Department of Chemistry, University of Toronto
This Molecular World

Speaker Profile:

Gilbert Walker - Eco-friendly Salmon Farming

Gilbert Walker

Wild fish stocks have been plummeting since the 1980s. Yet there are plenty of fish to be found at the grocery store as fish farming has expanded by leaps and bounds. While this brings delicious, health-giving protein to our tables, fish farms raise some of the challenges already known to land animal farmers. Fish growing up so close to each other can get sick more easily, just like people do in crowded places.

This story focuses on the challenges of making medicine and farming in ways that are safe for the marine environment. We have been working on two technologies. The first aims to replace copper used to keep salmon cage nets clean, so that the environment is not burdened with heavy metals and the fish are still provided with a high-oxygen environment. The second aims to control sea lice, which can afflict cage-farmed salmon and against which there are currently remarkably few available treatment options.


Professor Gilbert Walker received his B.A in Chemistry and Mathematics from Bowdoin College in 1985, and his Ph.D. from the University of Minnesota in 1991. He became assistant professor at the University of Pittsburgh in 1999, and in 2005 joined the University of Toronto, where he is the Canada Research Chair in Biointerfaces.

A surface chemist, Professor Walker aims to develop better design principles for controlling the interaction of surfaces with living matter and light. His group’s recent inventions have included surface-functionalized nanoparticles for cancer biodiagnostics from blood, methods and materials for biofouling control on marine surfaces, and scanned probe microscopes for characterizing energy transduction. As a youth, Gilbert worked in the herring weir fishery in the Bay of Fundy, and the changes to that ecosystem have motivated his interest in creating better materials for sustainable aquaculture.