Gillnet, Hook and Trap Fishery
Integrated Scientific Monitoring Program
2002/2003 Report to the
Australian Fisheries Management Authority
Sonia G. Talman, Lauren P. Brown,
Anne S.H. Gason and Sharon E. Berrie
2003
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Gillnet, Hook and Trap Fishery
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
TABLE OF CONTENTS
Executive Summary..................................................................................................... 1
Introduction ................................................................................................................. 2
Objectives of the ISMP ............................................................................................... 2
Sampling strategy ........................................................................................................ 3
ISMP sampling during 2002/03.................................................................................. 6
Acknowledgments...................................................................................................... 10
References .................................................................................................................. 10
Tables and Figures .................................................................................................... 11
Blue eye trevalla ............................................................................................... 25
Pink ling ............................................................................................................ 26
Ocean perch ...................................................................................................... 27
Ribaldo .............................................................................................................. 28
Blue grenadier .................................................................................................. 29
Gummy shark................................................................................................... 30
Marine and Freshwater Resources Institute
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Executive Summary
The Integrated Scientific Monitoring Program (ISMP) is funded by the Australian Fisheries
Management Authority (AFMA) with 80% cost-recovery from Industry. The principal objective
of the ISMP is to provide information on the quantity, size and age composition of the retained
and discarded catch of quota species caught in sectors of the Southern and Eastern Scalefish and
Shark Fishery (SESS). To meet this objective, on-board field scientists sample the retained and
discarded catches taken by vessels and port-based fish measurers sample the catches landed in
the major ports. This report summarises the ISMP work undertaken in the Gillnet Hook and
Trap Fishery (GHTF) during July 2002 to June 2003 and provides estimates of the discard rate of
quota species and non-quota species in the GHTF during the 2002 calendar year.
Overall, sampling proceeded well during 2002/03. On-board scientists worked on a total of 7
vessels, monitoring 332 individual shots from which 86 different species were identified.
Approximately 11,100 fish were measured from around 55 species, to obtain length-frequency
information. Port-based fish measurers measured 4,993 fish from 58 samples taken from catches
totalling approximately 49 tonnes. Six separate species were sampled for length-frequency
information.
During 2002/03 a total of 90 sea-days were undertaken by ISMP on-board scientists. This
includes the target 50 sea-days as well as 27 additional days done for Industry in order to meet
the requirements of auto-longlining permits. Five of the additional days addressed a shortfall
from the previous year, which means that an excess of eight days were done for the current
project. Despite efforts made by ISMP scientists, the mesh-net gear was not monitored during
2003/03 because operators infrequently deploy mesh-nets to target scalefish.
ISMP data collected during the first six months of the current project (July 2002 – December
2002) and during the later six months of the 2001/02 project (Jan 2002 – June 2002), along with
the 2002 GN01 logbook data were used to determine estimates and coefficients of variation
(CV’s) of the discard rates of quota and non quota species for the 2002 calendar year. Based on
the on-board monitoring carried out by the ISMP during 2002, we achieved all target CVs for
discard rate required across the fishery.
The total landing of GHTF quota species during the 2002 calendar year was about 855 t. The
total discard weight of quota species during the 2002 calendar year was estimated as 0.3 t.
Discard rates for all quota species were low (below 1%) except blue grenadier (5%). For nonquota species, the total retained weight during 2002 calendar year was 155 t while the discarded
weight was 246 t. Discard rates for non-quota species was 51%.
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Introduction
As a Commonwealth fishery, the Southern and Eastern Scalefish and Shark Fishery (SESS) is
managed by the Australian Fisheries Management Authority (AFMA). AFMA established the
Integrated Scientific Monitoring Program (ISMP) to provide information for stock assessment
and fisheries management, which is not available from logbooks or catch returns. The ISMP is
one of the most important research programs being conducted in the SESS, collecting extensive
information on the size, age and species composition of catches from three sectors of the fishery:
the South East Trawl Fishery (SETF), the Gillnet, Hook and Trap Fishery (GHTF) and the Great
Australian Bight Trawl Fishery (GABTF). Vessels in the GHTF use dropline, demersal longline,
mesh-net and traps to target blue warehou, blue eye trevalla and ling as the principal species.
In recent years, the Commonwealth Policy on Fisheries Bycatch and the Environment Protection
and Biodiversity Conservation Act (1999) has been developed to ensure fishing activities are
carried out in an ecologically sustainable manner. Strategic assessments of fisheries are also
underway to determine whether they meet ESD requirements. Bycatch Action Plans have been
developed by the Australian Fisheries Management Authority (AFMA) to provide fisheries with
a strategic approach to addressing bycatch and to help ensure ecological sustainability. An
important component of these Plans is the collection of detailed information on the species
composition of both the catch and bycatch. For all three sectors of the SESS, this information is
obtained through the Integrated Scientific Monitoring Program (ISMP).
The current report summarises the ISMP work undertaken in the GHTF during July 2002 to June
2003 and provides estimates of the discard rate of quota species and non-quota species in the
GHTF during the 2002 calendar year.
During 2002, there was an expansion of the auto-longline fleet and also the areas that trap
vessels could work within the GHTF. ISMP scientists monitored 25% of the trips undertaken by
these vessels in addition to the monitoring done for the current project.
Objectives of the ISMP
The main objectives of the ISMP are to collect information on the quantity, species composition,
size and age structure of retained and discarded catch of vessels in the SESS. We obtain this
information in two ways:
1. On-board monitoring - where field scientists work on vessels during normal fishing activities
to collect data on the total weight and size composition of retained and discarded catches;
and
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2. Port-based measuring - where “fish-measurers” monitor the size composition of fish landed
at specified ports, markets or processors.
