1st workshop on connecting the iotc science and … · sampling in land catch-and-effort...
TRANSCRIPT
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1st WORKSHOP ON CONNECTING THE IOTC SCIENCE AND MANAGEMENT
PROCESSES (SMWS01) Data needs and assessment approaches
INDIAN OCEAN TUNA COMMISSION Secretariat
http://www.iotc.org
http://www.iotc.org/http://www.iotc.org/http://www.iotc.org/
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Overview
Legal requirements of reporting data
Data types used in Assessments
The Scientific Process / Stock
Assessment Approaches
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Summary of IOTC Resolutions
IOTC Resolutions: IOTC and main shark species • IOTC Resolution 10/02 Mandatory statistical requirements for IOTC
Members and Cooperating Non-Contracting Parties (CPC’s) • Minima requirements for the reporting of statistics to the IOTC
• IOTC Resolution 13/08 Procedures on a fish aggregating devices (FADs) management plan • Minima requirements for the collection and reporting of data on FADs,
drifting or anchored, used by Purse seine and pole-and-line fisheries
• IOTC Resolution 13/03 On the recording of catch and effort data by fishing vessels in the IOTC Area of Competence • Minima data requirements for the collection of CATCH-AND-EFFORT
data
• IOTC Resolution 11/04 On a Regional Observer Scheme • Minima requirements sampling of catches in land and at-sea
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Summary of IOTC Resolutions (cont.)
IOTC Resolutions: Main sharks and other bycatch species • IOTC Resolution 05/05 Concerning the conservation of Sharks caught in
association with fisheries managed by IOTC • Minima requirements for the reporting of data on sharks caught on
IOTC fisheries
• Other Resolutions on sharks: Ban on catch retention and reporting
requirements for:
• Oceanic whitetip shark: IOTC Resolution 13/06 • Thresher sharks: IOTC Resolution 12/09 • Whale sharks: IOTC Resolution 13/05 (purse seine fisheries)
• IOTC Resolution 10/06 On reducing the incidental bycatch of Seabirds in
longline fisheries • Minima requirements for the reporting of interactions with seabirds (longline)
• IOTC Resolution 12/04 On Marine Turtles
• Minima requirements for the reporting of interactions with marine turtles
• IOTC Resolution 13/04 On the conservation of Cetaceans • Minima requirements for the reporting of interactions with cetaceans
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Data requirements at a glance
Types of fisheries data for which the Commission has set [data collection] and reporting standards; and data resolution requested by the Commission:
Coastal fleets
EEZ vessels less than 24 m LOA
Active Crafts (FC) Number of fishig craft per boat-gear type category per year
Surface fisheries: CE by
fishery, 1° grid and month
#FADs [Anchored
& Drifting: CE by
1° grid and month
(PS-BB)]
Supply vessels
Purse seine
fishery: Effort 1°
grid and month
Size data (SF)
Scientific observer data Sample of catches in land to cover at least 5% vessel activities
Socio-economic data
Foreign fleets EEZ catch Not applicable
Vessels with LOA ≥ 24 m and all high seas vessels
CE data for foreign licensed fishing vessels (above CE standards)
Sample of catches at-sea to cover at least 5% fishing operations
Individual lengths of IOTC species sampled, by fishery, species, 5° grid, and month
Longline fisheries: CE by fishery, 5° grid and month
Individual vessel data for all fishing ships catching IOTC species
Discard levels IOTC species, sharks, seabirds, marine turtles, Cetaceans per IOTC Area, gear, species and Year (in number of weight)
Nominal catches (weight) of IOTC Species, main species of pelagic sharks, and other bycatch, per IOTC Area, gear, species and Year
No standards have been set as yet
Statistical Requirements
Summary
Catch-and-Effort (CE) CE Data by fishery (type of boat-gear), area and period
Annual catches (NC+DI)
Industrial surface and longline fleets
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Applications to gear types
Presentation title | Presenter name
6 |
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Coastal Fisheries
Full Compliance: Coastal Fisheries
Reports Fishing Sector
