Hi. I have downloaded the original photo, cropped it and added it back to show the Myriophyllum leaves more clearly. See conversation on this sighting: Potamogeton crispus (Curly Pondweed) on 3 Dec 2018
This is definitely Myriophyllum verrucosum: leaf colour, shape and habit, are all collectively diagnostic. the Potamogeton leaves in the background are Potamogeton crispus.