Ecological Restoration of Ravenshill Pond: Aquatic invasive Iris pseudacorus assessment and removal

Abstract

In July 2012, in the district of Saanich, 11 km from Victoria, BC, the invasive species Iris pseudacorus was assessed, and some plants were removed/controlled. Also, bathymetric analysis of RavenShill pond took place in conjunction with ecosystem typing,
aquatic/terrestrial plant survey, pond cores, water data collection, and dam inspection to assist in developing a long-term invasive Iris eradication/control program. Bathymetric analysis was conducted to elucidate the ponds features and aquatic and terrestrial plant survey for future comparative analysis to identify potential invasive species spreading. Core samples were taken to identify the underlying ground matrix and its potential ability to allow heavy machinery into the pond area for maintenance, modification, and control of invasive species. Ecosystem typing was conducted to confirm that the pond was man-made. Water data was collected for future
reference/comparative analysis. Bathymetric analysis revealed a max depth of <2m. Pond cores revealed an underlayer of grey clay, ecosystem typing/site series of CwFd-Kindbergia (Western-Red Cedar, Douglas fir), and pond water was slightly acidic, with low dissolved oxygen. Removal of Iris pseudacorus is labor-intensive and requires it is recommended that machinery be hired to assist in the control/eradication of Iris pseudacorus.