Lichens, what are Lichens? These are the small round patches, slightly off colored green in the bark of trees in your backyard. They seem profuse in wet months and become dry patches during the summer.

Lichens are actually a combination of a fungal partner (mycobiont) and an algal partner (phycobiont). The fungal filaments surround and grow into the algal cells, and provide the majority of the lichen's physical bulk and shape.

Lichens can grow in soil, rock, or even the barks of trees.  It absorbs certain mineral nutrients from any of these substrates on which it grows, but is generally self-reliant in feeding itself through photosynthesis in the algal cells. Thus, lichens growing on trees do not feed on them like parasites on the trees.

Lichens are indicators of the health of an ecosystem in tropical regimes like our islands, the more the lichen load (in trees etc.,) the more robust is the nutrient cycle of that ecosystem. Several studies have shown serious impacts on the growth and health of lichens resulting from factory and urban air pollution. Because some lichens are so sensitive, they are now being used to quickly and cheaply assess levels of air toxins in Europe and North America.

Andaman & Nicobar Islands have a healthy ecosystem, when compared to other parts of our country. Lichens were seen even in the barks of road side trees of Port Blair city until recently. Though it still exists, of late it seems that Lichens are disappearing from the city limits. This is a matter of concern as they indicate the health of our eco system.

- Amlan Dutta, Ecologist

Pest control is one of the major problem in agriculture. Pesticides are widely used chemicals in the world for more than half a century to control the pests or insects that prevent the crops and on the other hand destroy, repel or mitigate any pests. Insects not only kill the crops but also sometimes humans by acting as a disease carrying agent. However, during the past decade, the use of chemicals increased steadily in the developing countries to enhance food production and to control vector-borne diseases. Although the use of most of the pesticides such as technical DDT and HCH were banned worldwide, illicit use of these chemicals still exist among few farmers and also regionally. In addition, the accumulation of these chemicals in the earth remain for a long-term, polluting the top soil. DDT is a well known, persistent and highly lipid soluble organochlorine pesticide. It was widely used to fight insect-borne diseases like malaria until legislative restrictions were imposed following the manifestation of ecological impairment. The low chemical and biological degradation, lipophilic nature and hydrophobicity have led DDT to accumulate into the biological tissues. In 1996, the World Health Organisation (WHO) assessed the acceptable daily intake for DDT from number of countries and found India as a largest consumers of DDT in terms of daily intake. In India, DDT has been used to control malaria since 1946. Due to awareness towards environment, measures were taken to control the use of this pesticide. The DDT applied for agriculture, not only accumulates into the sediment, but also contaminates water resources and through bio-chain it gets more concentrated (bio-magnification) and finally reaches humans. Especially, the coastal marine environment receives considerable input of DDT from various anthropogenic sources such as direct discharges or indirectly from river flows, runoff, as well as from long-distance transport through the atmosphere. The pesticides that reaches ponds, rivers, coastal oceans due to rain and runoffs affects the egg and sperm development, accumulates, initiates mutations in animals living in the aquatic environment. The concentration of DDT has significantly reduced after the ban on use of it in the year 1970, although it still remains as various of the environment such as air, sediments, fish and mammals and becomes a threat to human health. In humans, it is stored in the body fat and is excreted in the milk and reaches the infants from the time of birth. As, DDT persists for a long time in the community, the fear on adverse effects in future generations, metabolism and growth also exists. In India, we expect the day of real ban on the use of such chemicals like DDT. The use of such chemicals not only diminish the quality of the product but also the health of ours and future generations.

Contributed by: Dr. Arockiya Vasanthi, Scientist, NIOT.

In olden days, the area or land used for agriculture was high and the population it feed was less. Our forefathers used only the 'muck' as fertilizers and have enjoyed a healthy life by consuming a healthy food of quality and quantity. Muck is nothing but the moist farmyard dung or soil containing decaying plants, vegetables etc. or manure. Those days there were no fertilizers, pesticides, growth inducers or promoters to avoid pests or to increase the crop yield. Though, we have to accept the truth that our previous generations were healthy than what we are now, after modern science and technologies with introduction of new chemicals to kill insect pests and promoters for fast crop growths. The present system of agriculture has achieved an increased yield compared to older farming practices. But, the chemicals that we use for the crops not only affect the health of consumers (we) but also destroys the nature of the soil forever. Sometimes, over use of pesticides poison the land and nothing else will grow thereafter. So, what we can do to avoid this chemical accumulation in soil ? 1. Analyse your soil nutrients that is of less cost, so you will come to know which nutrient is deficient in your soil. 2. Do not go for repeated cultivation of same crops. For example., If you cultivate paddy in your field, once you harvest, sow some cereals and other pulses that are nitrogen-fixing crops. Crop rotation is the replenishment of nitrogen through the use of green manure and will improve your soil structure and fertility of the soil. 3. Go for organic methods of soil enrichment such as muck-spreading. They are actually cheap than any other growth promoters available in the form of chemicals in market. It even have the power to rejuvenate the soils destroyed by chemical intensive agricultural practices. 4. A recent and widely used method in organic farming is the soil re-mineralisation using finely crushed rocks (rock dust) that contain minerals and trace elements. The rock dusts are rich in silicon, potassium, sulfur, manganese, phosphorus, zinc, calcium, copper, cobalt and other necessary elements for soil enrichment and crop growth. Appropriate use of these methods will certainly give fruitful results in quality crop production as well save our earth from chemical pollutants. 

