Lesson video

Hi there.

I'm Ms. Roberts and welcome to today's geography lesson, which is from our unit of work about our coasts.

We are investigating what happens at the coast where the land meets the sea.

This lesson is all about what different types of habitats and ecosystems we can find along our coastlines.

By the end of the lesson today, you are going to be able to identify some threats to our coastal habitats, and you're going to be able to explain why these coastal habitats matter to our wildlife.

I'd like to begin by looking at four keywords.

These are words that are going to be very helpful to you to understand and use yourself during this lesson.

Our first keyword is ecosystem.

An ecosystem is a natural environment and all the plants and animals, all the living things that live and interact with each other in that environment.

That is an ecosystem.

Our next key word is habitat.

A habitat is another word for a home.

It's the natural home or the environment where an animal, plant, or other organism lives.

Next, we have pollution.

I'm sure you've heard of pollution because it's a very important issue today.

Pollution is anything that makes our environment dirty or unhealthy.

And finally, organism.

You heard me mention this word before.

An organism is a living thing.

Anything that is living is an organism, from the teeny, tiniest bacteria to the largest animals like elephants on earth, they are all organisms. There are two parts in today's lesson.

First, we are going to think about why coastal habitats are so important, and secondly, we are going to look at what threats exist to those habitats.

So let's begin now with the first part of our lesson and consider the important aspects of coastal habitats.

We have such a wide variety of coastal habitats on earth, and many of those are found here in the UK.

For example, we have shallow seawater, rock pools, we have dunes, we have beaches, caves and coves, and in all of those places we find a variety of different animals and plants that are suited or adapted to live there.

The kind of living organisms that inhabit or live at the coast form part of the special ecosystems that are found there.

The animals and plants that live in these ecosystems that the coast have to put up with some very difficult conditions, they must be able to survive in very salty water, and they also have to face lots of extreme weather, such as strong winds, as well as high tides.

For this reason, lots of the organisms that we find at the coast are not found anywhere else.

They are unique to the coastal habitats that they inhibit.

There are some very unique coastal habitats on earth that play a very big role.

They include mangrove forests, coral reefs, and estuaries.

So we're going to explore each of those important habitats now.

Beginning with mangrove forests.

A mangrove is a type of tree.

The photograph that you can see here is a very tangled mass of the roots of mangrove trees.

These roots are special because we can see them above the ground, unlike other trees where the roots are always hidden underground, mangrove roots are called aerial roots or stilt roots and they stick out of the salty, marshy grounds that the mangrove trees grow upon.

Mangroves are found in thick clusters along seashores or river banks.

They have a thick tangle of roots, as we've just explained, and these roots help to keep the waves from washing away the silt and the sand at that coastline.

So the mangroves are actually there helping to prevent that coastline from eroding.

Mangrove forests are found particularly in certain locations on earth.

They are found in parts of Asia, Africa, Australia, and the Americas.

You can see those places in green on the map are the coastlines where mangrove forests are found.

The thing that all of these places have in common is that these places have temperatures that are warm all year round.

You may recognise from the map that these areas are close to the equator and are in tropical regions.

Mangrove forests cannot withstand cool temperatures, which is why they are only found in these parts of the world.

Mangrove trees can grow in places where very few other trees can.

They are able to filter out the salt in salty water, which is why we find them at the coast.

And unlike other trees, which would just fall over, those long, tall, stilt roots help mangrove trees remain upright in very, very soft landscapes.

These trees are actually pretty amazing.

Do you want to know some more things that mangrove trees do? In fact, their root system, that big, tangled mess of roots, helps to provide a very sheltered habitat, which is really attractive to fish, as well as other marine organisms, and that's because within that tangled mass of roots, they can find shelter and they can find food.

Many different species actually use the mangrove tree roots as a nursery where they can shelter their young creatures until they are able to go out and fend for themselves.

Mangroves provides a habitat for thousands of species, and these species include sea turtles, manatees, crab-eating monkeys, and in some parts of the world, even the Bengal tiger.

The branches of mangrove trees are also home to many, many birds because they can feed on the shrubs and the fish and the crabs.

Mangroves truly are extremely important to a wide variety of wildlife.

Have you been listening carefully to all of that information about mangroves? Let's have a quick check for our understanding with a multiple choice question.

I simply want to know why are mangroves important? Pause the video now whilst you read these options and decide on your choice.

Be careful, there could be more than one correct option.

Ready? Okay.

Option A.

"Their roots help to prevent coastal erosion." Absolutely.

That's definitely one reason why mangroves are important.

Anything else? Option C is also correct, isn't it? Mangroves are important because they provide a habitat for thousands of species.

Is that everything here? No.

