When farmers use pesticides in their fields, they can end up killing far more creatures than they intended, for example:
- Pesticides kill many useful insects, including: a) insects that attack and kill pests, b) insects that help to pollinate fruit trees, c) insects that produce honey, d) insects that can be consumed by man.
- Pesticides kill many kinds of fish that live in ponds, rivers, irrigation canals and paddy fields. It is possible to produce rice and fish in the same field, but only if farmers stop using pesticides.
- Pesticides kill frogs, lizards, turtles and snakes. These creatures have an important role to play in maintaining the balance of nature.
- Pesticides kill birds and mammals, either by directly poisoning them or eliminating the smaller creatures that they eat.
Many people have noticed the decline in wildlife in Thailand. There are 48 species of mammals and more than 100 species of birds on the endangered list. These animals could disappear forever if we don’t take some action to save them. Pesticides are not the only reason for this problem; the destruction of our forests is also responsible. But by putting thousands of tonnes of poison into the environment we are certainly making the problem worse. Those chemicals are contaminating the soil and the water, and some of them stay in the environment for many years.
Ecology is the study of relationships between different plants and animals, and between living and non-living components of the natural world. An ecosystem is a group of these components that are interacting with each other. An agricultural ecosystem includes everything we can find in the field: sunlight, soil, water, plants, worms, insects, frogs, and so on.
When farmers use pesticides, they are not just killing certain insects, they are introducing poisonous chemicals into an ecosystem. These poisons often have a negative effect on processes that help keep the environment strong and healthy. Pesticides kill useful creatures and upset the balance between different species. Some of these chemicals can stay in the environment for many years and get passed from one animal to the next.