Option C: Impacts of humans on ecosystems

Pollutants become concentrated in the tissues of organisms at higher trophic levels by biomagnification.
​Skill: Analysis of data illustrating the causes and consequences of biomagnification.  Click link to illustrate NOAA biomagnification of mercury levels in fish and birds.  
 Competitive exclusion and the absence of predators can lead to reduction in the numbers of endemic species when alien species become invasive

This interactive simulation shows how populations behave when grown alone or when mixed together.  This is competitive exclusion - how can this be illustrated with an invasive species population?

Introduced alien species can escape into local ecosystems and become invasive.
Application: Study of the introduction of cane toads in Australia and one other local example of the introduction of an alien species.

Skill: Evaluation of eradication programmes and biological control as measures to reduce the impact of alien species.

Click the link to read about biocontrol of invasive species in Australia.

Application: Discussion of the trade-off between control of the malarial
parasite and DDT pollution.

 Macroplastic and microplastic debris has accumulated in marine environments. 
​Application: Case study of the impact of marine plastic debris on Laysan
albatrosses and one other named species.
International-mindedness:
Over 100 countries across the globe have agreed to ban the production of CFCs to reduce the depletion of the ozone layer.

Aims:
Aim 8: Many developed countries export toxic waste to less developed countries. Is financial compensation a fair exchange for hazardous waste?