Human Impacts on the Environment. What is an endangered species? A species that is at risk of...
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Transcript of Human Impacts on the Environment. What is an endangered species? A species that is at risk of...
Human Impacts on the Environment
What is an endangered species?
• A species that is at risk of extinction.
• Species with a small or declining population, or a very small range.
• Some species are so endangered that they could disappear completely within our lifetimes.
Tiger Golden frog Grandidier’s baobab
Why are species endangered?
Often as a direct result of human activity. Some of the most common threats include:
Habitat loss
Hunting and poaching
Invasive species
Climate change
Collection and the pet trade
Pollution Golden-crowned sifaka
Case Study: The Power of Plastic
Why is plastic such a problem?
• Around 275,000 tonnes of plastic are used each year in the UK alone.
• That’s about 15 million bottles per day.
• Globally, we make around 265 million tonnes of plastic each year.
• Plastic (generally) isn’t biodegradable and can take up to 500 years to decompose.
White stork
The Great Pacific Garbage Patch
• Waste has become trapped by rotating ocean currents
• Thought to cover an area around twice the size of France
• Plastic varies in size from household objects to tiny particles
• Estimates suggest that in this area, plastic particles outnumber plankton 6:1
• Not only affecting species at sea, also washing ashore.
American coot
How is this affecting species?
Example: Green turtle
Currently considered an Endangered species
Doesn’t start to reproduce until 26 to 40 years of age
Returns to breed only once every two to five years
The female hauls out onto the beach at night and digs a large nest with the back flippers Green turtle
Typical nesting habitat should look like this:
But is increasingly looking more like this:
Film: Hawaii – A Message in the Waves
The Laysan albatross breeds mainly on the northwestern Hawaiian islands.
It spends nearly all of its life at sea, only returning to land to breed.
It feeds mainly on squid and fish which it skims from the surface of the water, or catches by shallow diving.
Laysan albatross
Video: Hawaii: Message in the Waves
Measuring impactsFor scientists working in conservation, being able to measure and quantify our human impact on the environment is really important.
• Number of chicks successfully fledging (leaving the nest) each season.
• Chick mortality rates – how many die each season?
• Total population size trend – is the population getting larger or smaller?
• Quantity of plastic inside the albatross boluses.
• Quantity of plastic on the beach.
Laysan albatross bolus (above) and chick (below)
For the plastic waste example, you could measure:
The Power of Film
The Guardian (UK) 28th April 2007
http://www.guardian.co.uk/
BBC News (UK) 29th April 2007
http://www.bbc.co.uk/news/
What can we do?
Help clean up – participate in a litter pick or beach clean up
Reduce your use of plastic products
Reuse plastic bags and other plastic products where possible
Dispose of your plastic waste properly, always recycle where possible
REDUCE, REUSE, RECYCLE!
Your Task
• Choose a different human impact topic (not plastics) and pick a species affected by it which you would like to research.
• Using ARKive and other web resources, find as much information as you can about how your chosen species is affected by human impacts on the environment.
• Make a PowerPoint presentation introducing your species, explaining why it is threatened and describing how you could measure the impact humans are having on this species.
• Illustrate your presentation using photographs and films from the ARKive website.
Possible Topics
Habitat loss and deforestation
Hunting and poaching Invasive species
Collection / pet tradeClimate change
Golden-crowned sifaka Black rhinoceros Kakapo
Polar bear Siamang