Bioaccumulation Lesson 6

Bioaccumulation An increase in the concentration of a chemical in an organism over time, compared to the chemical's concentration in the environment. Occurs naturally And necessary for certain minerals and macromolecules

Bioaccumulation Problematic when bioaccumulate are toxins Common toxic chemicals in our environment: Mercury mad hatters, tuna DDT  insecticide, 1970’s,eagles Lead  gasoline PCB whales & belugas Strontium 90 – fallout from atomic bombs

Biomagnification The increased concentration of a toxic chemical the higher an animal is on the food chain. The higher an organism on the food pyramid the larger the concentration of chemicals

Example Suppose an osprey eats 300g of fish per day. The fish tissue consumed by the osprey has an average DDT concentration of 0.0001g/g. How much DDT is the osprey consuming in one day?   300g of fish x 0.00001 g/g of fish = 0.0003g of DDT per day for the osprey

Now, suppose a bald eagle also eats 300 g of food per day Now, suppose a bald eagle also eats 300 g of food per day. But, the bald eagle eats seal carcasses that have washed up on the beach.   The seal had eaten fish-eating fish with 0.0001g/g of DDT in their tissue. Much of the seal’s body is made up of blubber, and DDT bioaccumulates in the seal. So, the seal now has 0.0002 g/g of DDT in its tissue.

If the bald eagle eats 300 g of seal, how much DDT does the bald eagle consume in one day? 300g of seal x 0.0002 g/g of seal= 0.06g of DDT per day for the bald eagle

What is Mercury (Hg) Hg is a silvery, liquid metal at room temperature "heavy metals." Like water, Hg can evaporate and become airborne. Because it is an element, mercury does not break down into less toxic substances. Once mercury escapes to the environment, it circulates in and out of the atmosphere until it ends up in the bottoms of lakes and oceans.

Where Does Mercury Come From? Mercury is a naturally occurring element. Mercury ore - cinnabar - is mined

Mercury enters the environment from: Natural sources such as volcanoes and the weathering of rocks; Our intentional uses of mercury; Our unintentional releases of mercury from burning fossil fuels and smelting metals. CFL E-waste

Questions: In your own words, explain what bioaccumulation is How does biomagnifications Develop a food chain for the James Bay low lands that could potentially have biomagnifications happening.