14 16 18 20

PvJe

Figure llb: Scaled age frequency for female hoki from all Sub-Antarctic Tangaroa trawl surveys for the core 300-800 m survey area. Number offish aged ({values) are given with c.v.s in parentheses.

46 Novermer/December 1991 Novermer/Decermer 2000 200 ] ~ m=239(B3%) ': , , , m=117(75%) 1 dill 1°O~1~~ ,~,?=,~, 100 100 AprillMay 1992 Novermer/December 2001 m= 58 (78%) 50 50 m=212 (92%)

0+-~~~~~~~~L9~~~

100 Novermer/Decermer 1992 100~ 1November/December 2002 m=46(122%) 50 ~ m= 191 (82"")

.- ~ 0 +--...-=-r-r=-.-'--'-,,--,-=-r-.----.----,--.-----.---"i 11~lili c ~ 100 ::J May/June 1993 o m= 36 (106%) No, ..c 1°O~1 _/~2003 ~ 50 ~ . m = 186 (77",,)

~''"''""T''9

100 November/Decermer 2004 m 245 (8golo) 50 =

100 November/December 2005

50 m =146 (123%)

o 2 4 6 8 10 12 14 16 18 20 22 24 26

fo(;Je

Figure 12a: Scaled age frequency for male hake from all Sub-Antarctic Tangaroa trawl surveys for the core 300-800 m survey area. Number offish aged (m values) are given with c.v.s in parentheses.

47 100 1November/December 2000 f= 352 (53%) 50

o ,~,D,CJ.p1 100 Novermer/December 2001 f= 107 (54%) f= 349 (55%) 50

100 Novernber/Decermer 1992 100 j Novermer/Decermer 2002 f= 168 (49%) 50 50 ~ {= 377 (WIo)

--~ O+-~~~~~~~~-r-.-.~ o 7~r;=, c: ~ 100 May/June 1993 100 November/Decermer 2003 o f= 122(53%) j :5 50 50 ~ (=220(54%) ..c: -en i+= '5 O'~71""""T' ~ 100 Novermer/December 1993 100 Q) November/December 2004 .c f= 182 (50%) f=283 (67%) 50 50 :::JE Z

0+-~~~~~~=9~=r~-.~

100 November/Decermer 2005 ':0 1March/April 1996 f= 137 (7~1o) 50 f= 274 (53%)

,-, o 2 4 6 8 10 12 14 16 18 20 22 24 26 100 April/May 1998 f= 189(54%) 50

o 2 4 6 8 10 12 14 16 18 20 22 24 26

Figure 12b: Scaled age frequency for female hake from all Sub-Antarctic Tangaroa trawl surveys for the core 300--800 m survey area. Number offish aged ({values) are given with c.v.s in parentheses.

48 21 j Novermer/Decermer 1991 2] NoveomerIDeceJrr 2000 _ m=219 (24%) :J ,~ ~~2~(25%) o ,~ I I 'T' I I I I 2 April/May 1992 21 Noveniler/Deceniler 2001 m=216 (29%) _ m =268 (27%) :,~

2 j Noveniler/Deceniler 1992 21 1Noveniler/Deceniler 2002 _ m =225 (29",.) _ m= 224 (31%) :

.- en ,~, o c ,~,=r"f' oQ 2 May/June 1993 2 Novermer/Decermer 2003 °E m=256 (29%) m=242 (30%) J:: --en i+= o o+-~LV~~~~~~yo~-.~ ~ ~ 2 Novermer/Decermer 1993 2 Noverriler/Decermer 2004 § m = 247 (28%) m=256 (36%) z

2 2 March/April 1996 Novermer/Decermer 2005 m=331 (23%) m=279 (28%)

o 2 4 6 8 10 12 14 16 182022 242628 30 2 April/May 1998 m=271 (28%)

o 2 4 6 8 10 12 14 16 1820 22 24 26 28 30

Figure 13a: Scaled age frequency for male ling from all Sub-Antarctic Tangaroa trawl surveys for the core 300-800 m survey area. Number offish aged (m values) are given with c.v.s in parentheses.

