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1 - Purpose of this presentation is to provide an overview of - PDF document

Jan 29, 2023 •385 likes •531 views

1 - Purpose of this presentation is to provide an overview of monitoring activities in Rattray Marsh and the lower reaches of Sheridan Creek Will focus on data collected through CVCs watershed -scale IWMP, including - type of data we

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  2. - Purpose of this presentation is to provide an overview of monitoring activities in Rattray Marsh and the lower reaches of Sheridan Creek Will focus on data collected through CVC’s watershed -scale IWMP, including - type of data we collect, results and trends Information to be presented is not meant to be all encompassing – CVC - collects a wide variety of data in and around the marsh through a number of programs, partnerships and other initiatives 2

  3. Similar to the annual physicals we take at the doctors’ office. We may feel and look good, but if we get checked regularly, we hope to diagnose an issue early on and treat it before its too late. CVC now has over 10 years of data at several sites across the watershed. This gives us a powerful dataset to start to analyze, integrate and make conclusions and potentially recommendations at a landscape scale as well potentially at a site level. 3

  4. 11/21/2014 Blue – instream Darker green – land-based Hatched – complementary things we monitor to help explain what we’re seeing in the other attributes. 4

  5. This represents current land use, however we must not forget historical changes over the last two centuries also: before european settlement, dominated by forest and wetlands, then clearing for agriculture and dams. Since 1950s, CRW has seen extensive restoration efforts by LO, Municipalities and other agencies to reverse this forest decline. Note: Lower Watershed – expectation of some degradation in our results due to urban land use 5

  6. Before getting into the results, note that Rattray Marsh is part of a Centre for Biodiversity Includes the Conservation area, but also extends to include Turtle Creek as well as… • CVC is in the process of developing a Credit River Watershed Natural Heritage System (currently draft and undergoing stakeholder consultation). The system is made up of important mapped natural features and areas that CVC is committed to working to protect, enhance and restore. • A key component of the natural heritage system is Centres for Biodiversity. • CoBs are landscapes that contain the best representative aggregations of natural features such as woodlands, wetlands, aquatic habitat or open country habitat associated with the Credit River watershed’s major physiographic regions • The Rattray Marsh-Turtle Creek Centre for Biodiversity represents the top 1% in terms of area of a single habitat patch in Southern half of the watershed • Contains records for approximately 377 floral species • Recorded use by approximately 319 faunal species including 29 species at risk (21 birds, three reptiles, three mammals, one plant and one insect) 6

  7. • Have been monitoring water quality in Sheridan Creek as it enters Rattray Marsh since 1976 through a partnership with the Ontario Ministry of the Environment • Collect monthly samples, year round – representative of conditions across all seasons. • WQI – gives overall rating of general water quality for nutrients and metals; generates a number between 0 and 100 (0=poor; 100=excellent) • Sheridan Cr ranks as “Marginal” (or “Poor” according to 2013 results). Similar to other urban tributaries • Parameters that do not meet water quality guidelines include: phosphorus; metals such as aluminum, copper and zinc; and chloride – commonly associated with urban runoff. 7

  8. • Chlorides – commonly associated with urban watersheds due to winter road salt application • In Sheridan Creek, chlorides concentrations are well above the water quality guideline • have been increasing since the start of monitoring • Higher in winter but also elevated in the summer groundwater contributions accumulation of chlorides from road salt • Efforts to reduce chlorides – City of Mississauga begun using treated salt rather than sand-salt mixture (reduces chlorides by 50%) – expect to see this reflected through a reduction in chloride conc in stream • New Real-time water quality station installed fall 2013. 8

  9. = aquatic insects, worms, snails and other related organisms that live on a stream bottom • Commonly used as indicators of water and habitat quality – species have varying tolerances to pollution • In Sheridan Creek, benthic community is comprised of mainly pollution- tolerant organisms such as sow bugs, scuds and net-spinning caddisflies • Results are similar to other urban tributaries • Some monitoring in marsh – different community to what we find in-stream – expect habitat conditions to improve with restoration, therefore improvement in benthic community 9

  10. - Electrofishing in Sheridan Creek for more than 10 years - 12 species of fish captured. Common species include: Creek Chub, Fathead Minnow and Longnose Dace White Sucker, not caught in high numbers in CVC’s monitoring efforts, is - abundant in this area during its spring spawning period - Many of the fish species in Sheridan Creek are not typical of urban streams, e.g. Longnose Dace only typical of urban streams with high DO and clean riffles/gravels, Emerald Shiner and Lake Chub. Golden Shiner is uncommon across the watershed. 10

  11. CVC uses an Index of Biotic Integrity (IBI) score to assess the health of the fish community. The IBI is based on a sensitivity ranking of individual species combined with total weight, or biomass density (per square-metre of stream reach). The fish community in Sheridan Creek at Rattray Marsh ranks “Poor” and the IBI has remained stable at Sheridan Creek over the years. The poor ranking is similar to the results at other stations sampled in the Lower watershed. The presence of certain unique species in Sheridan Creek is encouraging. • restoration efforts to control invasive carp and increase marsh depth will benefit the resident fish community by allowing regrowth of native wetland vegetation (including submergent plants) and repopulation of native fish species. 11

  12. • includes vegetation and amphibian monitoring • Since 2004, four frog species have been detected at the wetland monitoring plot: American Toad, Green Frog, and Northern Leopard Frog and Wood Frog (one detection each) • Annual results indicate low species richness (no frogs detected in 2013 or 2014) – this is consistent with other wetland plots in the Lower watershed • Presence of Wood Frog is encouraging - indicative of good forest habitat and suggests Rattray Marsh has the potential to provide habitat for more sensitive species. • Veg community dominated by weedy or non-native species. However, no new invading species have moved into the plot in the past eight years. • Other wetland plots in the Lower watershed have similar findings • Positive: Water Smartweed is found at the plot and is a Species of Conservation Interest. 12

  13. Several initiatives in/around Rattray Marsh - Restoration efforts (sed removal, invasive species removal, etc) - Salt management initiatives – e.g. City of Mississauga switching from traditional sand-salt mixture to treated salt (MgCl) – reduces chloride loads by 50% IWMP is a long term program that will continue to monitor Sheridan Creek & Rattray Marsh. 13

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