Southern and Eastern
Scalefish and Shark Fishery
Slope Resource Assessment Group
(SLOPERAG)
MINUTES
CHAIR: MR SANDY MORISON
23–25 SEPTEMBER 2013
FREYCINET ROOM
CSIRO MARINE LABS
CASTRAY ESPLANADE TAS
SlopeRAG Minutes
Chair: Mr Sandy Morison
Date and Location: 23 – 25 September 2013, CSIRO, Hobart
Members
Mr Sandy Morison
SlopeRAG Chair
Dr Geoff Tuck
CSIRO
Mr Tom Bibby
Industry
Mr John Jarvis
Industry
Mr Simon Boag
Industry
Dr Sarah Jennings
UTAS, Economics
Mr Andrew Penney
ABARES
Dr Marcus Finn
AFMA, Manager Commonwealth Trawl Fisheries
Observers and invited participants
Mr Ross Bromley
AFMA, SlopeRAG Executive Officer
Dr Neil Klaer
CSIRO
Dr Jemery Day
CSIRO
Dr Judy Upston
CSIRO
Mr George Day
AFMA, Senior Manager, Demersal and Midwater Section
Dr Kevin Rowling
Invited participant
Dr Bruce Taylor
CSIRO Consultant
Professor Andre Punt
CSIRO by Skype
Dr Malcolm Haddon
CSIRO
Mr Patrick Cordue
ISL NZ. Consultant for SETFIA
Mr Craig Geier
AFMA, Observer Section
Apologies from members
Mr Les Scott
Industry
Dr Jeremy Prince
Biospherics Pty Ltd
Dr Sarah Jennings
UTAS, Economics. (Tuesday)
2
Preliminaries
Welcome and Introductions/Apologies
1. The Chair welcomed all SlopeRAG members and observers to the meeting and advised
the RAG of the objectives of the meeting. All in attendance introduced themselves and
declared any pecuniary interest.
2. The RAG accepted apologies from Mr Les Scott, Dr Jeremy Prince and Dr Sarah
Jennings (Tuesday only).
Declarations of Interest
Name
Interest Declared
Sandy Morison
SlopeRAG and ShelfRAG Chair, member of SEMAC and
SESSFRAG. Consultant with an interest in funding for research
purposes. Conducts fisheries related work consultancies for
Industry, companies and other Government departments.
Acquiring funding for research purposes
Chair of SETFIA and South East Trawl boat and quota SFR holder
South East Trawl boat and quota SFR holder
CEO of SETFIA, member of Victorian Fishing Advisory Council,
director of a fishing company that owns South East Trawl boat and
quota SFRs. Vice Chair Commonwealth Fisheries Association.
No pecuniary interest
No pecuniary interest
No pecuniary interest
No pecuniary interest
Acquiring funding for research purposes
Acquiring funding for research purposes
Acquiring funding for research purposes
No pecuniary interest
No pecuniary interest
Acquiring funding for research purposes
No pecuniary interest
No pecuniary interest
Acquiring funding for research purposes
Acquiring funding for research purposes
Geoff Tuck
Tom Bibby
John Jarvis
Simon Boag
Sarah Jennings
Andrew Penney
Marcus Finn
Ross Bromley
Neil Klaer
Jemery Day
Judy Upston
George Day
Kevin Rowling
Bruce Taylor
Patrick Cordue
Craig Geier
Andre Punt
Malcolm Haddon
3. John Jarvis and Simon Boag left the room in turn while the RAG discussed their conflicts
of interest. The RAG resolved that their conflicts did not preclude them from RAG
discussions and the RAG would deal with any conflicts as they arose. It was noted that
their experience in the fishery was desired by the RAG and that all commercial operators
would have similar conflicts of interest. No other members declared conflicts with any of
the agenda items.
Adoption of Agenda
4. The draft agenda was accepted.
3
Adoption of minutes and actions from SlopeRAG meeting November 2012
5. The RAG noted that the minutes of the previous meeting held in November 2012 had
previously been accepted out of session.
6. The RAG noted that the meeting would be recorded for the purpose of compiling the
minutes and that the recording would be destroyed once the minutes were confirmed.
Results of action items arising from SlopeRAG November 2012
Action item
Response
Action
person
Result
Alfonsino - Examine data from New
Zealand / high seas. Compare age
structure inside and outside the AFZ to
assess whether the ECDW Alfonsino
assessment needs to account for them.
To be presented
later at this RAG
Neil Klaer
Completed
Identify where the 7 apparently targeted
shots for Oreos mixed were taken to
determine if they were from the Cascade
Plateau or not.
To be presented
at the
November RAG
Neil Klaer
November
RAG
Oreos mixed – provide information on
observed shots of Oreos mixed in the west
since 2007.
To be presented
at the
November RAG
Judy Upston
November
RAG
Add the review of the Bergh et. al. (2009)
report to the list of research needs.
Completed
Sandy
Morison
Completed
Undertake sensitivity of removing the larger
vessels data from the Silver Warehou
assessment model.
Will be done for
the next Silver
Warehou
assessment
Malcolm
Haddon
To be
included in
the next SW
assessment
Silver Warehou - Deterministic projections
be done under 3 years of low recruitment
scenarios (low recruitment defined as the
average of 2002 – 2005) to inform a
projection of the next 3 years of the stock
estimates for a 3 year MYTAC.
Completed
Neil Klaer
To be
included in
the next SW
assessment
Send Ian Knuckey’s closure report to
SlopeRAG.
Completed
AFMA
manager
Completed
Circulate a copy of his analysis of Orange
Roughy catches in the proposed re-opening
of the western Deepwater area of the
>700m closure.
Completed
Malcolm
Haddon
Completed
4
Stock Assessments
Pink Ling – Tier 1
7. Marcus Finn, AFMA trawl manager, gave the RAG a brief summary of the background to
current management arrangements for eastern zone Pink Ling.

