Abstract

The bioaccumulation of mercury (Hg) and polyunsaturated fatty acids (PUFA) in zoobenthos varies across aquatic food webs. In this field study, contents of total Hg (THg), methylmercury (MeHg) and PUFA were investigated in zoobenthos of Chinese reservoirs and Swedish lakes, with contrasting environmental characteristics and algal diet sources, which can result in difference of Hg and PUFA in zoobenthos from these two habits. Using PUFA as dietary biomarkers of algae in zoobenthos, we evaluated effects of environmental factors and algal diet sources on the accumulation of THg, MeHg, and the highly required PUFA eicosapentaenoic (EPA, 20: 5n-3) and docosahexaenoic acid (DHA, 22:6n-3) in zoobenthos. Average THg and MeHg in zoobenthos were higher in Chinese reservoirs than Swedish lakes (p < 0.05). Average EPA content of zoobenthos was similar in these two habitats (p > 0.05), yet average DHA content of zoobenthos was higher in Chinese reservoirs than Swedish lakes (p < 0.05). Total Hg and MeHg contents of zoobenthos in Swedish lakes were predicted by environmental factors; e.g., negatively with pH and positively with dissolved organic carbon (DOC) concentrations, yet had no significant relationship with the algal dietary. In Chinese reservoirs, however, no environmental factor correlated well with THg contents in zoobenthos, and only DOC concentrations showed positive correlation with MeHg contents in zoobenthos. Besides, the algal dietary was also positively correlated with MeHg contents in zoobenthos. EPA and DHA contents of zoobenthos in Swedish lakes primarily associated with algal diet. By contrast, in Chinese reservoirs, EPA and DHA contents of zoobenthos were affected by both environmental factors and algal diet. (C) 2021 Elsevier B.V. All rights reserved.

Keywords

Zoobenthos; Mercury; Polyunsaturated fatty acids; Chinese reservoirs; Swedish lakes

Published in

Science of the Total Environment
2021, Volume: 782, article number: 146410
Publisher: ELSEVIER

SLU Authors

• Wu, Pianpian

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

• Bishop, Kevin

  • Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences
    

Associated SLU-program

Coastal and sea areas
Non-toxic environment
Lakes and watercourses


Sustainable Development Goals

Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Environmental Sciences


Publication identifier

DOI: https://doi.org/10.1016/j.scitotenv.2021.146410

Permanent link to this page (URI)

https://res.slu.se/id/publ/112207