Biomagnification Lesson

Pesticides What are they used for? Chemical substances used to kill insects that eat crops or cause disease

How do Pesticides end up in the environment? 1. Absorbed by crops 2. Surface runoff into lakes and rivers 3. Vaporized into atmosphere; returned by rainfall

Define bioaccumulation. Persistent Organic Pollutants Bioaccumulation= accumulation of substances (often chemicals) in an organism

Bioaccumulation Normal process how organisms accumulate minerals and nutrients in our bodies (fats, carbs, etc.) Also how we store toxins (poisons) in our bodies

Biomagnification Activity 1. You have a card on your desk determining your trophic level. 2. Write down your trophic level where it says assigned organism in your table. 3. You are to “eat” the prescribed number of the organisms below you by finding the people who are the trophic level below you (producers must obtain water from the different water sources around the room).

Biomagnification Activity 4. Write down the amount of toxin (ppm) gained from each organism you eat. Add up the total in the column at the bottom. Only eat as many as the card tells you to. 5. When you are done, write your total ppm gained on the board under your appropriate trophic level. Then, have a seat and wait until everyone else if finished. 6. You can start on the DDT reading while you wait.

Example: SECONDARY CONSUMER 100 ppm Eats 5 primary consumers PRODUCER Consumes 20 gallons of water from 4 different sources

Amount of Toxin Attained from Organism (ppm) Your Assigned Organism: Organism Eaten Amount of Toxin Attained from Organism (ppm) 1 2 3 4 5 6 Total ppm: (Add up all ppm)

Total PPM Producer Primary Consumer Secondary Consumer Tertiary Consumer 1 2 3 4 5 6 7 AVERAGE: What do we notice about the amount of toxin as we move up the food chain?

Biomagnification Tendency of toxins to concentrate in organisms at higher trophic levels Due to eating small organisms with small amounts of toxin present

DDT Reading You have 10 minutes to read through the Case Study and answer the 6 questions. We’ll discuss the answers in 10 minutes.