The AFMA recommended TAC for the 2013 fishing season was rejected by the
AFMA Commission due to their concerns that the biomass for the eastern stock
was estimated to be around B26.

A step down to a revised TAC of 250t was accepted by the Commission with the
caveat that arrangements must be implemented to constrain catches to this level.

A trigger of 200t has been exceeded by the fishery during the current season and a
50kg daily limit will come into force on 26 September 2013.

AFMA management recognises the effort put in by larger quota holders to avoid
this situation and acknowledged their preferred arrangements; however AFMA does
not have the legislative authority to implement their proposals.

AFMA acknowledges that limits are not ideal management tools nonetheless it
needs to base decisions on the best available knowledge.
8. In response to a query whether ling were measured as standard length or total length by
observers; Neil Klaer advised that recently standard lengths had been measured but he
had developed a conversion factor and this has been applied to the existing data.
9.
Andre Punt joined the meeting via Skype.
10. The RAG agreed that the data selection and model structure options should be judged
independently on their merits and the base case should be developed by taking the best
options from each of the two proposed approaches (Punt and Cordue).
Modeling and data options – Patrick Cordue
11. The RAG noted that assessments implemented with either Stock Synthesis 3 and or
CASAL, using the same data, will give similar results but there are some differences and
not all options can be implemented in both packages. The RAG requested that Andre
Punt and Patrick Cordue identify any differences in their assessments resulting from the
software used.
12. The RAG agreed that considering the Kapala data was collected over a small area it was
not likely to be representative of the abundance of the entire stock and should be
excluded from the assessment. Nevertheless, it was suggested that the size frequency
data from the first Kapala survey provided a good indication of the size composition of a
relatively unfished stock.
13. Stratification and scaling can be done using; space, time, depth or boats and different
strata are scaled up to represent the catch for the age and length data. Cordue used
three depth strata; 0 – 300m, 300 – 500m and >500m. There is a difference in length at
depth in the zones and therefore it is important to consider stratification by zone and
depth.
14. Cordue identified that there were strong zone and depth effects on length data from the
eastern zones and this means data that cannot be assigned a depth (port data) should
not be used in the eastern zone assessment. This effect is not apparent for western
zone data; consequently port and onboard data can be combined. The RAG supported
these approaches.
5
15. The RAG agreed that the stratification and scaling of trawl length frequencies be done by
zone and depth. Further details are described in Cordue’s report.
16. Spawning biomass. The RAG agreed that female spawning biomass is a good proxy for
egg production and this measure should be used in the new assessment (no change
from last year).
17. Patrick Cordue explained to the RAG that he had used mid-year spawning female
biomass estimates in his assessment. His reasoning is that at the start of the fishing year
(May in the SESSF) there was a larger female population that was fished down as the
season progresses and there was less female spawning population at spawning time
(October to November) than at the start of the season. A mid-year stock estimate better
reflects the stock available to spawn. It was noted that due to software constraints this
approach may be difficult to implement in SS3.
18. The RAG agreed to continue to allow the model to estimate growth.
19. The RAG agreed to use the same CV across all years for trawl CPUE.
20. The RAG agreed that data sets and relative weighting of CPUE would be weighted as
per Francis (2011).
21. The RAG agreed that any changes in catchability within the CPUE estimates are to be
dealt with within the CPUE standardization.
22. The RAG discussed using non-trawl CPUE in the assessment. The RAG noted Patrick
Cordue’s opinion that the non-trawl CPUE is not reflective of the stock abundance due to
the paucity of data and that data from auto longline operations targeting ling may
indicate hyperstability and not be indexing abundance. Andre Punt was of the view that
auto longline data could index abundance in the areas fished. The RAG deferred its
decision on using non trawl data until it had a chance to review plots of the data
coverage.
23. Patrick Cordue described his analysis of age-length data. He concluded that:

There were strong conditional age at length differences between trawl and line data
and across the eastern zones.

