Curly-leaf pondweed  (Discovered in Gull Chain many years ago)

(Dreissena polymorpha) 

From the Minnesota DNR website:

Common names: Curly cabbage, crisp pondweed.

Location: Grows from the shore to depths of up to 15 feet.

Description: Leaves are somewhat stiff and crinkled, approximately

1/2-inch wide and 2 to 3 inches long; leaves are arranged alternately

around the stem, and become more dense toward the end of branches;

produces winter buds can be confused with claspingleaf pondweed.

More information:

 

Map of Curly-leaf pondweed infestation in Minnesota

Curly-leaf pondweed factsheet

MISIN curly-leaf pondweed identification training module

Minnesota Sea Grant (U of M)