Terms of Reference

Options for exclusion of fish species at risk for drainage activities in Little Bear Creek, Ontario

Regional Science Response Process– Central and Arctic Region

April 2015
Burlington, Ontario

Chairperson: Kelly McNichols-O’Rourke

Context

Little Bear Creek is a tributary of Lake St. Clair and drains into the St. Clair River via the Chanel Ecarte in the Chatham-Kent Region. Little Bear Creek is home to several species at risk (SAR) fishes including Pugnose Shiner (Notropis anogenus), Lake Chubsucker (Erimyzon sucetta), Pugnose Minnow (Opsopoeodus emiliae), Grass Pickerel (Esox americanus vermiculatus), Blackstripe Topminnow (Fundulus notatus), and Spotted Sucker (Minytrema melanops). Little Bear Creek is classified as an agricultural drain and has been identified for drain maintenance. There is increasing pressure to complete a drain clean out of Little Bear Creek to decrease flooding of land owned by private landowners.

The Municipality of Chatham-Kent has submitted a “Drain Maintenance Request” under the provincial Drainage Act to excavate and remove accumulated sediment from the Little Bear Creek Drain. In-water works are proposed for 29.5 km from the mouth and upstream to Countryview Line, where the remaining drain portions are buried. Excavation will be a combination of drag-line crane rigging, and long and standard hydraulic excavators.  A number of culvert and enclosure works are also proposed in the headwater areas of the drain. Small brush and larger trees are also to be removed from the shoreline along the entire length of the drain.

Fisheries and Oceans Canada (DFO) Species at Risk Program has requested advice from DFO Science to help assess the potential role that fish exclusion techniques might play in minimizing harm to individuals of fish SAR (and as part of an overall mitigation approach for the clean out) within Little Bear Creek.

Objectives

The objectives were to provide advice on the effects of dredging in the lower Great Lakes on fish species at risk:

1. Determine if fish exclusion can be used as a mitigation strategy to minimize harm to SAR fishes present in Little Bear Creek in the area proposed for drain clean out;
2. Determine if reach-specific physical parameters  (e.g., size of waterway, water clarity) compromise the effectiveness of fish exclusion;
3. Determine if the resulting fish exclusion techniques can be practically implemented on the scale required for Little Bear Creek.

Expected Publication

• Science Response

Participation

• Fisheries and Oceans Canada (Science, Species at Risk)
• Ontario Ministry of Natural Resources
• University of Toronto