Research Document 2016/092

A Modelling-based Assessment of the Impacts of Drain Maintenance on Fish Species-at-Risk Habitat in Little Bear Creek, Ontario

By Montgomery, F.A., Mandrak, N.E., and Reid, S.M.

Abstract

Little Bear Creek drain, a tributary to Lake St. Clair in southwestern Ontario, supports 61 freshwater fish species, six of which are listed under the federal Species at Risk Act (SARA). In 2012, a drain maintenance request was proposed by the Municipality of Chatham-Kent, under the provincial Drainage Act, to repair and improve the functionality of Little Bear Creek drain. Proposed drain maintenance activities included the removal of substrate and vegetation from the creek, which may lead to the loss of critical habitat for fish species at risk. To predict the impacts of drain maintenance, the distribution and habitat requirements of fish species at risk in Little Bear Creek were modelled. Regression tree analysis was used to develop a statistical model (R² = 0.52; AUC = 0.75) to predict vegetation cover as a function of water depth (m) and distance from the mouth of the creek (m). The vegetation cover model was used to predict suitable habitat (defined as vegetation cover > 50%) for two of the six fish species at risk: the Endangered Pugnose Shiner (Notropis anogenus); and, the Special Concern Blackstripe Topminnow (Fundulus notatus). Impacts to suitable habitat were assessed under three drain maintenance scenarios:

1. no drain maintenance;
2. the proponent’s initial proposed maintenance; and,
3. the proponent’s revised proposed maintenance.

Complete document (PDF, 1.4 MB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.