ISCI 1A24 Lecture Notes - Lecture 20: Ecotoxicology, Heterotroph, Energy
22 Nov 2016
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Document Summary
Food webs and ecotoxicology objectives: understand interactions and flow of toxins, calculate approximate amounts of pollutant in a system. Nutrients organisms can absorb from their environment: simplified version. Volume of entire system (2. 3 x 107 m3) Pollution concentration - calculations: required amount of pollutant in lake, residence time - how long one particle of water will stay in the lake. = volume/ flow: amount of pollutant = input of pollutant x how many days it is added (residence time, concentration of pollutant = amount / volume (of the lake) *concentration is usually in ppm - must multiply by 106: dispersion = how much one organism is feeling. Energy transfer between trophic levels is 10% on average. Bioconcentration: amount of chemical in an organism compared to environment: only looking at passive transfer to the organism, not considering chemicals from its food intake.
