A1 Journal article (refereed)
Interacting effects of simulated eutrophication, temperature increase, and microplastic exposure on Daphnia (2021)

Hiltunen, M., Vehniäinen, E.-R., & Kukkonen, J. V. K. (2021). Interacting effects of simulated eutrophication, temperature increase, and microplastic exposure on Daphnia. Environmental Research, 192, Article 110304. https://doi.org/10.1016/j.envres.2020.110304

JYU authors or editors

Hiltunen, Minna
Vehniäinen, Eeva-Riikka

Publication details

All authors or editors: Hiltunen, Minna; Vehniäinen, Eeva-Riikka; Kukkonen, Jussi V. K.

Journal or series: Environmental Research

ISSN: 0013-9351

eISSN: 1096-0953

Publication year: 2021

Volume: 192

Article number: 110304

Publisher: Elsevier BV

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1016/j.envres.2020.110304

Publication open access: Not open

Publication channel open access:

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/78390

Abstract

The effects of multiple stressors are difficult to separate in field studies, and their interactions may be hard to predict if studied in isolation. We studied the effects of decreasing food quality (increase in cyanobacteria from 5 to 95% simulating eutrophication), temperature increase (by 3 °C), and microplastic exposure (1% of the diet) on survival, size, reproduction, and fatty acid composition of the model freshwater cladoceran Daphnia magna. We found that food quality was the major driver of Daphnia responses. When the amount of cyanobacteria increased from 5 to 95% of the diet, there was a drastic decrease in Daphnia survival (from 81 ± 15% to 24 ± 21%), juvenile size (from 1.8 ± 0.2 mm to 1.0 ± 0.1 mm), adult size (from 2.7 ± 0.1 mm to 1.1 ± 0.1 mm), and reproduction (from 13 ± 5 neonates per surviving adult to 0), but the decrease was not always linear. This was most likely due to lower availability of lipids, eicosapentaenoic acid (EPA), and sterols from the diet. Microplastic exposure did not affect Daphnia survival, size, or reproduction. Food quality had an interactive effect with temperature on fatty acid content of Daphnia. Total fatty acid content of Daphnia was almost 2-fold higher at 20 °C than at 23 °C when fed 50% cyanobacteria. This may have implications for higher trophic level consumers, such as fish, that depend on zooplankton for energy and essential lipids. Our findings suggest that as proportions of cyanobacteria increase, in tandem with water temperatures due to climate change, fish may encounter fewer and smaller Daphnia with lower lipid and EPA content.

Keywords: Cladocera; nutrition; nutrients (animals and humans); quality; water systems; eutrophication; temperature; lipids; sterols; fatty acids; survival; micro-litter; climate changes; plankton