The appropriate depth stratification zones are; 0 – 300m, 300m – 500m and >
500m

The data supports stratification by zones in the east but not in the west;

There are obvious gear effects and the data supports separating age-length data
by gear types; and

The data provides no evidence of cohort-specific growth and therefore it should not
be estimated in the assessment model.
24. The RAG agreed to an estimation of M within the model informed by a prior with a mean
of 0.2 and a CV of 0.2.
25. The RAG discussed the use of length based selectivities in the model and agreed that
this approach was fine if the assumption is that length based selectivity is the same for
trawl and non-trawl, however the data do not support this. The RAG agreed to use age
based rather than length based selectivities in the model.
26. The RAG considered the suitability of either the number of fish or the number of
operations as a tuning metric within the model. It was noted that because large numbers
of fish sampled could have come from a small number of operations this may not be
representative of the fishery. The RAG agreed to use the number of operations or
landings as a metric.
6
27. The RAG agreed to use the on board data in the assessment and to keep these data
separate to port samples because the selectivities between the two may differ.
28. Tom Bibby joined the meeting after lunch. He made a declaration of interest that he is
the holder of a Commonwealth Trawl Boat SFR and also quota SFRs. He left the room
while the RAG considered his declaration. The RAG resolved that his conflicts did not
preclude him from RAG discussions and the RAG would deal with any conflicts as they
arose.
29. The RAG reviewed the age at length proportions and zone data and noted:

A difference of age at length proportions between the zones

A difference in proportions of age at given length

Zone 10 has younger fish

Auto longline caught fish have a different age structure to those caught by trawl

There may be different availability of age at length in each of the zones

There are different lengths/mean age in the zones

There is no evidence of cohort specific growth or cohort effects.
30. The RAG also considered whether cohort effect on growth could be recognized in the
data. The RAG agreed that there was no evidence of cohort-specific growth in the data
and it should be left out of the model this year. The RAG agreed that these data should
be reviewed prior to next year’s assessment and the results of the review be discussed
at next year’s RAG.
31. The RAG discussed three approaches to spatial modelling:

Full spatial approach was recognised as probably the approach to adopt, however
some parameters the model estimates are biologically unreasonable e.g. M. The
RAG recognised that if estimates of these parameters were incorrect then the
potential for a bad outcome was high. The RAG agreed not to use this approach as
part of this base case but it may be considered in the future.

Semi-spatial (fleet) approach was proposed as a way to deal with unbalanced
data that avoids the need to fill in data gaps. This approach has also been shown in
simulation studies to perform better than models where heterogeneous data are
aggregated. Nevertheless, this approach was rejected because the RAG had
concerns with the requirement that the CPUE indices in individual zones index fullstock abundance, i.e. full stock mixing. The RAG also had concerns that definition
of the zones was arbitrary and that this approach requires accurate estimates of
stock wide parameters.

Standard (spatially aggregated) approach was discussed and adopted by the
RAG subject to the agreed changes in Attachment 1.
CPUE analysis
32. Patrick Cordue described his analysis of trawl catch and effort data:
Eastern zone

Depth filtering between 200-750m was used

Filtering of trawl records, based on the catches of species other than ling, was used
to try to define a consistent fishery from which ling was taken as a bycatch

There is an arithmetic drop in CPUE between 1999-2000 in Zones 10 and 20

There was a change in the trend of the proportion of trawls that reported retained
ling in Zones 10 and 20; an increasing trend reversed direction in about 2000. This
7
may be related to the sale of ling quota from the trawl sector in the eastern zones at
that time

Cordue used time blocking to estimate fleet effectiveness and vessel effects. The
time blocks are: 1986-1999, 2000-2006 and 2007-2012.