Time
Sampling in
land
Catch-and-
effort (statistical area, boat-gear,
species, month) Size frequency (statistical area,
boat-gear,
species, month)
Catch-and-
effort
estimation
Nominal Catch (Boat-gear, IOTC
area, Year,
Species)
Aggregatio
n
Catch-and-Effort (boat-gear, Stat
Area, Month,
Species)
Raising
Coverage ≥ 5% vessel
activities (e.g. trips)
Size Frequency (Species, boat-
gear, Stat Area,
Month)
At least 1 fish measured for size per ton of
catch
Socio-
Economic (Various)
Raising &
Aggregatio
n
Fishing Craft (number boats /
size category,
Gear, Year)
[Raising
]
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Surface Fisheries
Full Compliance: Surface Fisheries
Catch reports & Logbooks (Fishing Sector)
Time
Sampling in
land
Catch-and-
effort (1°Grid, boat-gear-fishing
mode, species,
month) Size frequency
(5°Grid, boat-gear-
target, species,
month)
Catch-and-
effort
estimation
Nominal Catch (Boat-gear-
fishing mode-
target, IOTC
area, Year,
Species)
Aggregatio
n
Catch-and-
Effort (boat-gear-fishing mode-
target, 1°Grid,
Month, Species)
Raising
Size Data (Species,
boat-gear-
target,
5°Grid,
Month)
Socio-
Econ. (Various)
Active
Vessel
List
Sampling at
sea At least 1 fish measured for size per ton of
catch
Size Data
estimation
Total Enumeration
FAD &
Supply [PS+BB]
Discards
Estimation &
Raising
Discards (Boat-gear-
target,
IOTC area,
Year,
Species)
Raising
Coverage ≥ 5% fishing operations
(e.g. sets)
Trip
Report
(1°Grid)
Aggr
egati
on
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Longline Fisheries
Full Compliance: Longline Fisheries
Catch reports & Logbooks (Fishing Sector)
Time
Catch-and-
effort (5°Grid, boat-gear-target
species, month,
species)
Size frequency (Species, boat-
gear-target
species, 5°Grid,
Month) Catch-and-
effort
estimation
Nominal
Catch (Boat-gear-target,
IOTC area,
Year, Species)
Aggregatio
n
Catch-and-
Effort (boat-gear-target,
5°Grid, Month,
Species)
Raising
Size Data (Species, boat-
gear-target,
5°Grid, Month)
Socio-
Econ. (Variou
s)
Active
Vessel
List
Sampling at
sea
Coverage ≥ 5% fishing operations
(e.g. sets)
At least 1 fish measured for size per ton of
catch
Size Data
estimation
Total Enumeration
Raising
Discards
Estimation &
Raising
Discards (Boat-gear-
target, IOTC
area, Year,
Species)
Trip
Report
(1°Grid)
Aggregatio
n
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Dissection of catch for a Fishing Trip
The IOTC definitions for nominal catches, bycatch, and discards may differ from those used in other areas Catch-and-effort and size data shall be collected for IOTC species and the main species of sharks, as identified by the Commission, from both, nominal catches and discards
Total catch Retained
catch
Dis
ca
rd
s Marketable
(Target)
• Tuna (-like)
• Sharks
• Other finfish
Marketable
(Other)
• Tuna (-like)
• Sharks
• Other finfish
Incidental catch
• Seabirds
• Marine turtles
• Cetaceans
Discards
commercial and
other species
• Tuna (-like)
• Sharks
• Other finfish
NOMINAL CATCH
DISCARDS
BYCATCH
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Importance of IOTC fisheries (2008-2012)
Indonesia, Iran, India, and Sri Lanka caught over 50% of the total catches (2008-12)
22%
33
43
52
60
67
71
7579
8285
87 8990 92
93 94 9596 97 98 99 100%
0
25
50
75
100
0
500
1000
1500
2000
WS-
Ind
on
esi
a
WS-
Iran
, Isl
amic
…
WS-
Ind
ia
WS-
Sri L
anka
EU-S
pai
n
WS-
Mal
div
es
WS-
Seyc
he
lles
Taiw
an,C
hin
a
WS-
Pak
ista
n
EU-F
ran
ce
WS-
Yem
en
WS-
Om
an
WS-
Mal
aysi
a
Jap
an
WS-
Thai
lan
d
Fran
ce O
T
Mya
nm
ar
NEI
-Fre
sh T
un
a
WS-
Mad
agas
car
Un
ite
d A
rab
Em
irat
es
Sau
di A
rab
ia
NEI
-De
ep-f
ree
zin
g
Au
stra
lia
WS-
Co
mo
ros
Ch
ina
WS-
Tan
zan
ia
Ko
rea,
Rep
ub
lic o
f
NEI
-Oth
er
EU-F
ran
ce(R
eun
ion
)
Qat
ar
WS-
Ban
glad
esh
Ph
ilip
pin
es
Erit
rea
EU-U
nit
ed K
ingd
om
EU-P
ort
uga
l
WS-
Ke
nya
WS-
Mau
riti
us
Sou
th A
fric
a
Egyp
t
Be
lize
Gu
ine
a
WS-
Djib
ou
ti
WS-
Mo
zam
biq
ue
Van
uat
u
Ku
wai
t
Jord
an
Bah
rain
Sud
an
Un
ite
d K
ingd
om
OT
East
Tim
or
% o
f to
tal c
atch
(ac
cum
ula
ted
)Me
tric
to
ns
(*1
00
0)
OTHER
Sharks
Billfish
Seerfish
Small tunas
Longtail tuna
Skipjack tuna
Large tunas
%
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Tropical Tuna Catch Series
