Help us identify these ​weeds and algae.

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Help us identify these ​weeds and algae.

Hello Everyone,

Kindly see attached pics of a lake in Gujarat, India. Can someone help us identify these weeds and algae and advice if these weeds/algae are good or bad for the lake ecosystem?

The lake houses thousands of fishes, 25/30 tortoises and approx. 10 crocodiles.

Looking forward to earliest advice as we wish to clean this lake before the monsoons start. We do not wish to disturb the lake ecosystem if the weeds and algae are good to the environment. Suggest with your experience wether these weeds and algae needs to be removed from the lake or should be allow growing. 

Thank you

Dilip Bhanushali

 

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12 Answers

  3. Hello All, Thanks for the prompt feedback. The weed seems to be Fanwort and has been seen in this lake recently. The lake depth is 6 to 8 feet. In some parts of the lake, the growth is in several sq meters and is surly blocking sunlight. The lake is under a local government body and we plan to get rid of this weed at the earliest. Chemical treatment may not be allowed as its a sacred lake for local residents. Uprooting from base may be a option. Will keep you all posted and upload pics of the clean lake too. Thanks again for all the information and assistance.

  4. Hi Dillip; I have viewed some of the responses that were provided previously and agree that there may be blue green algae in the pond (its actaully not a lake) and that is generally caused by high nutrient loading and high temperature. The water body looks fairly shallow based on the amount of emergent growth of what looks like a Canary Reed Grass. I agree with the assessment of a submerged aquatic that looks like a Fan Wort which typically is found in alkaline types of water. If I am not mistaken theer appears to be a stepped structure that was built into the pond at some time in the past and the banks appear to be built up so I have to ask if this is an impoundment and if so is there an outlet with flow from it? In the foreground there appears to be a road that runs beside the pond and debris and sediments from that would undoubtedly enter the pond and may be a source of some pollutants. It is important to gather information on the surrounding land use as well as the water quality before even looking at a chemical solution to a presumed algal problem. I have seen several of these types of old impoundments in Rajasthan usually at old temple sites that at first glance look polluted but which in fact suffer from a lack of flow through and the entry of human debris and wastes from the surrounding land use which when cleaned up improved the quality of the water system. In many cases the incoming water was of reasonable quality.

  5. 1,2 + 4 look like Chara spp. musk grass

  6. Hi Dilip The weed growth appears to be excessive, if the water is green with algae it means there is too much algae too. We have a good solution to grow Diatom Algae in the lake to keep it clean and prevent excess growth of weeds and Blue Green Algae. Diatoms are the natural food for fish, so the fish will grow very well. Our solution uses the nutrients in the water to grow fish, this is the most scientific solution to keep lakes clean.

  7. Dear Dillip, Keep weed growth and algae under control = clear, clean healthy water. That answer is the enhancement of the decaying process by the natural action of beneficial bacteria.There is no more cost effective solution to managing nuisance lakes weed and algae growth .It is a two-fold process that has proven to work best. It is done by adding mature healthy bacteria to the pond and giving it the means to survive. As plant life grows it absorbs carbon dioxide and gives off oxygen. The oxygen is needed by other life forms, (fish, bacteria etc.). Animal life also feeds directly off the plant life and this life becomes food for other life. When the plants and animals die, this dead organic matter sinks to the bottom and begins to decay. Bacteria begin to do their job. They turn the organic matter into ammonia, nitrites, nitrates and finally into nitrogen. Besides nitrogen, other plant nutrients (potassium, calcium, iron, phosphorus etc.) also are produced in order to keep the life cycle on going. Nitrogen basically is plant food. The nitrogen provides the means for new plant growth. The life cycle of algae works the same way. Bacteria eat the dead algae; small animals (zooplankton) eat the algae and the bacteria, which in turn is eaten by other life forms. Death is not a bad thing because it provides food for the living. Therefore in a balanced pond or lake the process provides each life with the means to survive. If this balance is disturbed in some way the entire ecosystem is affected. To illustrate, let us look at a pond that is out of balance or becoming unbalanced. The first signs of an out of balance pond are an overabundance of algae and weed growth. This happens because the available bacteria are not absorbing the decaying organic matter from previous growth at the natural cleansing rate. If the bacteria cannot keep up and dissolve (decay) this heavy loading of organic matter the pond begins to deteriorate. Left unchecked, sooner or later the pond fills with dead plant life and becomes a swamp. Side note: Actually this also happens in the natural order of things. Natural pollution can cause a pond to become a swamp, then a bog and finally a meadow. But that is on Mother Nature’s time line, which may not be what we want. AND we can slow this process way down or even stop it all together. Again without getting overly technical, in nature as plants die and sink to the bottom, they serve as additional plant food. As the organic load builds it robs the pond of oxygen. Stagnation sets in. Without oxygen the beneficial bacteria cannot live. As more and more of this process takes place the pond begins to die from the bottom up. It is Mother Nature’s way, but we can slow the process or increase it. Which brings us back to manmade pollution. Add some chemicals, which stimulate plant grown and you greatly; increase the prospects of the pond dying. On the other hand, add beneficial bacteria and oxygen (for the bacteria to flourish) and the dying process slows or stops. Herein lies the answer to how we can restore and/or maintain our ponds and lakes in a clear, clean healthy state. Following Disadvantages. 1. Blue-green algae can cause illness and sometimes fatalities in pets, livestock and wildlife. 2. Exposure to or ingestion of blue-green algae can also lead to a variety of discomforts in humans. 3. Algae contamination can discolour drinking water and create unpleasant odors and tastes. 4. Excessive algae growth can also impart distasteful flavour to fish. 5. Algae decomposition can deplete oxygen in bodies of water and kill fish. 6. Excess algae can impede water intake from fire ponds and irrigation systems. 7. Algae can elevate organic solid content and the biological oxygen demand in wastewater oxidation ponds. 8. Excessive algae growth can quickly change lakes, ponds, lagoons and shorelines from scenic to unsightly. Advantages of Algae Healthy lakes need algae. Algae are important to the productivity of a lake or water body. Algae are primary producers. They use sunlight (through photosynthesis) to produce carbohydrates and are eaten by grazers such as protozoa and zooplankton (little animals like water fleas and rotifers). The zooplankton are, in turn, grazed upon by fish, which are eaten by bigger fish, and on up the food chain. A productive lake produces large fish and good fishing for humans as well as supporting food and habitat for wildlife and waterfowl. In this context most algae are desirable for lakes. Regards, Prem Baboo