Option D is also a reason why mangroves are important.

It's because that big tangled mess of roots creates a sheltered area for young creatures.

Let's move on now to look at another unique marine ecosystem called coral reefs.

Coral reefs and mangroves have a lot in common with each other.

Coral reefs are actually living organisms. They are living underwater structures that have been built by teeny-tiny little sea creatures over the course of thousands of years.

Those tiny sea creatures called coral polyps produce calcium.

That calcium eventually solidifies to form a skeleton.

Some of the oldest coral reefs on earth actually began to form around 25 million years ago.

Within coral reefs, we find a massive variety of marine life forms. Thousands and thousands of creatures live in these beautiful places.

Coral reefs are only found in specific places on earth just like mangroves.

This is because coral reefs need warm and shallow water.

The water must be clean and clear so that they can obtain all of the oxygen and the nutrients that they need to grow and survive.

There are over 2,500 different species of coral found in oceans around the world.

Look at the area that is circled on this map.

What do you notice? The circled area is the same as the area where we find mangroves.

Mangrove forests are actually found in parallel with coral reefs.

Where we find coral reefs, we can also find mangroves.

That's because of the need for warm tropical water.

And we can see here that they are found in areas around the equator and within the tropics.

The Great Barrier Reef is an example of a reef, and this is actually the largest reef in the world.

It's found just off the coast of an area called Queensland, which is in Australia.

You might have heard of this before.

The Great Barrier Reef is the world's largest reef system and is the biggest structure on earth to be made by living organisms. It is so big, in fact, that it can be seen from space.

It was designated a World Heritage Site in 1981 in order to help to protect the Great Barrier Reef and ensure its survival into the future.

All coral reefs, including the Great Barrier Reef, are very important and they play a crucial role in our marine ecosystem.

If we think about how much area of the ocean floor that is covered by coral reefs, it's actually a very small percentage, only around 0.

2%.

But amazingly, within that small area of our vast oceans, we can find 25% of all of the ocean species on earth.

Coral reefs rival the tropical rainforests for the amount of diverse species that they contain.

Coral reefs also have a lot of other unique features that make them important.

The calcium carbonate that comes from the corals, from the structure, helps to maintain what we call the pH balance of the ocean.

This means that the ocean water doesn't become too acidic.

If it does, then it can become harmful to oceanic life.

The corals help to protect the coastlines from erosion by breaking up the waves.

They act as a buffer between the sea and the coastline itself, and in some places, coral reefs are said to absorb up to 97% of the energy from waves and storms and floods.

This, of course, helps to prevent coastal erosion.

It helps to prevent property damage, and importantly, can lead to say to preventing loss of life.

Within the coral reef, just as we discussed within the mangrove roots, there are plenty of sheltered hidey-holes that can be used as a nursery for young fish to grow and develop.

It offers shelter and protection to a lot of different marine species.

As there are so many varieties of fish found there, then the people can use coral reefs as a food source because they can go fishing and catch fish.

This contributes to the diets of local people.

It also provides jobs through fishing and through tourism.

Coral reefs, amazingly, are also an important potential source of new medicine.

A lot of research is being done currently into the use of specific parts of coral reefs by the pharmaceutical industry.

And of course, coral reefs are simply beautiful, underwater structures that are an endless source of fascination for people all over the world.

Have you been listening to all that information about coral reefs? Let's try a check for understanding now.

I would like to know which of these statements are true.

Pause the video whilst you read them and make your choice.

Ready? Okay.

Coral reefs are home to approximately 25% of the ocean's species.

Is that one true? Yes, it is.

Is that the only true option? I don't think so.

Corals protect shorelines by breaking up wave action is option B.

Is that one true? Yes, it is.

Is that the last one? No.

There's one more true option here, isn't it? And that's that coral reefs are a source, potentially, of new medicines.

Option C is absolutely incorrect.

Coral reefs are not found near to the Arctic Circle because coral reefs need warm, tropical waters to survive.

Okay, we are going to move on to the third special type of marine ecosystem that we were talking about, and that is estuaries.

Estuaries are found in areas where rivers are emptying into the ocean, so these are found where rivers meet the sea.

The important thing to remember about estuaries is that sea water is salty, but river water that is coming from inland is fresh water, it's not salty.

So within an estuary, what we have is the salty sea water and the inland fresh river water mixing.

Estuaries are usually very wide and very flat places, and the river in an estuary is said to be tidal.

That means that the level of the water in the river goes up and down according to the tide coming in and out.

When the tide is low and there is less water in an estuary, then any sediment which is being carried can be deposited, and usually this leads to the formation of mudflats around estuaries.

We can also find marshy areas such as salt marshes in these places too.

