(Dr. Abdul Majeed Kak, 63, was born and in Nowhatta, Srinagar. He received his primary education from the Government Middle School in Nowhatta and his secondary school education from Bagi Dilawar Khan Higher Secondary School in Fateh Kadal. He completed his college education at the Islamia College of Science and Commerce in Srinagar. In 1977 he was the first candidate from the University of Kashmir to be selected by the University Grants Commission (UGC) of the Government of India for a doctoral research scholarship at the university leading to a Ph.D. in Botany in 1980. He is currently the Research Coordinator in the Department of Botany at the Islamia College of Science and Commerce in Srinagar. Dr. Kak has over 35 years of teaching experience and research experience of over 25 years. He has received numerous research awards resulting in publication of 70 research papers and has authored two books on Botany. He is presently engaged in promoting and strengthening local and regional museums, a project supported by a grant from the Ministry of Culture, New Delhi.)
Azolla – A Nuisance, Needs Immediate Eradication
Azolla commonly known by various names such as Red Azolla, duckweed fern, fairy moss, and water fern with about six or seven species; some placing it in its own family Azollaceae others put it in a related family Salviniaceae. Azolla resembles duck weeds locally called Mangolae, but is differs from it in structure, size and in morphology. The plant that has infested our crystal clear waters is identified as Azolla filiculoids. Occurance of A. pinnata in our water bodies has already been refuted. Azolla species are difficult to identify because of the mess created by the systematists, in merging and separating them and creating sub species. This has led to many misidentifications, confusion and thus uncertainty over correct identification. Three species Azolla microphylla, A. mexicana，A. caroliniana are regarded as synonyms of A. cristata. Similarly. A. caroliniana and A. microphylla are synonyms of the previously described A. filiculoides. The taxonomy of the New World species of Azolla has been the subject of much debate and remains unsatisfactory. A. Filiculoids is mostly temperate or subtropical water fern compared to A cristata which is mostly tropical, less suitable for our temperate conditions. A. cristata is restricted in distribution compared to A. filiculoids which is cosmopolitan, easily infests new regions when carried by agents like water fowls and other migratory birds. The only ultramicroscopic difference between the two is that in A. filiculoids the hair like projection with the hooked tip (glochdia) arising from the mucilaginous extension (massulae) surrounding micro and megaspores and helping in buoyancy is up to 2 septa, while in A. cristata it is sometimes above two septa. It can be an ecological variation and is of less importance. Our main goal is the eradication or to keep this alien invasive under control so that it will not further add stress to our water bodies which are already debilitated.
Azolla, is an invasive alien noxious water weed that has recently invaded our water bodies with prolific growth and has formed thick deep green or red mats in every nook and corner of all valley lakes .This year it was also reported in Manasbal lake for the first time. Its early stages are green, but gradually turn red when continuously exposed to sunlight and reaches to maturation stage producing sporocarps.
Azolla though noxious and a health hazard is not harmful in many parts of the world but has been made beneficial to the aquatic environment in many ways. It was used as green fertilizer since times immemorial in Asia particularly in China from 540 AD (Chinese book of Agricultural techniques). Cynobacterium (Anbeana azollae) living as a symbiotic within thallus of Azolla helps to fix atmospheric nitrogen, converting it to ammonia and then nitrates, so it was used in paddy fields in European and African countries to increase rice yield. It is a beneficial biofertiliser and has many advantages over chemical nitrogenous fertilizers, being cheap, natural, safe and sustainable. Besides it also supplies additional nutrients to the crop and also improves soil structure. There is no run off to harm environment unlike chemical fertilizers. It is much helpful to remove nitrogenous compounds and being capable of absorbing heavy metals like lead and zinc from waste waters as well as from the environment. There are many other uses of Azolla such as it is the best livestock feed, supplement for cattle, chicken and ducks. When its thick layer covers the surface of water, it prevents mosquitoes to lay eggs and their larvae to breathe, hence also called mosquito fern. It is also considered as aesthetic plant and is cultivated in park pools because of its seasonal green or red colourations. It is also food source to various water fowls, insects, worms, snails and various crustaceans, besides providing them shelter. Thick mats of it also restrict exotic aquatic weeds to flourish. But why is it detrimental in the valley and has negative effects in our water bodies, multiple reasons are responsible for it.
1. It was reported for the first time in 2004 (Ref. GK, entitled “Dal – One more blow.” Oct.19th. Page 6th,) wherein LAWDA authorities at that time and scientific and monitoring wing was made aware about the impact and destruction of this alien invasive weeds on our water bodies in coming years if let it grow un noticed, since then no responsible officials of authority, nor any Government official has bothered to pay heed to our yelling and repeated suggestions for its eradication or to keep this noxious weed under control. Besides no practical steps were taken for the protection, conservation or restoration of our internationally reputed lakes, which are backbone to our state economy. Deaf ear was paid to the shouting of many respected citizens of state, national or international personalities who too have recorded their pain and agonies after seeing pathetic condition of these lakes. Every year money in truck loads is buried in some unknown corner of the Dal Lake. Practically no conservation or any improvement has taken place in our water bodies which are shrinking from all corners and rapidly from their centers as countless floating islands are arising by dumping thick layers of Azolla along with other weeds and lake a basin, first preparing vegetable gardens and then converting into residential places or for other business establishments fearlessly.
