Bioaccumulation The buildup of substances i e pesticides

Bioaccumulation The build-up of substances (i. e. pesticides) in an organism. ● toxins are absorbed faster than they are expelled

Bioaccumulation ● toxins get absorbed and stored in fat tissues - When animals expend energy fat tissue is burned - the toxin is released - acts as a poison

Biomagnification Occurs through the trophic levels - higher trophic levels have a greater concentration of pesticides/toxins in them

Increased levels of toxins as we ascend (go up) the trophic levels

Biomagnification example

Biomagnification example: DDT in humans? ● humans are subject to bioaccumulation. ● evidence that DDT insecticide was beginning to accumulate in humans was collected in the 1950’s and 1960’s. ● especially high in humans who lived where DDT was sprayed on crops. ● usage was banned in 1971 (and in the US in 1972).

DDT Problem has not ended. . . ● Migratory birds like the mallard duck, Canada goose, and peregrine falcon winter in Central America and Mexico, where DDT is still used. ● Fish living in the Atlantic and Pacific oceans also migrate up and down these coasts.

Pesticide resistant bugs! ● pests are adapting to be immune to pesticides ● new genes to make offspring resistant as well (high rate of reproduction) ● toxins still accumulate, and pass on to other organisms

https: //www. youtube. com/watch? v=6 GEQxrtt. M VE

Activity! Our classroom ecosystem. . .