Biomagnification Biology

When we try to pick out anything by itself, we find it hitched to everything else in the universe. John Muir When we try to pick out anything by itself, we find it hitched to everything else in the universe. John Muir

Biomagnification Definition: Definition: Biomagnification, also known as bioamplification, or biological magnification is the increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain Biomagnification, also known as bioamplification, or biological magnification is the increase in concentration of a substance, such as the pesticide DDT, that occurs in a food chain

Biomagnification Through the Food Chain

Energy Available to Consumers at Next Trophic Level Energy Lost by Respiration Energy Lost by Death and Decay Energy Lost by Excretion Energy Lost by Egestion of Feces Energy Ingested

Food Chain Example Let’s look at our food chain to see how biomagnification works: Let’s look at our food chain to see how biomagnification works:

Food Chain Let’s say, for example, that each piece of plant material has one microscopic drop of methyl mercury. Let’s say, for example, that each piece of plant material has one microscopic drop of methyl mercury.

Food Chain One insect eats 25 pieces of plant material, that would mean that each insect would have _______ microscopic drops of methyl mercury in its body. One insect eats 25 pieces of plant material, that would mean that each insect would have _______ microscopic drops of methyl mercury in its body.

Food Chain If one small fish needs 10 insects to live, then one fish would have _____ microscopic drops of methyl mercury. If one small fish needs 10 insects to live, then one fish would have _____ microscopic drops of methyl mercury.

Food Chain One big fish eats 5 small fish to live. So, one big fish would collect a total of _____ microscopic drops of methyl mercury in its body. One big fish eats 5 small fish to live. So, one big fish would collect a total of _____ microscopic drops of methyl mercury in its body.

Food Chain What about you and me? Lets say we eat 1 big fish a day for 3 days. We would collect total of ______ drops of methyl mercury in our body over the 3 days. This is how biomagnification works! What about you and me? Lets say we eat 1 big fish a day for 3 days. We would collect total of ______ drops of methyl mercury in our body over the 3 days. This is how biomagnification works!

Food Chain Now let’s say that methyl mercury makes living things sick. The more methyl mercury in the living organism, the more sick it would get. From our example above, which organism will be most affected by the toxin methyl mercury? Now let’s say that methyl mercury makes living things sick. The more methyl mercury in the living organism, the more sick it would get. From our example above, which organism will be most affected by the toxin methyl mercury?

Other Organisms Affected by Biomagnification

Peregrine Falcon The Peregrine Falcon became an endangered species because of the overuse of pesticides such as DDT during the 1950s, 60s, and 70s. Pesticide biomagnification interfered with reproduction, thinning eggshells and reducing the number of eggs that survived to hatching. The organochlorine build-up in the falcon's fat tissues resulted in less calcium in the eggshells, leading to more fragile eggs. In several parts of the world, such as the eastern USA and Belgium, this species became extinct as a result. The Peregrine Falcon became an endangered species because of the overuse of pesticides such as DDT during the 1950s, 60s, and 70s. Pesticide biomagnification interfered with reproduction, thinning eggshells and reducing the number of eggs that survived to hatching. The organochlorine build-up in the falcon's fat tissues resulted in less calcium in the eggshells, leading to more fragile eggs. In several parts of the world, such as the eastern USA and Belgium, this species became extinct as a result.

Bald Eagle

Once a common sight in much of the continent, the Bald Eagle was severely affected in the mid-20th century by a variety of factors, among them thinning of egg shells, attributed to the use of the pesticide DDT. DDT itself was not lethal to the adult bird, but it interfered with the bird's calcium metabolism, making the bird either sterile or unable to lay healthy eggs. Female eagles laid eggs that were too brittle to withstand the weight of a adult. Once a common sight in much of the continent, the Bald Eagle was severely affected in the mid-20th century by a variety of factors, among them thinning of egg shells, attributed to the use of the pesticide DDT. DDT itself was not lethal to the adult bird, but it interfered with the bird's calcium metabolism, making the bird either sterile or unable to lay healthy eggs. Female eagles laid eggs that were too brittle to withstand the weight of a adult.

Pesticide Resistance In the beginning, most pests were sensitive to DDT but a few were resistant The resistant forms survived and reproduced In the end, most pests were resistant to DDT

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