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Cultus Lake Yellow Flag-Iris Mapping


The Fraser Valley Invasive Species Society (FVISS) and the Cultus Lake Stewards (CLASS) are seeking observations of Yellow Flag-Iris (Iris pseudacoru) around Cultus Lake. YFI is an aquatic perennial plant that grows in clumps, forming dense mats in riparian areas like slow-moving streams and marshes. This plant out-compete native vegetation and restricts water movement, which can have detrimental effects on fish and waterfowl who use the riparian spaces.

Washington State Noxious Weed Control Board

(Photo credits are linked if not taken by FVISS: M.Garlick, Washington State Weed Control Board





In order for us to start managing this invasive plant, we first need to know where the plants are located. Once the locations are known, we can return to clip seed heads in late-summer and begin planning for removing the plants. So get your boat, canoe, kayak or SUP - Help us map this aquatic invasive plant!

Anyone can participate using the phone application iNaturalist which can be downloaded from either the Apple App Store or Google Play store. Once you have downloaded the app and created a profile, you can find the Cultus Lake - Yellow Flag-Iris Mapping project and sign up to be a member. Then you can go ahead and start observing!

To help make mapping of YFI easier to accomplish, we have split upthe shoreline of Cultus Lake into 8 sections. For this project, you can choose to survey just one of the sections or more.

WHEN: May - June, while the plants are flowering!

WHERE: Cultus Lake

HOW: Use your phone to photograph any YFI you see on the shore from your canoe/kayak/SUP and upload to iNaturalist. Make sure you are a member of our project!