2.1 Ecosystems of the Planet

2.1.1 Ecosystems consist of interdependent components

Ecosystems include abiotic and biotic components which are independent:

Ecosystems are natural areas in which plants, animals and other organisms are linked to each other, and to non-living elements of the environment, to form a natural system. Each ecosystem is made up of biotic and abiotic elements.

Biotic = all living parts of the ecosystem (e.g. plants, animals and bacteria). Plants are known as flora and animals are known as fauna.

Abiotic = all physical, non-living parts of the ecosystem, including temperature, water and light.

Large scale ecosystems, known as biomes, spread across continents and have types of plants and animals that are unique to them. For example, polar bears are not found anywhere other than in the Arctic tundra. Biomes cover a wide area and are identified by their climate, soils, plants and animal species.

Each part of an ecosystem is interdependent. This means that they all rely on each other. Climate has the greatest influence over vegetation and soil within an ecosystem. Less rain means less vegetation can grow, which then means less food for the animals to eat. However, humans are increasingly changing ecosystems for our own use.

2.1.2 Ecosystems have distinct distributions and characteristics

Overview of the global distribution of ecosystems:

Climate and latitude are important factors that contribute to the location of the world’s major biomes, which broadly match the world’s climate zones. The world contains 8 major biomes. Each biome has its own climate characteristics which create distinct environments for a range of plants and animals to survive.

The map below shows the distribution of the world’s major biomes.

The table below shows the distribution of biomes according to temperature. Temperate means a region that has milder temperature, it is not too hot nor too cold. The UK has a temperate climate.

Temperature World ecosystems

Tropical1. Tropical rainforests2. Tropical grasslands3. Hot deserts

Warm temperate

4. Mediterranean

Cool temperate5. Temperate deciduous forest6. Temperate grasslands

Cold 7. Coniferous forest8. Tundra

Overview of the climate, plants and animals within these ecosystems:

You need an awareness of the characteristics of each of the eight major biomes. These are summarised below.

Polar Regions (e.g. Arctic Tundra) - found to the far north and south (poles)

Climate

- Long, cold winters and short, cool summers- Covered by snow and ice throughout the year but extent varies with the

seasons- Temperatures rarely rise above freezing (due to low angle of the sun in the sky)- Spend half of the year in darkness and half of the year in daylight- Tend to be dry, receiving as little as 250mm of precipitation per year

Flora (plants)

- Consists of permafrost, which means that the ground is permanently frozen- The above means that the poles are treeless- Low shrubs, reaching around 2m high, mosses, grasses and some flowering

plants grow- Approximately 1700 species of plant found in the tundra- Even less plants in Antarctica with around 100 species of moss found here

Fauna (animals)

- Land mammals include polar bears (Arctic only), wolves, foxes and reindeer- Sea mammals include walruses and whales.- Some mammals from the Arctic migrate south during the winter months- In Antarctica, penguins feed in the sea but live on land.

Tropical rainforests – found within the Tropics of Cancer and Capricorn

Rainforests now cover less than 6% of the Earth’s land surface, though this figure was once much higher. It is thought that Tropical Rainforests contain 50% of all plant and animal species. They are under threat due to deforestation (cutting down of the trees)

Climate

- High temperatures all year as the sun is directly overhead with variation over the year of only around 2°C (26°C - 28°C)

- Hot and wet climate- No seasons- Each day has 12 hours of daylight and 12 hours of darkness- Annual rainfall is very high, often over 2000mm- A heavy, thunderous downpour can be expected most afternoons

Flora (plants)

- The climate creates the perfect growing conditions for plants- Growing season is constant throughout the year- 15,000,000 plant and animal species have been identified with others yet to be

discovered- Vegetation consists mainly of trees.- In Amazonia, there may be as many as 300 species of trees in any one square

kilometre, such as mahogany, ebony and rosewood- There are distinct layers to the vegetation of the tropical rainforest: emergent

are the tallest at around 50m; then the canopy, which receives 70-80% of the sunlight and 80% of the rainfall, at about 30m; the under canopy is beneath at around 20m; with the shrub layer at the bottom where only small trees and shrubs survive. Less than 5% of sunlight reaches the forest floor

