advertisement

Supplementary materials Parameter estimates used to vital rate of tilapia population Intrinsic survival probability Pathiratne (1999) showed that the percentage survival of O. mossambicus fry under non-exposure condition. Therefore, the parameters (b and k) of intrinsic survival probabilities (S0(t)) can be estimated by using the Eq. T1-8 to fit the survival data. Species-specific growth coefficient (A0) Chen et al. (2012) showed that the body mass of 14 days old larva and 30 days old juvenile under non-exposure condition were 0.008 ± 0.002 (mean ± SD) and 0.025 ± 0.15 g wet wt. Huang (2010) showed that the body mass of 210, 217, 224, 231, and 238 days old adult under non-exposure condition were 8.74 ± 2.44, 9.85 ± 3.23, 11.41 ± 4.28, 13.09 ± 5.3, and 13.44 ± 5.58 g wet wt. This study used the West growth model (Eq. T3-1) to fit the body mass data from Chen et al. (2012) and Huang (2010) for estimating the species-specific growth coefficient (A0) under non-exposure condition. Body burden for x% maximum growth inhibition This study used the Hill-based stander 3-parameter sigmoidal dose-response equation to fit the published data of larva and adult growth inhibitions (Wu et al., 2003; Huang, 2010) to estimate the body burden for 50% maximum growth inhibition (IEC50) and calculate the IEC10 and IEC1 of larva and adult stages, E (t , Cb ) E max IEC 50( t ) 1 Cb n , (S1) where E is the growth inhibition (–), Emax is the maximum growth inhibition (–), Cb is the body burden (μg g-1), and n is the Hill coefficient (–). Then, using the IEC10 and IEC1 in adult stage to estimate the growth rate parameters in juvenile stage by Eqs. (T3-3) – (T3-5). Fecundity parameters This study conducted the relationship between body mass and fecundity, and to estimate the fitted coefficients (m and d) by using the Eq. (T1-7) to fit the body mass-dependent fecundity data from Riedel (1965). Survival rate (σ) The estimates of b and k can be substituted into Eq. T1-8 for predicting the intrinsic survival probabilities (S0(t)) (background survival probabilities without pollutants) and the TK/TD parameters (k1, k2, kr, and kk) can be substituted into threshold damage model for predicting the survival probabilities (S(t))of life-stage tilapia exposed to pulsed Cu activities. Then, linking the estimates of S0(t) and S(t) at same time t to estimate the survival rate (σ) by using Eq. T1-4. Growth rate (γ) Wb0, Wmax0 and A0 can be substituted into the West growth model for describing the growth trajectories of tilapia under non-exposure condition. Then stressed effects on growth for tilapia were occurred when tilapia exposed to pulsed Cu activities. Therefore, the IEC10 and IEC1 of larva, juvenile, and adult stages can be substituted into stress function (Eq. T3-3) and applied to reflect the different mode of action on growth effects. Then, the stress function and the West growth model could be linked to predict the growth trajectories of tilapia under pulsed Cu activities exposures. Fertility rate of adult stage (F3) This study assumed that only in adult stage had fertility capacity. First, we used the estimates of m and d to estimate the mass-dependent fecundity (Fei(W(t)). Here, we link the time-dependent mass with the mass-dependent fecundity for conducting the relationship between age and fecundity. Then, the daily fecundity rate can be estimate by the differential of age-specific fecundity. Second, the daily fecundity rate multiplied by E and Fm can be estimated the fertility rate (F3). Population abundance Fig. S1 shows stage-specific population abundance over a 2-generation projection for constant and Cu-pulse exposure populations using initial individual of 10 as input. In the constant exposure populations, stage-specific tilapia abundance followed a monotonic increase fashion over time (Fig. S1a – c). Compared to the constant exposures, the pulsed scenarios A and B produced relatively the largest reduction in abundance in all stages over time (Fig. S1d – i). In view of projection matrix [A], the probabilities of surviving and staying in larval stage (P1) decreased from 0.6049 – 0.0002 and 0.7841 – 0.0057, whereas the probabilities of surviving and growing from larval to juvenile stages (G1) decreased from 0.0121 – 4.65×10-6 and 0.0157 – 0.0001, respectively, with increasing pulsed Cu activities, for pulsed scenarios A and B, and thus provided the explanation. A notable finding was that pulsed scenario C produced a similar projection over time of stage-specific population abundance with that of the constant exposures (Fig. S1a – c, j – l). Larvae Juveniles Adults Constant exposure 15 15 a Cu activity Control 12 12 12 9 9 6 6 3 3 3 0 0 0 1.6 1.8 2.0 9 6 5 400 200 0 200 0 d 400 0 4 4 3 3 2 2 2 1 1 1 0 0 400 0 0 3 200 5 200 400 0 Median pulsed frequency scenario 5 5 g h 4 4 4 3 3 3 2 2 2 1 1 1 0 0 400 0 0 200 15 400 k 12 12 9 9 9 6 6 6 3 3 3 0 0 0 200 400 200 400 200 400 200 400 i 0 12 0 400 0 200 Low pulsed frequency scenario 15 15 j 200 f e Cu activity 1.5–3 1.5–6 1.5–9 0 c High pulsed frequency scenario 5 5 4 Log (population abundance) 15 b 0 200 400 l 0 Age (d) Fig. S1 Population abundances of tilapia in a, d, g, j larval, b, e, h, k juvenile, and c, f, i, l adult stages exposed to different waterborne constant and sequential pulsed exposure scenarios varied with Cu activities (g L-1). Reference Chen WY, Lin CJ, Ju YR, Tsai JW, Liao CM (2012) Assessing the effects of pulsed waterborne copper toxicity on life-stage tilapia populations. Sci Total Environ 417-418: 129-137 Huang YH (2010) Biokinetic and biodynamic modeling approach to characterize chronic copper toxicity and ecophysiological response of tilapia (Oreochromis mossambicus). Master’s Thesis, China Medical University, Taiwan, ROC Pathiratne A (1999) Toxicity of fenthion in Lebaycid to tilapia, Oreocheomis Mossambicus (Peters): Effects on survival, growth and brain acetylcholinesterase activity. J Natl Sci Found Sri Lanka 27:79-91 Riedel D (1965) Some remarks on the fecundity of tilapia (T. mossambica Peters) and its introduction into middle Central America (Nicaragua) together with a first contribution towards the Limnology of Nicaragua. Hydrobiologia 25:357-388 Wu SM, Jong KJ, Kuo SY (2003) Effects of copper sulfate on ion balance and growth in tilapia larvae (Oreochromis mossambicus). Arch Environ Con Tox 45:357-363