There is a wide array of aquatic plants. There are many species and varieties that are beautiful, add to your ponds function and aesthetics, and serve a purpose to your pond or lake. We like to call these desirable aquatic plants. Then there are the many that quickly take over your pond, can potentially hurt your ponds ecosystem, are an eye sore, and don't serve much purpose to your pond or lake. These are known as undesirable aquatic plants and are what we are referring to when we discuss aquatic plant problems.
Often times, it is not difficult to distinguish between desired and undesired aquatic plants. However, as with many things, the difference can be determined by balance and personal taste. Aquatic plants are essential to a healthy pond ecosystem. They can serve as a food source for organisms in your pond, hiding places for fish and insects, nutrient sinks (using up available nutrients), and also provide oxygen. Aquatic plants can also enhance the aesthetics of your pond and create a beautiful, peaceful area.
Non invasive, native plants are much more desirable than non native, invasive varieties. Non native plant species out compete native species for nutrients because the native species are in better balance with the entire system. The non native species that overtake a pond are rapid growers and do not have the organisms to keep them in check because they are not native to the area. Native plants can also grow rapidly if not monitored and held in check. Therefore, the key is balance and preventing one specific aquatic plant from overtaking your entire pond. A nice mix of species will provide a healthy pond ecosystem and also a beautiful setting.
These pages are reprinted from www.gotalgae.com, courtesy of www.kascomarine.com