Take a look at the estuary in the photo.

Here we have the Rio de la Plata, which is found in South America.

And here there are two rivers, the River Parana and the River Uruguay, and they are both emptying into the Atlantic ocean.

You can see how muddy and flat the estuary is there.

We have estuaries here in the UK as well.

In fact, this map shows an area called the Wash, which is the biggest estuary in the UK, and it stretches for over 100 miles from Skegness to Hunstanton in the east coast of England.

The Wash is what we could call a coastal wetland.

It has a very wide range of wildlife living there.

It is made of huge banks of sand and mud, there are salt marshes, there are some very deep channels, and there are some areas of very shallow water as well.

Places like estuaries, including the Wash, are often referred to as the nurseries of the sea because so many species rely on these areas for breeding and for nesting.

Saltmarshes can be found all around the UK, and they are some of the most important habitats on our coasts.

Approximately, 10% of the UK saltmarshes are found here in the Wash.

The Wash is a vital habitat, especially for migrating birds because they can graze in the wetlands and they can eat the plants that are found there.

The Wash is also famous because there are vast numbers of worms, shellfish, and shrimps, and lots of other small crustaceans that live in the sand and the muds there.

It also attracts enormous numbers of migrant birds, especially wading birds like the pink-footed geese.

These geese arrive here from Iceland and Greenland in the early winter and many of them will roost around the offshore banks of the Wash.

The Wash is also special because it supports one of the largest populations of common seals that are found in England.

You can see a seal here in the picture.

Let's stop and check our understanding about estuaries.

I would like you to respond in your own words to this question.

You can do this verbally or you can make some notes and you can work with a geography buddy to talk about this if you'd like to.

Why are estuaries often called the nurseries of the sea? Pause the video now, and when you're ready, come back and I will share some ideas with you.

Ready? Well done.

I think that estuaries are often called the nurseries of the sea because so many species rely on this coastal habitat for nesting and for breeding, and that's how species survive.

Moving on now to task A.

Here we have a table, which creates a bit of a fact file really about coastal habitats.

I would like you to choose one of the coastal habitats and complete the table by making notes about it, so you could choose mangrove forests, you could choose coral reefs or estuaries.

If you have extra time, you could repeat this for the other two habitats.

Pause the video now and when you come back I'll be sharing an example of how I would complete the table about coral reefs.

Ready? Good job.

Here's what I wrote for coral reefs In this table, they are located in tropical and subtropical waters.

They are bright and colourful underwater structures that are made of animals called polyps.

Coral reefs were built thousands of years ago by those tiny sea creatures.

Many animals live there including fish, lobsters, clams, seahorses, sponges and sea turtles.

And why is it important for the health of the planet? Well, coral reefs are home to approximately 25% of the earth's ocean species.

They help to stop ocean water becoming too acidic.

They protect shorelines by breaking up the wave action, and they are potentially an important source of new medicine.

Did you choose coral reefs and did you have some of those ideas? Well done.

Now let's move along to the second part of today's lesson, and think about what threats exist to those precious habitats that we have been looking at.

Sadly, most coastal habitats on earth are under threat because of things that us humans do.

Human activity causes problems including climate change, pollution, farming, fishing and tourism.

These all threaten our important coastal habitats.

Let's find out how.

Let's start by looking at the threat of climate change.

Global sea temperatures are rising, the water is getting warmer.

Coral reefs do need warm water, but they can't survive in water that is too warm.

As sea temperatures are rising, this is causing corals to become stressed.

When corals are stressed, they cannot function in the same way, and this causes the beautiful corals that we are familiar with to lose their colourful appearance and become white, as you can see in this photograph.

This process is known as coral bleaching.

Eventually, if this happens continually, the coral will die.

Scientists predict that we could lose more than 90% of the coral reefs on earth if we don't reduce our greenhouse gas emissions.

Pollution is another huge threat to coastal ecosystems. Lots of settlements exist at the coast, we know this.

Within those settlements, there are lots of humans with businesses, there are factories, there are houses, there are power stations.

This all causes pollution.

Factories can release chemicals into water bodies.

And there can be huge amounts of litter that builds up from humans, as you can see in the photograph.

River estuaries in particular, are areas where we can see a lot of this pollution having an impact.

Farming and fishing.

These are both essential processes for humans.

We have to farm and fish in order to have food to survive.

But these two activities pose threats to our coastal ecosystem.

Coastal habitats can be destroyed by overfishing.

That's when we fish too much and start to deplete an area and harm it.

Equipment from fishing vessels can also be very damaging.

Mangroves can sometimes be used because they are chopped down as timber.

This is when they are used as a building material, so the wood of the mangrove tree is used to make a product.