49 2 j November/December 1991 f=349 (23%) 1

o I~'T'I I I I I I 2 2 j April/May 1992 November/December 2001 1 (=310(24%) f=326 (25%)

o '~''T'' 2 November/December 1992 21 j NoverrberIDecerrber 2002 f=350 (24%) ~ (= 350 (24%)

(i) 0 -+-r='lo....y--Y--Y-Y-'-,-L.r;:LY:::>;--,--~-r--, c o,~" oQ 2 May/June 1993 2 November/December 2003 °E f=370 (25%) f= 332 (27%) --~en t+= o O-+-~LY--Y--Y-Y-'-~UY~~~~--, ~ Q) 2 2 .0 November/December 1993 November/December 2004 E ::l f=346 (24%) f= 339 (30%) Z

o+-~~~~~~~~~~~~

2 March/April 1996 2 November/December 2005 f=274 (29%) f= 300 (30%)

o 2 4 6 8 10 12 14 16 1820 22 24 26 28 30 2 j April/May 1998 1 • . (= 296 (28"")

O~"""o 2 4 6 8 10 12 14 16 182022 242628 30

/l{Je

Figure 13b: Scaled age frequency for female ling from aU Sub-Antarctic Tangaroa trawl surveys for the core 300-800 m survey area. Number offish aged ({values) are given with c.v.s in parentheses.

50 10000 -.------, rho = 0.30 • N --I E • ~ • ~ • ••• .. --Q) ..,. -~ 1000 ..c ..• ,e u • __ tIt -cou • .. . ,.. .. 3: .. -. .... • ~ • •••• I- " • • .,....• .: .....•• • 100 +------.------,-----~ 0.01 0.1 1 10

Acoustic density in bottom 10 m (m 2 km-2)

10000 rho = 0.37 • N --I E • ~ OJ • ~ • • • • • --Q) , • • -....co 1000 • ..c ..r . u • • co •••• • •• -u .~.'. ;. 3: co .• "' ..•• • .... , I •• ~...... l- • • . .. , • • 100 0.1 1 10 100

Total acoustic density (m 2 km-2)

Figure 14. Relationship between total trawl catch rate (all species combined) and acoustic backscatter recorded during the trawl in the Sub-Antarctic in 2005. Rho values are Spearman's rank correlation coefficients.

51 TranM~'1 l, SUatum ~ar",'h+Stll!psh>;lt f T1"•• Ul:

--45

---_'\4

- -.<) 550 -ffl

wo

---« I

--1<-1

50 100 I:'iO 200 300 Trnosmit Number FrmnSOl Ike 17 I0:49:D 2(X)5 '0 S.!1kc 1711:110\:431015 ,AlllpUiudc: Piltt.'T: -IS.OdD iu nOdS lromLAT:44724SS LONG: 16643.535EulL-1.T:49 7.8.13$ LONG: 16639A.~5E

Figure 15: Example of an echo gram collected on 17 December 2005, showing spawning hake close to the bottom on the Stewart-Snares shelf in Stratum 3B. The horizontal scale is equivalent to about 5 km. Acoustic transects (see Figure 16) were run perpendicular to the direction ofthis echo gram.

52 46

48 ) tJ 50

500m

Figure 16: Maps showing location of acoustic survey area (upper panel) and the distribution of hake acoustic backscatter plotted in 10 ping (-100 m) bins (lower panel). Symbol size in the lower panel is proportional to the log of the acoustic backscatter.

53 488 ) 11 P 9 50

{) 0

9 "7.9 52

"7.6

54

164 166 168 170 172 174 176 E

Figure 17: Surface water temperatures (OC). Squares indicate station positions. Not all temperatures are labelled where two or more stations were close together. Contours show isotherms estimated by eye.

