(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.