impacts of humans on ecosystem (biomagnification)
biomagnification
Pollutants become concentrated in the tissues of organisms at higher trophic levels by biomagnification.
Bioaccumulation: When toxins build up in the body of organisms particularly if the toxin is fat-soluble and not easily excreted.
Biomagnification is the process by which chemical substances become more concentrated at each trophic level. At each stage in a food chain, the predator will accumulate higher concentrations of the toxins than its prey. This is because the predator consumes large quantities of prey during its lifetime and bioaccumulates the toxin that they contain.
Some organisms have greater concentrations of body lipids and so the accumulation is not even across trophic levels, also sometimes the toxin can be taken up directly from the abiotic environment rather than the food chain.
The concentration of toxins in the highest trophic levels may be lethal, even when the concentrations in organisms at the start of the food chain were very low.
The figure bellow shows the concentration of PCBs in an aquatic food chain in the Great Lakes, these chemicals were used as insulators in electrical devices and as flame-retardants.
Bioaccumulation: When toxins build up in the body of organisms particularly if the toxin is fat-soluble and not easily excreted.
Biomagnification is the process by which chemical substances become more concentrated at each trophic level. At each stage in a food chain, the predator will accumulate higher concentrations of the toxins than its prey. This is because the predator consumes large quantities of prey during its lifetime and bioaccumulates the toxin that they contain.
Some organisms have greater concentrations of body lipids and so the accumulation is not even across trophic levels, also sometimes the toxin can be taken up directly from the abiotic environment rather than the food chain.
The concentration of toxins in the highest trophic levels may be lethal, even when the concentrations in organisms at the start of the food chain were very low.
The figure bellow shows the concentration of PCBs in an aquatic food chain in the Great Lakes, these chemicals were used as insulators in electrical devices and as flame-retardants.