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The fishing areas 2006 2010
Purse-
seine
Longline
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The fishing areas-Most Recent 2011 2012
Purse-
seine
Longline
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Building blocks of Tuna stock assessments
• Catch-and-effort data
• Landed (Nominal) catch (sale slips; sampling)
• Discard levels (observers; logbooks)
• Effort (logbooks; sampling)
• Size/age composition (sampling; tagging)
• Abundance trends
• Fishery CPUE (fine-scale operational data from
logbooks)
• [Size/age/sex composition (logbooks; sampling;
tagging)]
• Exploitation rates (tagging)
• Life history information
• Longevity/natural mortality (tagging; otoliths)
• Growth (tagging; otoliths)
• Maturation (biological samples)
Spatial
and
seasonal
patterns
Routine
Data
Collectio
n
Data
Collection
through
specific
projects
(updated
regularly)
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Building blocks of management advice
Slide from R. Method
modified by Joseph E.
Powers
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Input files prepared for the assessments
IOTC SECRETARIAT
• Catch [and effort] data by species, time-period (usually quarter),
fishery (groups of Flag-Gear combinations depending on the
selectivity) and areas (depending on the dynamics of the fleets and
species for assessment)
• Number of fish sampled by species, size bin, time-period… (as
above)
• Length-weight, growth, and other functions used for each species
• Life history information
FLAG STATES
• Indices of abundance (from as many fleets as possible); estimated
using fine-scale operational data (logbooks)
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Assessment tools and models used by the
IOTC scientific community
Basic indicators
(Catch trends, CPUE, mean size, etc.).
Stock reduction Approaches, Biomass dynamic models (Production models); delay-difference models
ASPIC
Age-structured production models
(ASPM)
Integrated models; catch-at-age or catch-at-size models
(e.g. SS2)
Spatially disaggregated, integrated models
(SS3, MULTIFAN-CL)
Tagging data essential!
Increasing complexity -> better approximation but more data are required!
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How do we deal with Uncertainty?
4 Approaches
Parameter Uncertainty (assumptions on
parameter choice).
Data uncertainty (weights, inverse
variance)
Model uncertainty (e.g. Spatial
assumptions, time varying selectivity).
Derived parameter uncertainty, i.e.
estimation error (MCMC Runs).
Projections (Kobe II): So far use the
above framework with deterministic
projections at varying catches.
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Skipjack-Parameter
Uncertainty -I
30
S1
0S
10
N3
0N
20E 40E 60E 80E 100E 120E
R1 R2
R3
Skipjack-Parameter
Uncertainty -II
Bigeye-Spatial uncertainty
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0 10 20 30 40
0.0
00.0
20.0
40.0
6
Age class (quarter)
Fis
hin
g m
ort
alit
y (
quart
erly)
MSY (1000s mt)
Density
130 140 150 160 170 180
0.0
00.0
10.0
20.0
30.0
4
SB2011/SBmsy
Density
1.2 1.3 1.4 1.5 1.6
01
23
45
6
F2011/Fmsy
Density
0.25 0.30 0.35 0.40
02
46
810
12
Bigeye-
Derived Parameter
Uncertainty using
MCMC
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Tunas as a highly migratory species in the
Indian Ocean: the case from tagging
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Yellowfin tuna:
• Half the catch from
small-scale and
artisanal fisheries
• Large percentage of
catches from the
high-seas
• Important catches
from FAD’s for purse-
seine
• Distribution of purse-
seine effort less
affected by piracy
than longline
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Yellowfin tuna: the history
• Catch history
• CPUE history
0
100,000
200,000
300,000
400,000
500,000
600,000
1950
1954
1958
1962
1966
1970
1974
1978
1982
1986
1990
1994
1998
2002
2006
2010
Catc
h (t
)
FS LS LL LF BB GI HD TR OT
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Yellowfin tuna: the history
• CPUE history
• CPUE history
1980 1990 2000 2010
0.0
00.1
00.2
00.3
0
LL 1
1980 1990 2000 2010
0.0
0.5
1.0
1.5
LL 2
1980 1990 2000 2010
0.0
0.5
1.0
1.5
LL 3
1980 1990 2000 2010
0.0
0.2
0.4
0.6
LL 4
