1. Human Impacts on the Environment

2. 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.
Start with a discussion with the class about endangered species, asking if anyone can explain what an endangered species is.
Endangered species are species that are at risk of extinction.
They are usually species with a small or declining population size, meaning that there are simply not many individuals left, or species with a very limited range. For example, a species found only on a single island could be wiped out completely by an extreme weather event, or the introduction of a new predator to the island.
Some species are so endangered that they could disappear completely within our lifetimes.
This is something which affects all groups of life on earth.
Tiger
Golden frog
Grandidier’s baobab

3. 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
Ask the class if anyone can suggest why species might be becoming endangered.
Animals and plants face a large number of different threats, and sadly many of these are as a direct result of human activity. Some of the most common threats include:
Habitat loss and habitat fragmentation – The ever expanding human population constantly requires additional space and resources. Land is being cleared to harvest products such as timber as well as to make way for human settlement, agriculture and transport links. (For example, huge areas of the orangutan’s habitat has been cleared to make way for palm oil plantations).
Hunting and poaching – A wide variety of animals have been hunted, or fished, beyond sustainable levels and now face possible extinction. Some are hunted because they provide a resource such as food or parts which are used in traditional ‘medicine’, while others have been persecuted after gaining a negative reputation for feeding upon livestock or crops or posing a threat to human safety. (For example, the black rhinoceros has been poached to the brink of extinction because of the demand for rhino horn).
Invasive species – Humans have introduced non-native species (both intentionally and accidentally) to a wide variety of habitats, often with devastating consequences. Introduced species may prove highly adaptable and outcompete native species for resources. Introduced predators can decimate local species which are not adapted to avoid predation. (For example, introduced rats prey on the chicks of ground nesting birds like the Henderson petrel).
Climate change - Droughts, ocean acidification, the loss of sea ice and an increase in storms and extreme weather events can all threaten species’ survival. Sedentary species like plants or specialist species which inhabit small ranges or islands, or those with specific habitat requirements are particularly vulnerable. (For example, the polar bear is threatened by the loss of arctic sea ice, which it requires as a platform from which to hunt its prey).
Collection/pet trade – Many animals and plants have been collected from the wild beyond sustainable levels to be sold through the pet trade or be kept in private horticultural collections. (For example, the Venus flytrap is a popular plant often illegally collected from the wild).
Pollution – Acid rain, heavy metals, pesticides, and oil spills all harm the environment and put species at risk. Chemicals for instance are particularly harmful to species that live in water. (For example, sea birds in oil spills).
Explain that the session today will focus on one example of pollution in particular – plastic waste.

4. Case Study: The Power of Plastic
White stork
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.
Plastic waste is a clear example of how human activity can have a huge negative impact on the natural world. This slide contains a few statistics that should give the class an idea of the scale of the problem.
Around 265 million tonnes of plastic are produced each year around the globe, and only a very small percentage of this is recycled, meaning that vast quantities will end up in landfill sites, or be washed or blown into the world’s oceans. This is a particularly serious problem because plastics are generally not biodegradable.
Can anyone in the class explain what ‘biodegradable’ means?
Biodegradable means that, unlike plastic, a substance can be broken down (or degraded) by other living organisms. Scientists have produced some biodegradable plastics using natural products like corn starch, or by using additives that help to break the plastic down, but this process is expensive and currently not very widespread.
Although plastic isn’t biodegradable, it does get physically broken down over time, creating smaller and smaller fragments which can be just as damaging to wildlife as larger plastic items when they end up in the food chain.
Other interesting plastic facts:
1500 plastic water bottles are consumed every second in the US.
Out of the 50 billion bottles of water being bought each year, 80% end up in a landfill, even though recycling programs exist.
17 million barrels of oil are used in producing bottled water each year.
Total number of plastic bags used worldwide annually - 1 trillion
Total number of plastic bags China consumes everyday - 3 billion
Total number of plastic bags used every minute in the US - 1 million
13 billion plastic carrier bags are used in the UK each year
Total number of years it takes for a plastic bag to degrade - 1,000 years
Total amount of plastic bags that were discarded in million tons
Total amount of plastic floating in every square mile of ocean - 46,000 pieces
Percent of plastic made every year that will end up in the ocean - 10%

5. 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
The ‘Great Pacific Garbage Patch’ is a term used to describe a huge accumulation of plastic waste in the North Pacific which has become trapped by rotating ocean currents known as a gyre. Although the name may give the impression of a floating island of rubbish, it’s actually more like a soup of plastics, from large household objects to tiny plastic particles, spread out over an area estimated to be about twice the size of France, although no one knows exactly how large it is.
Shockingly, scientists have found that in this area, plastic particles in the water outnumber plankton by 6:1, so it is easy to see how huge amounts of plastic end up in the ocean food web, as plankton is the primary producer in the ocean.
And not only is this plastic affecting species at sea, which we will look at in more detail later, it is also washing ashore on Pacific islands such as Hawaii in enormous quantities.

6. 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
The green turtle is a clear example of how plastic waste can have a devastating impact on species.
Having been hunted far beyond sustainable levels for many years, and with individuals being very slow to mature and reproduce (sexual maturity isn’t reached until between 26 and 40 years of age!), the green turtle is currently considered to be an endangered species. With the female only returning to shore to breed every 2 to 5 years, damage to this species’ nesting habitat is a serious problem.