2. There is no check of effluents, garbage and solid wastes of more than forty thousand people living in the interior of Dal and Nageen lakes that is directly dumped in the lakes, besides sewage and discharge from the 700 house boats which has completely changed water chemistry for the past decade or two. This has resulted in addition of nutrients in the lake particularly essential nutrients like nitrogen and phosphorus that has benefitted Azolla to bloom. This is the reason that it grew at such a fast speed doubling its biomass within 3-4 days and leading to eutrophication.
3. No scientific method was implemented or even tried for the past 8 years to check, control or to eradicate this noxious weed by Lake Authorities. They are mere spectators with their folded hands. The engineering wing is active in selecting and procuring the modern machines for de-weeding and apparent cleaning in a particular portion of the Dal Lake only leaving its Nigeen basin as such where lot of deterioration has already taken place. Many a times whenever we were on exploration in these water bodies it was noticed that the drivers are sleeping and the machines are stand still to save the fuel as much as possible.
4. Cash crop Nadur (lotus) is cultivated on war footing basis (being highly profitable) has further added misfortune and stress by hindering water movement. The water remains stagnant, or moves at snail’s pace paving ways for putrification and deterioration and leading to eutrophication and helping in the rapid growth of Azolla. These thick mats of Azolla further help in creating obstruction to all inlets and outlets of the lakes. Nobody takes a serious note of it.
5. Azolla in our water bodies is highly detrimental. Its thick covering causes deoxygenation that is fatal to the underwater organisms, like fish and other aquatic plants and animals. No light penetration means no photosynthesis, respiration leading to the ultimate death of many valuable, nutritional and medicinally important plants. Live example is what happened to 30,000 fish in Nageen Lake recently. Later death and decay of many other weeds causes foul smell and effects the whole population residing nearby.
Countless articles and lot many suggestions have been frequently written for the general awareness of the common man, politicians, bureaucrats and custodians of these lakes with this intension to make them well aware about the importance of our prestigious water bodies that are shrinking every second by the cruel hands of merciless influential people and politicians. Let us forget tourist industry and lake products for a while, on which millions of people earn their bread, we have to ponder for our sustenance and the sustenance of our posterity, for its water. Presently six water pumps are sucking the water from Dal Lake supplying it to the city and the adjacent area. It is evident that the time is approaching when this majestic lake will turn into housing estate.
A few of the suggestions that I want to convey to lake authorities and the concerned officials that must be necessarily taken are mentioned below. These are in addition to what has already been suggested in various local dallies.
This obnoxious weed can be controlled by mechanical means by putting barriers at various places, particularly near lake shores and inlets, so that it can be collected with the help of water and air currents and then removed either by machines, big meshes or flushed out by first raising water level of the lake. This technique although adapted by LWDA has not remained successful, because of lacking basic scientific knowledge; sporocarps along with spores after their formation immediately sink to the bottom, remain dormant then germinate after the resting period. Surface removal should be frequent, continuous, so that little chances are provided to the weed for the formation of spores. Removal should be extremely careful because the fragile plants break into various parts each segment regenerates into a new adult plant. Surface removal or flushing out just once or twice a year is not sufficient.
Azolla can be controlled by the application of some permissible chemicals effectively applied to control this weed. Chemical Asulam (as Asulox) is quick effective herbicide and Azolla is highly susceptible to it but this chemical is not permissible to be used in the potable waters. Diquat or Glyphosate when spread over the fronds of Azolla has proven effective, Diquat (as Reglon) burns Azolla and other weeds but does not kill it but glyphosate kills all weeds even other emergent macrophytes. This is possible only when the thick mats of Azolla are collected at various vulnerable points by providing barriers and these permissible chemicals spread repeatedly before the formation of sexual spores. It should be handled and monitored seriously by expert scientific hands till every spore that germinates and floats on the surface gets effectively eradicated.
Biological control is one of the cheapest and most effective method for eradication or controlling A. filiculoids. Tiny insect Stenopelmus rufinasus, called weevil is host specific. This has scientifically proved successful in S. Africa and N. America. It is an easy biological agent to control Azolla. It feeds, reproduces quickly and completes its life cycle on this weed, generation after generation. Once weevil is released on Azolla little or no maintenance is required. It is inexpensive and most environmental friendly. It can control Azolla throughout the season. This technique can be applied easily by only one operator.
Weevil is monophagous, that means it feeds, reproduces and completes its life cycle on a particular species, so when infested on Azolla en mass, weevils are highly devastating. They reproduce vigorously within a short period of time, and its population can reach up to several millions. All stages of its life, adult and larvae feed on Azolla voraciously. Only care is to be taken for weevil during winters, to protect the seeds for next generation. Why doesn’t LWDA or State government apply above methods in our precious water bodies instead spending such huge amount is a debatable question.