Virtual Ontario Pub Night- Tuesday November 2, 2021

Impacts of a whole lake addition of nanosilver on fishes

Presented by Dr. Michael D. Rennie

Director, Aquatic Toxicology Research Centre, Lakehead UniversityJoin us for an engaging talk from the comforts of your own home! Socializing begins at 6:30 PM, the talk begins at 7 PM. When:  Tuesday November 2nd from 6:30 – 8 PM RSVP:  Please complete the RSVP form to receive the Zoom meeting link. Cost:  Pay what you want to support future student awards ($2 members, $4 non-members or an amount of your choosing). Contact:  Rebecca Dalton (becca.dalton@gmail.com) Abstract: Nanosilver (AgNP) is a ubiquitous antibacterial compound used in many commercial products, and as such is becoming more commonly found in the environment with high potential for non-point source release. At the International Institute for Sustainable Development (IISD) Experimental Lakes Area (ELA), we conducted a large collaborative study to evaluate the impacts of AgNP on a whole lake. Yellow perch populations demonstrated clear oxidative stress responses at the cellular level, reductions in consumption and activity at the individual level, and reduced densities and gross consumption at the population level. Similarly, Northern Pike populations demonstrated reduced growth rates and reductions in consumption and activity at the individual level and reduced gross consumption at the population level. Stable isotope analysis indicates that both perch and pike shifted towards more pelagic resources during and after AgNP additions, which we speculate is a result of settling AgNP reducing benthic productivity. This combination of both direct and indirect responses of fishes to this emerging contaminant indicates the potential risks of AgNP release into waterways at environmentally relevant concentrations. Biography: Dr. Michael Rennie is an Associate Professor and has held a Canada Research Chair in Freshwater Ecology and Fisheries since joining Lakehead University in 2015. He is also a Research Fellow with the International Institute for Sustainable Development (IISD) Experimental Lakes Area (ELA) where he has led the fish populations program since 2010. Since 2018, he has been the director of the Aquatic Toxicology Research Centre at Lakehead University. His research at the ELA and in the Great Lakes is largely focused on how human disturbance and novel contaminants alter food web structure and function (e.g., rates and pathways of energy flow through foodwebs).