7. Typical nesting habitat should look like this:
But is increasingly looking more like this:
These images clearly show the impact of plastic waste on the nesting beaches of the green turtle, reducing the amount of suitable habitat available for nesting.
And the problem for turtles doesn't just stop here. Individuals are also killed by ingesting plastic – turtles have been known to mistake inflated plastic bags for jellyfish, and they can also become tangled in plastic waste out at sea.

8. Film: Hawaii – A Message in the Waves
The Laysan albatross breeds mainly on the northwestern Hawaiian islands.
It spends nearly all of it’s 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
Explain to the class that you are going to show them an extract from a film about the impact of plastics on the wildlife of Hawaii.
Rebecca Hosking was making a film about the wildlife of Hawaii, but was shocked and dismayed about the amount of plastic rubbish she saw in the water and the damage this was doing to the local wildlife – and so the story of her film changed.
This clip focuses on one species in particular, the Laysan albatross. The Laysan albatross is a large seabird with a wingspan of just over 2 metres. Most Laysan albatrosses breed on the northwestern Hawaiian Archipelago and off Baja California, and spend the non-breeding season out at sea where they feed on squid, fish and crustaceans.
The video can be found here –
You will need internet access to watch it on the website, or you can download it in advance.
After introducing the film, hand out the question sheets to the class and ask the students to read the questions they will need to answer during or after the film.

9. Video: Hawaii: Message in the Waves
You will need to play the video from the Laysan albatross species profile on ARKive.
The video can be found here –
You will need internet access to watch it on the website, or you can download and save it in advance.

10. Measuring impacts Living indicators Non-living indicators
For scientists working in conservation, being able to measure and quantify our human impact on the environment is really important.
Living indicators
Non-living indicators
Number of chicks successfully fledging each season
Chick mortality rates
Total population size trend
Quantity of plastic inside the albatross boluses
Quantity of plastic on the beach
Quantity of plastic inside the stomachs of the dead albatrosses
Explain to the class that for scientists working in conservation, being able to measure and quantify our impact on the environment is really important. Ask if anyone can explain why?
First and foremost, measuring these impacts helps us to determine the cause of the problem, and exactly how much damage is being done.
Statistics can then be used to educate and inform others about the impact humans are having on the environment. As well as highlighting the scale of the problem, and encouraging the general public to do their bit to help, studies can be used to encourage governments to implement changes, such as improved recycling schemes, the creation of marine protected areas or national parks, and even targets for things like reduced carbon emissions.
They are also important in terms of measuring the success of environmental work and conservation projects – if we can measure the impact we are having on the natural world, we can also measure how successful we are at preventing more damage from being done and protecting species.
Ask the class if anyone can suggest ways in which the impact of plastic waste on the Laysan albatross could be measured, thinking about living and non-living indicators.
Living indicators could include:
Number of chicks successfully fledging each season
Chick mortality rates – how many die?
Total population size trend – is the population getting larger or smaller?
Non-living indicators could include:
Quantity of plastic inside the albatross boluses – you could repeat this measurement over a number of dates, or compare different nesting colonies in different locations.
Quantity of plastic on the beach – likewise, you could sample various beaches over time, is the problem getting worse?

11. The Power of Film Ask the class how the film made them feel.
It certainly seems that a lot of other people were shocked and moved by the film. The film maker was appalled by what she saw, and took it upon herself to show this film to the shopkeepers in her local town back home in Devon, in the UK. They found the film so powerful that Modbury became the first town in the UK to become plastic bag free. This hit the headlines and has catalyzed a huge knock-on effect, with supermarket chains racing to become plastic bag free, and Ireland being named as the first plastic bag-free country in Europe. This just goes to show the impact that a successful film can have.
The Guardian (UK) 28th April 2007
BBC News (UK) 29th April 2007

12. What can we do? REDUCE, REUSE, RECYCLE!
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!
Help clean up – participate in a litter pick or beach clean up – Organisations like the Marine Conservation Society run a “Beachwatch” project
Reduce you use of plastic products – Use alternatives wherever possible, like re-useable canvas bags
Reuse plastic bags and other plastic products where possible – Bag for life, takeaway containers etc...
Dispose of your plastic waste properly, always recycle where possible – to make sure your waste doesn't end up in the Great Pacific garbage patch, on a Hawaiian beach, or worse still, in the stomach of a Laysan albatross
It may sound simple but it really helps – Reduce, Reuse, Recycle!

13. 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.
Explain to the class their task for this session and give them the handout. If there is time and the students are confident to do so, they could present their work to the rest of the class at the end of the session.
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. Can you find any statistics?
Make a PowerPoint presentation to show your findings. Introduce your species, explain why it is threatened and describe how you could measure the impact humans are having on this species.
Illustrate your presentation using photographs and films from the ARKive website.

14. Possible Topics Habitat loss and deforestation Hunting and poaching
Invasive species
Black rhinoceros
Golden-crowned sifaka
Kakapo
Climate change
Collection / pet trade
Here are some possible topic ideas, these examples will also be on the handout along with some species suggestions to get you started.
Polar bear
Siamang