- The tallest trees are supported by buttress roots. These emerge over 3m above ground level to give the trees support

- Trunks are usually thin and branchless- Leaves are dark green and smooth and often have ‘drip-tips’ to shed excess

water- Vine-like plants, called lianas, grow around and between tree trunks and can

reach lengths of 200m

Fauna (animals)

- Many birds and insects live in the canopy layer.- Insects make up the largest single group of animals, such as stick insects and

ants- Toucans, jaguars, monkeys, chameleons, frogs and snakes are also found in

rainforests. The rainforests of the Borneo are one of the last habitats of orang-utan

- There is an abundance of amphibian species, such as the poison dart frog which has enough poison to kill 10 men!

Coral Reefs - found in tropical and sub-tropical oceans (between the Tropics of Cancer and Capricorn)

Found in the waters of 109 countries worldwide, on the seabed around the land, before the water depth increases. This is known as the continental shelf.

Climate - Needs to be warm water all year round, with a mean temperature of 18°- Water needs to be clear and shallow – no deeper than 30m

Flora (plants)

- Some of the most productive and diverse communities on Earth – nicknamed the ‘rainforests of the oceans’

- Less than 1% of the world’s ocean surface but contain around 25% of all marine life

- Relatively small range of plant species- Algae produce energy though photosynthesis, giving coral its bright colours- Sea grasses such as turtle grass and manatee grass are found in the Caribbean

Sea- Plants provide shelter and habitat for reef animals and provide food for

herbivores

Fauna (animals)

- Estimated 2,000,000 species living in Coral Reefs and 4000 species of fish alone- Made up of thousands of coral polyps which live together in reefs or colonies.

Although coral looks like a plant, it is in fact an animal related to the jellyfish- A single polyp is 2-3cm in length and feeds on tiny organisms such as plankton- Each polyp is a small and simple organism consisting of a stomach topped with

a mouth and tentacles- They secrete calcium carbonate to make a mineral skeleton which helps to build

the structure of the reef.- Corals take a long time to grow, averaging between 0.5 and 2cm per year- Examples of fish include parrot fish, starfish, clams, eels, molluscs, worms,

crustaceans and sponges. Larger mammals such as dugongs, which are related to elephants.

Tropical grasslands (also known as savannah) - found between 5° and 30° north and south of the Equator, within central parts of continents (e.g. Central Africa and northern Australia).

Range from the fringes of the rainforests to the beginning of the deserts.

Climate

- Depending upon location, can range from tropical wet to tropical dry- Temperatures are high throughout the year, averaging 25°- Cloud cover limited for most of the year- Two seasons: a longer dry season and a shorter wet season- Rainy season sees around 80% of annual rainfall- Longer dry season has rainfall as low as 100mm

Flora (plants)

- Grasses, such as pampas grass, can grow to over 3m in height during the rainy season

- Baobab tree has adapted to the conditions- Many trees are drought-resistant (xerophytic) or fire-resistant (pyrophytic) to

help survive the dry seasonFauna (animals)

- Over 40 species of hoofed animals, more than anywhere else in the world- Herbivores include gazelles and impalas, elephants, giraffes, wildebeest, zebras

and rhinos- Carnivores include cheetahs, lions and leopards.

Temperate grasslands - found between 40° and 60° north and south of the Equator, within central parts of continents (e.g. plains of North America and steppes of Eurasia).