54 488 ) 5 I 50

0 0

52

54

164 166 168 170 172 174 176 E

Figure 18: Bottom water temperatures (DC). Squares indicate station positions. Not all temperatures are labelled where two or more stations were close together. Contours show isotherms estimated by eye.

55 Temperature (C) 6 7 8 9 10 11

O+------L------~--_.--~~------~._----~ 02

100+------~~~-=------~

200 +------M~------~

.- E --~ 300+------~~------~ 15.. Q) o

400 +------~~------~

500+------~~------_4

600~------~

Figure 19: Comparison of vertical profiles of temperature from the net-mounted CTD on tows in stratum 9 at approximately 50 45' Sand 169 00' E in 2002 (TAN0219 station 54, on 6 December), 2003 (TAN0317 station 45, on 29 November), 2004 (TAN0414 station 54, on 14 December), and 2005 (TAN0515 station 42, on 6 December). Labels indicate the year (i.e., 2002 is '02'), the profile from 2005 is the bold line.

56 Appendix 1: Description of gonad development used for staging male and female teleosts

Research gonad stage Males Females

Immature Testes small and translucent, Ovaries small and translucent. threadlike or narrow membranes. No developing oocytes.

2 Resting T estes thin and flabby; Ovaries are developed, white or transparent. but no developing eggs are visible.

3 Ripening Testes firm and well Ovaries contain visible developed, but no milt is developing eggs, but no present. hyaline eggs present.

4 Ripe Testes large, well developed; Some or all eggs are milt is present and flows when hyaline, but eggs are not testis is cut, but not when extruded when body is body is squeezed. squeezed.

5 Running-ripe Testis is large, well formed; Eggs flow freely from the milt flows easily under ovary when it is cut or the pressure on the body. body is pressed.

6 Partially spent Testis somewhat flabby and may Ovary partially deflated, be slightly bloodshot, but milt often bloodshot. Some still flows freely under hyaline and ovulated eggs pressure on the body. present and flowing from a cut ovary or when the body is squeezed.

7 Spent Testis is flabby and bloodshot. Ovary bloodshot; ovary No milt in most of testis, but wall may appear thick there may be some remaining and white. Some residual near the lumen. Milt not easily ovulated eggs may still expressed even when present. remain but will not flow when body is squeezed.

57 Appendix 2: Scientific and common names, species codes and occurrence (Occ.) of fish, squid, and other organisms.

Species Scientific name Common name code Occ.

Agnatha Myxinidae: hagfishes Eptatretus cirrhatus hagfish HAG

Chondrichthyes Squalidae: dogfishes Centrophorus squamosus deepwater spiny dogfish CSQ 22 Centroscymnus crepidater longnose velvet dogfish Cyp 27 C. owstoni smooth skin dogfish CYO 10 C. plunketi Plunket's shark PLS 6 Deania calcea shovelnose dogfish SND 17 Etmopterus baxteri Baxter's dogfish ETB 43 E. lucifer Lucifer dogfish ETL 53 Scymnorhinus licha seal shark BSH 13 Squalus acanthias spiny dogfish SPD 45 Oxynotidae: rough sharks Oxynotus bruniensis prickly dogfish PDG 2 Scyliorhinidae: cat sharks Apristurus spp deepsea catsharks APR 6 Cephaloscyllium isabellum carpet shark CAR 1 Halaelurus dawsoni Dawson's catshark DCS 4 Proscyllidae: finback cat sharks Gollum attenuatus slender smoothhound SSH Narkidae: blind electric rays Typhlonarke spp numbfish BER Rajidae: skates Bathyraja shuntovi longnosed deepsea skate PSK 1 Dipturus innominata smooth skate SSK 5 D. nasuta rough skate RSK 7 Pavoraja asperula smooth bluntnosed skate BTA 13 P. spinifera prickly bluntnosed skate BTS 5 Chimaeridae: chimaeras, ghost sharks Chimaera lignaria giant chimaera CHG 1 Chimaera sp brown chimaera CHP 1 Hydrolagus bemisi pale ghost shark GSP 86 H novaezelandiae dark ghost shark GSH 10 Rhinochimaeridae: longnosed chimaeras Harriotta raleighana longnose chimaera LCH 41 Rhinochimaera pacifica widenose chimaera RCH 13

