Michele Nicholson

 

I completed a Bachelor of Environmental Science (Honours Co-op, Water Resources) at the University of Manitoba in 2013, and began my MSc at Queen’s in the Arnott lab in January 2014. In general, my goal is to use science to find progressive and sustainable solutions to environmental problems. My key areas of interest are aquatic ecology, water quality, ecotoxicology, and aquatic invasive species.


Being in the co-operative education program at the University of Manitoba afforded me the opportunity to get a wide range of experiences related to my academic interests. I was able to spend work terms at Environment Canada, Manitoba Hydro, and the Experimental Lakes Area, working on water monitoring and aquatic ecosystems research. I also worked for the Manitoba Government as an Aquatic Invasive Species Watercraft Inspector, which laid the groundwork for my interest in the management of invasive species, and brought my attention to the need for environmentally-safe strategies to control zebra mussel populations and eradicate new infestations. This got my wheels turning and got me thinking about graduate research.

Zebra mussels are invasive freshwater mollusks that have created ecological and economic problems across North America since their introduction to the Great Lakes in the 1980s. A lack of viable, specific control methods for open water treatment has led to rapid infestation of most major inland water systems in North America, resulting in billions of dollars in damages and losses to industry, fisheries, recreational water uses, and ecosystem services each year. The mussels colonize underwater surfaces, causing fouling of beaches, boats and equipment, and raw water-drawing infrastructure, including water intake pipes, cooling systems, and outfalls. Zebra mussels feed by filtering algae out of the water, which can have dramatic effects on water clarity and temperature dynamics, aquatic food webs, and habitat for organisms such as fish.

I came across a new product called Zequanox™, which is made from dead soil bacteria and is touted to be highly effective at killing zebra mussels, yet completely non-toxic to other species. Zequanox™ is still in the testing and licencing stages, mainly for use as an alternative to chlorine in industrial water systems. To my knowledge, it has never been tested in a natural environment in Canada, and past toxicity tests have focused on lethality in single-species laboratory tests. Laboratory toxicity tests are very useful and tend to be highly sensitive (and thus, protective, when results are applied to natural systems), even though they are not necessarily representative of a “real-life” scenario. However, these lab tests often neglect to characterize the sub-lethal negative effects that may occur as a result of toxicant exposure in natural systems, such as induced behavioural changes that can affect complex interactions like predator-prey dynamics.


I decided that I wanted to carry out an independent study to determine both the effectiveness and non-target toxicity of Zequanox™ in a natural environment, focusing on indirect and community-level effects. The study will be carried out in mesocosms at QUBS with communities of algae, zooplankton, benthic invertebrates, and both invasive and native mussels. My experiment will compare treatments of Zequanox™ with an alternative molluscicide and controls, and will also include treatments without mussels, to account for any non-target toxicity or negative impacts that may arise from the presence of dead and decomposing mussels (such as stress or death caused by oxygen depletion).


I am hoping to find that Zequanox™ is as good as they say, and that it is highly effective at killing zebra mussels, yet completely safe for other organisms. If that is true, we may have a useful new tool to help us manage zebra mussel infestations and potentially eradicate new invasions in open water systems.