Departmental Performance Report for the period ending March 31, 2010

DFO on the Job

Managing a fish species at risk in agricultural drains

Maintaining agricultural ditches for proper drainage of farm fields and, at the same time, for managing of healthy fish populations and habitats, is a challenge. It is even more challenging when a fish species at risk is involved. DFO Science is leading a study that examines the potential impact of maintenance on Grass Pickerel (“Special Concern”) populations in agricultural drains in the Niagara region of Ontario. Drain maintenance is usually undertaken by removing sediment build-up that causes water to back up in the channel and onto the flood plain. However, Grass Pickerel use the flood plains in the spring as spawning areas and the potential impact of reduced wetted flood plain areas on pickerel populations is unknown.

To better understand the habitat needs of Grass Pickerel, the study has tagged over 800 individuals to determine population size, and seasonal movements and habitat utilization. Based on these data, a habitat supply model will be developed to determine the relationship between population size and habitat availability. This model will then be used to determine the effect of different drain maintenance scenarios on Grass Pickerel populations. The scenario results will used to determine the best drain maintenance approach, which will be subsequently undertaken. The Grass Pickerel populations will be monitored to determine how well the model predicted the actual effect. If the model is successfully validated, it could then be used to manage the maintenance of agricultural drains that contain Grass Pickerel throughout southern Ontario, and modified to manage other drain-dwelling fishes across Canada.

This project is an excellent example of a cooperative approach to providing science advice to benefit both species and stakeholders - the Bert Miller Naturalist Club, Friends of Fort Erie Streams, Municipality of Fort Erie, Niagara College, Niagara Peninsula Conservation Authority, Ontario Ministry of Agriculture and Rural Affairs, Ontario Ministry of Natural Resources and private land owners are all project partners.

Prime Grass Pickerel habitat in Beaver Creek

Tag being inserted into a Grass Pickerel