On-board field scientists and port-based measurers also collect other information from fish,
which helps us to understand more about their biology and life history, such as otoliths for
ageing, gonads for determination of sex and reproductive stage etc. These various types of
biological information can be combined with catch and effort data and other information and
incorporated into mathematical models and stock assessments to give fishery scientists important
insights into the impact of fishing on fish stocks. Advice is then given to fishery managers who
decide on appropriate levels of fishing and endeavour to ensure the long-term viability of fish
resources.
Thus, the sole objective of the ISMP is to collect biological and fishery information for use in
research and management. AFMA understands the importance of this and has stated that the
ISMP does not have any compliance related objectives. As such, participation of vessels in the
ISMP is voluntary with only partial at-sea coverage of effort.
Sampling strategy
At sea monitoring of discard rates in the GHTF was not included in the original ISMP
sampling regime designed by Smith et al. (1997) because data were limited for this sector and
discard rates were thought to be small. A pilot GHTF (originally called ‘non-trawl’)
monitoring program was undertaken in 1999/2000. This program demonstrated that,
compared to the trawl sector, non-trawl discard rates were generally low and precise estimates
did not require an extensive on-board monitoring program (Knuckey et al. 2001).
Nevertheless, the South East Non-Trawl Management Advisory Committee (SENTMAC)
determined that a base level of independent on-board monitoring of the non-trawl fishery
should continue, at least to meet the requirements of strategic assessment. It was determined
that a total of 50 days would be monitored annually. While the general stratification of the
fishery was based on Knuckey et al. (2001), allocation of sea-days between gear and regions
was flexible to match continual changes in fishery dynamics (Knuckey et al. 2002).
The non-trawl sector was included in the development of a design model for an adaptive
ISMP sampling regime and strata were identified (Knuckey and Gason 2001). It has since
become apparent, however, that gear x region categories change continually so that the strata
identified by Knuckey and Gason (2001) are no longer completely relevant. The actual
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allocation of gear-specific days to regions has been a flexible arrangement, determined by the
manager of the GHTF and based on current fishing activity in each region.
Estimates of discard rates and CVs
The data gained from the ISMP on-board scientists during 2002 were used to estimate discard
rates and CVs for the main quota species in each stratum for the 2002 calendar year. For each
quota species, calculations were made based on gear x region strata. For each trip, the discard
rate (discard weight / total weight x 100) for each species was calculated from the scientist data
recorded for each shot in that trip. The mean weighted discard rate and corresponding CV for
each species in each stratum were calculated across all trips. The weighting factor used was the
total catch of each species in each trip. The total discard rate and CV for each species across
strata was calculated from the mean discard rates in each strata weighted by the total SAN2
landings from each stratum. The difficulty in this second weighting process was assigning the
SAN2 data to the appropriate strata as outlined below.
In order to estimate the catch weight and composition of GHTF landings for any strata, it was
necessary to match-merge data from both the GN01 and SAN2 data sets. This is because only
the GN01 database has species composition together with the gear, position and depth
information needed to allocate it to the same strata as the ISMP data, whereas the SAN2 database
has the more accurate figures on the actual landed catch of quota species.
In theory, all of the landed quota catch information in one vessel’s SAN2 record should match up
with the sum of quota catches recorded for each shot of the vessel’s most recent trip. In practice,
however, this is often not the case. AFMA does not reconcile the GN01 and SAN2 databases for
validation and as a result, discrepancies between these datasets with respect to dates, boat names,
ports and amount and type species landed prevent the match-merging of a significant number of
records on a trip-by-trip basis. As a result, there is a “dropout” of records from one dataset that
do not match up with records of the other dataset. It was beyond the scope of the current project
to undertake any validation and correction of these datasets. Instead, we investigated various
ways of match-merging on different spatial and temporal scales to reduce the proportion of
dropouts without compromising the objectives of the project. The assumptions that were made
with respect to these two datasets were that the landed weights of quota species in the SAN2
were correct and the relative catch composition of quota species and position and depth
information recorded in the GN01 logbooks were correct.
Efforts to match-merge the GN01 and SAN2 data for a given trip resulted in an unacceptable
data dropout rate. Consequently, GN01 and SEF2 data for each vessel were summed over the
period for which the vessel landed its catch at a given port to obtain a weighting factor for each
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species caught by each vessel at a given port over that period. This weighting factor was then
applied to the GN01 shot data to weight it up (or rarely down) to the SAN2 landings for each
species caught by each vessel in each port. This enabled merging of 99% of the GN01 data
without the need to make subjective decisions in cases where GN01 and SAN2 dates and
landings did not correspond. In the few cases in which quota species from a GN01 shot could
not be matched to a SAN2 landing, those species catches for those shots were not included. This
difference was then compensated by the weighting factors from other shots.
Having established the discard rate and CV for the defining strata, which represents the bulk of
the landings of each species, it was then necessary to add information from the catches in other
parts of the fishery to enable total discard weights across the fishery to be calculated. To do this,
the same process as above was applied to all other ‘non-defining’ strata and the results were
pooled together as ‘Other’. Discard weights for each species across entire fishery were then
estimated by summing the discard weights from the defining and other strata. Note: Inshore and
offshore ocean perch are not differentiated in the AFMA databases. To overcome this, SEFAG
has previously agreed to consider the ocean perch (offshore) catches as those caught in depths
greater than 200m in each strata and ocean perch (inshore) catches as those caught in depths less
than 200m in each strata.
