IGCSE Geography-Coasts-Coastal Ecosystems

Match

Match the following

• What is the name of the movement of water up the beach?

• What is the name given to the distance of open water the wind has travelled?

• Which wave has a stronger backwash?

• Which type of erosion is when waves throw rocks at the cliff wearing it away like sandpaper?

• what is the name given to the movement of sediment along a beach in a zigzag movement?

Swash

Fetch

Destructive wave

Abrasion

Longshore drift

• Swash

• Fetch

• Destructive wave

• Abrasion

• Longshore drift

Open Ended

What is a mangrove?

• A mangrove is a shrub or small tree that grows in coastal saline (salty) or brackish (mixture of fresh and salty) water. 

• At low tide mangroves are dry

At high tide mangroves flood

​What is a mangrove?

Open Ended

Look at the map. the red areas show the location of mangroves. Using the CLOCC, write a description of the distribution

​Answer

​

Mangroves are most common in South-East Asia where they were thought to originate before spreading around the globe. Today, most mangroves are found within 30’ latitude of the equator, but a few hardy types have adapted to temperate climates. They reach as far as the North Island of New Zealand

1.What is name given to the zone between land and sea?

2.What is the nickname given to mangroves?

3.What fraction of tropical fish are born in mangroves?

4.How does mangrove improve the water quality?

5.What other benefits do mangroves bring?

6.What fraction of the world’s mangroves have been destroyed?

7.Why have they been destroyed?

1.What is name given to the zone between land and sea?

•Intertidal zone

2.What is the nickname given to mangroves?

•Walking trees

3.What fraction of tropical fish are born in mangroves?
•¾

4.How does mangrove improve the water quality?

•Filters out nutrients and toxins

5.What other benefits do mangroves bring?

•Protection from storms

6.What fraction of the world’s mangroves have been destroyed?
•1/3

7.Why have they been destroyed?

•Coastal development, aquaculture, lumber

Mangroves are formed when a pioneer species colonises an area. This is through seed dispersion.  As they grow it traps more sediment hence why the ground becomes taller. As they form at an inter-tidal zone, the high tide brings with it fresh nutrients

​How are they formed?

Open Ended

What factors do mangrove trees need to survive?

•Mangroves need a high level of rainfall of between 1500mm and 3000mm per year. This can be obtained from rainfall or moisture in the air making tropical climates ideal.

•Mangroves need a high temperature around 27’C otherwise it will not grow

•Mangroves need a shallow water between 0.5 – 2.5 metres depth but can survive where tidal ranges go slightly above or below this level.

•Mangroves need high levels of humidity between 75-80% to enable them to grow.

​Mangrove environment

They live in a constantly changing environment. They are regularly flooded, flooded by fresh water which changes the salt level, temperature changes

​Mangrove Characteristics

Open Ended

How are mangroves adapted to their environment?

•Snorkel like roots - allow for the transport of atmospheric gases to the underground roots

•Buttress roots (large base) to keep them upright/stable

•Seedlings float  - grow somewhere else (seed dispersion)

​Adaptations

• large prop roots

• anchor trees in soft mud

• stabilize and trap

sediments

• up to 30 ft. tall

• thick, waxy leaves - reduce water loss

Open Ended

Explain how mangroves are adapted to the intertidal zone.

​Lesson Objectives

​

• To identify and explain the main threats to coral reefs and the solutions we can use to protect them.

• To analyse how different threats affect coral reefs and evaluate the effectiveness of conservation strategies for them.

• To describe the importance of mangroves in coastal protection and explore how they complement coral reef ecosystems.

​Lesson Objectives

​To identify the goods and services of the mangrove ecosystem.

To analyse the threats and solutions to the mangrove ecosystem.

To summarise coastal ecosystems and practice exam technique

Open Ended

Can you spot 7 benefits of mangroves?

​Fish Nursery

​

• Mangroves provide nursery habitat for many commercial fish and crustaceans, and thus contribute to sustaining the local abundance of fish and shellfish populations & hence fishing industries.

• 75% of game fish & 90% of the commercial species in South Florida are dependent on Mangroves.

• 75% of commercially caught prawns and fish in Queensland, Australia, depend on Mangroves for part of their life cycles.

