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 impacts
For scientists working in conservation, being able to measure and
quantify our human impact on the environment is really important.
For the plastic waste example, you could measure:
• 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)
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
Black rhinoceros
Golden-crowned sifaka
Climate change
Polar bear
Kakapo
Collection / pet trade
Siamang