DDT Pesticide Effects on Ecology

DDT (dichloro-diphenyl-trichloroethane):

DDT (dichloro-diphenyl-trichloroethane) pesticide was introduced after the Second World War. It was effective for the control of insects like mosquitoes which transmit malaria. DDT prevented the deaths of many people by killing insects which cause endemic illnesses like Malaria. Perhaps for that reason it became a popular product for farmers who were not aware of the damage caused by their extensive use.

DDT Effects on Nature

When DDT applied to fields, it is carried by rain into underground waters or other water supplies in the ecological system. If it is analyzed in water content the level might not be high, but aquatic organisms, especially zooplankton absorb them and reaches very high levels. Thus, DDT level gradually increases within the food chain. So that the fishes that feed on zooplankton have higher concentrations and birds are the most damaged species by DDT. The eggs of birds are born devoid of a thick covering to protect them and so when the mother is “brooding”, the shell is too weak to support the weight and the eggs hatch before the due time.

Just as DDT generates environmental problems, so does the most chemical pesticides same effect. Because they contaminate not only the vegetables but also the animals that feed on them and indirectly reaches up to the human beings.

Although we mentioned the example of DDT in an aquatic environment, it can be sampled also in land areas. Its effects are seen on the food chains and d indirectly on food producers are consumers.

Chemical pesticides affect the balance of the ecosystem by inferring in food chains ; eliminate other plant and animal species, and polluting the atmosphere. A pesticide used without control alters the characteristics of water, air and soil.

Unfortunately, many farmers don’t mind expert advices, and they use improper pesticides ignoring their side effects to the nature.

An alternative to kill pests is biological control, which is conducted by the introduction of “enemies” preying natural and reduce the number of individuals of that harmful species.

There are many companies that produce biological pesticides. One of them, thanks to the application of genetics, has managed to produce different types of bacteria to be supplemented to plants and crops. Some are intended to efficiently alter the structure of the plant. For example cotton plants treated by means such as this produces a protein that affects the digestive system of pests. Insects that bite or sting to feed die by the presence of the hormone in a few hours.

Spiders, despite being repulsive in appearance to many people, are great pest controllers and cause little damage to man.

Other Biological Control measures include the use of guard dogs to ward off or protect livestock animals, introduction of insectivorous birds, such as woodpeckers, swifts or swallows, hens, chickens, ducks, geese, etc…

Crop rotation reduces the reproduction of pests, as many of them specifically target one type of plant. if it is changed each year, the pest population will also decrease.

Why pesticides can be dangerous?

One of the most serious problems is the development of genetic resistance of “pest organisms.” When pesticides are used, many insects die, but there will always be some pests that will survive tougher and the genetic characteristics of those will be more strong against the same kind of pesticides. The pesticide used initially will do the most harm but, as time passes; future generations will be able to resist its effects. That particularly happens when farmers resort to a more effective chemical and repeat the cycle again. The danger is that the substances are increasingly toxic, generate more pollutants and may provide advantages for other harmful species and thus deteriorate the overall balance of the ecosystem. In addition, the economic cost will become higher. There will be more investment and more expensive products grown. Furthermore, pesticides will run off to streams and other inland water areas affecting their quality and altering the biology of many species of fish, birds and mammals.

A better alternative would be crop rotation. For example, first year you plant corn stripes, snuff and cotton that remove substances such as nitrogen, and the next year you plant legumes, such as beans or lentils, which adds nutrients and nitrogen to the soil through their roots. Thus, the balance is restored; erosion prevented and provided more control on pest.

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