Habitat Survey and Management Recommendations for a Walleye Spawning Shoal in Severn Sound

Session: Poster Session

Keith Sherman, prev. Severn Sound, Environmental Association, [email protected]
Lex McPhail, Severn Sound Environmental Association, [email protected]
Aisha Chiandet, Severn Sound Env. Assoc., [email protected]
Paula Madill, Severn Sound Environmental Association, [email protected]
Carl Lesperance, Severn Sound Environmental Association, [email protected]

Abstract

Walleye are an important sportfish in Severn Sound, Georgian Bay. A habitat survey was completed in an important spawning shoal area below a Trent Severn Waterway dam to provide flow management and timing window recommendations. Operation of the dam may have adverse impacts on the area by altering water levels and flows over the spawning bed, affecting reproductive success by rendering some of the spawning shoal dry or stagnant during the spawning and hatch period, or by flushing the shoal during high flows, carrying eggs to unsuitable hatching areas. The hydrodynamic model River2D was used to model stream velocities and habitat conditions using depth, flow, and substrate as inputs, estimating a relative suitability index for spawning at low-flow and chart datum water level conditions. Water temperature, based on continuous ice-free season data collected downstream of the dam, was also considered as a factor influencing reproduction. Knowing when the optimal temperature range occurs can help managers ensure there is sufficient flow to cover the shoals during critical periods. Based on modelling and temperature data analysis, recommendations for a management plan are made, and include specific flow and depth ranges for the entire months of April and May, and optimal substrate type.

Twitter handle of presenter
@SSEA_SSRAP