Controlling “Parthenium” or “Congress Grass” (September Week 2(2005))
Times of India and Financial express reported on the campaign by The National Research Centre for Weed Science for biological control of the Mexican parthenium weed by importing beetles from Mexico.
The weed was imported into India along with the PL 480 Mexican wheat seeds in the ‘50s.. It is capable of re-growing from cut or broken parts. It has no natural enemies such as insects and diseases. It has spread rapidly all over India. The plant is known to
cause health hazards such as skin allergy, hay fever and asthma. It is said to be toxic to livestock.
One of the ways to control the weed is to uproot the plant before flowering. Spreading seeds of self perpetuating competitive plants can also reduce the plant invading an area.
The biological control method through Mexican beetle is likely to be slow. Hence this program needs to be integrated with plantation of suitable competitive plants available locally.
Interlinking rivers: is it the solution? (Issue of the week, September Week 1(2005))
V. Rajamani, Professor of Geology at Jawaharlal Nehru University has raised some valid concerns in the Hindu.
A river flows on land in response to tectonic features and climate of the region. The ecology of the land and coastal areas also exists in response to these basic earth processes.
Rivers in India, especially those flowing in the peninsula, are geologically several tens of million years old. They are mostly rain-fed, with some contribution from glacial melting to the Himalayan rivers. Therefore, these rivers have survived through major
climatic changes, monsoon variations, sea level changes, and tectonic activities. Most of them have built extensive flood plains and deltas. These alluvial plains and deltas are historically the main farmlands in India. These rivers store the excess water
in the floodplains and deltas during monsoons and release it during dry periods to maintain the minimum flow and to sustain agriculture. The geological, physiographic, and climatic set-up in India allows agriculture in low lying and groundwater-bearing floodplains
and deltas, and forestry in upland, river catchment areas. This was the practice in India till large dams began to be built in upland areas.
Interlinking of rivers requires construction of a large number of huge dams. In addition to several ecological and social consequences, this causes a near total removal of suspended sediment load from the stream flow, which would otherwise get deposited on
land through flooding. Part of the dissolved solute load (bio-available nutrients) also gets removed along with settling silt — clay-sized (less than 60 micrometres) sediments — from water flowing downstream of the dams (in river channels and irrigation canals).
Consequently, irrigation water becomes nutrient depleted and this necessitates the extensive use of chemical fertilizers for agriculture. Consequences of water pollution (both surface and subsurface) due to the use of inorganic fertilizers and pesticides and
of nutrient-depleted food on the health of the ecosystem including that of humans are somewhat known. Besides, unlike a natural river channel (bed), a canal cannot provide for ecological niches for diversity of aquatic life.
We must realise that river flooding created fertile plains, by depositing nutrient-rich sediments, which had acquired the textures and mineralogy to hold enormous quantities of water and nutrients. River flooding is a constructive geological process and not
a disaster as it is considered to be by the urbanised civilisation. Annual flooding removes the agricultural wastes/toxins, deposits nutrient-rich sediments, recharges the groundwater in the farmland, and sustains various riparian habitats. Low frequency and
high magnitude flooding makes new cultivable farmland, in addition to all of the above. River flooding, in lowland areas particularly, is good for agriculture and ecology. If all human civilisation and development are due to sustainability of agriculture then
there is no earth process that is more beneficial to mankind than natural river flooding. Flooding becomes a hazard from the human perspective when the floodplains are taken over for human habitation.
Dams in the upstream part of a river not only deprive the downstream region of its natural supply of sediments but also increases the hydraulic gradient locally. Both these factors increase the erosive power of water leading to bank erosion provided water is
allowed to flow downstream. Curtailing floods in the lower reaches amounts to virtual stoppage of natural recharging of groundwater in the cultivated floodplains and deltas. These areas in peninsular India receive much lower rainfall during the southwest rainfall
for direct recharging of groundwater. At the same time, the very same deltaic region has already been subjected to overexploitation of groundwater to maintain agricultural productivity.
The cumulative effect of all these on the landscape in terms of its vegetative cover and its potential for desertification needs to be evaluated. In regions of semi aridity with high inter-annual variability of rainfall, intense cultivation, without regard
to groundwater recharge potential, could lead to desertification. Absence of periodic river flooding in such regions would only accelerate this process of desertification.
Along the east coast of India, all major peninsular rivers had built extensive deltas on a geological timescale and, therefore, made intensive agriculture possible for the past several millennia. Delta building activities continue even today. This clearly implies
that in all cases, river action in terms of sediment transport is far more dominant than the combined action of waves, tides, and littoral currents. Damming the rivers for linking will cut down the sediment supply and this could cause coastal and delta erosion
by waves and the prevailing, south-moving, littoral longshore currents.
On a geological timescale, if not on a century or a decadal scale, this will result in a loss of productive farmland as well as in small-scale sea transgressions. If the much debated discussion on global warming and consequent sea level rise has any relevance
to the east coast, the cumulative effect of coastal erosion due to reduction of sediment supply and the sea level rise could lead to large scale sea transgressions into the developed coastal areas.