Estimates of the discarding of non-quota species were made by applying the above procedure to
all non-quota species pooled into one category called “Non-quota”. The discard rate and CV
was calculated for every stratum and then pooled across all strata for the total fishery estimate.
The only difference in estimating non-quota discards was the factors used in the weighting. The
weight of retained non-quota species for each stratum was estimated using the ratio of non-quota
- quota retained recorded by the ISMP and weighting this up to SAN2 quota landings. The same
method was used to estimate discarded non-quota. A mean-weighted estimate of discard rates
and CVs for non-quota species was then calculated for the total fishery.
Therefore the non-quota landed weight NLi. in stratum i is given by
S
NLi. =
∑ QL
s =1
S
si
∑ QR
i =1
× NRi.
si
where QLsi. is the landed weight for each quota species in stratum i ,
QRsi. is the retained weight for each quota species in stratum I
and NLi. is the retained weight for all non-quota species in stratum i .
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The method by which the discard rates and CVs were calculated for both quota and non-quota
groups is represented below.
The mean discard rate D si for species s in stratum i is given by
D si =
1 k d sij wsi
×100 where i ∈ [1, n] , trip j ∈ [1, k ] and w is the weighting factor.
∑
k j =1 d sij + rsij
The mean discard rate for species s was weighted up using landed catches by
n
D s. =
∑D
si
i =1
× L si
, where L si is SEF landed catch for species s and stratum i.
n
∑L
i =1
si
The variance of the discard rate V ( D s. ) for species s is given by
∑ L V (D )
n
V ( D s. ) =
i =1
2
si
si
 n

 ∑ L si 
 i =1

2
( )
, where V D si is the variance of the discard rate of species s and stratum i.
The coefficient of variation (CV) of species s was hence determined. The discard rate for
species s was then converted to a discard weight (t) as follows:
n
Dsw = 1 × 10 −3 ∑
i =1
D si / 100 × Lsi
, where Dsw is the discarded weight (t) for species s.
1 − D si / 100
(
)
ISMP sampling during 2002/03
On-board monitoring
On-board scientists worked on a total of 7 vessels, monitoring 332 individual shots from which
86 different species were identified. There was a good coverage of the species composition of
the retained and discarded components of the catches from all gear types.
Overall, the
composition of more than 105 t of catch was monitored across the fishery, which is 20 t more
than the previous year. Approximately 11,100 fish were measured from around 55 species, to
obtain length-frequency information.
During 2002/03 a total of 90 sea-days were undertaken by ISMP on-board scientists. This
includes the target 50 sea-days set by SENTMAC as well as 27 additional days done for Industry
in order to meet the requirements of auto-longlining permits (Table 1, Figure 1). Five of the
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additional days addressed a shortfall from the previous year, which means that an excess of eight
days were done for the current project.
As highlighted in the 2001/02 report, the fishery is dynamic both in terms of gear deployed and
area fished. During 2002 there were two full time and one part time longline vessels. The two
full time longliners fished between the east, south and west coasts of Tasmania, and are now
competent at targeting both blue eye trevalla and ling. One operator ceased longlining to go
droplining in the northern part of the GHTF. Operators rarely set mesh-nets for scalefish, which
meant that ISMP scientists were unable to monitor this fishing method during the 2002/03
contract.
Dropline
Over the year, 23 sea-days were spent monitoring the catches of two dropline vessels operating
throughout the GHTF. Catches were monitored from a total of 218 shots comprising 21,850
hooks (Table 2). From these, 8343 kg of fish were caught of which 582 kg (7% by weight) were
discarded (Table 2). A total of 24 species (6 quota species) were caught, with blue eye trevalla
(5,974 kg) and pink ling (1,397 kg) being the main target species and accounting for the bulk of
the catch (Tables 3 and 4, Figure 2). On average, the dropline retained catch per shot of blue eye
trevalla for the Eastern Victoria and North of Barrenjoey Head zones was 17 and 64 kg,
respectively. The dropline retained catch per shot of pink ling for the Eastern Victoria zone was
27 kg (Table 4). The other main species retained were Richardson’s boarfish (105 kg), piked
dogfish (83 kg), thresher shark (75 kg), hapuku (43 kg) and offshore ocean perch (24 kg). The
discarded catch was dominated by piked dogfish (386 kg) and draughtboard shark (126 kg). A
small quantity of blue eye trevalla (11 kg) were discarded due to damage.
During the on-board monitoring of dropline catches, length-frequency data was collected from
1,576 fish, most of which were blue eye trevalla (914) and pink ling (308). Other species
measured included piked dogfish (183), Richardson’s boarfish (55) and offshore ocean perch
(27). The length-frequency distributions of blue eye trevalla and pink ling caught by dropline
vessels are shown in Figures 5 and 6, respectively.
Longline
Fifty-nine days of on-board monitoring was undertaken on four demersal longline vessels with
auto-longlining gear. Overall, catches were monitored from a total of 97 shots comprising
355,585 hooks (Table 2). Over 86,444 kg, comprised of 70 species (9 quota species), was caught
(Tables 5 and 6, Figure 3). Pink ling (31,584 kg), blue eye trevalla (21,862 kg) and ribaldo
(11,071 kg) accounted for most of the retained catch. The mean longline retained catch per shot
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of blue eye trevalla were similar for the Eastern and Western Tasmania zones (254 and 262 kg
respectively, Table 6). The mean longline retained catch per shot was slightly higher for pink
ling caught in the Eastern and Western Tasmania zones (305 and 362 kg respectively, Table 6).