Contributed by: Dr. J. Benjamin Franklin, Scientist, NIOT, Port Blair.

Deposits for Drinks in One-Way Drinks Packaging's

We Indians follow the British or Europeans in few aspects like using their dress code that doesn't suit our climate or western style of living that ruin our tradition. However, we never obtain or follow certain excellent stuff they do. Only in the past few years we realized that dumping of  plastic wastes will spoil our own ground.  Although, the Indian government struggle to prevent soil ecological pollution, we do not have a systematic scheme or policy from our own ground to succeed. The government says no to plastic bags, what is the alternate they provide?. Is it a paper bag as it is biodegradable? do they want to cut all the trees to make paper bags to escape from pollution by plastics in the soil? or the alternate cloth bags that has no ability to hold fluid items (but these bags could be used for other shopping purpose). Although we ban plastic carry bags, still lot of plastic materials as food and beverage empty packages are thrown every day into the trash. In Europe, a systematic scheme called "Compulsory Deposit" governed by 'Deutsche Pfand System GmbH' is organized from 2003 for the collection and deposit clearing of compulsory-deposit of one-way drinks packaging's. The DPG Deposit Scheme supports retailers and drink industry to fulfill the legal requirements of its nation. In these 9 years period they have developed this scheme into a perfect system by making many amendments. This system also mentions about which drink contents in which one-way drinks packaging require a compulsory deposit. They have classified the drinks in to four as 1. Soft drinks (carbonated & non-carbonated), 2. Beer bottles, 3. Mixed alcoholic drinks and 4. Water bottles (carbonated and non-carbonated). Retailers offering only non-reusable drinks packaging's are entitled to draw the attention of their customers to the fact that they do not collect reusable drinks packaging's or drink crates. Non-reusable drinks packaging's made of those types of materials such as glass, plastic, metals, PPK  in the range should be recollected by the retailer regardless to the fact whether it has been sold by him or by his competitor and to refund a small amount for the deposit. In Germany, the reverse vending machines that accepts used beverage containers and returns money to the users were installed in all departmental stores and nowadays we can also see in the road sides of Europe, Japan and many other developed countries in addition to dust bins. People while going for purchase they use to take all empty or used cans to let it recycle also get money for the cans that could be used for their purchase. The mechanism of the reverse vending machine is, when it receives the bottle, it scans, identifies and process it by crushing it to avoid liquid spillage and to increase storage capacity. In India, we do have a scheme in the same name as 'Compulsory Deposit Scheme' (22nd May, Act, 1963) not for the cause of secure environment but to develop nations economy from tax payers. We could also develop such well planned system to keep our environment clean. As a settlers or people living in this pristine Islands, we have less space than our main land to dump non-degradable materials. If you go around our coast during high tide you can see thousands of empty bottles floating on the shore side. Also, in the beach, you can see the broken glasses of alcoholic bottles that could hurt beach walkers or create a feel of discomfort to foreigners and tourists. Especially these broken glasses tear the foot of the children playing in beaches. Practically speaking even if you teach people for a long-term about pollution and the effects of pollution due to dumping of non-degradable materials in the land, they will never stop doing that. But when it is legalized by a organizational framework of the Government, along with a small reward for every deposit, certainly  the mind of people will change and they will keep the environment clean. In India, Bisleri International Pvt Ltd and Inorbit Mall were the first to start a PET bottle collection center in Inorbit Mall,  Vashi, NavyMumbai on 14th February, 2012. That event has also marked the inauguration of India’s first ever plastic bottle recycling machine for the consumers. This kind of initiative by the Government itself will intend to provide an opportunity for the people to recycle PET bottles and be conscious of recycling and ecological sustainability.

Contributed by Dr. J. Benjamin Franklin, Scientist, NIOT