Wednesday October 7 th In Notebook Identify a

Wednesday October 7 th In Notebook: Identify: a primary producer, primary consumer, and secondary consumer.

Today’s Learning Targets Agenda: 1. Formative Assessment 2. Ecological Pyramids 3. Bioaccumulation/Biomagnification

Food Web vs. Food Chain

Write. Share. SHARE! Interpret these pyramids. Do you think these pyramids depend on each other or are they independent? What trends do we see in common for all these pyramids?

Biomass Pyramid • The total mass of living matter at each trophic level • Why is there more biomass in the lower trophic levels and less biomass in the higher trophic levels?

Energy Pyramid • Shows trophic (feeding) levels and energy available to each level – 10% energy gets passed to each level – 90% energy lost (living/respiration)

Example: Fill in the levels of the food chain with the energy passed on. 10, 000 J of energy

Example: Fill in the levels of the food chain with the energy passed on. 750, 000 J of energy

While transferring energy what else can be transferred? ? . . .

Bioaccumulation vs. Biomagnification • Bioaccumulation = the accumulation of a contaminant or toxin in or on an organism from all sources (e. g. , food, water, air) – accumulate in living things and stored faster than they are broken down or excreted • Biomagnification = the increase in concentration of toxin as it passes through each level of the food web

What affect does _____ have on biomagnification? Trophic Level Life Span Lactation Write. Share. SHARE!

Example: • • DDT: a pesticide used for mosquito and pest control • In animals DDT is metabolized to DDE, which is stored in fatty tissues and is insoluble in water. • Banned in U. S. A. in 1972 Damage from DDT: reproductive failure (birds have thinning eggshells), immune system problems, nervous system damage, death

Biomagnification of a DDE in Aquatic Environment Amount of DDE in Tissue Level Tertiary Consumer 3 -76 µg/g ww (fish eating birds) Secondary Consumers 1 -2 µg/g ww (large fish) Primary Consumers (small fish) Primary Producers (algae and aquatic plants) 0. 2 -1. 2 µg/g ww 0. 04 µg/g ww

What does this mean for us? Watch where your food comes from!

Practice! • Use the following information to construct a food web in a meadow ecosystem: • Red foxes feed on raccoons, crayfishes, grasshoppers, red clover, meadow voles, and gray squirrels • Red clover is eaten by grasshoppers, muskrats, red foxed, and meadow voles • Meadow voles, gray squirrels, and raccoons all eat parts of the white oak tree • Crayfishes feed on green algae and detritus, and they are eaten by muskrats and red foxes. • Raccoons feed on muskrats, meadow voles, gray squirrels, and white oak trees. • Identify all of the herbivores, carnivores, omnivores, and detritivores in the food web. • Describe how the muskrats would be affected if disease kills the white oak trees.