Variable toxicity of silver nanoparticles to Daphnia magna: effects of algal particles and animal nutrition
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- 作者：Andrea L. Conine ; Paul C. Frost
- 关键词：Silver nanoparticle toxicity ; Daphnia ; Nutrition ; Binding ; Ecological stoichiometry
- 刊名：Ecotoxicology
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：26
- 期：1
- 页码：118-126
- 全文大小：
- 刊物类别：Earth and Environmental Science
- 刊物主题：Environment, general; Ecotoxicology; Ecology; Environmental Management;
- 出版者：Springer US
- ISSN：1573-3017
- 卷排序：26
文摘
Aquatic environments vary widely in aspects other than their physicochemical properties that could alter the toxicity of novel contaminants. One factor that could affect chemical toxicity to aquatic consumers is their nutritional environment as it can strongly affect their physiology and life history. Nutrition has the potential to alter an organism’s response to the toxin or how the toxin interacts with the consumer through its food. Here we determined how growth and survival responses of Daphnia to an emerging contaminant, silver nanoparticles (AgNPs), are affected by the presence of food and its stoichiometric food quality. We used a series of survival tests, each slightly modified, to determine whether variable toxicity in different nutritional environments resulted from algal sequestration of AgNPs in a nontoxic form or from changes to the nutritional status of the test animals. We found that the presence of algae, of good or poor quality, reduced the toxicity of AgNPs on animal growth and survival. However, the decrease in AgNP toxicity was greater for animals consuming P-rich compared to P-poor food. We found evidence that this effect of food quality was due to greater algal uptake of AgNPs by P-rich than by P-stressed algae. However, we also found animal nutrition, in the absence of algal AgNP binding, could affect toxicity with P-nourished animals surviving slightly better when exposed to AgNPs compared to their P-stressed counterparts. Our results show an important role for algal particles and their P content in determining the toxicity of AgNPs in natural waters primarily due to their binding and uptake abilities and, less so, to their effects on animal nutrition.