What do we do about algae? Keep in mind that lakes are not pools- they are not treated with chlorine to keep them clear and bacteria free. Natural bodies of water require everyone in the community to participate in maintaining and protecting the environment surrounding lakes and streams. In a lake the cleaning work is carried out by micro-organisms which exist together in equilibrium. There is an expectation that algae will be present, along with fish, frogs and other wildlife. Two types of algae have been prolific this late spring and summer in Lake Mohawk. Algae crowds shorelines and disturbs many lakefront residents.
Filamentous algae are important because they produce oxygen and food for animals that live in the water, but they also can cause problems such as clogs and stagnancy. Filamentous algae do not have roots. Most filamentous green algae are not harmful to humans. Excessive growth of this algae may indicate that there are other pollutants that have washed into the water. These pollutants may come from runoff from septic systems, lawns and golf courses. Long-term control of overabundant aquatic plants is best accomplished by reducing or redirecting nutrient sources from the water. This meanspumping your septic system regularly, limiting use of fertilizer, keeping a barrier of tall vegetation within 10 feet of the water’s edge, removing animal waste, and keeping waterfowl from congregating on the waterfront.
It is not uncommon for water bodies to develop large floating mats of algae during July and August in response to fertilization of lawns and animal wastes in the watershed. This year growth was seen in June. Blooms are a natural part of the aquatic ecosystem and the annual cycle of plant growth. Water that is largely covered in algal mats (more than 20%) are more likely to have fish kills and noxious odors due to lack of oxygen and increased sedimentation. Treatment with Aquablue Shading Agent may be used to help reduce sunlight penetration and control photosynthesis on the lakes. Herbacides are also used. This year new herbacides are being tested around Lake Mohawk.
Chara is a form of algae often mistaken for a plant. It grew fast and early this year because of the lack of ice on our lakes. Chara stabilizes bottom sediments; provides food for waterfowl and cover for fish. Chara coverage supports insects and other small aquatic animals, which are important foods for bluegills, small mouth bass, and largemouth bass. Chara is consumed by many species of ducks. It has a musky odor when crushed. Calcium deposits give the algae a gritty texture. Small areas can be hand raked.
Recognizing that these plant blooms are normal and using natural methods to reduce them are best for our lakes and the humans and animals who live around them. Herbicides, alum and other chemicals are used to reduce proliferation of algae only when needed. Help us reduce the use of chemical agents!