Biomagnification, Plastics, and Rewilding

What is biomagnification?

Increase in toxin concentration at successive trophic levels

Why does biomagnification occur?

Fat-soluble toxins cannot be excreted

Why do predators accumulate more toxins?

They consume large quantities of contaminated prey

Which toxin commonly biomagnifies in fish?

Mercury

Why should large fish be avoided in diets?

They contain higher mercury concentrations

Why has mercury uptake increased despite reduced emissions?

Rising seawater temperatures increase uptake

What is DDT?

An insecticide that accumulates in fat tissue

Why was DDT banned in many countries?

Due to biomagnification and ecological harm

What are plastics?

Non-biodegradable polymers

What are macroplastics?

Plastic pieces larger than 5 mm

What are microplastics?

Plastic particles smaller than 5 mm

Why are plastics harmful to marine life?

Animals ingest or become entangled in them

How do microplastics affect food chains?

They bioaccumulate and biomagnify

What are ecosystem consequences of human degradation?

Loss of biodiversity, extinction, and ecosystem services

What is rewilding?

Restoring ecosystems by allowing natural processes to return

What is an example of rewilding?

Hinewai Reserve in New Zealand

How does rewilding occur in Switzerland?

Through strict protection and no human interference

What interventions can speed up rewilding?

Reintroducing keystone species, reconnecting habitats, removing livestock