Other species retained in the longline catch included small quantities of brier shark, red gurnard,
offshore ocean perch, school shark, blue grenadier and gummy shark. Overall, 15,118 kg (17%
of the catch) was discarded. The discarded component of the catch was dominated by various
shark species including draughtboard sharks (7,425 kg), brier shark (3,312 kg), bight skate
(1,558 kg) and green eyed dogfish (695 kg). Length-frequency information from over 8,196 fish
was collected during the on-board monitoring of longline catches, most of which were from the
major commercial species, namely blue eye trevalla, pink ling, offshore ocean perch, ribaldo,
blue grenadier and gummy shark (Figures 5 to 10).
Mesh-nets
Historically mesh-nets have been deployed to target blue warehou on fishing grounds off the east
coast of Victoria but his practice has become infrequent over recent years. As a consequence, no
on-board monitoring of mesh-net vessels was done during July 2002 to June 2003.
Traps
In the trap fishery, 17 shots comprising of 418 traps were observed over 8 days (Table 2). There
were 11 different species (3 quota species) caught in traps totalling 10,403 kg, of which only 8
kg (0.1%) was discarded (Tables 7 and 8, Figure 4). The target species was pink ling (10,347
kg). On average, the retained catch per shot of pink ling for the Eastern Victoria and Western
Tasmania zones was 225 and 727 kg respectively, The other retained species included ribaldo
and offshore ocean perch. The discard species included damaged ribaldo, crabs, starfish and
banded bellowsfish. Length-frequency measurements were taken from 1,303 pink ling (Figure
6).
Discard rates
The sea-days monitored in each of the gear x region strata for the 2002 calendar year is presented
in Table 9. Estimates and coefficients of variation (CVs) of the discard rates of quota species
and non-quota species for each of strata are shown in Table 10. The estimates and CVs of the
discard rates of all quota species weighted across their defining strata and non-quota species
across the GHTF are shown in Table 11. All achieved CVs were well under the target CVs.
Discard rates within individual strata were combined with GN01 and SAN2 figures on the
landed catch to estimate the total discarded catch across the fishery for each quota species and all
of the non-quota species pooled (Table 11). The total landing of quota species during the 2002
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calendar year was about 855 t. The total discard weight of quota species during 2002 was
estimated as 0.3 t. Discard rates for all quota species except blue grenadier were low (below
1%). A medium level (5- 20%) of blue grenadier discarding occurred (5%, 0.1 t). For non-quota
species, the total retained weight during the 2002 calendar year was 155 t while the discarded
weight was 246 t. Discard rates for non-quota species were 51%.
Port-based sampling
In addition to on-board monitoring, the ISMP collects length-frequency information on the
landed catches from the GHTF. A number of port-based fish measurers undertake this work at
the major ports in south-eastern Australia.
During July 2002 to June 2003, length-frequency information was collected from 4,993 fish (16t
from catches totalling 49t), comprising 6 species (blue eye trevalla, gummy shark, school shark,
blue warehou, pink ling, and hapuku, Figure 11). This was obtained by sampling 58 catches
from the three fishing methods (no trap catches were sampled) (Tables 12 and 13).
Otolith collection
Based on the agreed AFMA / CAF workplan (Central Ageing Facilty – Workplan for GHTF
2002/2003), a total of 1500 otoliths needed to be collected from the GHTF during 2002/03
(Table 14). Overall, 855 non-trawl otolith samples were collected, which is under the target for
the July 2002 to June 2003 period. Collections of mesh caught blue warehou are very difficult
to achieve because there is no longer a significant mesh-net fishery for this species. This
component of the CAF work plan should be reconsidered for 2003/04. The collection of 274
otoliths from male and female pink ling samples from the demersal longline fishery was near the
2002/03 target due to concerted efforts by ISMP staff to work closely with industry members of
the GHTF (sampling of the different sexes required fishers to keep some pimk ling without gill
and gutting). Collections of line caught blue eye trevalla proceeded slowly during 2002/03 until
the employment of ISMP scientist Russell Hudson in Hobart during January 2003. We have
now collected 515 blue eye trevalla otoliths.
Wildlife interactions
As reported previously, the presence of orcas on the fishing grounds has had a notable effect on
the dropline fishery working out of Tasmania. Many operators are not bothering to go fishing if
whales are in the area. Not only does their presence scare fish away, but the whales prey on fish
hooked on the droplines. For a similar reason, the growing population of seals is also a problem
for the fishers. Despite their increasing numbers, there was no incident of whales or seals getting
hooked by the gear during shots observed by the ISMP. Large numbers of seabirds are often
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observed around vessels during fishing operations, but although a total of over 350,000 hooks
were monitored, no seabird captures or injuries were noted.
Acknowledgments
The authors are grateful for the wide-spread support of the South East Non-Trawl Fishing
Industry. In particular, we would like to thank the owners, skippers and crews of the FV Kiella,
FV Kobus, FV Petuna Endeavour and FV Starfire for their co-operation. Ron Hately, Russel
Hudson, James Parkinson, Ken Smith and Sue Strong are thanked for their technical assistance.
This research study was funded by through the Australian Fisheries Management Authority.
References
Knuckey, I.A., Berrie S., Talman, S. and Brown L.P. (2002). Integrated Scientific Monitoring
Program for the South East Non-Trawl Fishery – Final Report to the Australian Fisheries
Management Authority.
Knuckey, I.A. and Gason, A. (2001). Integrated Scientific Monitoring Program. Development of
a “design model” for an adaptive ISMP sampling regime – Final Report. Australian
Fisheries Management Authority, Canberra.
Knuckey, I.A., Gill S. and Gason, A. (2001). South East Fishery Non-Trawl Pilot Monitoring
Program – Final Report to the Australian Fisheries Management Authority.
