BIOACCUMULATION

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BIOACCUMULATION

• Lauren Campbell

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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.

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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.

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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.

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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.