Use of time-blocking (with linked vessel effects) increases CPUE indices from 1999
onwards

There is a very strong depth and latitude effect on ling catches

There are no unreasonable vessel effects or changes in vessel effects.
Western zone

Time blocks used were; 1986-2006, 2007-2012

Depth and species-based filtering as for the eastern stock

The use of time-blocking had little effect on the CPUE indices

There is a moderate depth effect and a close to linear trawl duration effect

The is a weak to moderate latitude effect

There are no unreasonable vessel effects or changes in vessel effects
33. Cordue noted that inclusion of time blocks increased the difference in eastern zone
estimated CPUE between CSIRO and the estimate he calculated. This effect was not
apparent when time blocks were used in the western zone.
34. The RAG summarised its agreed changes to the Ling base case as per Attachment 1
The meeting adjourned at 17:20
Tuesday 24 September
35. The RAG noted an apology from Dr. Sarah Jennings for today’s meeting.
Pink Ling - continued
36. The RAG discussed whether running a Markov Chain Monte Carlo (MCMC) analysis
was appropriate and warranted for the Pink Ling assessment. The RAG advised the
benefits of running a MCMC for the following reasons. The MCMC:

provides estimates of error within the model;

considers if the model has considered minimum values; and

checks estimates of the parameters within the model.
37. AFMA management and industry supported doing a MCMC on the assessment this year.
Blue Grenadier
38. Geoff Tuck presented the preliminary 2013 Blue Grenadier assessment. The RAG
noted:

The last assessment was undertaken in 2011

The data were updated to include 2012

The steepness was changed from 0.9 in 2011 to 0.75
8

The large cohort that the fishery depended on is now coming to an end and catch
rates have been declining

An estimated large recruitment in 2010 is the second largest on record and is
predicted to increase biomass
39. Industry informed the RAG that:
Australian supermarkets import large quantities from New Zealand and that they
may not be able to catch Blue Grenadier economically in the future irrespective of
the size of the TAC

Some operators had increased the mesh size of their nets to avoid large discards of
small Blue Grenadier and this may need to be considered when looking at CPUE
and vessel selectivity

In the west, fish were widespread. Warmer water from a strong Leeuwin current (3
degrees warmer at normal Blue Grenadier depths) meant fishers had to use gear
deeper, and the size of fish varied with location. In the east small fish were found as
far north as Greenwell Point, There was colder water close to the coast and there
had been a drop off in catches. It is unsure if this can be related to the water temp.
Action item – AFMA to establish; if net and mesh sizes are recorded by ISMP observers, to
what detail and if these data are entered into the database. AFMA.
40. The RAG noted the outcomes of the 2013 assessment:
The 2011 assessment was rerun with the latest SS software and when compared
with the 2013 assessment there was no difference

Early recruitments were poorly estimated and have been removed from the
estimation and recruitment estimates now begin in 1974

Model fits to CPUE in the early 2000’s are unexplainably low, however fits to CPUE
since 2005 are quite good. As the later fits are used for management purposes this
was considered to be the most important and no attempt was made to change the
model to get a better fit to early CPUE

The 2013 assessment picks up the 2010 recruitment and this results in a more
optimistic outlook. This is a good sign for the fishery, however it will have to be
seen if this flows through into future catches

The RAG agreed that removal of the egg survey should be done as a sensitivity

The RAG agreed that the Francis (2011) tuning method for data would be done as
a sensitivity

Preliminary results of the assessment estimate a virgin female biomass of 38,365 t
(estimated at 39,983 t in 2011) and biomass of 77% of unfished levels (estimated
2014 90%).
41. The RAG noted Geoff Tuck’s suggestions for further development:
Explore a better fit to discards as a sensitivity

Use an average recruitment estimate. The RAG to provide advice on catch
scenarios to inform MYTAC considerations if the estimated recruitment is weaker or
does not enter the fishery under current assumptions

Revisit the breakout rules
42. To inform MYTAC decisions the RAG will provide advice on 3 and 5 year constant catch
estimates and 5 year projections.
9
Alfonsino
43. There were no reported catches of Alfonsino in the East Coast Deepwater fishery in
2006, 2008,and 2010, but there were catches reported in 2011 and 2012 so the analysis
conducted in 2011 (Haddon, 2012b) was updated. However, there was only a single
vessel active and the information remained sparse so the resulting catch rates are highly
uncertain and still cannot be used to conduct a Tier 4 analysis.
44. Alfonsino are a straddling stock and there have been catches taken from the high seas
area of the eastern Lord Howe Rise by Australian and non–Australian boats.
45. Australia reports its high seas catch to SPRFMO however Alfonsino are also taken by
other nationalities on the high seas between Australia and New Zealand.
46. There are data from the New Zealand fleet but not from the Russian fleet that fished in
the high seas area in the past. Andrew Penney has provided New Zealand’s high seas
data however there are probably only a few records.
47. The RAG resolved to use the Australian and New Zealand data within the overlap area
adjacent to the AFZ and provide RBC advice for the straddling stock and AFZ only.
Blue eye Trevalla (Cascade Plateau hook closure)
48. AFMA presented a paper seeking RAG clarification on whether the rationale for
maintaining the spatial closure of the Cascade Plateau (CP) to hook fishing methods is
still applicable.
49. The RAG noted the original rationale for closing the CP was an assumption that the Blue
eye Trevalla (BET) shelf stock relied somewhat on the spawning CP stock for stock
replenishment.
50. The RAG discussed the closure and the discussion points and questions can be
summarised as follows:

The assumption for the closure is that CP BET are the part of the SE Australian
stock and provide recruitment into the fishery. There is a need to consider if this is
correct and if fishing effort on the CP affects overall recruitment more than fishing
elsewhere

Juvenile BET are semi pelagic and capable of moving considerable distance

The New Zealand experience is that their (NZ) stocks are connected

BET are slow growing and have low productivity

If the CP is opened would that change the TAC?

