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Exotic, invasive aquatic plants threaten waterways

When I was a child, my grandfather owned some land on a lake in Liberty County. When I visited him in Savannah, he would often take me to this lake and we would go fishing. Over time, the lake became unusable due to an exotic aquatic plant called hydrilla, or water thyme. The infestation was so bad that even boats could barely navigate the lake, and the fishing came to a standstill.

There are many exotic plant species that can damage Gwinnett County waterways. Water hyacinth, water lettuce, hydrilla, watermilfoil, aligatorweed, lotus, etc. are all introduced plants that can be serious pests in our waterways. These same plants are sold in nurseries as ornamental pond plants. They escape when birds visit koi ponds and then fly to native water. In several of our parks, for instance, shortsighted citizens have introduced water hyacinth into ponds. These infestations have become very serious and have cost individual pond owners and the Gwinnett taxpayers money to clean up.

Aquatic weeds are undesirable in ponds for several reasons. They provide cover for small bream, which results in overcrowding. Weeds use nutrients and they can become so abundant that boat traffic or fishing becomes difficult. Extensive weed coverage reduces dissolved oxygen levels during warm, cloudy weather.

Sacred lotus, which has pink flowers, has become established in scattered localities as a result of cultivation as an ornamental. Once established, the species forms large colonies.

Parrot's feather is an invasive water plant sold widely at pond plant retail outlets. A feathery aquatic plant with stems that can grow up to 6 feet in length, the tips of the stems frequently protrude from the water up to 18 inches. The short leaves grow in tight whorls and are shades of bright yellow and green.

Water hyacinthe is a floating aquatic plant used in many home water gardens, is a potentially devastating invasive plant. Many people believe the plant does not survive the winter in our region. Unfortunately, in Gwinnett County, we have several populations that have become established in local ponds.

Everyone should take precautions to prevent the spread of noxious exotic aquatic weeds into our reservoirs. Never release any water plant into native watersheds. Make sure ornamental water plants are properly disposed of when you remove them from backyard water gardens or aquariums. Compost them or put them into trash bags for pickup. If you take your boat to some other state thoroughly sanitize your boat before putting it into any Georgia waterway. Never collect water plants from what you think are wild populations and spread them. Noxious water plants multiply rapidly, so use some caution when giving them to friends.