Redside dace are at risk…

Numéro du REO

019-8016

Identifiant (ID) du commentaire

95920

Commentaire fait au nom

Habitat Design & Stewardship (self-employed field biologist)

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Commentaire

Redside dace are at risk because we have altered and/or removed their habitat, supporting habitat and hydrologic features from the landscape. Redside dace habitat of coolwater conditions is heavily reliant on a replenished groundwater table and resultant groundwater discharges to rivers and streams, so recovery of redside dace is linked to watershed-wide water management of stormwater and groundwater resources, not just stream reaches that are occupied by redside dace and adjacent areas.

Recovery of the redside dace means increasing good quality habitat, and most fish, including redside dace, move throughout a river system, and move through less desirable reaches to get to the available good reaches ... so again, it is not appropriate to reduce the protection for redside dace to occupied areas and adjacent areas ... the entire length of the river and its watershed should be targeted for recovery of supporting habitat for redside dace and the coolwater/coldwater communities of Ontario rivers.

Stormwater management using traditional pipe-to-pond design heavily impacts redside dace due to discharge of erosive flows and pulses of turbid, nutrient laden, poor temperature quality water. The use of pipe-to-pond stormwater treatment should be eliminated or reduced as much as possible throughout the watershed of coolwater/coldwater rivers with a preferred use of overland stormwater treatment. Redside dace recovery would be best served through implementing overland stormwater treatment throughout the watershed for new development or re-development.

The greatest opportunity we have to improve habitat for redside dace throughout the watershed is to build back 1st and 2nd order stream valleys of supporting habitat and maintain or regain groundwater recharge through the use of overland stormwater treatment. Every landuse change through development/re-development is the opportunity to fix coolwater/coldwater rivers by using overland stormwater treatment. Overland stormwater treatment systems directly support redside dace habitat by producing temperature-moderated, clean, flow-moderated discharges to rivers and streams, and by maximizing groundwater recharge across the landscape. Humber Flats Ecopark overland stormwater treatment system in Richmond Hill, ON, is the example in Ontario of how overland stormwater treatment has improved and extended habitat for redside dace.