Metal Exposure and Sex Shape the Fatty Acid Profile of Midges and Reduce the Aquatic Subsidy to Terrestrial Food Webs

Pietz, Sebastian; Kainz, Martin J.; Schroeder, Henning; Manfrin, Alessandro; Schaefer, Ralf B.; Zubrod, Jochen P.; Bundschuh, Mirco

doi:10.1021/acs.est.2c05495

Abstract

Aquatic micropollutants can be transported to terrestrial systems and their consumers by emergent aquatic insects. However, micropollutants, such as metals, may also affect the flux of physiologically important polyunsaturated fatty acids (PUFAs). As certain PUFAs have been linked to physiological fitness and breeding success of terrestrial consumers, reduced fluxes from aquatic systems could affect terrestrial populations and food webs. We chronically exposed larvae of the aquatic insect Chironomus riparius to a range of environmentally relevant sediment contents of cadmium (Cd) or copper (Cu) in a 28-day microcosm study. Since elevated water temperatures can enhance metals' toxic effects, we used two temperature regimes, control and periodically elevated temperatures (heat waves) reflecting an aspect of climate change. Cd and Cu significantly reduced adult emergence by up to 95% and 45%, respectively, while elevated temperatures had negligible effects. Both metal contents were strongly reduced (& SIM;90%) during metamorphosis. Furthermore, the chironomid FA profile was significantly altered during metamorphosis with the factors sex and metal exposure being relevant predictors. Consequently, fluxes of physiologically important PUFAs by emergent adults were reduced by up to & SIM;80%. Our results suggest that considering fluxes of physiologically important compounds, such as PUFAs, by emergent aquatic insects is important to understand the implications of aquatic micropollutants on aquatic-terrestrial meta-ecosystems.

Keywords

aquatic-terrestrial linkage; riparian consumers; PUFA; aquatic insects; Chironomus riparius; copper; cadmium

Published in

Environmental Science and Technology
2023, volume: 57, number: 2, pages: 951-962
Publisher: AMER CHEMICAL SOC

SLU Authors

Bundschuh, Mirco
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
- University of Kaiserslautern-Landau (RPTU)

Global goals (SDG)

SDG6 Clean water and sanitation
SDG15 Life on land

UKÄ Subject classification

Environmental Sciences

Publication identifier

DOI: https://doi.org/10.1021/acs.est.2c05495

Permanent link to this page (URI)

https://res.slu.se/id/publ/121190