One way that food webs can be disrupted is through the accumulation of toxic materials along food chains. This happens when organisms lower down in the food web are exposed to harmful substances like pesticides.
These toxic materials can then be passed up the food chain as they are consumed by higher-level organisms. This phenomenon, known as bioaccumulation, can have devastating effects on entire ecosystems. It can lead to declines in population and even extinction of certain species.
A good example of this can be seen when pesticides are used in agriculture and get passed along the food chain. In this case, spraying pesticides does not only cause damage to the targeted pests. It also harms other organisms.
Let’s look at an example:
The pesticides are transferred along the food chain. This happens because these substances are not easily excreted by organisms and therefore accumulate in their bodies over time.
The animal at the top of the food chain, which is the eagle, will consume the highest concentration of pesticides. This is because it feeds on lower-level organisms that have already accumulated pesticides.
The accumulation of pesticides can make the eagle sick, which can lead to death. Also, these pesticides can affect various other organisms in the food chain, which can lead to the extinction of certain species.
DDT is an insecticide that kills and repels mosquitoes. It was widely used to reduce the spread of malaria, as well as in crop fields. However, DDT is a toxic material that can pass up the food chain from insects to small birds. This can lead to the death of many predatory birds.
As the organisms in a food web are dependent on each other for food, the accumulation of DDT can have a disruptive effect on the ecosystem. If one of the species in a food web is wiped out, the whole web can be affected. This is one of the reasons DDT has been banned in many countries.