Recovery of fish populations after infrastructure investments at municipal wastewater plants

Session: 07. - Effects of Environmental Contamination on Fish Communities

Gerald Tetreault, Environment and Climate Change Canada, [email protected]
Keegan Hicks, University of Waterloo, [email protected]
Meghan Fuzzen, McMaster University, [email protected]
Katie McCann, University of Waterloo, [email protected]
Leslie Bragg, University of Waterloo, [email protected]
Mark McMaster, Environment and Climate Change Canada, [email protected]
Mark Servos, University of Waterloo, [email protected]

Abstract

The objective of this study was to assess whether major treatment upgrades at a WWTP would reduce endocrine disruption previously observed in wild fish.  The WWTP located in Kitchener, Ontario, is a conventional activated sludge plant that discharges effluent into a heavily urbanized reach of the Grand River.  Multiple years of data has been collected for a sentinel fish species, the rainbow darter (Etheostoma caeruleum), associated with the Kitchener WWTP outfall since 2007.  Intersex in male fish has been the most consistent effect observed, and this has been linked to reduced reproductive success.  In 2012, major upgrades took place to convert the WWTP from non-nitrifying to a fully nitrifying activated sludge plant.  Effluent quality improved with declines in contaminants such nutrients and select pharmaceuticals, which are also reflected in the river water downstream the WWTP.  The effluent estrogenicity was measured as high as 17 ng/L total 17?-estradiol equivalents prior to treatment changes but has decreased with implementation of the upgrades.  Intersex was assessed in male rainbow darter downstream the Kitchener WWTP in three consecutive years post-upgrade.  There was a reduction in intersex incidence by as much as 85%, suggesting that the rainbow darter is responding to process upgrades.

1. Keyword
urban watersheds

2. Keyword
biomonitoring

3. Keyword
fish populations