How would opening the CP affect the Tier 4 assessment?

There is an assumption that all BET in the SESSF are protected from over fishing
by the TAC and there is no need for additional measures, such as spawning
closures, to protect the stock

The RAG agrees with the single stock hypothesis and that the single stock is
assessed by a Tier 4 assessment

Closure of the CP does provide a small insurance, however if the TAC is correct a
closure is not required

An advantage to opening the CP is that fishing effort is spread over a larger area

What proportion of BET habitat is closed and is it appropriate to use this as a proxy
for a discount factor?
10

There is no evidence to support the hypothesis that closing areas of spawning
adults increases recruitment into the BET fishery

The RAG advised they had no evidence that the CP contributes disproportionally to
recruitment to the east coast

There are other protections in the form of Gulper and deepwater closures and the
TAC that provides protection to BET.
51. The RAG resolved to defer its advice until the BET assessment was discussed at the
November meeting.
3.4 Blue eye Trevalla – Tier 4 stock assessment
52. Kevin Rowling presented a paper on the status of BET off south-eastern Australia. The
paper can be summarised as follows:

Similar declines in CPUE have been observed in the SESSF, NSW and New
Zealand

BET are widely distributed in their preferred depth range throughout the southern
oceans

Genetic studies concluded that gene flow between different areas was sufficient to
prevent any differentiation of stocks. This genetic homogeneity could result from
dispersal of larvae or juveniles, however it is difficult to estimate rates of migration
or migration patterns

Little is known of the early life stage of BET but settlement occurs at about 45-50cm
LCF

BET are caught in the SESSF on the east and south east slope and east of Long
155°E (Tasmantid Seamounts)

BET are now known to be a relatively long lived, late maturing species, which
appears to be highly susceptible to line & hook fishing.

The detailed structure of the BET stock has not been captured in the population
models developed to date – but the declines in catch rate observed across fisheries
in different parts of the species’ range suggest a reasonably well mixed stock that
has been significantly impacted by fishing.
53. The RAG thanked Kevin Rowling for his presentation.
54. The RAG noted an ongoing FRDC Project “Developing improved methods for stock
assessment in spatially complex fisheries using Blue eye Trevalla as a case study”.
55. The RAG discussed BET stock structure hypotheses; true stock separation between the
eastern seamounts and the shelf; and a single meta-population with adult residency. The
RAG supported the hypothesis that the BET was a single Australian stock separate to
New Zealand.
56. Catches east of Long 155°E are currently excluded in the Tier 4 assessment however
catch rates are included. The RAG discussed continuing to exclude catches taken east
of Long 155°E (Tasmantid seamounts) from the assessment and noted that catches in
the reference period (1997-2005) were very high and may have been due to operators
attempting to qualify for higher quota allocation. The RAG also noted that catches from
the eastern seamounts have become a substantial proportion of the total catch in the last
two years
57. The RAG recommended that catches east of long 155°E be included in the reference
period.
11
58. Andrew Penney explained that the east coast and seamounts have different densities of
BET and changes in densities in each area can be used to index BET abundance in that
area. This information can be used separately or together if the different CPUEs can be
standardised.
Action item. Malcolm Haddon undertook to provide further information on the CPUEs from
the east coast and seamounts at the November meeting.
59. The RAG queried if the standardised CPUE is representative of stock abundance due to
the presence or absence of Orcas. Pease (2012) estimated a reduction in CPUE and a
loss in catch of up to 60% in the 25% of shots when Orcas were present an overall
reduction of about 15%. The proportion of Orca presence and effect in Pease is
consistent with work done by Ian Knuckey. The RAG requested that Malcolm Haddon
include fishing mortality attributable to Orcas as discards as sensitivity (if possible) when
exploring different scenarios in the reference years.
Action item. Malcolm Haddon to include fishing mortality attributable to Orcas as discards as
a sensitivity (if possible) when exploring different scenarios in the reference years.
Orange Roughy – results of AOS
60. Rudy Kloser and Tim Ryan gave a presentation on the preliminary results of the Acoustic
Optical Survey (AOS) that was conducted in the eastern Orange Roughy (OR) zone
during the winter of 2012:

Survey objectives included obtaining an acoustic estimate of spawning OR biomass
in the eastern zone and to collect biological data to support target strength, age,
length, weight and reproductive potential analyses.

