Grant: Engage Grants Program

Worldwide water quality degradation of lakes and streams due to increasing nutrient loads from surrounding catchments is increasingly problematic. Different approaches can mitigate the elevated primary production (algal and cyanobacterial blooms) in lakes with high nutrient loads. Some, such as introducing policies to reduce nutrient loading from the catchment and removing nutrients from waste water via tertiary treatment, are preventative, but require coordinated effort across multiple levels of government and land-owners and can be slow to take effect. Other approaches are reactive and focus on culling the nuisance producer species through the addition of algal toxicants, grazers, or light-shading dyes. These approaches act much more quickly and can be controlled at a more localized scale, but often modify the ecosystems and often result in unpredictable and undesirable ecosystem-level changes. A third approach, mitigative in nature, is to reduce nutrient availability to nuisance primary producers (such as bloom-forming algal and cyanobacterial species) in lakes and wetlands by diverting nutrients into the growth of more desirable producer species, which can then be harvested and composted on land for use as fertilizer on gardens or cropland. Curry Industries Ltd. in Winnipeg MB, has developed a prototype for a Cattail Bio-Platform Harvesting System (TM) that allows for nutrient removal from the water column by cattails growing on a floating frame in eutrophic aquatic systems; plants can then be harvested at the end of the growing season and the biomass composted to fertilizer. The proposed ENGAGE grant will establish a collaborative research partnership between the applicant and Curry Industries to determine if early, low-level fertilization accelerates initial cattail growth and increases subsequent nutrient uptake from lake water. Our work will assist in the development of management best practices for this promising remediation technology.