Figure S2
Fig. S2: Annual abundance and standard deviation of Atlantic bluefin tuna (Thunnus thynnus) in the Gulf of Lions, estimated from aerial surveys.
Figure S3
Fig. S3: Relationship between tuna age and length (left) and weight (right), as modelled by the Dynamic Energy Budget model for Atlantic bluefin tuna (Thunnus thynnus). For comparison, the growth curve used by ICCAT (International Commission for the Conservation of Atlantic Tunas) is also plotted (red line).
Figure S4
Fig. S4 Age-length keys of anchovy (Engraulis encrasicolus), sardine (Sardina pilchardus) and sprat (Sprattus sprattus) calculated from the small pelagic survey data over the period 2008 to 2013. For sprat (n=100, years = 2013) a linear model was used, where L(t) is the expected length at age t. For sardine (n=4744, years = 2009-2014) and anchovy (n=4412, years = 2009-2014) seasonal variability was accounted for using Somers’ model (Somers 1988), with , where L∞ is the model asymptote for average length, K is as measure of the exponential rate of approach to asymptotic length, t0 is the theoretical age at which the average length would be zero, C is the amplitude of the growth oscillation and ts is the inflexion point.
Table S1
Table S1. Biological parameter values of major prey species found in the stomach contents of juvenile Atlantic bluefin tuna (Thunnus thynnus). The ranges of energetic densities were taken from literature (see Appendix 1: Energetic density). Lengths of sardine, anchovy and sprat were calculated using the linear relationship between otolith (oto) length and individual (ind) fish length (), and their body mass was obtained by converting these lengths using an annual length weight key (). Direct length measurements were not needed for mackerel and squid, and otolith lengths or beak lower rostral lengths (LRL) were directly converted to weight (). All relationships were calculated from the small pelagic survey biological data. Parameter estimates and relationships were always significant. We specified the number of data points (N) on which the relationships were based and the range of values for which it was specified.
Energetic density (kJ/g wet weight)
|
Sardine
|
Anchovy
|
Sprat
|
Mackerel
|
Squid
|
4.00-14.40
|
2.67-12.81
|
3.7-12.40
|
6.00-10.30
|
5.01-6.46
|
|
|
R2
|
a
|
b
|
N
|
range
|
range
|
Sardine
|
0.86
|
0.46
|
0.14
|
50
|
1.6 - 2.9
|
9.3 - 17.5
|
Anchovy
|
0.78
|
0.62
|
0.18
|
53
|
1.9 - 3.8
|
8.6 - 3.8
|
Sprat
|
0.24
|
0.98
|
0.06
|
47
|
1.2 - 1.8
|
0.9 - 11.1
|
|
|
|
c
|
d
|
N
|
range
|
range
|
Mackerel
|
|
0.88
|
3.09
|
36
|
7.2 - 36.2
|
2.0 - 3.1
|
Squid
|
|
7.07
|
2.24
|
61
|
3.0 - 215.2
|
0.9 - 4.2
|
|
|
year
|
e
|
f
|
N
|
range
|
range
|
Sardine
|
2011
|
4.40*10-3
|
3.2
|
229
|
1.7 - 45.0
|
6.5 - 18.0
|
|
2012
|
2.29*10-3
|
3.47
|
220
|
2.0 - 46.0
|
6.5 - 17.0
|
|
2013
|
4.09*10-3
|
3.24
|
216
|
2.5 - 27.0
|
7.5 - 15.0
|
Anchovy
|
2011
|
2.97*10-3
|
3.29
|
195
|
3.0 - 22.5
|
8.5 - 15.0
|
|
2012
|
4.76*10-3
|
2.1
|
168
|
4.0 - 22.0
|
8.5 - 15.0
|
|
2013
|
4.10*10-3
|
3.18
|
126
|
2.0 - 22.0
|
8.0 - 15.0
|
Sprat
|
2011
|
6.50*10-3
|
3.03
|
139
|
1.7 - 13.0
|
6.5 - 18.0
|
|
2012
|
5.19*10-3
|
3.15
|
171
|
2.0 - 15.0
|
7.0 - 11.5
|
|
2013
|
6.61*10-3
|
3.03
|
153
|
1.0 - 10.8
|
6.0 - 11.5
|
Table S2
Table S2 Dynamic equations of the non-standard Dynamic Energy Budget model developed and validated for Pacific bluefin tuna (Thunnes orientalis, Jusup et al. 2011) and reparameterised for Atlantic bluefin tuna (T. thynnus) for use in this study. t denotes time and T temperature. Processes are usually defined in terms of energy and are thus measured in J.
State and auxiliary variables
|
Symbol
|
Definition
|
unit
|
E(t)
|
Amount of energy in reserve tissue
|
|
J
|
V(t)
|
Volume of structural tissue
|
|
cm3
|
L(t)
|
Structural volumetric length
|
|
cm
|
EH(t)
|
Level of maturity
|
|
J
|
ER(t)
|
Status of the reproductive buffer
|
|
J
|
E0
|
Initial energy reserve of an egg
|
|
J
|
Energy fluxes
|
Metabolic process
|
Energy flux
|
|
Assimilation (A)
|
|
Utilization (C)
|
|
Somatic maintenance (S)
|
|
Growth (G)
|
|
Dynamics of state variables, reproduction state
|
State variable
|
Dynamic equation
|
|
Energy in reserve
|
|
Structural length
|
|
Maturity (H) level
|
|
Auxiliary functions
|
Auxiliary functions
|
Functional form
|
|
Shape correction function
|
|
Efficiency of internal heat production
|
|
Arrhenius equation
|
|
Shape factor
|
|
Table S3
Table S3 Dynamic Energy Budget parameters for Atlantic bluefin tuna (Thunnus thynnus) and their values.
Symbol
|
Definition
|
Value
|
Unit
|
Basic DEB parameters
|
{ṗAm}
|
Maximum surface-area-specific assimilation rate
|
124.8
|
J cm-2 d-1
|
[EG]
|
Volume-specific cost of structure
|
7163
|
J cm-3
|
v̇
|
Energy conductance
|
0.09542
|
cm d-1
|
[ṗM]
|
Volume-specific somatic maintenance rate
|
5.149
|
J cm-3 d-1
|
{ṗT}
|
Surface-area-specific somatic maintenance rate
|
1877
|
J cm-2 d-1
|
k̇J
|
Maturity maintenance rate coefficient
|
1.362
|
10-2 d-1
|
κ
|
Fraction of mobilized reserve allocated to soma
|
0.8222
|
|
EbH
|
Maturity at birth (b)
|
0.2253
|
J
|
EpH
|
Maturity at puberty (P)
|
2.937
|
107J
|
Other DEB parameters
|
EjH
|
Maturity at the end of the larval stage
|
2566
|
J
|
E2H
|
Half-saturation maturity
|
7050
|
J
|
EyH
|
Maturity at the end of the early juvenile phase
|
1.629
|
106 J
|
TA
|
Arrhenius temperature
|
6398
|
K
|
δ1M
|
Shape factor in the larval stage
|
0.1475
|
|
δ2M
|
Shape factor in the adult stage
|
0.2531
|
|
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