Climate

- Cooler than the savannah, it is an ecosystem of extremes.- Summer temperatures can reach over 38°C and winter temperatures can

plummet as low as -40°C- Average rainfall varies from 250mm to 750mm- Around 75% of rainfall during the summer season- Can experience droughts during the summer months

Flora (plants)

- Vegetation doesn’t grow as rapidly as in the savannah- Trees and shrubs struggle to grow, but some trees, such as willow and oak,

grow along river valleys- Tussock grass reach heights of 2m- Buffalo grass and feather grass grow up to around 50cm- Flowers such as sunflowers and wild indigos grow among the grass

Fauna (animals)

- Lots of burrowing animals, such as gophers and rabbits and large kangaroos, bison and antelopes (depending on location)

- Carnivores include coyotes and wolves as well as large birds such as eagles and hawks

Temperate Forests - found between 40° and 60° north and south of the Equator, within central parts of continents. Includes a wide range of forest types, but forests are mostly made up of deciduous or evergreen trees. This is where the UK is located (deciduous forest).

Climate

- Four seasons of equal length: winter, spring, summer and autumn- Summers are warm and winters are mild- Rainfall ranges from 750mm to 1500mm- Average annual temperature is 10°C- Cloud cover helps to keep temperatures warmer in winter- Precipitation falls throughout the year- Has the second highest rainfall after tropical rainforests

Flora (plants)

- Trees have a growing season of 6-8 months and may grow only 50cm per year- Deciduous trees shed their leaves during the winter season- In Britain, oak trees can grow 30-40m high and each tree can produce 90,000

acorns per year- Elm, beech, sycamore and chestnut trees grow less tall- Trees and shrubs also found here, growing to about 5m in height- Forest floor is often covered with brambles, grass, bracken and thorns

Fauna (animal

- Animals must adapt to cope with the warm summers and colder winters, including migration and hibernation

s)

- Type of animals depend on the location in the world with many native to certain places

- Australia’s temperate forests include koalas and opossums- Black bears are found in North America- In the northern hemisphere, squirrels are widespread. Owls and pigeons are

found in almost all temperate forests- In Britain, rabbits, deer, mice and foxes are found

Hot Deserts - found between 5° and 30° north and south of the Equator, usually on the west coast of continents (e.g. the Sahara and Arabian deserts). Cover around 1/5 of the Earth’s land surface.

Climate

- Experience a fairly high number of daylight hours ranging from 14 hours in the summer to 10 hours in the winter

- Temperatures during the day can reach 36°C, with extremes as high as 50°C recorded

- At night, temperatures plummet well below freezing, down to -12°C or lower- Annual precipitation is around 40mm and unreliable- In Death Valley, California, rain may fall only once every 2-3 years

Flora (plants)

- Most plants are xerophytic, meaning they can cope with very little water- Cacti and yucca plants are examples- Where rainfall is slightly higher, grasses can grow

Fauna (animals)

- Lack of plants makes it difficult for deserts to support many animal species- Many animals are small and nocturnal (only come out at night)- With the exception of camels, animals could not survive in the sun so burrow

into the sand- Examples include meerkats, scorpions, lizards and sidewinder rattlesnakes but

this depends on which part of the world you are in

2.1.3 There are major tropical rainforests in the world2.1.5 Bio-diverse ecosystems are under threat from human activity – Tropical Rainforests

Location of tropical rainforests:

Tropical rainforests are found in a broad belt through the Tropics, from Central and South America through central parts of Africa, South East Asia and into the northern parts of Australia.

Processes that operate within tropical rainforests, including the nutrient and water cycles:

Nutrient cycling is rapid in the rainforest. Figure 3 shows the relationship between biomass, soil and litter. The size of the circles indicates the amount of nutrients held in each store.

- The forest floor is hot and damp, which enables dead plant leaves to decompose quickly. This explains the small circle for the leaf litter. This decomposition can occur within three to four months in the rainforest, whereas in the UK, it can take two or more years for leaves to decompose.