There is a strong symbiosis between marine and land life systems on earth. The hydrologic cycle provides fresh water to the land from the oceans. Water, fallen on land either as rainfall or snowfall, weathers rocks on land and picks up the nutrient elements
as dissolved solutes, and carries them through surface run-off (rivers) as well as subsurface flows to the sea. Thus the land life gets water from the oceans and the marine life gets some essential nutrients from land.
Effect on Bay of Bengal
If only little water is returned to the oceans because of interlinking of rivers, there are at least two major consequences. (1) Marine life is deprived of nutrient supply (although wind can transport mineral dust from land, which contain nutrients but not
readily in bioavailable form) and marine productivity could get adversely affected. (2) The Bay of Bengal (BoB) is uniquely characterised by the presence of a less-dense and low-saline layer of water. The presence of this low-salinity layer helps in the maintenance
of high sea-surface temperatures (greater than 28 degrees C), a requirement thought to be responsible for the intensification of summer monsoon in the BoB. It is also well known that a very large part of the Indian subcontinent gets summer monsoon rainfall
because of the development and maintenance of a low-pressure system in the Bay of Bengal.
It appears as though the BoB gets back more water from land than it gives by evaporation to maintain the low-density layer. If so, what will be the effect on the monsoon system of the river-linking project? Or, how much minimum water should be returned to the
BoB from land to maintain the low salinity layer and therefore the monsoon system? How much land water is likely to be returned to the BoB annually after the completion of all linkages? We simply do not know. If the monsoon system from the BoB slowly shuts
itself off on a decadal or a century scale in the event of land-water not reaching the sea, then rivers on the Indian continent may not exist to sustain their linkages. This is very serious. We need to generate sound and credible scientific data on the monsoon
system taking into account all possible air-sea-land-life interactions.
A very thorough scientific study on all aspects discussed above including consequences of flood mitigation, lack of sediment, water and nutrient supply in the downstream and coastal region, and more importantly in the BoB, is essential for evaluating the long-term
consequences of interlinking of rivers in India. At present most of these aspects are huge unknowns. Elementary wisdom tells us that when in doubt leave things as they are. Alternatively, we can take advantage of the knowledge available in this ever-flattening
Counting of Tigers (September Week 1(2005))
The Times of India gave prominence to the proposed tiger census. Here are relevant excerpts.
Amid doubts and scepticism, the government spent the day telling top wildlife officials from all states about the changes in the rules of the game when they get down to estimating tigers, leopards and major prey from November 2005 in a nationwide census organised
every four years. The Centre will not involve NGOs, with whom it has had a running battle on tiger counts, but states are free to do so.
It called state officials for the first time Monday to prepare them for the new census system devised with the help of the Wildlife Institute of India (WII) and decide training schedules so every state is ready to do the count-or, rather, estimation-the way
Ensnared in a tiger count controversy for much of the year, Project Tiger chief Rajesh Gopal says the entire process will be overseen by a panel from abroad. The names are still being finalised.
"It's clear we need a different method," said additional director-general (wildlife) R P S Katwal. "Anything new has teething problems but it's achievable, it's just a question of changing the mindsets of forest guards." Some officials had reservations, believing
it would need much more money, men and expertise than the Centre seemed to believe or that it may need to be modified for difficult terrain such as the Sundarbans. Centrally-funded exercise will cover all areas controlled by forest departments. It may need
more than 82,000 officials covering over 41,000 territorial beats-each beat is about 25-30 sq km. Each state will decide a period between November and February when it wants to do the census. Primary data collection will take eight days.
Each of 17 tiger states may get upto Rs 50 lakh to do the work, non-tiger states will get money for the estimation of leopards and other animals. By next June, WII scientists say they should have an accurate estimate of tigers, to some extent leopards, some
important species such as cheetal, sambhar, neelgai, wild dog and sloth bear, as well as vegetation quality and human disturbance.
Stage One consists of spatial mapping and monitoring of tigers, prey and habitat. Then, scientists will estimate density by setting camera traps and using a refined pugmark method in the mark-recapture framework. They won't take casts of pugmarks but photograph
them. Densities will be correlated with relative abundance and scientists will come up with a range-an upper and lower limit, with scientists taking the middle number. Within reserves, scientists would like to monitor numbers annually, maintaining photo IDs
Plastic ban is alright, but the alternatives don’t look brighter (September Week 1(2005))
A week after the government pronounced a blanket ban on plastic bags and pouches of all thicknesses, consumers are not the only ones unsure of how their lives will change. Retailers of high-end cloth stores, too, are in the dark over the implications.
‘‘We use virgin-quality plastic for milk pouches that you will never find clogging drains because of their high recyclable value,’’ says R S Sodhi Chief General Manager of Gujarat Co-operative Milk Marketing Federation (GCMMF), whose marketing unit Amul supplies
25 lakh litres of milk per day to the city.