  8. Here is an 1977 USEPA document with information on alga

  9. Dilip, There definitely is some cyanobacteria (blue/green algae) in the lake. The toxins that will be released can be fatal to the fish and any animals that drink the water. One very efficient and non-imntrusive way to get rid of the algae is ultrasonics. You will not need chemicals of any kind and will disturb any part of the ecosystem. You just put the unit in the water run it on and walk away. In only two to three weeks the algae will die off allowing the water to bo clearer and much more habitable for the fish and other aquatic species. Contact me if you would like more information.

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  10. Here is a website that provides guidance for identifying aquatic weeds as well as provides biological, mechanical, and chemical control methods. http://aquaplant.tamu.edu/plant-identification/category-submerge-plants/ I see evidence of water sedge around the perimeter, American Pondweed, and what appears to possibly be Fan Wort or Hydrilla. There are many chemical treatments that can be used where water is for drinking water. Most have short half lives. Use of these are the only practical means of removing aquatic weeds in a short time frame. The detritus that will from once the weeds die off will become nutrients for future aquatic plankton and plants. A balance of biological population of both plants and animals is needed for a flourishing bio-system. You may want to consider a contact herbicide ranger than a systemic herbicide like Flouridone, to allow you to treat specific areas while allowing others to remain populated with weeds. Unlike the other comment, Roundup is not permitted (at least in the US) for aquatic weed control. The active ingredient, Glyphosate, is permitted and contained in many permitted formulations, but would only be effective on the sedges since it is a contact herbicide that is applied to plants above the water surface..

  11. It depends on what they are. Some cyanobacteria produce toxins that can harm livestock (and humans who drink the water). The big blooms of algae occur because of nutrient run off into the water body. The problem becomes that when the algae die, and decompose, the decomposition reduces oxygen in the water leading to fish kills. dead/decomposing fish will make it worse (LOTS of nutrients) Run off into water bodies is not easy to control. Sustainable agricultural practices such as reducing fertilizer use/not over fertilizing in proximity to the water can help in the long term. The biomass can be removed. (often the bad blooms of cyanobacteria float on the surface of the water. Be aware that the material can cause rashes and skin irritation, depending on what kind of algae it is). It can be dried and pelletized to burn for fuel needs. It can be anaerobically digested to produce biogas. It can be composted for use as a soil amendment (be aware the biomass can concentrate metals and that is good to test before applying to soil where food is grown). Check out Oilgae.com, and algaeindustrymagazine.com as these sites (and many others) have information on these uses of biomass.

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  12. algae in nature is usually a mix. you need to take it to a lab to be identified. but if you see things that are clumping...that blocks sunlight from penetrating to the bottom, you generally have to get rid of it. as for the weeds, if its not a foreign species, you are set. they grow mainly because of the availability of nutrients. same as algae and cyano bacteria. and how are you going to remove them? it may do more harm that good. traditional, they would use copper for algal ...but that actually does more long term harm than good. same with the weeds. roundup kills the weeds then it gets into the food chain. best is with bioremediation. a biocleaner system would very quickly get rid of cyano bacteria and produce chlorella. it will suck up nutrients faster than weeds. best way to get rid of nutrients is via fishing. if your bioremediation is successful, the nutrients will be converted by sunlight into chlorella and diatoms. these can be eaten by the fish. and if the water is free of heavy metals, the fish should be eaten by man. or pets. the fish would grow very fast. we have a unit being used in Roarke, India. and in 10 weeks, the fries have grown to fish that is over 250 grams.