Smith, D.C., Gilbert, D.J., Gason, A. and Knuckey, I., (1997). Design of an Integrated Scientific
Monitoring Program for the South East Fishery. 50 pp.
Marine and Freshwater Resources Institute
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2002/2003 Report to AFMA
Tables and Figures
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Table 1.
Description of the GHTF strata used in the ISMP and the agreed target sea-days
required by on-board scientists. The days that have been undertaken between July 2002 and
June 2003 are provided. Values in parentheses are additional trips undertaken by ISMP scientists
to meet auto-longline permit conditions.
Zone
Gear
Total days
Total days
required
undertaken
North of Barrenjoey Head
Dropline
0
19
NSW
Demersal Longline
4
0
Eastern Victoria
Dropline
5
4
Mesh-net
7
0
Traps
7
3
Dropline
8
0
Demersal Longline
0
37 (17)
Dropline
4
0
Demersal Longline
11
22 (10)
Traps
0
5
Dropline
4
0
50
90 (27)
Eastern Tasmania
Western Tasmania
Western Victoria
Total days
Table 2.
Summary of on-board monitoring of GHTF vessels undertaken during July 2002
to June 2003.
Monitoring Level
Fishing
Method
Catch
Retained
Vessels
Days
Shots
2
23
218
Longline
4
59
97
0
0
0
Trap
1
8
17
TOTAL
7
90
332
net
Catch
(kg)
Dropline
Mesh-
Effort
Marine and Freshwater Resources Institute
21,850
hooks
355,585
hooks
0 nM
418
traps
Discarded
Catch (kg)
Total
Catch
(kg)
% Weight
Fish
discarded
measured
7,761
582
8,343
7%
1,576
71,326
15,118
86,444
17%
8,196
N/A
N/A
N/A
N/A
N/A
10,395
8
10,403
0.1%
1,346
89,481
15,707
105,188
15%
11,118
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Table 3. All species caught by dropline vessels in shots monitored by ISMP scientists during
July 2002 to June 2003.
Species
CAAB
No. shots
Catch (kg)
Retained
Blue eye trevalla
Ling
Richardson's boarfish
Piked dogfish
Thresher shark
Hapuku
Ocean perch - offshore
Green-eyed dogfish
Ribaldo
Bass groper
Ocean blue eye
Big-spined boarfish
Alfonsin
Redfish
Long-finned boarfish
Draughtboard shark
White spotted shovelnose ray
Gemfish
Thornback skate
Endeavour dogfish
* Family * triakidae
Sharpnose seven-gill shark
Basket-work eel
Jackass morwong
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
37
445001
228002
367009
020006
012001
311006
287093
020007
224002
311170
445014
367004
258002
258003
367005
015013
026001
439002
031007
020001
017000
005001
070001
377003
136
51
21
55
1
3
9
4
5
3
1
5
5
2
1
9
1
3
1
3
2
1
1
1
5974.5
1397.0
104.5
83.0
75.0
43.0
24.0
15.0
11.0
11.0
9.0
8.0
3.0
2.0
1.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Discarded
11.0
0.0
0.0
386.0
0.0
0.0
1.0
0.0
3.0
0.0
0.0
0.0
0.0
0.0
0.0
126.0
25.0
10.0
8.0
6.0
3.0
2.0
1.0
1.0
Table 4. Retained and discarded quota species caught by dropline vessels in shots monitored by
ISMP scientists during July 2002 to June 2003.
Species
Blue eye trevalla
Zone1
No. shots
Retained (kg)
Mean
17.41
± SE
2.11
Total
4.00
Discarded (kg)
Mean
± SE
0.07
0.07
VIC EAST
58
Total
1010.0
NTH B/JOEY
77
4964.5
64.47
7.83
7.00
0.09
0.06
Eastern gemfish
VIC EAST
3
0.0
0.00
0.00
10.00
3.33
1.33
Jackass morwong
VIC EAST
1
0.0
0.00
0.00
1.00
1.00
0.00
Ocean perch –
VIC EAST
9
24.0
2.67
1.46
1.00
0.11
0.11
Pink ling
VIC EAST
51
1397.0
27.39
3.50
0.00
0.00
0.00
Redfish
VIC EAST
2
2.0
1.00
0.00
0.00
0.00
0.00
Inshore
1
NTH B/JOEY as North of Barrenjoey Head and VIC EAST as Eastern Victoria.
Marine and Freshwater Resources Institute
Page 13
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Table 5. All species caught by longline vessels in shots monitored by ISMP scientists during July
2002 to June 2003.