The AOS may not get representative biological samples due to the nature of the
fishing undertaken, i.e. avoiding the main spawning plume.

All years of the AOS since 2006 have indicated stock recovery, however it should
be noted that the recruitment into the fishery is from pre-fishing recruitment and it
should be noted that proportion spawning has been shown to be variable.

There has been an increase in OR fecundity by 75% in 2010 compared with an
estimate in 1992.

Changes in OR biology should be factored into an assessment.

Results from 2012 are reasonably consistent with 2011.

St Helen’s had 37% less biomass than 2010, St Patrick’s 15% more biomass. It
should be noted that inter annual variability may produce short term reversals
contrary to an expected upward recovery trend.

Estimates from the 2012 AOS of the maximum combined spawning biomass at St
Helens and St Patricks Head are between 17,672 and 19,194t. These estimates
are about 25% lower than estimates from the 2010 survey, (proportion spawning
has been shown to be variable).
61. Rudy Kloser presented the preliminary results of the July 2013 eastern zone AOS:

Significant OR aggregations were observed at both St Patricks and St Helens
grounds.

These aggregations were dynamic at both grounds.

The area of extent at St Patricks was larger than previous years.

To have large aggregations at both St Helens and St Patricks is unusual –
historically one or the other ground has been the dominant biomass ground
12

Although unquantified it appears the biomass was large and very different to the
situation encountered in 2012.
62. Rudy Kloser presented a summary of the surveys at St Patrick’s and St Helen’s 1999 to
2013:

Proportions of surveyed stock are variable between St Patricks and St Helens, for
most years usually one is dominant.

1999 survey had high cv’s.

2006, 2009 and 2010 appeared to have similar schooling behaviours, 2012 was
odd schooling behaviour at St Helens.

2013 schooling behaviour was similar to 2010 except high biomass appears to be
at both grounds.

The snapshot biomass from the surveys in all years is higher that the model
estimated biomass.

There was a decline (~15 years) in OR mean age between 1987 and 2010.

There has been a 73 % increase in length standardised fecundity since the start of
the fishery in 1987. This can be inferred as a density dependency effect as stock
reduced to <20% B0 and suggests a positive feedback for recovery.
63. Rudy Kloser made some observations and raised some questions regarding strategies
for managing the OR eastern zone fishery:

Assuming resolution of the model age data and acoustic biomass conflict may not
be possible, what other indicators could be used to meet harvest strategy
objectives that ensures an acceptable recovery time frame and long term
sustainability.

Is it possible to have low level fishing under a research quota (RQ) arrangement to
ensure appropriate monitoring.

What is the risk of a staged opening with monitoring to determine the appropriate
trajectory based on an adaptive management plan? Can a simple approach of
taking a small percentage of biomass each year meet the HCR.

Should broader habitat/associated species indicators be included.

Can we reduce cost of annual surveys by AOS to facilitate long term monitoring
and what is the appropriate timing for more detailed biological/AOS survey and
model synthesis of results (i.e. every 4 years) costs?
64. The RAG recommended:

Work up the 2012 and 2013 AOS results.

A Tier 1 assessment be undertaken in 2014.

The assessment incorporates tuning as per Francis (2011). It is hoped that by
reducing the weighting of the age data as per Francis that this may help resolve the
conflict between the age data and the AOS results.

Review the single stock structure hypotheses for the base case and sensitivities.

A workshop is conducted in mid-2014; refer to Judy Upston’s Future Work
document as a basis for agenda planning. The workshop should include; designing
a modelling approach, how data is used in the model review of single stock
hypotheses. The RAG agreed that some elements of the assessment should be
externally reviewed.
65. The RAG does not support continuing the AOS until the current work is written up and a
way to utilise the existing AOS data in the stock assessment is developed.
13
66. The RAG asked for an update on catches of OR taken in the recently reopened Western
Deepwater Shark (WDS) area.
Action item – AFMA to provide details of catches of OR taken in the reopened WDS area.
67. The RAG agreed that the current OR incidental bycatch TACs in the eastern, southern
and western zones were still appropriate and recommended the current TACs remain for
the next season.
68. The RAG noted there was little OR fishing on the Cascade Plateau (< 6t) during the
2011/12 season and therefore no data to update an assessment. The RAG
recommended that the TAC for the Cascade Plateau remain at 500t.
Orange Roughy Zone
2013/14 TAC (t)
Recommended 2014/15 TAC (t)
Eastern
25
25
Southern
35
35
Western
60
60
Cascade Plateau
500
500
69. The meeting adjourned at 17:00
Wednesday 25 September
General Updates
Report on management issues
70. Marcus Finn, AFMA Manager of the Commonwealth Trawl Fishery, gave a report to the
RAG. It is summarised below:

