Understandings:

• Introduced alien species can escape into local ecosystems and become invasive.
• Competitive exclusion and the absence of predators can lead to reduction in the numbers of endemic species when alien species become invasive.
• Pollutants become concentrated in the tissues of organisms at higher trophic levels by biomagnification.
• Macroplastic and microplastic debris has accumulated in marine environments.

Applications and skills:

• Application: Study of the introduction of cane toads in Australia and one other local example of the introduction of an alien species.
• Application: Discussion of the trade-off between control of the malarial parasite and DDT pollution.
• Application: Case study of the impact of marine plastic debris on Laysan albatrosses and one other named species.
• Skill: Analysis of data illustrating the causes and consequences of biomagnification.
• Skill: Evaluation of eradication programmes and biological control as measures to reduce the impact of alien species.