Species
CAAB
No. shots
Catch (kg)
Retained
Ling
Blue Eye Trevalla
Ribaldo
Brier Shark
Red Gurnard
Ocean Perch - Offshore
Blue Grenadier
School Shark
Gummy Shark
Bight Ghost Shark
Hapuku
Bight Skate
Australian Tusk
Owston's Dogfish
Spiky Oreo
Black Shark
Southern Whiptail
Alfonsin
Barracouta
Skates And/Or Rays
Ogilby's Ghost Shark
Jackass Morwong
Porbeagle Shark
Giant Crab
Gemfish
Blue Shark
Toothed Whiptail
Blue Warehou
Elephant Fish
Common Saw Shark
King Crab
Imperador
Southern Dogfish
Green-Eyed Dogfish
* Family * Anguillidae
Ocean Perch- Inshore
Endeavour Dogfish
N.Z. Rock Ling
Thresher Shark
Grey Skate
Striped Trumpeter
Spotted Warehou
Whitefin Swell Shark
Sawtail Shark
Southern Conger Eel
Mirror Dory
Speckled Stargazer
White-Spotted Dogfish
Moller's Deepsea Shark
Draughtboard Shark
Whitley's (Melbourne) Skate
Whiptails/Rattails
Long-Nosed Skate
Deepwater Dogfish
##Etmopterus Baxteri
Blind Shark
White Spotted Skate
Piked Dogfish
Banded Whiptail
Basket-Work Eel
* Family * Congridae
Lantern Shark
Cookie-Cutter Shark (Cigar Shark)
King Crab (Tasmanian Giant)
Long-Finned Eel
Green Stargazer
Harrisson's Dogfish
Crabs
Jack Mackerel
Round Skate
37 228002
37 445001
37 224002
37 020003
37 288001
37 287093
37 227001
37 017008
37 017001
37 042003
37 311006
37 031010
37 228001
37 020019
37 266001
37 020002
37 232001
37 258002
37 439001
37 900V01
37 042001
37 377003
37 010004
37 702T04
37 439002
37 018004
37 232004
37 445005
37 043001
37 023002
37 702T02
37 258001
37 020011
37 020007
37 056000
37 287001
37 020001
37 226001
37 012001
37 031028
37 378001
37 445006
37 015013
37 015009
37 067007
37 264003
37 400018
37 020008
37 020005
37 015001
37 031006
37 232000
37 031005
37 020012
37 020021
37 013007
37 031003
37 020006
37 232002
37 070001
37 067000
37 020907
37 020014
37 701001
37 056002
37 900V10
37 020010
37 702000
37 337002
37 031001
Marine and Freshwater Resources Institute
96
85
80
39
50
30
59
14
12
48
10
75
9
13
28
18
24
26
13
7
11
15
1
2
6
3
27
5
2
3
5
3
4
13
15
1
1
1
1
22
1
1
80
42
25
1
1
8
37
6
4
12
4
1
3
1
3
6
6
2
2
2
4
1
1
1
1
1
2
1
31584.4
21862.9
11070.6
1061.0
841.8
695.0
574.6
566.0
478.0
468.8
357.1
237.2
222.1
206.0
199.0
166.0
154.0
88.0
59.2
59.0
44.0
41.4
30.0
29.0
28.0
25.0
22.5
20.0
16.0
15.0
14.0
13.5
12.0
10.0
10.0
10.0
6.0
6.0
6.0
5.0
3.0
3.0
2.0
1.0
1.0
1.0
1.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
Discarded
2.0
0.0
24.0
3311.5
4.5
4.0
19.4
118.0
303.0
31.6
0.0
1557.6
1.6
136.0
0.0
80.0
114.6
0.0
5.2
48.0
0.0
0.0
0.0
2.5
0.0
1.7
70.5
0.0
0.0
0.0
2.0
0.0
3.6
695.0
20.3
0.0
0.0
0.0
0.0
154.3
0.0
0.0
7425.0
272.5
61.1
0.0
0.0
187.2
106.2
94.0
65.5
40.4
26.0
24.0
20.0
16.0
14.0
9.3
9.0
8.0
8.0
8.0
4.5
2.0
2.0
2.0
1.0
1.0
0.6
0.0
Page 14
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Table 6. Retained and discarded quota species caught by longline vessels in shots monitored by
ISMP scientists during July 2002 to June 2003.
Species
Zone
Blue eye trevalla
TAS EAST
50
12695.8
253.92
56.04
0.0
0.00
0.00
TAS WEST
35
9167.1
261.92
62.03
0.0
0.00
0.00
TAS EAST
29
283.8
9.79
2.69
11.0
0.38
0.18
TAS WEST
30
290.8
9.69
2.00
8.4
0.28
0.11
TAS EAST
3
9.0
3.00
1.00
0.0
0.00
0.00
TAS WEST
2
11.0
5.50
4.50
0.0
0.00
0.00
Eastern gemfish
TAS EAST
6
28.0
4.67
0.71
0.0
0.00
0.00
Jackass morwong
TAS EAST
14
40.4
2.89
0.86
0.0
0.00
0.00
TAS WEST
1
1.0
1.00
0.00
0.0
0.00
0.00
Mirror dory
TAS WEST
1
1.0
1.00
0.00
0.0
0.00
0.00
Ocean perch –
TAS EAST
23
511.0
22.22
3.43
3.0
0.13
0.07
TAS WEST
7
161.0
23.00
5.36
0.0
0.00
0.00
TAS EAST
55
16753.4
304.61
37.34
2.0
0.04
0.04
TAS WEST
41
14831.0
361.73
40.23
0.0
0.00
0.00
TAS WEST
1
3.0
3.00
0.00
0.0
0.00
0.00
No. shots
Total
Blue grenadier
Blue warehou
Retained (kg)
Mean
± SE
Discarded (kg)
Total
Mean
± SE
offshore
Pink ling
Spotted warehou
1
TAS EAST as Eastern Tasmania, TAS WEST as Western Tasmania and VIC EAST as Eastern Victoria.
Marine and Freshwater Resources Institute
Page 15
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Table 7. All species caught by trap vessels in shots monitored by ISMP scientists during July
2002 to June 2003.
Species
CAAB
No. shots
Catch (kg)
Retained
Ling
Ribaldo
Ocean perch - offshore
* Family * anguillidae
Blue eye trevalla
Draughtboard shark
Octopus
Basketwork eel
Spider crab
Starfish
Banded bellowsfish
37
37
37
37
37
37
37
37
37
37
37
228002
224002
287093
056000
445001
015013
601000
070003
702T03
905610
279001
17
5
9
4
1
1
1
1
2
1
1
Discarded
10347.0
18.0
13.5
6.5
5.0
2.0
1.5
1.0
0.0
0.0
0.0
0.0
3.0
0.0
0.0
0.0
0.0
0.0
0.0
3.0
1.0
0.5
Table 8. Retained and discarded quota species caught by trap vessels in shots monitored by
ISMP scientists during July 2002 to June 2003.
