Elodea Effects

Although Elodea provides great benefits to the ecosystem such as oxygen, water filtration, and as a food source to various fish and animals, it can also negatively impact us as well. According to the University of Alaska Fairbanks, bodies of water in Alaska are at risk for becoming inhabited by Elodea. It seems that Elodea can “interfere with salmon spawning and deplete lake nutrients” (Frisch). Elodea was first introduced as an aquarium plant to Alaska. The negative effects of Elodea include affecting the oxygen in water nutrients and its ability to “outcompete native plants to grow in dense mats in sandy habitats along lake shores where salmon like to spawn” (Frisch). Elodea also may become entangled in floatplane rudders as well as boat

propellers, which leads to motor malfunctions. This is significant to the people of Alaska as their food supply and way of receiving supplies are crucial to their survival.

This is just one of the places in which Elodea is being researched and observed as its overgrowth has led to many problems over the last few years. Additionally, it seems that Canadian Pondweed, or Elodea canadensis, was introduced to the UK accidentally through imported timber that was used for building railways. It is believed that Elodea attached itself to the timber and eventually led to a quick colonization of the United Kingdom’s waterways. It multiplied because its natural predators and pests were not present in this new habitat. As a result, Elodea flourished and became a nuisance to the passage of boats (Naylor). These examples predict a similar reaction if left untreated in the waters of our home, North America. This leads one to question what will happen to the fish and native plants and flora if Elodea is not

controlled.
It is believed that one simple way to solve this increasing overgrowth of Elodea is to introduce consumers of Elodea into the water that are inhabited by them. One solution is the introduction of goldfish as they are one of the top consumers of Elodea plants. Most other fish do not eat Elodea, as it is more of a type of shelter for them. They use it as shade from the Sun and to hide from predators. Turtles also eat anarchis, or Elodea (Libal). This may be a quick fix for the problem of Elodea, but it can affect the ecosystem of the animals that already inhabit those waters. The introduction of goldfish would not create the desired impact on Elodea. This may make the animals begin to fight for food and even harm them. Adding turtles to a new habitat may bring unwanted diseases to the native inhabitants. This starts a chain reaction and leads to even more animals and plants to become affected by these actions. Instead of helping to solve the problem of the overgrowth of Elodea, the problem has grown to affect the plants and animals that are native to those waters. This leads one to question what can humans do to help solve this problem with resources that are readily available.
Instead on focusing on introducing fish or turtles to Elodea infested waters, one should consider another route.

This includes using Integrated Pest Management (IPM) solutions. What is IPM? IPM is a “planned program that coordinates economically and environmentally acceptable methods of pest control with the judicious and minimal use of toxic pesticides” (“Integrated Pest management,” 1). These programs use a careful assessment of local conditions that factor in climate, soil quality, and government regulations. A few examples of using an IPM strategy would be to introduce fish such as triploid grass carp or other biological control agents. There are many factors to consider before introducing a species to a habitat. First, you must identify the vegetation that needs to be controlled. In this case, Elodea is that vegetation. Grass carp does prefer pondweeds and hydrilla as a food source, but it does eat Elodea. The benefits of using triploid grass carp are many and by far outweigh any negative aspect of introducing them to new water habitat. They are inexpensive, are sterile and will not reproduce, feed only on plants, do not feed on young fishes or fish eggs, live for at least ten years, are difficult to catch using conventional methods of fishing, are dormant in the winter until the water temperatures reach sixty-eight degrees then resume extensive feeding, and they feed from the top of the plant downward (“Will Triploid Grass Carp Work for You?”). An added benefit of

using triploid grass carp is a bloom in alga and reduced water clarity, which aids in the survival of other fish and vegetation. These reasons make triploid grass carp a great choice for controlling waters with Elodea overgrowth.
There are many guidelines to follow in order to introduce triploid grass carp into the desired habitat. First and foremost, one must apply for a permit to do this. It important to note that there is no guarantee of acceptance of the application. There are some environmentally sensitive areas that have endangered, unique, or threatened species and may not allow this introduction into their natural habitats. In order to obtain a permit, one must download a form from the Texas Parks and Wildlife Department or call the TPW to request an application by mail. This application will then be reviewed by a District Fisheries Management Biologist and may or may not include a visit to the site to ensure that the grass carp will not escape into any surrounding public waters. This application process may take up to five weeks. Once one is granted a permit, the triploid grass carp may only be purchased from a specific person. This commercial farmer must hold an Exotic Species permit that authorizes their possession of the carp. This is found on a specified list that is obtained once the permit is approved (“Will Triploid Grass Carp Work for You?”).
This process is extensive and may also require the permit seeker to provide additional water barriers to prevent the escape of the triploid grass carp. These fish seek flowing water and may escape before they have controlled the desired aquatic plants. This can threaten the plants of the area outside of the targeted area. The desired screening device to keep the carp contained in a specific area is the horizontal parallel steel-bar design. This device allows the passage of small debris, but restricts the carp from escaping. This requires little maintenance and does not clog the waters. These bars must be the thickness of one-fourth to one-half inch and must have round bars so debris can pass through easily. The horizontal bars must be attached to vertical support posts that are attached to concrete and are spaced two inches apart. The height of this spillway barrier must be two feet above the normal high water level as triploid grass carp are considered to be great jumpers (“Will Triploid Grass Carp Work for You?”).
Once this barrier is in place, the carp can then be introduced into the new site. There are a few guidelines as to how to stock the carp. Small carp are more likely to be eaten by larger fish, so the triploid grass carp must be about twelve inches long. It is recommended to stock five carp per acre if the body of water has fifty percent or less plant coverage or ten per acre if plant coverage is greater than fifty percent. The best time to introduce these carp is early spring. This is not a one-time event as it may take several years to reach the desired control of the Elodea. Restocking the carp every five to seven years will be needed to reach the greatest effectiveness (“Will Triploid Grass Carp Work for You?”). Along with the introduction of the triploid grass carp, there is an alternative. The pesticide, Aquaplant, can also provide the management of most aquatic plant species but also requires a permit. In Texas the Texas Commission on Environmental Quality (TCEQ) would be the one that enforces the state regulations if this permit is desired (“Aquaplant”).
Controlling invasive water species such as Elodea will take much time and effort, but is possible. Using Integrated Pest Systems such as the introduction of the triploid grass carp as well as the pesticide Aquaplant can help control Elodea. Studying these plants more closely can lead to additional knowledge and can help the habitats of waters that contain Elodea. As Wangari Maathai said, “The environment and the economy are really both two sides of the same coin. If we cannot sustain the environment, we cannot sustain ourselves.”