The land that is cleared is then used to farm fish and shrimps, but this is happening more and more often, which means that more and more mangroves are being chopped down.

Tourism.

Everybody likes to go on holiday, and we know that coasts are very popular for tourists.

I've been on holiday at the coast.

Have you been on holiday at the coast? Coasts are what we call tourist hotspots.

However, thoughtless tourism sometimes causes damage and threatens the ecosystems in these beautiful places.

For example, coral reefs.

Coral reefs can be damaged when people throw anchors from boats.

People can step on corals.

Diving gear can be dragged over them which breaks them.

Sometimes corals are actually chopped down and used to make jewellery or ornaments, and sometimes, people will break them deliberately to take home as souvenir.

All of those things threaten our precious marine ecosystems. Let's now check what you know about those ecosystems with this check for understanding.

Here are three definitions about threats to coastal habitats.

I would like you to pause the video and match up each definition with the correct threat.

All done? Great.

Let's have a look.

First of all, we have climate change, and this is to do with global sea temperatures rising, which causes corals to be stressed and can lead to coral bleaching.

Next, we have tourism.

Tourism causes a threat, for example, coral reefs can be damaged when people anchor their boats on them, and diving gear is dragged all over them or they are even chopped down for jewellery.

Pollution is when litter, sewage or chemicals produced by humans damages the fragile coastal ecosystem.

How then can we protect our ecosystems from these threats? Because we are so aware of the threats to our coastal environments, there are more and more initiatives being carried out to help protect the coast.

Some areas of our coast and seas are now protected by special laws because we understand how important they are for our wildlife.

Some areas are designated as marine protected areas or MPAs.

These are similar to a nature reserve that you would find on land, but they are found in the sea or at the coast, and they are set up as a means of protecting either a specific species that is found somewhere or a whole habitat in a particular place.

Marine Protected Areas can help to reduce destructive activities that are harming the coast, and can help to protect and recover the biodiversity of the area.

Another effort to reduce these threats is something called eco-tourism.

This is a way of trying to reduce the environmental damage caused by tourism, by focusing on outcomes that are actually beneficial for the wildlife.

In Indonesia, for example, eco-tourism involves people travelling to see the beautiful country, but whilst they are there, they explore plants and care for the mangrove forests that are there.

It helps tourists to understand the importance of the coastal ecosystems while still experiencing their holiday.

Time for another check for understanding.

What is eco-tourism? Pause the video and decide which of these is the best description of ecotourism, A, B or C.

All done? Good job.

There's only one correct option here, and that is option A.

Eco-tourism is a way of trying to reduce environmental damage by working in ways that are good for the wildlife.

Time for task B now.

This is an opportunity for you to do some research of your own about a coastal ecosystem.

You can choose to do this task about any coastal ecosystem, so mangroves or coral reefs or estuaries, but if you choose the same ecosystem from task A, then you already have a lot of information that you will be able to use.

I would like you to create an informative, engaging, and easy to understand presentation.

Now, you could do this as a PowerPoint presentation or as a podcast.

You could even make a poster.

I want you to try to include information about why the ecosystem is important, the threats that it faces, and what we can do to protect it.

I'd like you to pause the video now.

Complete your presentation and share it with others.

And then when you return, I'll be sharing an example from one of the Oak Academy children.

Off you go.

All done? Excellent.

Did you enjoy doing all that research and creating your presentation? I hope so.

Here is what Laura from Oak Academy has done for her presentation about coral reefs.

She says that she made a PowerPoint presentation and used the first few slides to explain how coral reefs are home to 25% of the ocean species.

She also explains that they help stop the ocean water from becoming too acidic and can protect the shorelines by breaking up the energy of the waves.

She also mentioned that they are an important source of new medicine.

She then says that she explained how climate change, pollution and tourism, they are the threats to coral reefs, and she ended by explaining or suggesting what we could all do to help protect the precious ecosystem.

Well done, Laura.

And well done you for all your hard work today.

Here's a quick summary of everything we have covered in this lesson.

Coastal habitats and their unique ecosystems are under threat from human activity and climate change.

We know that coastal settlements and industries that are found at the coast all have significant impacts on natural habitats, and they can affect the wildlife populations.

River estuaries can be hotspots for pollution, emptying frequently into the rivers and oceans there.

We also know that there are some things we can do to protect our coastlines, for example, eco-tourism, which can help to redress their environmental damage and help to work in ways that are good for wildlife.

Coastal habitats really are very important and we all have a duty to protect them.

I wonder if there are any protection schemes at a coastline near you.

Perhaps you could find out.

I hope to see you again for another exciting lesson about our amazing coastlines.

Bye for now.