Transcript Slide 1
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