Dennis et al.: Using otolith chronologies to identify extrinsic drivers of growth 141 
Age (year) 
Figure 4 
Von Bertalanffy growth curves for (A) common jack mackerel (Trachurus declivis) and (B) redbait (Emmelichthys 
nitidus) collected during 2014-2016 from waters off Kangaroo Island (KI; dark circles, solid line) and New South 
Wales (NSW; light triangles, dashed line) in Australia. Points indicate decimal ages based on presumed birth dates 
and collection dates. Also shown is predicted otolith increment growth (in millimeters) for (C) common jack mackerel 
and (D) redbait from KI (solid line) and NSW (dashed line). Shaded areas above and below the lines represent 95% 
confidence intervals. 
combination of the variables of Year and YearClass, with 
Table 2 and without random slopes of Age and random intercepts 
Estimates of von Bertalanffy growth parameters for (Suppl. Table 1) (online only). The best growth models that 
common jack mackerel (Trachurus declivis) and redbait excluded environmental variables included only Age as a 
(Emmelichthys nitidus) collected off Kangaroo Island and fixed effect (Suppl. Table 2) (online only). This was shown by 
New South Wales in Australia during 2014-2016. The the decrease in otolith increment growth (in millimeters 
parameters include the asymptotic length (Z,.) and the per-year) as Age increased (Fig. 4, C and D). 
growth coefficient (k). Standard errors of the mean (SEs) Interannual variability in growth from the long-term 
SES GAVE In PAM NESS. mean ranged from —0.07 to 0.06 mm FL for common jack 
mackerel and from —0.02 to 0.04 mm FL for redbait. A pro- 
nounced increase in growth from the long-term mean 
T.declivis Kangaroolsland 299.40 (2.5) 0.41 (0.2) occurred in 2013 for common jack mackerel from KI, and for 
T. declivis New South Wales 249.52(1.6) 0.77 (0.2) both species from NSW, but not for redbait from KI (Fig. 5, 
E.nitidus Kangaroolsland 259.79(1.3) 0.54 (0.1) A-D). Although a similar increase in growth was not 
E. nitidus NewSouth Wales 238.89(1.2) 0.84 (0.2) observed for redbait from KI, a similar trend was observed 
the following year (Fig. 5C). Growth of redbait from NSW 
Species Location L,, (SE) k (SE) 
