Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure

PLoS One. 2017 Sep 27;12(9):e0184725. doi: 10.1371/journal.pone.0184725. eCollection 2017.

Abstract

The Laurentian Great Lakes contain one fifth of the world's surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations.

MeSH terms

  • Endpoint Determination
  • Environmental Monitoring*
  • Estradiol / analysis
  • Geologic Sediments / chemistry
  • Lakes / chemistry*
  • North America
  • Water / chemistry
  • Water Pollutants, Chemical / analysis*

Substances

  • Water Pollutants, Chemical
  • Water
  • Estradiol

Grant support

HLS (St Cloud State University) and MEB (U.S. Geological Survey) received funding from the US Fish & Wildlife Service for this project. Funding was provided from the Great Lakes Restoration Initiative through the U.S. Fish and Wildlife Service's CEC Team. Additional support for field work in Chicago was provided to HLS by a National Science Foundation grant (CBET 1336062). In-kind support from the Metropolitan Water Reclamation District of Greater Chicago is acknowledged.