1980 1990 2000 2010
0.0
0.4
0.8
LL 5
CP
UE
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Yellowfin tuna: the assessment
Model feature MFCL
Population spatial structure / areas
5
Uses Catch-at-length Yes
Tagging data Yes
Age-structured Yes
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5
0.0
0.5
1.0
1.5
2.0
SB=SBmsySBSBmsy
SB/SBmsy
F=
Fm
sy
F<
Fm
sy
F>
Fm
sy
F/F
msy
Ove
rfis
hin
g
Overfished
19952000
2005
20102009
2010
Blim Btarg
Ftarg
Flim
Model feature ASPM
Population spatial structure /
areas 1
Uses Catch-at-length Yes
Tagging data No
Age-structured Yes
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Catch 2011: 368,663 t
Average catch 2008–2012: 317,505 t
MSY (in thousands): 344 t (290-453)
F2010/FMSY (80% CI): 0.69 (0.59–0.90)
SB2010/SBMSY (80% CI): 1.24 (0.91–1.40)
SB2010/SB1950 (80% CI): 0.38 (0.28–0.38)
The decrease in longline and purse seine effort in recent
years has substantially lowered the pressure on the Indian
Ocean stock as a whole, indicating that current fishing
mortality has not exceeded the MSY-related levels in recent
years. As the security situation in the western Indian Ocean
has improved, a rapid reversal in fleet activity in this region
may lead to an increase in effort which the stock might not be
able to sustain, as catches would then be likely to exceed
MSY levels. Catches increased by 68 Kt in 2012 as compared
to 2011, warranting a new assessment soon.
Yellowfin Summary
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Situation of other IOTC species
Neritic Tunas • Essential for the economy of the IOTC coastal States
• Status still unknown for most species, but analyses are progressing
in the past two years.
• Status on Longtail (overfishing) and likely the same for Kawakawa.
Other billfish (Marlins, sailfish and spearfish) • Not targeted by tuna-fishing vessels
• Status unknown although concern exists about apparent declines
Sharks • A growing concern as they are target species for several fleets that
also catch tunas
• Apparent declines in oceanic whitetip and silky sharks
• Thresher under protection but still being caught
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IOTC Stock Status Overview
(Tropical and Temperate Tuna)
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IOTC Stock Status Overview
(Billfish and Neritic Tuna)
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Stock Indicators Advice
Bigeye F2012/FMSY= 0.42 (0.21–
0.80) SB2012SBMSY= 1.44 (0.87–
2.22)
Probably not overfished, and overfishing is
probably not occurring. Probably near full
utilization
Yellowfin F2010/FMSY=0.69 (0.59–0.90)
SB2010/SBMSY= 1.24 (0.91–
1.40)
Probably not overfished, and overfishing is
probably not occurring. Probably near full
utilization
Skipjack F2011/FMSY= 0.8 (0.68-0.92)
SB2011/SBMSY= 1.2 (1.01-1.4)
Highly productive species and robust to
overfishing.
Albacore F2010/FMSY = 1.33 (0.9–1.76) SB2010/SBMSY=1.05 (0.54–
1.56)
F above MSY levels. Further declines likely due
to effort displacement (piracy). Almost
exclusively LL.
Swordfish F2010/FMSY= 0.79 (0.58-0.84)
SB2010/SBMSY= 1.31 (1.13-
1.46)
The overall stock size and fishing pressure are
estimated to be within acceptable limits
Striped
Marlin
F2011/FMSY= 1.28 (0.95–1.92)
B2011/BMSY= 0.416 (0.2–
0.42)
Stock is overfished, though maybe recovering
due to recent decline in catch levels.
Blue Marlin F2011/FMSY= 0.85 (0.63–1.45)
B2011/BMSY= 0.98 (0.57–
1.18)
The overall stock size is optimal. Fishing rates
are likely below FMSY, though highly uncertain.
Longtail F2011/FMSY=1.11–1.77
B2011/BMSY=1.11–1.25
Increased catches in recent years indicate
that the stock is experiencing overfishing
though is not overfished. This is primarily due
to a change in effort from Tropical to Neritic
Tuna.
Stock status Stocks under IOTC mandate are in relatively good shape (at optimal
utilization), but no room for further fleet expansion.
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Current and Future work
Albacore operational model set up for MSE.
Skipjack operational model set up for MSE.
Eventually, have a model that incorporates all
Tropical Tuna Species and develop MSE
procedures simultaneously.
Dialogue initiated on identifying clear
management objectives.