- As organic material, such as leaves, decays, it is recycled so quickly by the nutrient-hungry plants and trees that few nutrients ever reach the soil. The circle for the soil is even smaller than the litter. This is why many trees have their roots close to or above the surface of the ground, so that they are poised to take advantage of any nutrients available.

- The greatest store of nutrients is in the biomass, the living plants and animals.

Key words: Litter = total amount of organic matter, including humus (decomposed material) and leaf litterBiomass = the total mass of plants and animals in the ecosystem

The water cycle:

Amazon

Central American

Congo River Basin

Madagascan

South East Asian

Australasian

Rainforests produce their own rainfall. As the rainforest heats up during the morning, the water evaporates into the atmosphere and forms clouds to make the rainfall for the next day. This is called convectional rainfall.

Water is lost through pores in leaves and then evaporated by heat in a process known as evapotranspiration. The roots of plants take up some moisture through transpiration, but much of the water is evaporated from the canopy later. The canopy also intercepts most of the rainfall.

The removal of trees by exploitative practices means that there is less moisture in the atmosphere and rainfall declines. This can sometimes lead to drought, as can happen is the Amazon region.

Tropical Rainforest Case Study: the Peruvian Amazon

Located in South America, Peru has the second largest portion of the Amazon Rainforest, after Brazil. Tropical Rainforest makes up 60% of Peru, yet only 5% of Peruvians live in this region. The Peruvian Amazon is the third largest rainforest in the world.About 44% of all bird species and 63% of all mammals live in the Peruvian rainforest. It is a fragile ecosystem that involves complex interrelationships and interdependence between abiotic and biotic factors such as plants, animals and humans. Interdependence in a tropical rainforest:The diagram to the right shows some of the interdependence within a tropical rainforest. For example, the vegetation relies on the sun and rain for growth, and they are in eaten by herbivores. Carnivores rely on herbivores for their food supply. Animals excrete (poo) and leaves drop their leaves, which with the help of decomposers, help nutrients return to the soil to help the plants to grow. Humans rely on the rainforests for food supply and for the wood that can be found there.

Value to humans:1. Biodiversity – Peru has 2937 known species of animals, 16% of which do not exist in any

other country2. Timber – there are many highly valued hardwood trees in Peru and logging is widespread3. Minerals – there are valuable minerals including oil, natural gas and gold4. Hydro-electricity – there are plans to construct 15 large dams in the Peruvian Amazon,

primarily to export electricity to Brazil 5. Indigenous tribes – many traditional tribes live in the Peruvian Amazon, some of which

have never been contacted. They live a simple, but sustainable life, deep in the jungle6. Medicinal plants – the Peruvian Amazon has been described as a ‘pharmacy’ because of al

of the medicinal plants that exist. Scientists believe that some rainforest plants can help cure diseases such as cancer, and the possibility of more plants as yet to be discovered.

Value to the planet:1. Water cycle – rainforests give off water from their leaves during the process of

transpiration. This increases humidity in the atmosphere and increases rainfall. When rainforests are cut down the climate becomes drier

2. Carbon cycle – rainforests take in carbon dioxide from the air as they grow and photosynthesise. The trees store a lot of carbon. Carbon dioxide is a greenhouse gas which is partly responsible for climate change and global warming. Less trees equals more carbon in the atmosphere.

Threats to biodiversity: Rainforests across the world are under threat from a variety of pressures and deforestation is a global concern. The main threats in the Peruvian Amazon are:

1. Timber – the many valuable hardwood trees in the rainforest, in particular the mahogany, has resulted in extensive logging. Up to 95% is thought to be illegal. Profits are so high that trees are even being felled in protected areas such as National Parks. Deforestation is a brutal operation that often takes out great areas of forest, severely affecting biodiversity

2. Energy – there are valuable reserves of oil and natural gas in the Peruvian Amazon. China has invested in oil exploitation in Madre de Dios region, an area that is home to more than 10% of the world’s bird species. The extraction of oil can lead to oil leaks and serious pollution of water

