Ecophysiological responses and population dynamics of tilapia Oreochromis mossambicus exposed to pulsed waterborne copper
Date Issued
2012
Date
2012
Author(s)
Lin, Chia-Jung
Abstract
The purpose of this thesis was to investigate the effects of pulsed waterborne Cu on the ecophysiological responses and the population dynamics of tilapia. This study reanalyzed the published acute and chronic toxicity and bioaccumulation data of tilapia and took into account the bioavailability for estimating the ecophysiological parameters of each life stage. This study used mechanistic models to estimate the vital rates for tilapia. Further, this study used matrix population model with the estimated vital rates to estimate population growth rates (λmax) and the tilapia population abundances in constant and different pulsed exposure scenarios can also be predicted. Results showed that larvae had the highest bioconcentration factor, BCF of 6157 mL g-1 greater than those of juveniles (3805 mL g-1) and adults (1208 mL g-1). Results showed that adults had the highest 4d-LC50 of 6228 μg L-1 greater than 2553 μg L-1 of juveniles and 204 μg L-1 of larvae. 3d-IEC50 of larvae and juveniles and 7d-IEC50 of adults were 4.54, 4.89, and 10.15 μg g-1, respectively. Furthermore, the results indicated that the daily survival and growth probabilities of larvae, juveniles, and adults under non-exposure scenario were 0.9983 and 0.166, 0.9990 and 0.048, and 0.9989 and 0.025 d-1, respectively. The fertility of adults was 0.38 d-1. Under constant Cu activity (1.8 μg L-1) and pulsed scenarios with the highest Cu activity (1.5 – 9 μg L-1) exposures, the daily survival rates of larvae were decreased nearly 34 and 91 – 98%, respectively, and the daily growth rates of larvae were decreased nearly 90 and 88 – 89%, respectively. Results indicated that the λmax for non-exposure scenario was 1.0865 d-1, whereas for pulsed scenarios, λmax were below 1 d-1, indicating that there was potential risk for decrease in the tilapia abundance. The sensitivity analysis revealed that λmax was most affected by the larval growth and adult survival probabilities. In conclusion, this study provides an approach for assessing the population dynamics for tilapia in real field situation in response to pulsed Cu exposure and is able to estimate the most influential parameters in tilapia population dynamics and assess the pulsed metal exposure risks of framed fishes in the future study.
Subjects
Matrix population model
Tilapia
Copper
Pulsed exposure
Bioavailability
Bioconcentration
Type
thesis
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