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