Species
Zone
No. shots
Total
Retained (kg)
Mean
± SE
Total
Discarded (kg)
Mean
± SE
Blue eye trevalla
VIC EAST
1
5.0
5.00
0.00
0.00
Ocean perch –
VIC EAST
4
11.0
2.75
1.03
0.00
0.00
0.00
TAS WEST
5
2.5
0.50
0.00
0.00
0.00
0.00
VIC EAST
4
900.0
225.00
55.45
0.00
0.00
0.00
TAS WEST
13
9447.0
726.69
118.55
0.00
0.00
0.00
offshore
Pink ling
1
TAS EAST as Eastern Tasmania, TAS WEST as Western Tasmania and VIC EAST as Eastern Victoria.
Marine and Freshwater Resources Institute
Page 16
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Table 9. Definition of GHTF strata for estimation of discard rates during the 2002 calendar year.
Stratum 1
Gear
Defining zones
DL EAST
Dropline
Eastern Victoria, Bass Strait, NSW
8
DL SW
Dropline
Eastern Tasmania, Western Tasmania, Western Victoria
3
DL NBJ
Dropline
North of Barrenjoey Head
10
Days at sea
DL Total
21
LL EAST
Longline
Eastern Tasmania, Eastern Victoria, Bass Strait, NSW
27
LL WEST
Longline
Western Tasmania, Western Victoria
10
LL Total
MESH ALL
37
Mesh-net
All zones – Western Victoria, Western Tasmania, Eastern
Tasmania, Eastern Victoria, Bass Strait, NSW
2
MESH Total
2
TR EAST
Trap
Eastern Tasmania, Eastern Victoria, Bass Strait, NSW
3
TR WEST
Trap
Western Tasmania, Western Victoria
5
TR Total
8
TOTAL
68
Table 10. Estimated discard rates and (CVs) for each species within their defining strata during
the 2002 calendar year (see Table 9 for strata codes).
Species
Gemfish
DL EAST
1.00
DL SW
DL NBJ
0.00
(0.00)
0.00
(0.00)
0.00
(0.00) 0.08
(0.53)
(0.00)
0.00
(0.00) 0.00
(0.00)
0.00
(0.00) 0.00
(0.00)
0.01
(0.13) 0.01
(0.67) 0.00
(0.00) 0.68
Pink ling
0.00
(0.00) 0.00
Jackass morwong
1.00
(0.00)
Redfish
0.00
(0.00)
Ocean perch
0.02
(0.22) 0.00
(0.00)
Blue eye trevalla
0.00
(0.24) 0.00
(0.00) 0.00
Non-quota
0.00
0.40
LL WEST
(0.00)
Blue grenadier
Spotted warehou
LL EAST
(0.00) 0.00
(0.03) 0.06
Marine and Freshwater Resources Institute
MESH ALL
TR EAST
TR WEST
0.00
(0.00) 0.00
(0.00)
(0.80)
0.00
(0.00) 0.00
(0.00)
(0.00) 0.00
(0.00)
0.00
(0.00)
(0.00) 0.47
(0.01) 0.78
(0.00)
(0.46) 0.93
(0.02) 0.22
(0.19) 0.01
(1.02)
Page 17
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Table 11. Estimates and coefficients of variation (CVs) of the discard rates of all quota species
and “other” non-quota species across the GHTF during the 2002 calendar year.
Species
Discard
CV of
rate 1
discard
(Disc/Tot*
rate
100)
0
<1
Gemfish
Target
CV
Estimated Estimated
SD of
SD of
discarded retained discarded retained
weight
weight
weight
weight
(t)
(t)
(t)
(t)
1.5
0.01
3.31
0
0.14
Blue grenadier
5
0.63
0.8
0.12
2.06
0.03
0.27
Pink ling
0
0
1.5
0
463.83
0
33.06
<1
0
1.5
0
0.88
0
0.08
0
0
1.5
0
0.08
0
0
Ocean perch
<1
0.43
1.5
0.14
18.99
0.01
1.49
Blue eye trevalla
<1
0.83
1.5
0.04
362.76
0
19.65
Spotted warehou
0
0
1.5
0
0.58
0
0.07
Blue warehou
0
0
1.5
0
2.93
0
0.12
0.31
855.42
245.92
155.26
15.01
9.04
Jackass morwong
Redfish
Total quota
Total non-quota
51
0.02
0.4
1
The discard rate is the estimated discard rate of each species across the fishery based on ISMP data. Discard rates
were combined with total landed catch to estimate the total retained and discarded catch ± 1 standard deviation
(SD).
Table 12. Length-frequency information collected by port based fish measurers during July
2002 to June 2003 summarised by port.
Gear
Port
No. of species
measured
2
No. of catches
sampled
42
Weight of fish
sampled (kg)
9924
Weight of catches
sampled (kg)
20169
No. of fish
sampled
2894
Dropline
Beachport
Dropline
Lakes Entrance
1
2
704
2479
232
Longline
Triabunna
1
1
870
870
295
Mesh-net
Lakes Entrance
3
13
4273
25909
1572
Total
Total
7
58
15771
49427
4993
Marine and Freshwater Resources Institute
Page 18
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Table 13. Length-frequency information collected by port based fish measurers during July
2002 to June 2003 summarised by species.
