Table 1.
Instantaneous and cumulative mortality rates of YOY tunas and small pelagic species. Age is indicated in days post-hatching or days post exogenous feeding (dpef).
Table 2.
Parameters and references used for computation of steepness and population growth rate of bluefin tuna population.
Figure 1.
Overview of daily mortality rates and M0 with comparisons to other species.
(a) Distributions of daily mortality rates over 30 days after fertilization. Fine vertical grey lines represent the range between 5 and 95% quantiles, thick grey lines the interquartile range. Points represent observed mortality rates of scombrids larvae : · tunas (field observations), mackerel (field observations),
tunas (rearing observations). (b) Boxplots of cumulative mortality rates over 15 days after fertilization, comparison with cumulative mortality 180 days after fertilization. (c) Estimated distribution for bluefin tuna. Comparison on x-axis to M0 of 4 small pelagic species.
Figure 2.
Boxplots of mean contribution to reproduction in number of oocytes.
Table 3.
Summary statistics of estimated demographic quantities for bluefin tuna population.
Figure 3.
Population growth rate r plotted in relation to age 0 mortality rate with marginal distributions of each parameter represented along respective axes.
Figure 4.
Relationships between stock-recruit quantities, steepness and M0.
(a) Steepness h plotted in relation to age 0 mortality rate (b) Steepness h plotted in relation to recruits per spawning biomass α. (c) α plotted in relation to M0 (d) h plotted in relation to spawning biomass per recruit Wbpr. Marginal histogram of each parameter is represented along respective axes.
Figure 5.
Steepness h (left panel) and population growth rate r (right panel) plotted in relation to different distributions of M0 (age 0 mortality rate).
(a-e) the whole distribution of M0 (mean 13.4 and CV 35%) (b-f) a simulated Gaussian distribution with mean equal 12.5 (median value of the whole distribution) and CV = 10% (c-g) Gaussian distribution with mean equal to 18.5 and CV = 10% (d-h) Gaussian distributions with mean equal to 21.5 and CV = 10%.
Figure 6.
Distributions of the steepness (h) and the population growth rate (r) obtained with an acceptance-rejection procedure to limit r range to [0,+∞]and h range to [0.2, 1].
Table 4.
Summary statistics of estimated demographic quantities for bluefin tuna population obtained with the acceptance-rejection procedure.
Figure 7.
Comparison between cumulative early mortality including or not variance of McGurk's log-regressions.
(a) Sample cumulative mean mortality rates µMd(x) from 1 to 8 days after fertilization., µMd(x) = a+b.log(wd(x)) for wd<0.00504 and µMd(x) = a'+b'.log(wd(x)) for wd>0.00504 (b) Sample cumulative mortality rates Md(x) from 1 to 8 days after fertilization, taking into account Zσ and Zσ' the estimated variances around McGurk's log-regressions.