Match

Match the following

• Which region's fishing industry relies on mangroves for 75% of commercially caught prawns and fish?

• What percentage of game fish in South Florida are dependent on mangroves?

• What percentage of commercial fish species in South Florida depend on mangroves?

• Mangroves contribute to the nursery habitat for many commercial fish and what other group of species?

• In which region are 90% of commercial fish species dependent on mangroves for their life cycle?

Queensland, Australia

75%

90%

Crustaceans

South Florida

• Queensland, Australia

• 75%

• 90%

• Crustaceans

• South Florida

​

Improving Coastal Water Quality:

​

• Mangroves tangled root systems slow water flow, increasing deposition of sediment. 

• Pollution & nutrients coming off the land can be bound into this mud & locked away.

• Hence, filtering them out of the water before they can escape into the sea & harm offshore coral reefs.

• The existence and health of coral reefs are dependent on the buffering capacity of these shore based Mangrove ecosystems

Reorder

Reorder the following

• Mangroves' tangled root systems slow water flow, increasing deposition of sediment.

• Pollution and nutrients coming off the land can be bound into this mud and locked away.

• Hence, filtering them out of the water before they can escape into the sea and harm offshore coral reefs

• The existence and health of coral reefs are dependent on the buffering capacity of these shore-based mangrove ecosystems.

1

2

3

4

• 1
• 2
• 3
• 4

​Coastal Protection

​

• Because of their tangled above-ground root systems, Mangroves protect shorelines during large storms by absorbing wave energy and reducing the velocity of water.

• A report by the International Union for Conservation of Nature (IUCN) published after the devastating 2004 Tsunami compared two coastal villages in Sri Lanka that were hit by the wall of water.

• It showed that two people died in the settlement with dense mangrove and scrub forest, while up to 6,000 people died in the village without similar vegetation.

• Wave energy may be reduced by 75% as the wave's pass through 200 meters of mangrove forests.

​

• Mangrove covered shorelines are less likely to erode, or will erode far  more slowly, than un-vegetated coasts during storms as their roots hold the soil together

• Mangrove forests act as very efficient natural protection & is far cheaper than seawalls and similar manmade controls, which can actually increase erosion in front of the structure & further along the coast.

Drag and Drop

Mangroves protect shorelines during large storms by absorbing ​

Placeholder

and reducing the velocity of water.

A report by the International Union for Conservation of Nature (IUCN) showed that in a Sri Lankan village with dense mangrove and scrub forest, only ​

Placeholder

people died during the 2004 tsunami.

In comparison, up to ​

Placeholder

people died in a village without similar vegetation.

Wave energy can be reduced by ​

Placeholder

as waves pass through 200 meters of mangrove forests.

Mangrove-covered shorelines are less likely to ​

Placeholder

during storms, as their roots hold the soil together.

Drag these tiles and drop them in the correct blank above

75%

wave energy

2

6,000

erode

wind energy

10,

flood damage

50%,

1,000

​Succession and the creation of new land:

​Mangroves gradually extend land seaward, by the build up of sediment between their tangled roots – eventually to be replaced by land plants = ecological succession.

​CO2 Sequestration and mitigating global warming

Open Ended

Evaluate the benefits of the mangrove ecosystem.

(Which one is the best and why)

​In just the last decade, at least 35% of the world's mangroves have been destroyed, exceeding the rate of the disappearance of tropical rainforests

​Lesson Objectives

​To identify the goods and services of the mangrove ecosystem.

To analyse the threats and solutions to the mangrove ecosystem.

To summarise coastal ecosystems and practice exam technique

Open Ended

Why are mangroves being destroyed?

​

1. Coastal developments (industrial/residential building)

2. Shrimp aquaculture

3. Agricultural expansion (mainly rice) 

4. Unsustainable tourism

​Human threats to mangroves

​Mangroves at risk

​

• Mangrove forests are lost when they are torn up, filled in and dug under for other purposes such as agriculture, aquaculture and other development activities.

• People often wrongly perceive mangroves as unsightly and want them removed so as to enhance the environment.

• Mangroves then often become garbage dumps.

• Pollution degrades the quality of the plant life and the water in the swamp, which in turn adversely affects the insects and animals that also live there.

• The roots of the mangroves can become easily clogged with man-made sediments and petroleum.