‘‘Does Mumbai want to go back two decades when less hygienic, costlier milk bottles were used?’’ he asked.
His view was echoed by Chief Executive Officer of Pantaloons, Kishore Biyani. ‘‘It does not make economic sense to revert to using paper bags which will be three to five times more expensive. The consumer will have to bear the cost.’’ Pantaloons has not yet
taken any step to substitute plastic carry bags.
As the proposed ban allows manufacturers to continue production for sale outside the State, it is the retailers who are caught in a bind. ‘‘We have sent a letter to the chief minister seeking a review of this blanket ban. We will try to meet and convince him
to consider doing this in phases,’’ said Gibson Vaidmani, CEO Retailers Associaition of India.
Though the State’s proposal was announced on August 26, it is yet to be notified. A month will be given for appeals and suggestions after the notification before the proposal can be made a law.
Kunkis helping in reducing man-elephant conflict (September Week 1(2005))
The Assam Tribune reported the on the continued practice of using “Kunkies".
Groups of tame elephants called kunkis have been able to lower the raids made by their wild cousins into some areas situated on the north bank of the Brahmaputra. The novel measure was implemented as part of the Human Elephant Conflict Mitigation Strategy,
under the North Bank Landscape Project of the World Wildlife Fund (WWF).
The number of persons killed by wild elephants in Sonitpur district was more than 25 in 2003, while the number of elephants killed was close to 30 in 2001. The fatalities dropped after the kunkis were introduced last year. That year the number of persons who
died was less than 15, while 10 elephants were killed.
The kunkis are at the core of the anti-depredation squads, which have been formed with support from the WWF. The State Forest department is in charge of the tame elephants, which have been stationed in strategically chosen places where frequent elephant raids
Till now, 50 anti-depredation units have been formed, which comprise forest staff, searchlights, sound generators and mahouts manning the kunkis. More than 213 raids have been conducted to prevent wild elephants from causing damage to human settlements.
The operations are planned in meticulous detail with information about appearance of wild elephants being relayed to forest department and local people. The kunkis then proceed to the site that needs to be protected. The presence of the kunkis along with artificial
lights and sounds has a restraining effect on the wild elephants.
The majority of the people residing in the areas of human elephant conflict have appreciated the work of the anti-depredation squads. The Forest department also seems to have found a proven method to halt the threat from wild elephants, which had eroded public
support for them.
However, the results of the effort are yet to be seen in other areas. Even within the Sonitpur district, there are areas, where shortage of manpower and kunkis has inhibited anti-depredation drives. Recently, training was imparted to members of the anti-depredation
staff so that their skills could be better utillised under trying circumstances.
The North Bank Landscape in Assam has lost out close to 65 per cent of forests between1972-2004.
Bhitarkanika forest officials on save mangrove mission (September Week 1(2005))
The Pioneer did a story on the dying mangroves of Orissa.
In an effort to retain the fast decaying mangrove cover in Bhitarkanika, due to biotic pressure and man-made threats, the Forest Department has started regenerating mangrove in the coastal patches of Kendrapara.
Locals have destroyed the thick mangrove cover and converted it into paddy fields, using it for fuel-wood, honey, medicine and timber.
Rs 55 lakh, funded by the Orissa Government, was spent by the Forest Department in the past three years in planting mangrove species in 564 hectare of land at coastal patches of the district, informed a Rajnagar (mangrove) forest official.
As per official sources, the State Government provided funds to plant mangrove vegetation in coastal pockets to save the coastal ecology and to save the flora and fauna of the Bhitarkanika National Park.
Mangroves protect the coast and its nearby areas from the wrath of nature as they stand as a barrier against all natural calamities and prevent soil erosion and protect watershed at river mouths and seashores.
Mangroves have the capacity to check erosion as its deep-root system acts as a barrier against tidal waves and sea currents.
Due to depletion of mangrove forests, the coast and its nearby areas have become susceptible to natural disasters. This has led the Forest Department regenerate mangroves in these areas, official sources said.
According to official sources, the 262.5km-stretch mangrove forest of Bhitarkanika, the second largest in the country, next to Sunderban in West Bengal, is fast vanishing.
These forests, which were once enriched with flora and fauna, are being subjected to mass destruction due to excessive human settlements and mushrooming prawn farms.
Mangroves also play an important role in the growth of estuarine fishery resources. The decaying twigs and leaves make the soil more porous. But due to the decrease in mangrove vegetation, land has already lost its fertility and turned barren in coastal pockets.
Mangroves also treat the effluent, which come from fertiliser factories, by absorbing the nitrates and phosphates and reducing the salinity of the riverbanks and shores, informed the DFO of Rajnagar Forest Division, AK Jena.
According to official sources, the biggest reason behind decaying mangrove cover is the on-shore dollar-spinning prawn business and commercial fishing. Locals are encroaching into the forestland by denuding the green mangrove cover to earn a fast buck.