On‐Site Exposure to Treated Wastewater Effluent Has Subtle Effects on Male Fathead Minnows and Pronounced Effects on Carp

Abstract

This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on-site exposures using a mobile laboratory. Total estrogenicity of effluents was 10-to 20-fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol-A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long-term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency-recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.(KEY TERMS: fish; toxicology; environmental impacts; urban areas; point source pollution; treated wastewater effluent.)

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

“…The three most urbanized rivers in our data set, the Chicago, Little Calumet, and Cuyahoga Rivers predictably contained the highest chemical concentrations, largest number of chemicals detected, and largest diversity of chemical classes in water. Previous studies have also noted the presence of a large number of CECs in highly urbanized aquatic ecosystems [ 4 , 64 , 90 , 91 , 92 ], particularly those with wastewater treatment plant effluents present. Wastewater treatment plant effluents are a well-studied and consistent source of CECs (reviewed in [ 93 ]) and were a prominent source in the current study.…”

On‐site, serial exposure of female fathead minnows to the Elkhorn River, Nebraska, USA, spring agrichemical pulse

“…This is different from feminization of male fish, in which the activation of estrogen-responsive traits is unlikely to be induced by environmental factors. Although a number of studies have characterized seasonal effects in the feminization of male fish after environmental estrogens downstream of wastewater treatment plants [2,[26][27][28][29] considerably fewer studies have investigated in situ anti-estrogenic exposures [9,10,17].…”

Spatial and Temporal Patterns of Endocrine Active Chemicals in Small Streams Indicate Differential Exposure to Aquatic Organisms

“…Collected fish were anesthetized with clove oil, sampled for blood from the caudal vasculature, and then sacrificed. Livers and gonads were removed from each fish and histologically processed (as described in Minarik et al, 2014) to allow for an assessment of the metabolic state of the tissue. Livers under acute pollutant stress often respond with an increased prominence of vacuoles in liver hepatocytes (Roberts, 2012), which were assessed using a unit-free scoring system from 0 (no visible vacuoles) to 4 (extremely prominent vacuoles).…”

“…Methodology for plasma vitellogenin analysis followed published protocols (e.g., Minarik et al, 2014). Briefly, blood samples were stored in heparinized vacutainers on ice until return to the laboratory (within 48 h of collection).…”