​

• Mangrove Swamps often are mistakenly thought to be breeding grounds for mosquitoes and either flooded with insecticides or filled in with dirt hoping to prevent a mosquito infestation.

• Pruned mangroves grow fewer prop roots and fruit and this in turn provides a lower quality habitat.

• Pruning also diminishes shoreline protection and reduces the number of bird species using this habitat.

Match

Match the following

• Mangrove swamps are mistakenly thought to be breeding grounds for mosquitoes.

• Pruned mangroves grow fewer prop roots and fruit.

• People perceive mangroves as unsightly and want them removed

• Mangrove roots become clogged with man-made sediments and petroleum

• Pruning mangroves reduces shoreline protection

Leads to insecticide use.

Lowers habitat quality.

Increases shoreline erosion.

Pollution degrades plant life

Less root support for stability.

• Leads to insecticide use.

• Lowers habitat quality.

• Increases shoreline erosion.

• Pollution degrades plant life

• Less root support for stability.

Labelling

match the threats

Drag labels to their correct position on the image

pollution

overharvesting

climate change

river changes

destruction of coral

clearing

overfishing

​

1. Clearing– Mangrove forests have often been seen as unproductive and smelly, and so cleared to make room for agricultural land, human settlements and infrastructure, and industrial areas.

2. Overharvesting – While harvesting has taken place for centuries, harvesting of mangroves become unsustainable and threaten their future. Taking more than is replaced.

3. River Changes – Dams and irrigation (artificial watering of land) reduces the amount of water reaching mangrove forests, changing the salinity of water in the forest.

4. Overfishing – The global overfishing crisis facing the world’s oceans has effects far beyond the directly overfished population. The ecological balance of food chains and mangrove fish communities can also be affected.

​

Destruction of Coral Reefs – Coral reefs provide the first barrier against currents and strong waves. When they are destroyed, the stronger-than-normal waves and currents reaching the coast can undermine the fine sediment in which the mangroves grow. This can prevent seedlings from taking root and wash away nutrients essential.

Pollution – Fertilizers, pesticides, and other toxic man-made chemicals carried by river systems from sources upstream can kill animals living in mangrove forests.

Climate Change – Mangrove forests require stable sea levels for long-term survival.

Open Ended

Describe the changes that have happened to the mangrove forests in Nicaragua

​

One of the greatest threats to the world's remaining mangrove forests, particularly in Southeast Asia is shrimp mariculture.

​Shrimp aquaculture

Open Ended

What does this graph tell us and how will it impact mangroves?

Open Ended

How can mangroves be protected?

​International agreements

​

The Ramsar Convention 

• Examples of sustainable management of wetlands exist at varying scales due to the Ramsar Convention

• The Ramsar Convention was developed in Iran in 1971

• Over 60 countries endorse the Ramsar Convention 

• The aim of the Ramsar Convention is “the conservation and wise use of all wetlands through local and national actions and international cooperation, as a contribution towards achieving sustainable development throughout the world”

• The convention requires signatories to do the following:

  • Designate international wetlands

  • Sustain their ecological character

  • Plan for wise use

  • Allocate certain areas as nature reserves

• Over 500 Ramsar sites span 30 million hectares around the world

Open Ended

Summarise how Bangladesh is protecting its mangroves.

Open Ended

1. Name one benefit

2. Name one threat

3. Name one way to manage mangroves

​

All ecosystems  give us a wide range of natural resources we can harvest, collect or capture to sell and to make money from. This makes them valuable, however, it is threatening their existence. 

​Ecosystems

Categorize

Options (11)

Salt

Fish and shellfish

Construction materials

Land for settlement

Fishmeal and animal feed

Sea wood for food and industrial use

Protection from storms

Harbours

Biodiversity and wildlife habitats

Shelter

Recreational opportunities

Dilution and natural treatment of wastes

Organise the following into ‘goods’ (material resources that be extracted or used) and ‘services’ (general benefits and advantages)

goods

services

Open Ended

Write at least 2 reasons why each ecosystem is important.

Open Ended

List two threats for each ecosystem

Open Ended

Complete the exam question

​Lesson Objectives

​To identify the goods and services of the mangrove ecosystem.

To analyse the threats and solutions to the mangrove ecosystem.

To summarise coastal ecosystems and practice exam technique