The Aquatic Plant Restoration Program in Illinois

Gary W. Lutterbie
Illinois Department of Natural Resources 301 S. Date Street, Gibson City, IL 60936 217/784-4730

Aquatic and wetland plant restoration is primarily needed for larger impoundments and renovation of wetland. Illinois' larger impoundments are generally void of aquatic vegetation. High wave action caused by wind and recreational boating, and water level fluctuations are believed to be the main reasons for the lack of aquatic vegetation establishment. Other factors might include turbidity, lack of an adequate seed bed and uprooting of plants caused by carp and other fish species. Biologists have tried transplanting aquatic vegetation from other lakes or purchasing plants and root stock from private nurseries. Transplanting from other lakes is discouraged due to introduction of unwanted species that might be attached or come in with the plants (i.e. zebra mussels, the spiny water flea, Eurasian milfoil, curlyleaf pondweed). The Department is also concerned about genetic strains of plants and would prefer not to buy plants, tubers or seed from private nurseries unless they can guarantee the use of local seed for their nursery stock. The Mason Tree Nursery in our Division of Forestry has undertaken a program to try and furnish the needs of the biologist from the Divisions of Natural Heritage and Fisheries. Nursery personnel have been experimenting with the culturing of different aquatic and wetland plants to meet the needs of the biologist. It is up to the requesting biologist to furnish the seed, proper identification and location from where the seed were obtained. The nursery will then raise the plants in trays containing 45 tubes which can then be easily transported to the biologist for planting at the appropriate time. Much of the work has been conducted at Clinton Lake, a 5000 acre impoundment located in central Illinois. Early (1990) attempts to plant sago pondweed (Potamogeton pectinatus) and wild celery (Vallisneria sp) failed even though they were protected with plastic snow fencing. The reason for failure was thought to be due to high turbidity and possibly the late planting date, July 2. Limited success was obtained with American pondweed (Potamogeton nodosus). The American pondweed grew well the first year though failed to come back the following year. Water willow (Justica americana) was planted from 1991 through 1998, except in 1994. In each year five to nine beds were established. Evaluations conducted in July and August 1998 indicated that an average of 70% (33 to 89%) of the beds planted between 1991 and 1998 were successful. Plantings from 1991 through 1995 were primarily along the main shoreline in order to provide shoreline protection as well as fish habitat. Average bed survival for these years was 56% (range 33-86%). Plantings from 1996 through 1998 occurred in protected coves, or in the upper arms of the lake where wave action was less severe. Average bed establishment was 88% (range 86-89%). Substrate type and protection from wave action probably increased survival in these areas. Planting clumps of water willow plants vs individual plants increased survival greatly. From 1996 through 1998 15 beds of wild celery were planted. Evaluations in August 1998 indicated that 53% of these beds were still actively growing. Beds protected with geo-jute and snow fencing planted in ambient water temperatures, in clear water and where depth was at least 12 in deep in August performed the best. The recent establishment of lizards tail (Saururus cermuus) and water willow along stream banks is showing some promise. Recent attempts to grow the wetland plants hardstem bulrush (Scirpus acutus), three-square bulrush (Scirpus americanus), river bulrush (Scirpus fluviatilus), deep-water duck potato (Sagittaria rigida) and spadder dock (Nuphar Iuteum) have met with mixed success. Wetland renovation is becoming a bigger part of watershed management and will require more attention to determine which plants will provide the best habitat in the various types of wetlands.