Pink Ling. After initially rejecting the proposed TAC, the AFMA Commission
accepted a notional TAC of 250t in the eastern zone with AFMA to develop
additional management arrangements if a 200t trigger was reached. AFMA
implemented three closures in areas of historic high catch rates; however this
measure did not constrain catches sufficiently. A Closure Direction to limit Pink Ling
catches in the eastern zone to a daily limit of 50kg will come into effect on 26
September. Future management arrangements, including TAC splitting are being
considered.

Orange Roughy Conservation Program. The program is currently being updated.

Updates of the location of seabird and seal interactions.
71. The RAG raised concerns that:

The 50kg Ling daily limit may cause avoidance and this would degrade the CPUE
series.

It is emphasised to the observer section that it is important to get good coverage of
the fleet during the Direction period.

There may be an “observer effect” and fishing activities, location and discard
behaviour. Simon Boag undertook to provide a list of boats that he believed filled
logbooks in correctly at all times to enable a comparison to be made with the rest of
the fleet.
14
Action item. Simon Boag undertook to provide a list of boats that he believed filled logbooks
in correctly at all times to enable a comparison to be made with the rest of the fleet.
72. The RAG noted that:

There are three data points from the Fishery Independent Survey (FIS) and this
survey is designed to reduce the reliance on CPUE as an index of abundance for
many of the main quota species.

Concerns with the accuracy of logbook records emphasised the importance of
conducting a FIS.
AFMA Commission’s comments on the 2013/14 TACs
73. Blue eye Trevalla

Agreed with RAG concerns about the CPUE indices

Asked that AFMA engage with NZ about their experiences, and whether there were
any signals that in hindsight could have signalled stock decline

Noted a need to quantify Orca depredation

Asked that any positive impacts from gulper closures be acknowledged.
74. Pink Ling comments have previously been noted.
ABARES Fishery Status Report 2012
75. FRDC will be producing the Key Australian Fish Stock 2014 report. These reports may
replace the ABARES Fishery Status Reports in the future.
Observer Report
76. Deferred until the next meeting.
Upper Slope Dogfish management arrangements
77. AFMA submitted a paper “4.5 Upper Slope Dogfish Management Strategy – Review of
management arrangements applying to ‘Power Handline”. The RAG was asked to
provide scientific advice on:

the proposal to remove the trigger limit and move on provisions for the ‘power
handline’ method when fishing in gulper shark closures on the Tasmantid
Seamounts.

Monitoring requirements for the power handline method when on the Tasmantid
Seamounts.

The RAG noted that the estimated survivability of Upper Slope Dogfish caught by
the power handline method was approximately 95%.
78. The RAG provided the following advice:

The RAG had difficulty in providing advice because even though there was
assumed to be 95% survivability of Dogfish after capture; the RAG did not have an
estimate of the appropriate level of potential biological removals (PBR) for these
species. The RAG noted that the risk of exceeding the PBR will dictate the
appropriateness of monitoring measures. However the RAG noted that it was
important in species like Upper Slope Dogfish that the interaction rate is kept as low
as possible even with high survivability.
15

The RAG queried whether further monitoring was required if previous 100%
coverage had indicated low mortality.

The RAG noted that fine scale detection of interaction rates will require high
observer coverage.
Outcome
79. The RAG supports a 10% monitoring program, as per normal and the removal of the
trigger limit on Upper Slope Dogfish for the power handline method if interaction rates
are as low as those indicated by previous monitoring.
Research priorities for 2013/14
80. SESSF outputs will be put forward to the AFMA Research Committee
Update of SESSFRAG issues
81. The Chair reported briefly on the results of recent SESSFRAG meetings. SESSFRAG
had discussed the application of discount factors and noted that the paper by Gavin Fay
et.al. has been finalised. SESSFRAG noted the papers main conclusions:

that there is no default discount factor suited to all species on a particular Tier level
but the appropriate discount needed to maintain risk equivalence needs to be
determined on a species by species basis

that stability of CPUE is not a good reason not to apply the discount factor.
SlopeRAG noted, however, that SESSFRAG had not explicitly changed its previous
advice about when the discount factor need not be applied and requires specific
advice from SESSFRAG as to whether stability in the CPUE estimate is sufficiently
precautionary not to apply the appropriate discount factor
Action item – SESSFRAG to provide advice by the next RAG meeting if stability in the CPUE
estimate is sufficiently precautionary not to apply the appropriate discount factor?
SESSFRAG
82. Other SESSFRAG matters reported:

SESSFRAG had accepted that current funding would allow AFMA to conduct a
winter FIS only, every second year.

