SS3.06 Large Scale Change in Prominent Ecosystems
Date: Wednesday, June 12, 2002
Time: 2:15:00 PM
Location: Lecture Theatre
 
Chow-FraserP, McMaster University, Biology Department, Hamilton, Ontario, Canada, chowfras@mcmaster.ca
 
MEASURED SUCCESS IN THE RESTORATION OF COOTES PARADISE MARSH, A DEGRADED COASTAL WETLAND OF LAKE ONTARIO
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Cootes Paradise Marsh, a 250-ha urban wetland, was once a vibrant cattail marsh and a “paradise for game of all kinds”. A carp-exclusion program was initiated in 1997 to enhance fish habitat by improving water clarity and encouraging the growth of submergent vegetation. An effectiveness-monitoring program (comparison of data from 1993, 1994 and 1996 with data from 1997 to 2000 inclusive) indicated that water clarity had improved significantly following carp exclusion, but the effects had not been long-lasting, and depended greatly on the response of the lower food web to onset of planktivore migration into the marsh. The recently developed Wetland Zooplankton Index (WZI), was used to assess changes in wetland quality of the marsh as it underwent restoration. Based on changes in the plant, zooplankton and fish communities, the quality of the marsh has improved significantly in vegetated areas where there are residual emergent communities, but in open, deeper, more wind-exposed areas of the marsh, there have been no significant improvements.