Osteichthyes Notacanthidae: spiny eels N se.xspinis spineback SBK 42 Synaphobranchidae: cutthroat eels Diastobranchus capensis basketwork eel BEE 20 Congridae: conger eels Bassanago bulbiceps swollenheaded conger SCO 23 B. hirsutus hairy conger HCO 23 Argentinidae: silversides Argentina elongata silverside SSI 34 Bathylagidae: deepsea smelts Bathylagus spp deepsea smelt DSS Nansenia spp deepsea smelt NAN

58 Appendix 2 cont: Scientific and common names, species codes and occurrence (Occ.) of fish, squid, and other organisms.

Species Scientific name Common name code Occ.

Alepocephalidae: slickheads Alepocephalus australis small-scaled brown slickhead SSM 17 Alepocephalus sp big-scaled brown slickhead SBI Platytroctidae: tubeshoulders Persparsia /wpua tube shoulder PER 2 Sternoptychidae: hatchetfishes Argyropelecus gigas giant hatchetfish AGI 2 Species not identified hatchetfish HAT Chauliodontidae: viperfishes Chauliodus sloani viperfish CHA 9 Stomiidae: scaly dragonfishes Stomias spp scaly dragonfish STO 5 Astronesthidae: snaggletooths Borostomias mononema snaggletooth BMO I Species not identified snaggletooth AST 2 Melanostomiidae: scaleless black dragonfishes Opostomias micripnus scaleless black dragonfish OMI 2 Malacosteidae: loosejaws Species not identified loosejaw MAL Idiacanthidae: black dragonfishes Idiacanthus sp black dragonfish illI Gonostomatidae: lightfishes Diplophos spp lightfish DIP 2 Sternoptychidae: hatchetfishes Sternoptyx spp hatchetfish STE Photichthyidae: lighthouse fishes Photichthys argenteus lighthouse fish PHO 23 Paralepididae: barracudinas Magnisudis prionosa barracudina BCA Species not identified barracudina PAL Omosudidae: omosudid Omosudis lowei omosudid OMO 2 Myctophidae: lanternfishes Diaphus spp lanternfish DIA 1 Gymnoscopelus spp lanternfish GYM 2 Lampanyctus spp lanternfish LPA 5 Species not identified lanternfish LAN 5 Moridae: morid cods Antimora rostrata violet cod VCO 8 Austrophycis marginata dwarf cod DCO 6 Halargyreus johnsoni Johnson's cod HJO 17 Lepidion microcephalus small-headed cod SMC 10 Moramoro ribaldo RIB 45 Pseudophycis bach us red cod RCO 9 Gadidae: true cods Micromesistius australis southern blue whiting SBW 23 Merlucciidae: hakes Lyconus sp LYC 1 Macruronus novaezelandiae hoki HOK 89 Merluccius australis hake HAK 43

59 Appendix 2 cont: Scientific and common names, species codes and occurrence (Occ.) of fish, squid, and other organisms.

Species Scientific name Common name code Occ.

