BIOACCUMULATION Lauren Campbell
What Is Bioaccumulation? • Bioaccumulation is the build up of a biological substance in organisms. This can happen at any trophic level. • In farming, some pesticides are not biodegradable, so are unable to be broken down by microbes in the soil. • The pesticides build up in soil, water and organisms.
Why Does It Happen? • The pesticides build up in the soil, so are absorbed by plants. • The plant gets eaten, and the pesticide gets passed along the food chain. • The pesticides can also get into rivers and streams via runoff from the fields, so the pesticide gets into the aquatic life as well.
What Are The Effects Of Bioaccumulation? • At each link in a food chain, the amount of pesticide is magnified- each trophic level needs to feed on a larger biomass to get enough energy. • The concentration of pesticides is also magnified by solubility in fatty tissues and storage. When organisms need to use their fatty tissues, the pesticide gets released into the system of the organism, and can cause death. • The pesticides are toxic to living organisms, so the magnification of the pesticide is the strongest at tertiary consumers- the pesticide can be immediately toxic, causing death, or affect the reproduction of organisms.
How Can Bioaccumulation be overcome? • To overcome bioaccumulation, farmers can use biodegradable pesticides, so there will not be a build up of the pesticide in the soil. • Farmers in developing countries often experience the pests becoming resistant to the pesticides, so use more. To overcome this problem, farmers should use a different pesticide, not apply more.