At demographic equilibrium, size-selective angling induces positive selection differentials on annual reproductive investment for wide ranges of average reproductive investment values (Fig. 3A).
We study selection differentials on annual reproductive investment under size-selective exploitation in a highly demanded freshwater recreational fish species, northern pike (Esox lucius L .. We find that recreational angling mortality exerts positive selection differentials on annual reproductive investment, in agreement with predictions from life-history theory.
It is important to note that even under extremely high MSLs (corresponding to total catch-and-release fishing) there are always positive selection differentials on annual reproductive investment, so that recreational fishing-induced selection cannot be avoided by standard harvest regulations alone.
Changes in treatment patterns or guidelines may also lead to differential growth of annual utilisation.
The annual differential mean costs among the patients with overweight, obesity, severe obesity and very severe obesity were 75, 302, 719, and 790 euro higher, respectively, than in normal weight individuals (fourth panel of Table 3).
A recent study in M. guttatus has shown that an inversion on chromosome 8 containing several hundred genes contributes to the differential adaptation of annual and perennial ecotypes (Lowry and Willis 2010).
To address the second objective of our study (i.e., to investigate the potential for standard harvest regulations to counteract recreational fishing-induced selection), we analyzed the effects of changing harvest regulations on the selection differentials acting on annual reproductive investment (Fig. 4).
The average annual income differential of those with a college degree vs. those with a high school education is $17,500... and the gap is widening.
Building on a method pioneered by Swain et al. (2007) study of fisheries-induced evolution in cod, they then used this annual selection differential to predict the shift in mean return migration timing of offspring.
