1.3.20

Bioaccumulation

Test yourself

Bioaccumulation

In food webs, toxins can enter the system and build up in organisms. The build up of these toxins in organisms is called bioaccumulation.

Illustrative background for Toxins in the environmentIllustrative background for Toxins in the environment ?? "content

Toxins in the environment

  • Toxins are harmful chemicals that affect organisms in an ecosystem.
  • Toxins are normally released because of human activity.
  • Toxins can reach the environment by:
    • Leaking from the chemical industry into land and water systems.
    • Pollutants can also be released into the atmosphere.
Illustrative background for BioaccumulationIllustrative background for Bioaccumulation ?? "content

Bioaccumulation

  • In food webs, toxins can enter the system and build up in organisms.
    • When these toxins build up in organisms, this is called bioaccumulation.
Illustrative background for Bioaccumulation of pesticidesIllustrative background for Bioaccumulation of pesticides ?? "content

Bioaccumulation of pesticides

  • Pesticides are used to kill pests and encourage more crop growth.
  • Pesticides can be absorbed in the roots of plants.
    • Pesticides then find their way into water systems.
Illustrative background for BiomagnificationIllustrative background for Biomagnification ?? "content

Biomagnification

  • Plants are producers.
    • Plants are then eaten by primary consumers.
    • Primary consumers are also eaten.
    • The toxin is then passed from one trophic level to the next.
  • The toxin accumulates in larger concentrations with the apex predator at the top of the food chain.
    • This accumulation is called biomagnification.

Bioaccumulation

In food webs, toxins can enter the system and build up in organisms. The build up of these toxins in organisms is called bioaccumulation. Mercury and DDT can bioaccumulate.

Illustrative background for Bioaccumulation of DDTIllustrative background for Bioaccumulation of DDT ?? "content

Bioaccumulation of DDT

  • Chemicals that have been researched to bioaccumulate in the environment include DDT.
    • DDT is an insecticide.
    • DDT caused the shell weakening of birds of prey it bioaccumulated in.
Illustrative background for Bioaccumulation of mercuryIllustrative background for Bioaccumulation of mercury ?? "content

Bioaccumulation of mercury

  • Mercury can bioaccumulate.
    • Mercury is used to prevent barnacles growing on ship hulls.
    • Mercury found its way into fish and has even been discovered in humans.
  • Mercury has also entered the marine ecosystem from burning fossil fuels.
Illustrative background for Mercury in humansIllustrative background for Mercury in humans ?? "content

Mercury in humans

  • Mercury levels in tuna have been monitored since the 1970s.
    • Mercury levels are reported as being stable.
  • Stable mercury levels are a concern as humans eat a lot of tuna.
    • Higher levels of mercury affect the nervous system and the brain.
    • Mercury can also affect the development of unborn babies if accumulated in pregnant women.
Illustrative background for How mercury bioaccumulatesIllustrative background for How mercury bioaccumulates ?? "content

How mercury bioaccumulates

  • Mercury is absorbed by plankton once it reaches their environment.
  • Small fish eat the plankton.
  • Tuna eat the small fish.
  • Tuna are caught and eaten by humans.

Jump to other topics

1Biology

1.1Cells, Tissues & Organs

1.2Reproduction & Variation

1.3Ecological Relationships & Classification

1.4Digestion & Nutrition

1.5Plants & Photosynthesis

1.6Biological Systems & Processes

2Chemistry

2.1Particles

2.2Chemical Reactions

2.3Atoms, Elements, Compounds

2.4The Periodic Table

2.5Materials & the Earth

2.6Reactivity

2.7Energetics

2.8Properties of Materials

3Physics

3.1Energy

3.2Forces & Motion

3.3Waves

3.4Electricity & Magnetism

3.5Matter

3.6Space Physics

4Thinking Scientifically

Go student ad image

Unlock your full potential with GoStudent tutoring

  • Affordable 1:1 tutoring from the comfort of your home

  • Tutors are matched to your specific learning needs

  • 30+ school subjects covered

Book a free trial lesson