3. Gold mining – gold is found in alluvial (river) deposits in the Peruvian Amazon. This is exploited by huge machines and often involves the blasting of the river banks and the removal of rainforest to provide access. Mercury is used and this is highly toxic, causing harm to aquatic ecosystems and poisoning local tribes who depend upon rivers for food and water

4. Highways – one of the most significant threats to Peru’s rainforests in the south-eastern part of the country is the Trans-oceanic Highway, a road project that will connect Pacific ports to a major highway in Brazil. It is feared that the road will lead to deforestation and worsen illegal logging. In 2015, plans were announced to extend the road through Manu National Park, described by UNESCO as a place where biodiversity ‘exceeds that of any other place on earth’

5. Agriculture – increasingly lowland areas are being deforested to create land for farming, particularly for growing soybeans and for rearing cattle. Fires used to clear land can sometimes burn out of control, wiping out valuable habitats and killing animals.

Attempts to mitigate these threats through sustainable use and management:Despite its economic riches, the Peruvian government is acutely aware of the need to conserve its rainforest for future generations. Several NGOs, such as the World Wide Fund for Nature, are working with the government to encourage sustainable management and conservation of forest resources and wildlife in the Peruvian Amazon.

- Since 2000, management plans are required for all forest-related harvesting activities. The emphasis is on sustainable management in line with the requirements of the Forest Stewardship Council (FSC). With so much illegal logging and such a vast area to police, implementation of this law faces huge problems.

- Indigenous community reserves have been established, giving local communities land ownership and rights over the extraction of materials from their land. These communities have their own sustainable management plans.

- National Parks and National Reserves have been established to protect certain areas of high biodiversity.

The Purus-Manu Conservation CorridorLook at Figure 12. It shows the so called Purus-Manu Conservation Corridor in the Madre de Dios region in southeast Peru close to the border with Brazil. It is made up of the Alto Purus and Manu National Parks together with several territorial reserves for indigenous communities.The Purus-Manu Conservation Corridor project supports long term biodiversity conservation in benefiting the native communities living in the Corridor. Comprising an area of over 10 million hectares, this is the largest preserved area in the Peruvian Amazon. It is recognised as being one of the most biodiverse regions in the world.The 60 or so local communities depend on the rainforest for water, food, medicine, clothing and housing. Some of these communities are among the most isolated in the rainforest and wish to remain so. Elsewhere, they have been driven out by illegal logging, ranching and highway construction. It is the largest area of responsibly managed forest in Peru and functions as a refuge for threatened species, such as river dolphins, red howler monkeys, spectacled bears and mahogany.Management strategies to control developments and protect indigenous communities were put in place in 2015, to enable the Corridor to be managed in a sustainable way for the future.

2.1.4 There are major coral reefs in the world2.1.5 Bio-diverse ecosystems are under threat from human activity – Coral Reefs

Location of coral reefs:

A coral reef is a rocky ridge built up from the seabed by coral animals. It is one of the richest ecosystems on Earth and is extremely biodiverse. Some living reefs are several million years old.Coral reefs are extremely important ecosystems. They support a great number and a huge variety of fish and other organisms. Millions of people living close to coral reefs depend on them for their livelihoods, and from their protection from tropical storms and tsunami.Warm coral reefs need certain conditions to survive and thrive. This explains why they are found in the Tropics.

There are three main conditions needed for coral reefs to form.- Temperature – they only live in seawater that has an average temperature of 18°C and

over. The ideal temperature is between 23°C and 25°C. This explains why coral reefs are found in the Tropics.

- Light – corals feed on tiny algae and the algae need light to photosynthesise and grow. If there is not enough light, there will be no algae and if there is no algae there will be no coral. This explains why coral reefs are found in relatively shallow water where there is maximum light available.

- Clear water – corals survive best in clear unpolluted water. Sediment in the water affects the coral’s ability to feed as well as reducing the amount of light. This explains the lack of extensive reefs close to river mouths.