Inclusion of discards in catch rates in Tier 4 assessments should be made by the
appropriate RAG on a species by species basis dependant on the accuracy of the
data set.

Discards in Tier 1 assessments should be estimated within the model.

When calculating MYTACs: if changes in RBCs for successive years are within
10% use the average of those years to set the TAC, if this is not the case then use
the RBC to set the TAC. State catches and all discards would need to be reviewed
yearly on a species basis. SlopeRAG agreed with this approach in principle but
pointed out that there was little difference in the amount of work to monitor a Tier 3
or 4 MYTAC when compared to doing a new assessment.

A decline of CPUE below the 95% confidence interval of the predicted CPUE
triggered a review of the Silver Warehou MYTAC. As this was not unexpected
SESSRAG agreed not to undertake a new Tier 1 assessment.

Some secondary species in the SESSF are suitable to be managed at a lower
target. AFMA has agreed that the Ribaldo and Redfish target should be amended
to B40.
16

Orange Roughy east are scheduled for a SlopeRAG Tier 1 assessment next year.
Contingent on this year’s results the RAG will decide at the next meeting if Pink
Ling will also be assessed.
83. The next SlopeRAG meeting will be held in the Freycinet Room at CSIRO from 6-8
November 2013.
84. Meeting closed at 11:30am.
17
Attachment 1 - Summary of agreed changes to Pink
Ling base case, 23 – 25 September 2013
Data

Include non-trawl, subject to adequate spatial coverage

Tune model on number of landings/operations

Exclude Kapala data

Length frequencies to be stratified and scaled by depth and zone, details to be
provided by Patrick Cordue

Keep port and on board data separate

Age/length data. Include unsexed data; however look at the growth curves and
down-weight the age/length data so growth is consistent with the sexed data.

Shift the selectivity change in the eastern zone to 1999/2000 to match the CPUE
time blocks
Modelling

Use the mid-year spawning female population estimates definition in SS3 if
possible

Constant CV for trawl CPUE between years

Data sets to be weighted in the model as per Francis (2011)

Use CPUE time blocking with linking vessels if robust. Patrick Cordue to provide
information of the “robustness” of linking vessels

No cohort specific growth

Use age and length based selectivity as a sensitivity.

Allow the model to estimate M with a prior of 0.2 and CV of 0.2. Use the prior for
the eastern zone for the western zone if necessary
Spatial Structure

Do not use zone based spatial structure
Sensitivities

Run all the standard sensitivities and include the zone based and full spatial models
using the settings from the base case.
18
Action items arising from SlopeRAG 23 – 25
September 2013
Action item
Person
responsible
Result
Plot of coverage of non-trawl Pink Ling effort to be
provided to inform the decision whether non-trawl
data is used in the Pink Ling assessment.
Malcolm Haddon
Circulated,
waiting Andre’s
comments, Nov
meeting
Test robustness of the CPUE filtering decisions, e.g.
species and depth in Patrick Cordue’s draft
assessment.
Patrick Cordue
Document
circulated. To
be discussed at
Nov meeting
Do the ISMP observers record net and mesh sizes,
if so to what detail, is this entered into the database.
Ross Bromley,
AFMA
Yes, net and
mesh sizes
recorded and
entered into the
database
Blue eye Trevalla. An estimate of fishing mortality
due to Orca is to be included as discards as a
sensitivity exploring different years back to 2001 (if
possible).
Malcolm Haddon
Done
Malcolm Haddon undertook to provide further
information on the CPUEs from the east coast and
seamounts at the November meeting.
Malcolm Haddon
Orange Roughy. The 2012 and 2013 AOS results to
be worked up as soon as possible.
Rudy Kloser and
Tim Ryan
Ongoing
Provide the RAG with details of Orange Roughy
catch taken during this season in the reopened
western Deepwater shark area.
AFMA
6790 kg
Simon Boag to provide a list of boats that he
believed filled logbooks in correctly at all times to
enable a comparison to be made with the rest of the
fleet.
Simon Boag
Not to be
continued
AFMA to provide an ISMP observer report to the
RAG at the November meeting.
AFMA
Mike Yates
present and will
present at Nov
meeting
The RAG requires an explicit decision from
SESSFRAG on the application of discount factors
when the standardised CPUE is flat.
SESSFRAG
Ongoing
Approach SESSFRAG to consider recommending
Francis (2011) tuning method as the most
appropriate way of weighting data for all stock
assessments.
AFMA/SESSFRAG
Ongoing
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