Hill's pondweed (Potamogeton hillii) COSEWIC assessment and status report: chapter 16
Appendix 1. Results of Potamogeton hillii field surveys
| Extent Occurrence number | Location |
Date last seen | Estimated population | Area of occupancy | Notes |
Sample taken? |
|---|---|---|---|---|---|---|
| 001 | Albemarle Brook, Bruce County | 1983 | Species not found. Good habitat. Abundant Elodea canadensis. Extensive survey not possible due to cut-grass and stinging nettle. | |||
| 002 | Miller Lake, Bruce County | August 2003 | 4000 | marsh ~1 ha | In channels of Phalaris-dominated wetland, also Chara vulgaris. Population estimate by Makkay. | sterile |
| 003 | St. Thomas, Elgin County | 1951 | Site not visited; population historic and assumed possibly extirpated | |||
| 004 | Credit River / Green Lake, Peel Region |
August 2003October 2003 | 100 | Small amount found in north end of Lake. Population estimate by Makkay. MNR, Ontario, staff reported plants in fruit spread throughout the eastern portion of lake (an area of about 500m X 150m (M.J. Oldham, pers. com., Feb 2005 to E. Haber; no population estimate provided) | sterile fruiting on 2 October |
|
| 005 | Mindemoya, Manitoulin Island | 1983 | Species not found. Mostly cattail marsh. | |||
| 006 | Smoky Creek / Mallet River, Wellington County | August 2003 | 4000 | creek ~0.1 ha | In sluggish creek upstream of bridge. Population estimate by Makkay. | sterile |
| 007 | Crane River (Willow Creek), Bruce County | August 2003 | 32,000 | creek / ditch ~0.1 ha | In ditch on NE side of Hwy 6. Population estimate by Makkay. | sterile |
| 008 | Bethel Creek, Wellington County | 1978 | Species not found. Abundant Elodea canadensis, Potamogeton crispus. The latter is an exotic species. | |||
| 009 | West of Cameron Lake, Bruce County | August 2003 | 500 | marsh ~ 0.6 ha | With Chara vulgaris and Potamogeton natans. Population estimate by Makkay. | sterile |
| 010 | South Baymouth, Manitoulin Island | August 2003 | 1000 | pond ~ 0.1 ha | Pond west of small boat docking area with P. natans, Utricularia vulgaris, Chara vulgaris. Population estimate by Makkay. | yes – ID confirmed |
| 011 | South Bay, Manitoulin Island | August 2003 | 6000 | shallow creek, ~ 0.1 ha | E side of bridge with Elodea canadensis, Ceratophyllum demersum and Nuphar varigatum. Population estimate by Makkay. | sterile |
| 012 | Black Creek, Manitoulin Island | 1983 | Species not found. Water level very low and cloudy from cattle access. | |||
| 013 | Providence Bay Road, Manitoulin Island | 1983 | Species not found. Suitable habitat. | |||
| 014 | Srigley Bay, Manitoulin Island | Site not accessible. This record is based on a 1995 report to Ontario Ministry of Natural Resources by Nobel. No actual date for last seen is available in the records. | ||||
| 015 | Caledon Lake Forest ANSI, Peel Region | 1986 | Could not access site at lake. Species not found in stream. | |||
| 016 | Scott Point, Bruce County | August 2003 | 10,000 | marsh ~ 0.1 ha | Downstream of culvert in stream. Population estimate by Makkay. | yes – ID confirmed |
| 017 | McVicar Swamp, Bruce County | August 2003 | 4000 | marsh ~ 5 ha | In creek in Phalaris dominated marsh, with Potamogeton natans, Sparganium. Population estimate by Makkay. | yes – ID confirmed |
| 018 | Hope Bay Forest ANSI, Bruce County | 1992 | Site not found | |||
| 019 | Cabot Head, Bruce County | 1991 | Site not accessible | |||
| 020 | Crane Lake, Bruce County | August 2003 | 40,000 | marsh ~12.5 ha | In deep channels of Phalaris-dominated marsh, very abundant. Population estimate by Makkay. | yes – ID confirmed |
| 021 | Spring Creek Wetland, Bruce County | 1990 | Species not found. Habitat not suitable – water too fast, little aquatic vegetation. Not sure if proper site was found. | |||
| 022 | Little Eagle Harbour, Bruce County | 1901 | Species not found. Few aquatic plants in the stream. Did not appear to be suitable habitat – water too fast. Likely extirpated. | |||
| 023 | Shingle Marsh, Bruce County | August 2003 | 2000 | With Utricularia vulgaris, Chara vulgaris. Population estimate by Makkay. | sterile | |
| 024 | McLander Marsh, Bruce County | August 2003 | 16,000 | marsh & pond ~ 0.1 ha | Downstream side of road growing with P. natans, Chara vulgaris and Utricularia vulgaris. Population estimate by Makkay. | in flower, fruit not mature |