The map below show the location of the world’s coral reefs (red dots)

The process of nutrient cycling that operates within coral reefs:

Nutrient cycling involves the flows of nutrients (foods) within an ecosystem. Coral reefs are one of the most diverse and complex ecosystems in the world. Described as the ‘tropical rainforest of the sea’, in common with rainforests, their interrelationships are very fragile. The slightest change can have serious knock-on effects.Corals live in nutrient-poor waters. It is only through very efficient nutrient recycling that corals maintain such a diverse ecosystem. At the heart of the recycling is a symbiotic relationship that exists between coral and algae. Symbiotic means that both organisms benefit from an association with each other.

- Zooxanthellae (plant-like algae) live within the tissues of the coral polyp (see right). They are able to harness the light from the sun, converting it into energy, just like plants, to provide nutrients to the corals.

- In exchange, the zooxanthellae benefit by having exclusive access to the waste nutrients produced by the coral. These wastes (nitrogen and phosphorus) fertilize the algae. They also have somewhere to live!

The most important nutrient is nitrogen. The symbiotic relationship between the algae and the coral captures and retains nitrogen very effectively. It is simply passed back and forth between the two organisms. In open waters, free-floating algae and marine animals lose nitrogen to the water, so nitrogen recycling is less effective.

The close relationship between coral and algae is supported by nutrients obtained from the water and from the consumption of microscopic prey called zooplankton (see left). Zooplankton obtains nutrients by consuming phytoplankton, a primary producer living in the ocean that converts light from the sun directly into energy. Corals are also able to digest bacteria and edible detritus that often enter the system by upwelling from the ocean floor.

Fish also have a role to play. They constantly excrete ammonia (a dissolved form of nitrogen) into the water and this can be absorbed by corals and algae. Fish also benefit from coral reefs in finding both food and shelter from predators.

Coral Reef Case Study: the Andros Barrier Reef, Caribbean

The Andros Barrier Reef is part of an extensive coral reef system in the Bahamas, off the southeast coast of Florida, USA (see right). The entire reef is the third most extensive coral reef system in the world. The Andros reef, centred on Andros Island, is called a ‘barrier reef’ because it forms a linear feature parallel to the shoreline separated from it by a lagoon.The Andros Barrier Reef stretches for approximately 200 km. A shallow lagoon with mangrove forests separates the land from the main reef itself. The outer edge of the reef is marked by a steep drop to a depth of over 2000 m known as the ‘Tongue of the Ocean’.Interdependence in a coral reef:Over 164 species of fish and coral make up the reef community. They include the red snapper, reef shark, rock lobster, sharp nose puffer and the green turtle, together with many colourful species of coral.The different species are closely interrelated in this unique habitat. The fish benefit from the safety and shelter of the reef for breeding. They obtain their food from the plankton, crustaceans and other fish. Coral benefits from nitrogen excreted through the gills of fish and from detritus swept up by the swirling fish shoals.The warm tropical climate is ideal for reef formation and the waters are relatively clean and clear. This enables sunlight to penetrate into the water so that zooxanthellae and phytoplankton can photosynthesise effectively. Phytoplankton is at the bottom of the food chain. Without it, the ecosystem would not survive.Humans are an important part of the coral reef ecosystem. They can cause damage to the ecosystem through overfishing, tourism and mining. Coastal developments can lead to silt being washed into the reef system, clouding the waters and choking the corals. On the positive side, people can act as stewards monitoring coral reefs and helping to protect and preserve them.Value to humans and to the planet:The Andros Barrier Reef is important for several reasons:

- Coastal protection – Coral reefs act as buffer zones providing vital shoreline protection from storms and tsunami. The Bahamas occasionally gets struck by tropical storms and the shallow water above a reef forces waves to break early before reaching the islands. This reduces coastal erosion and the risk of flooding.