Macrouridae: rattails, grenadiers Caelorinchus aspercephalus oblique-banded rattail CAS 34 C. bollonsi Bollons's rattail CBO 22 C. Jasciatus banded rattail CFA 83 C. innotabilis notable rattail CIN 19 C. kaiyomaru Kaiyomaru rattail CKA 14 C. matamua Mahia rattail CMA 12 C. oliverianus Oliver's rattail COL 60 C. parvifasciatus small-banded rattail CCX 2 Coryphaenoides dossenus humpback rattail CBA 8 C. murrayi abyssal rattail CMU I C. serrulatus serrulate rattail CSE 15 C. striaturus abyssal rattail CTR 1 C. subserrulatus fourrayed rattail CSU 27 Lepidorhynchus denticulatus javelinfish JAV 90 Macrourus carinatus ridge-scaled rattail MCA 30 Mesobius antipodum blackjavelinfish BJA 6 Trachyrincus aphyodes white rattail WHX 11 Ventrifossa nigromaculata blackspot rattail VNI 23 Ophidiidae: cusk eels Genypterus blacodes ling LIN 84 Carapidae: pearlfishes Echiodon cryomargarites messmate fish ECR 2 Ceratiidae: seadevils Cryptopsaras couesi seadevil SDE Trachipteridae: dealfishes Trachipterus trachypterus dealfish DEA 1 Trachichthyidae: roughies Hoplostethus atlanticus orange roughy ORR 16 H mediterraneus silver roughy SRR 8 Diremidae: discfishes Diretrnus argenteus discfish DIS 3 Berycidae: alfonsinos Beryx splendens alfonsino BYS Zeidae: dories Capromimus abbreviatus capro dory CDO 3 Cyttus novaezealandiae silver dory SDO 7 C. traversi lookdown dory LDO 40 Macrorhalllphosidae: snipefishes Centriscops humerosus banded bellowsfish BBE 2 Scorpaenidae: scorpionfishes Helicolenus spp sea perch SPE 3 Trachyscorpia capensis cape scorpion fish TRS 2 Oreosomatidae: oreos Allocyttus niger black oreo BOE 13 Neocyttus rhomboidalis spiky oreo SOR 4 Pseudocyttus maculatus smoothoreo SSO 15 Congiopodidae: pigfishes Alertichthys blacki alert pigfish API Hoplichthyidae: ghostflatheads Hoplichthys haswelli deepsea flathead FHD 2

60 Appendix 2 cont: Scientific and common names, species codes and occurrence (Occ.) offish, squid, and other organisms.

Species Scientific name Common name code Occ.

Psychrolutidae: toadfishes Cottunculus nudus bonyskull toadfish COT 1 Neophrynichthys angustus pale toadfish TOP 17 Psychrolutes sp blobfish PSY 7 Percichthyidae: temperate basses Polyprion oxygeneios hapuku HAP 2 Apogonidae: cardinal fishes Epigonus lenimen bigeye cardinalfish EPL 11 E. robustus cardinal fish EPR 2 E. telescopus black cardinalfish EPT 8 Brarnidae: pomfrets Brama brama Ray's bream RBM 9 Chiasmodontidae: swallowers Chiasmodon niger black swallower CNI Uranoscopidae: armourhead stargazers Kathetostoma spp banded giant stargazer BGZ 1 K giganteum giant stargazer STA 20 Percophidae: opalfishes Hemerocoetes spp opalfish OPA Gempylidae: snake mackerels Paradiplospinus gracilis false frostfish PDS 2 Rexea solandri gernfish SKI 3 Centrolophidae: raftfishes, medusafishes Centrolophus niger rudderfish RUD 8 Hyperoglyphe antarctica bluenose BNS 1 ICichthys australis ragfish RAG 2 Schedophilus huttoni SUR Schedophilus sp SUS 1 Serio lelia caerulea white warehou WWA 18 S. punctata silver warehou SWA 6 Bothidae: lefteyed flounders Arnoglossus scapha witch WIT 3 Neoachiropsetta milfordi finless flounder MAN 25 Pleuronectidae: righteyed flounders Axygopus pinnifasciatus spotted flounder SDF

Other marine organisms

Porifera unspecified sponges ONG 29 Demospongiae Scleritoderrniidae Aciculites pulchra maroon pimpled ear sponge APU 1 Hexactinellida glass sponge GLS 29

Cnidaria Scyphozoa unspecified jellyfish JFI 10

61 Appendix 2 cont: Scientific and common names, species codes and occurrence (Occ.) of fish, squid, and other organisms.

Species Scientific name Common name code Occ.

