Plastic Pollution

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Understanding:

•  Macroplastic and microplastic debris has accumulated in marine environments

    
Plastics are a type of synthetic polymer found in certain types of clothes, bottles, bags, food wrappings and containers

  • Most plastics are not biodegradable and persist in the environment for many centuries


Large visible plastic debris (> 1 mm) is defined as macroplastic, while smaller debris (< 1 mm) is defined as microplastic

  • Macroplastic debris can be degraded and broken down into microplastic debris by UV radiation and the action of waves
  • Ocean currents will concentrate plastic debris in large oceanic convergence zones called gyres


Plastic debris will leach chemicals into the water and also absorb toxic contaminants called persistent organic pollutants

  • Microplastics will absorb more persistent organic pollutants (POPs) due to their smaller size (more available surface area)


Both macroplastic and microplastic debris is ingested by marine animals, which mistake the debris for food

  • This leads to the bioaccumulation and biomagnification of persistent organic pollutants within marine animals
  • It may also damage the stomach of animals or cause them to stop feeding (by taking up space in the digestive tract)


Plastic Debris in Marine Environments

plastic debris



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Understanding:

•  Case study of the impact of plastic debris on Laysan albatrosses and one other named example

    
Case Study One:  Laysan Albatross

  • The Laysan albatross nests on islands found in the North Pacific gyre, where large amounts of plastic debris is found
  • The albatross feeds by skimming the ocean surface with their beak, causing them to ingest large quantities of plastic
  • Adults can regurgitate the plastics they have swallowed, but chicks are unable to – as such it fills up their stomachs
  • Consequently the mortality rate in albatross chicks is very high (estimated 40% die before fledgling)


Plastic Swallowed by Laysan Albatrosses

 Excerpt from the BBC documentary: Hawaii – Message in the Waves 


Case Study Two:  Sea Turtles

  • Sea turtles will commonly mistake plastic bags for jellyfish (one of their primary food sources)
  • Ingestion of the plastic can be fatal – the plastic can become lodged in the esophagus and cause future feeding problems
  • Plastic debris can also become wrapped around the turtle, restricting movement and developmental growth
  • It is estimated that plastic pollution harms ~100,000 sea turtles and other marine animals each year


Effect of Plastic Pollution on Sea Turtles

sea turtle