- Fish breeding grounds – Corals provide sheltered conditions for the growth of mangrove forests, which themselves are important breeding grounds for fish. Fish are important commercially and for tourism, as well as being vital elements in the reef ecosystem. In the Bahamas, local and export markets for snapper, grouper, lobster and conch generate millions of dollars.

- Tourism – The reefs in the Bahamas are the base for commercial and recreational activities like fishing, sport fishing, cruising, snorkelling and scuba diving. These industries bring in over US$150 million per year. The vertical wall and sunlight penetration due to its east-facing aspect makes Andros Barrier Reef one of the most spectacular diving experiences in the region.

- Healthy coral reef – The Andros Barrier Reef is recognised as being one of the healthiest reefs in the world. As such it is superb outdoor laboratory for scientific research in the face of serious problems faced by coral reefs elsewhere.

On a larger scale, coral reefs are important to humans and the planet. They provide jobs, livelihoods, food, shelter, and protection for coastal communities in the tropics.Threats to biodiversity: In many parts of the world, coral reefs are under threat from natural causes – primarily climate change – and the actions of people. They are considered by scientists to be one of the most endangered ecosystems on the planet.The Andros Barrier Reef – in common with many reefs elsewhere in the world – faces among threats to its biodiversity. Some of these can be seen below:

- Over-fishing – Commercial fishing and intensive tourism can cause immense harm to the ecosystem, causing it to become unbalanced. Corals can be killed by physical contact with anchors, boat hulls and even people’s feet. The harvesting of sponges is an important local industry but can also have a harmful impact on the reef ecosystem.

- Pollution – This can involve agricultural chemicals, sewage and silt, eroded from hillslopes and discharges by rivers. Silt causes the water to become cloudy restricting the penetration of sunlight used by zooxanthellae to photosynthesise.

- Climate change and global warming – Higher water temperatures trigger a stress reaction in corals causing them to expel the zooxanthellae. This has a huge effect on nutrient flows and causes the coral to become bleached, turning white. Eventually the coral dies. Projections from climate models suggest that reefs in the Bahamas will experience thermal stress severe enough to cause bleaching after 2040.

- Marine-based pollution – This results from oil and chemical discharges from boats and ships. The Andros Barrier Reef is very popular for deep sea fishing and such discharges can be harmful to both corals and fish.

Attempts to mitigate these threats through sustainable use and management:Management of coral reefs in the Bahamas is shared by the Department of Marine Resources (DMR) and the Bahamas National Trust (BNT). The government is committed to protect 20 per cent of its near-shore habitat by 2020. There are several National Parks and Reserves established to help preserve parts of the valuable reef ecosystem.

- The Andros West Side National Park, includes Andros Island and part of the coral reef. The National Park was designated by the government in 2002 to balance longstanding traditions of the island, such as fishing and sponging, while also promoting resource conservation, recreational fishing and ecotourism. Developments in the National Park are strictly controlled.

- The North Marine Park and South Marine Park were established in 2002 on the eastern side of the island. These are areas of conservation where some activities are regulated or prohibited, such as fishing and collecting wildlife, mining, vessel anchoring, scuba diving and the discharging of materials.

- The Crab Replenishment Reserve has been identified as the best land crab habitat in central

Andros. This area was set aside to ensure a sustainable crab population for future generations.

- In the Exuma Cays Land and Sea Park, a coral nursery has been established. Here, threatened species are conserved and monitored-prior to being planted back in the coral reef.

- There are plans to establish a new National Park to the north of Andros Island at Joulter Cays. This part of the reef is prized for its fishing and for its varied and extensive shallow water ecosystem. It is under pressure from excessive fishing, damage from boats and marine discards.

Several organisations monitor the environmental quality of the reef ecosystem to assess coral bleaching and to identify any harmful impacts from human activity. Fortunately, the Andros Barrier Reef remains one of the healthiest reefs in the world.