Anthozoa Actinaria unspecified sea anemones ANT 6 Actiniidae Bolocera spp smooth deepsea anemone BOC 3 Actinostolidae deepsea anemone ACS 24 Honnathiidae warty deepsea anemone HMT 19 Liponematidae Liponema spp deepsea anemone LIP 3

Tunicata Acidiacea unspecified tunicates ASC 3

Mollusca Gastropoda unspecified gastropods GAS Ranellidae Fusitron magellanicus FMA 14 Volutidae unspecified volute VOL I

Cephalopoda unspecified squid SQX Cranchidae unspecified cranchiid squid CHQ Histioteuthidae Histioteuthis spp violet squid VSQ 5 Octopoteuthiidae Taningia danae giant squid TDQ Ommastrephidae Nototodarus sloanii arrow squid NOS 45 Todarodes ji/ippovae Antarctic flying squid TSQ 8 Onychoteuthidae Moroteuthis ingens warty squid MIQ 70 M robsoni warty squid MRQ 7

Octopoda unspecified octopod OCP 2 Octopodidae Enterocfopus zealandicus yellow octopus EZE Graneledone spp deepwater octopus DWO 15 Opisthoteuthididae OSQ 1 Opisthoteuthis spp umbrella octopus OPI 5

Arthropoda Crustacea Oecapoda Caridea Aristeidae Aristaeopsis edwardsiana scarlet prawn PED N ematocarcinidae Lipkius holthuisi omega prawn LHO 41 Oplophoridae Acanthephyra spp subantarctic ruby prawn ACA 5 Notostomus auriculatus NAU Pandalidae Plesionika martia golden prawn PLM 2

62 Appendix 2 cont: Scientific and common names, species codes and occurrence (Occ.) of fish, squid, and other organisms.

Species Scientific name Commonnarne code Occ.

Pasiphaeidae Pasiphaea barnardi deepsea prawn PBA 3 Pasiphaea sp PAS 9 Solenoceridae Haliporoides sibogae jack-knife prawn HSI Astacidea Nephropidae Metanephrops challengeri scampi SCI Polychelidae Polycheles suhmi deep-sea blind lobster PSU

Anomura + Brachyura unspecified crabs CRB 5 Anomura Lithodidae Lithodes murrayi southern stone crab LMU 4 Neolithodes brodiei NEB 5 Paralomis aculeala KCU 2 P. zelandica stone crab PZE 1 Paguridae unspecified hermit crab PAG 2 Parapaguridae Sympagurus dimorphus hermit crab SDM Brachyura Majidae Leptomithrax australis masking crab SSC 2

Echinodermata Asteroidea + Ophiuroidea unspecified starfish SF! 3

Asteroidea unspecified asteroid ASR 37 Asteriidae Cosmasterias dyscrita cat's-foot star CDY Sclerasterias mollis cross-fish SMO Astropectinidae Plutonaster knoxi abyssal star PLT Brisingidae arm-less star BRG Goniasteridae Ceramaster patagonicus pentagon star CPA 13 Hippasteria trojana trojan star HTR 24 Lithosoma novaezelandiae rock star LNV 8 Odontasteridae Odontaster benhami pentagonal tooth-star ODT Solasteridae Crossaster japonicus sun star CJA 11 Solaster torulatus chubby sun-star SOT 2 Zoroasteridae Zoroaster spp rat-tail star ZOR 26 Astropectinidae Dipsacaster magnificus magnificent sea-star DMG 10 Psi/aster acuminatus geometric star PSI 5

Holothuroidea unspecified sea cucumbers HTH 46 Stich opus mollis SCC 3

63 Appendix 2 cont: Scientific and common names, species codes and occurrence (Occ.) of fish, squid, and other organisms.

Species Scientific name Common name code Occ.

Echinoidea Cidaridae Goniocidaris parasol cidarid urchin GPA G. umbraculum cidarid urchin GOU 7 Echinidae Dermechinus horridus deepsea urchin DHO Gracilechinus multidentatus deepsea kina GRM Echinothuriidae unspecified Tam O'Shanter urchin TAM 28 Spatangidae Paramaretia peloria heart urchin PMU

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