Today, 3/13/14 Notes – Bioaccumulation/Biomagnification Operation: Cat Drop Activity Individual work Review Exit Slip Notes – Bioaccumulation/Biomagnification Operation: Cat Drop Activity Individual work Review Exit Slip

Threats to Ecosystems Agricultural practices Monocultures/ GMOs reduce biodiversity Erosion of topsoil Pesticides/ insecticides/ fertilizers Deforestation reduces primary productivity Invasive species reduce native species and disrupt natural energy transfer Increase in diseases Decrease in genetic diversity Toxins entering food chains (pollution) Agricultural practices Monocultures/ GMOs reduce biodiversity Erosion of topsoil Pesticides/ insecticides/ fertilizers Deforestation reduces primary productivity Invasive species reduce native species and disrupt natural energy transfer Increase in diseases Decrease in genetic diversity Toxins entering food chains (pollution)

Toxins Toxins enter ecosystem through human activities Agricultural practices (fertilizers, pesticides, insecticides) Prescription drugs into waterways Mining Manufacturing processes (factories) Industrial cleaners Illegal dumping Leaking underground storage tanks Etc. Toxins enter ecosystem through human activities Agricultural practices (fertilizers, pesticides, insecticides) Prescription drugs into waterways Mining Manufacturing processes (factories) Industrial cleaners Illegal dumping Leaking underground storage tanks Etc.

Toxins cont’d Toxins enter the tissues of organisms and accumulate in the organism Through the food chain the toxin is magnified in consumers in the higher trophic levels The highest order consumers are at the greatest risk (top of the food chain) Toxins enter the tissues of organisms and accumulate in the organism Through the food chain the toxin is magnified in consumers in the higher trophic levels The highest order consumers are at the greatest risk (top of the food chain)

Bioaccumulation Bioaccumulation: The buildup of toxic substances in the bodies of organisms Occurs because the toxin cannot be broken down in the organism, or it is taken up faster than it can be used/ excreted by the organism Occurs WITHIN a trophic level Examples of toxins that accumulate: DDT (a pesticide now banned) Mercury (many uses, mainly from mining and medical equipment) Bioaccumulation: The buildup of toxic substances in the bodies of organisms Occurs because the toxin cannot be broken down in the organism, or it is taken up faster than it can be used/ excreted by the organism Occurs WITHIN a trophic level Examples of toxins that accumulate: DDT (a pesticide now banned) Mercury (many uses, mainly from mining and medical equipment)

Bioaccumulation

Biomagnification Biomagnification: The increased concentration of toxic substances with each step in a food chain Persistent organic pollutants are biomagnified and stay in the environment for long periods of time and over long distances. Biomagnification: The increased concentration of toxic substances with each step in a food chain Persistent organic pollutants are biomagnified and stay in the environment for long periods of time and over long distances.

Biomagnification

Operation: Cat Drop You have 15 minutes to complete the activity Read the scenario Follow instructions to create a food web Be ready to answer the question: Overall, how did DDT impact the ecosystem? You have 15 minutes to complete the activity Read the scenario Follow instructions to create a food web Be ready to answer the question: Overall, how did DDT impact the ecosystem?

Operation: Cat Drop