Transcript seapodym model

SEAPODYM
Applications
• Understand Tuna Climate interactions.
• Forecast effects on climate change on tuna
distribution and abundance.
• Capture meso-scale distribution information
which allows for more EEZ level estimates of
distribution and abundance.
• Assistance for national and sub-regional tuna
management planning.
The evolution in resolution
Pre 2009- 2 degree x month physical
forcing (no data assimilation)
2009-2010 2 degree x month physical
forcing (with data assimilation)
The evolution in resolution
2010-2012 - 1 degree x month physical
forcing (with data assimilation)
2012 - ¼ degree x week physical
forcing (with data assimilation)
December 2007 SODA 1°
06 December 2007 GLORYS ¼°
Improved Resolution
• Taken a number of years for the physical forcing
data to become available.
• Need 1 degree resolution for EEZ level analyses
otherwise results barely differ from regional
averages.
• Optimised 1 degree models for skipjack, bigeye,
south pacific albacore and swordfish.
• New ¼ degree data has become available in 2013
which corrects equatorial anomalies.
EEZ – Climate – Analyses
Skipjack Recruitment (PNG)
NECC
SEC
SECC
5N
170E
150E
160E
1
170E
5N
1
5S
10S
15S
5N
1
5S
10S
150E
160E
170E
1 11
Month
140E
150E
160E
170E
1 12
Month
1
10S
15S
15S
140E
170E
15S
140E
10S
1
1
5S
10S
160E
1
160E
1
Month
8
5N
170E
150E
0
160E
1 10
Month
140E
0
5N
15S
150E
15S
150E
170E
10S
1
140E
0
5N
0
5S
10S
15S
140E
160E
1
Month
7
5N
170E
150E
0
160E
1
Month
9
140E
0
5N
0
1
10S
150E
0
5N
170E
Month 4
5S
160E
1
Month
6
15S
15S
140E
5S
15S
10S
1
150E
5S
5S
0
5N
140E
5S
170E
5S
160E
1
Month
5
Month 3
0
5N
0
1
150E
10S
1
5S
10S
140E
1
Month 2
15S
15S
10S
1
5S
0
5N
Month 1
140E
150E
160E
1
170E
140E
150E
160E
1
170E
6
5
4
200
250
10
20
NCEP 1971-2003
4
3
5
6
b
SST anomalies - El Nino
2
1
0
200
250
10
6
5
4
1
150
150E
200
160W
x
250
110W
Longitude
ZONE 1 (Western)
• SST decreased, thermocline shallowing
ZONE 2 (Central) & ZONE 3 (Eastern)
•SST increased, thermocline deepening,
weaker currents
2
z
20
e
0
1
2
15
3
5
3
4
6
d
0
z
15
f
4
0
1
2
f
3
5
6
a
150
El Nino
3
1
0
150
Neutral
3
2
c
3
c
0
1
2
La Nina
4
5
6
EEZ – Climate – Analyses
ENSO-SP Albacore recruitment
10
15
y
Latitude
20
EEZ/Sub regional Fisheries Analyses
• Fishery impacts
Area 1 Potential Yield (SKJ)
Average CPUE
60,000
12
50,000
10
40,000
8
30,000
6
20,000
4
10,000
2
0
0
0
10,000
20,000
30,000
40,000
Equilibrium Effort (days)
50,000
Equilibrium CPUE (tonnes / day)
Equilibrium catch (tonnes)
Average catch
Climate Change
• Predicting the past to understand the future.
• IPCC has developed an ensemble of models
predicting future climate scenarios under
different atmospheric assumptions
• Only 1 (IPSL) has been coupled with the PISCES
model to predict future primary production.
• Optimised the model with historical data and
then simulate into the future under the A2
scenario defined by IPCC.
Skipjack and temperature
SKIPJACK LARVAE
(A2 scenario)
The model has a bias in temperature
Temperature transect at longitude 180°
2nd Exp after T° correction
2000
1st Exp with IPSL-CM4
2050
≠ 4°C
2099
Bias correction
Projecting Climate Change impact
SKIPJACK TOTAL BIOMASS
2nd Exp after T° correction
2000
1st Exp with IPSL-CM4
(Both simulations used average 1990-2000 fishing
effort to project fishing impact)
2099
2050
1
2
actual fishing effort
2 average 1990-2000 fishing effort
1
Under this fishing effort scenario,
the stock biomass is predicted to
be mainly driven by larval
recruitment
Albacore and oxygen
Albacore
(A2 scenario)
With modeled oxygen
Increasing pCO2 could lead
to changes of C/N ratio
(Oschlies et al. 2008)
With climatological O2
(ie no change from
present conditions)
Total biomass
Total biomass
2000
2050
There is still a large
uncertainty on O2
modeling while
this is a key variable for
tunas
2099
2099
2050
2000
Total biomass
Bigeye (A2 scenario)
First experiment with IPSL CM4
Larvae 2000
Larvae 2099
Total B 2000
Total B 2099
Second experiment (IPSL CM4) with T correction
Larvae 2000
Larvae 2099
Total B 2000
Total B 2099
Summary for Climate Change Analyses
• Results are consistent for the 3 species with an eastwards shift in
spawning and forage habitat.
• Currently assuming no adaptation to changing temperatures
with SST >33-34°C estimated to be a threshold for spawning of
tropical tunas.
Albacore
2000
2099
Skipjack
Bigeye
Climate Change Summary
• New simulations with temperature corrected forcing predict a lower
skipjack biomass and a decreasing trend after the 2070’s, driven by large
extension of unfavourable equatorial spawning grounds.
• Application to albacore is highly sensitivity to O2, for which the
biogeochemical models are still unclear.
• Parameter estimation using the IPCC models is adequate but inferior to
ocean models with data assimilation. The climate models lack historical
variability.
• Climate model ensemble simulations could help to solve the problem of
bias.
• Ideally we would use climate model simulation with realistic historical
variability (ENSO, PDO, NAO). These may be available in the near future.
• Climate projections for 10-15 years into the future probably more
tangible for current fisheries planning.
Immediate Future
Tagging really matters
• All optimisations so far have struggled to estimate movement.
• Integrating conventional tagging data in the optimization
approach improves movement estimation.
• Times series of tagging data extremely beneficial.
movement
threshold value of dissolved oxygen
optimal spawning SST
optimal temperature for oldest tuna
Incorporation of tagging data
• Preliminary (2 years of tagging data)
Predicted distributions of skipjack tuna in g/m2 (both young and adult life stages) as the result of
experiments conducted with different likelihood composition: (left) including CPUE and length
frequencies components only; (right) CPUE, LF and Tagging data components.
Summary
• 1 degree models that allow meaningful EEZ and subregional extraction of information.
• Prepare national climate profiles.
• Prepare climate change analyses within the IPCC
framework.
• Assist sub-regional and SPC members with tuna
management planning.
• New ¼ degree physical forcing available in 2013 that
will also allow simulation to end 2012.
• Full incorporation of PTTP tagging data to better
parameterise movement.