Gear
Species
No. of catches
sampled
15
Weight of fish
sampled (kg)
2879
Weight of catches
sampled (kg)
4606
No. of fish
sampled
430
Dropline
Hapuku
Dropline
Blue eye trevalla
39
7749
18042
2696
Longline
Pink ling
1
870
870
295
Mesh-net
Gummy shark
13
3759
23468
1327
Mesh-net
School shark
4
294
943
93
Mesh-net
Blue warehou
2
220
1498
152
Table 14.
Sector
Non-trawl
The Central Ageing Facility work plan for 2002/03.
Species
Component
Sample size
Sample size
required
collected
Blue warehou
Mesh-net
250
16
Ling
Trap
200
50
Ling
Line
300
274
Blue eye trevalla
Line
750
515
1,500
855
Total non-trawl
Marine and Freshwater Resources Institute
Page 19
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Presentation of data
Figures
Pie graphs are used to illustrate the percentage composition (by weight) of quota, non-quota
commercial and non-commercial species in the retained and discarded catch of SEF trawlers
during 2001. The species composition (by weight) of the retained and discarded catch are shown
separately.
Length frequencies are provided for all quota species. Data for each species is presented
graphically, with on-board data summarised by zone and port-based data summarised by port. A
diagram is included for each species, which shows the measurements used for the lengthfrequencies: TL (total length); DSL (dorsal standard length); SL (standard length); and LCF
(caudal fork length). Correct marketing names are given for each species, as well as their
scientific name, Code for Australian Aquatic Biota (CAAB), AFMA and Victorian codes.
To graphically represent the sampling conducted by ISMP on-board scientists, the average
weight per shot of the retained and discarded catch of each species is provided. Error bars (I)
are standard errors, and provide an indication of the variation around this average. In addition,
the length frequencies of both the retained (black bars) and discarded (white bars) fish measured
by ISMP on-board scientists are given. The number of shots observed and number of fish
measured are also provided.
Marine and Freshwater Resources Institute
Page 20
Integrated Scientific Monitoring Program
Figure 1.
Fishery.
2002/2003 Report to AFMA
Fishing zones used to define the spatial stratification of the Gillnet Hook and Trap
Marine and Freshwater Resources Institute
Page 21
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Figure 2a.
Percentage composition (by weight) of the retained and discarded catch of
dropline vessels during 2002/03.
Figure 2b.
Species composition (by weight) of the retained and discarded catch of dropline
vessels during 2002/03.
Marine and Freshwater Resources Institute
Page 22
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Figure 3a.
Percentage composition (by weight) of the retained and discarded catch of
longline vessels during 2002/03.
Figure 3b.
Species composition (by weight) of the retained and discarded catch of longline
vessels during 2002/03.
Marine and Freshwater Resources Institute
Page 23
Integrated Scientific Monitoring Program
0.1%
2002/2003 Report to AFMA
99.9%
Figure 4a.
Percentage composition (by weight) of the retained and discarded catch of trap
vessels during 2002/03.
Figure 4b.
Species composition (by weight) of the retained and discarded catch of trap
vessels during 2002/03.
Marine and Freshwater Resources Institute
Page 24
Integrated Scientific Monitoring Program
Species
Blue eye trevalla
2002/2003 Report to AFMA
Scientific name
Hyperoglyphe antarctica
deep sea trevalla
big eye
CAAB
37445001
AFMA: TBE
VIC: 451
LCF
Figure 5.
Mean catch and length-frequency distributions for blue eye trevalla by gear.
Marine and Freshwater Resources Institute
Page 25
Integrated Scientific Monitoring Program
Species
Pink ling
2002/2003 Report to AFMA
Scientific name
Genypterus blacodes
TL
CAAB
37228002
AFMA: LIG
VIC: 771
Figure 6.
Mean catch and length-frequency distributions for pink ling by gear.
Marine and Freshwater Resources Institute
Page 26
Integrated Scientific Monitoring Program
Species
Ocean perch
2002/2003 Report to AFMA
Scientific name
Helicolenus barathri - offshore
CAAB
37287093
AFMA: REG
VIC: 631
TL
Figure 7.
Mean catch and length-frequency distributions for ocean perch by gear.
Marine and Freshwater Resources Institute
Page 27
Integrated Scientific Monitoring Program
Species
Ribaldo
2002/2003 Report to AFMA
Scientific name
Mora moro
CAAB
37224002
Deepsea cod
Ghost cod
AFMA:
TL
Figure 8.
VIC:
Mean catch and length-frequency distributions for ribaldo by gear.
Marine and Freshwater Resources Institute
Page 28
Integrated Scientific Monitoring Program
Species
Blue grenadier
2002/2003 Report to AFMA
Scientific name
CAAB
Macruronus novaezelandiae
227001
whiptail
hoki
STL
blue hake
AFMA: GRE
VIC: 226
Figure 9.
Mean catch and length-frequency distributions for blue grenadier by gear.
Marine and Freshwater Resources Institute
Page 29
Integrated Scientific Monitoring Program
Species
Gummy shark
2002/2003 Report to AFMA
Scientific name
Mustelus antarticus
CAAB
37017001
AFMA: GUM
VIC: 651
TL
Figure 10.
Mean catch and length-frequency distributions for gummy shark by gear.
Marine and Freshwater Resources Institute
Page 30
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Figure 11 . Examples of length-frequency distributions obtained from port-based sampling.
Marine and Freshwater Resources Institute
Page 31
Integrated Scientific Monitoring Program
2002/2003 Report to AFMA
Figure 11 cont. Examples of length-frequency distributions obtained from port-based sampling.
Marine and Freshwater Resources Institute
Page 32