Chapter 1 Gateway 2 Flashcards
Describe how coast can be used for fisheries and aquaculture.
The worldwide demand for fish has grown so much that large areas of the world’s ocean are overfished. Thus, people rear fishes in fisheries. Fisheries are areas where fish are bred and raised to meet the demand for fish. Aquaculture include farming fish in cages or ponds close to coasts, in rivers or converted wetlands. In Ca Mau, Vietnam, more than 60,000 hectares of coastal mangroves were cleared and converted to shrimp farms in the 1980s. Production of shrimp farms accelerated and reach a record high of US$800 million in 2010.
Explain how coast can be used for housing and transportation.
Housing refers to shelter provided for people, example is stilt houses. These houses are connected by walkway and there are boats to facilitate movement, which are mode of transportation. Kukup, Malaysia is a place with stilt house community. Air Masin is one village in Kukup with about 180 stilit houses. Boats are used for local fisherman to facilitate their fishing activities. There are also frequent and scheduled ferry services which visitor use to visit Kukup island.
Explain how coast can be used for tourism and recreation.
Tourism involves the temporary movement of people, primarily for leisure and recreational purposes. Recreation involves activities done for enjoyment when one is not working. Coasts are therefore popular for tourism and recreation. In Sentosa, Singapore, ONE॰ 15 Marina Club which has world-class marina services. Its marina is in a harbour with wharfs offering maintenance services for boats and yachts. It also have recreational boating facilities. Resorts World Sentosa has also maximised the use of its waterfront bybuilding its hotel, museum and marine life park on the coast. With these attraction, it is not surprising that the island had 19 million visitors in 2011.
What are coral reefs?
Coral reefs are structures that develop at, or slightly below sea level on the seabed They are built by and made up of thousands of tiny animals known as coral polyps, which secrete rock-like deposits of calcium carbonate to protect the soft and delicate body of the polyp. After colonies of coral polyps die, new polyps continue to live on the reef, while calcium carbonate skeletons accumulate as limestone
What are the envornomental condition suitable for growth of mangrove?
Average seawater sanlinity of 34 to 37 parts per thousand.
A moderate amount of water movement ensures that coral reefs receive sufficient level of oxygen.
Low amount of sediments as sediments may suffocate coral reefs.
Sea surface temperature not lower that 17 to 18 degree celsius.
Clear saline water between 10 and 60 metres deep allow sufficient sunlight to penetrate, triggering algae photosynthesis.
The turbidity of water, which refers to its level of murkiness, is low enough to allow sufficient sunlight to penetrate.
Explain the value of coral reefs to man and the environment.
Coral reefs absorb wave energy, thus protecting the adjacent land mass from erosion.
Coral reefs supports natural ecosystems, allowing a wide range of marine creatures to breed and grow. It is also habitats for plants and animals to live in.
Coral reefs provide food for larger creatures. For example, parrot fish graze on the living coral polyps and larger fish prey on the parrot fish.
With reference to examples, explain the pressures on coral reefs.
In Philippines, there is an overcollection of corals for personal and commercial use. The overcollecting of corals weaken them and disrupts the coral ecosystem, making them more vulnerable to threats.
In Philippines and Indonesia, there is dynamite blasting and the use of cyanide to stun fish, resulting in coral reef habitat being destroyed.
In Belize Bonaire, the Netherlands, there is spearfishing. The selective depletion of fish population disrupts the food chain in the ecosystem. For example, the spearfishing of parrotfish, which feed on algae, lead to the increased algae growth that affects corals.
In Sri Lanka, there is tourism activities usch as the sometimes unplanned expansion of coastal resortd and the anchoring of boats. Sewage waste discharged into the water and oil spills from boats pollute the water. Boats anchors may damage corals.
In Japan, there is reclaimation and extension of land areas by dumping rock and sand onto reefs. Coral reefs are suffocated by sediments and are destroyed.
In Florida, the expansion of coastal resorts and urban housing increases the waste being deposited into the sea. Coral reefs are suffocated by sediments and destroyed.
In Seychelles, due to climate change, rapid changes in sea temperatures and sea level is faster than the ability of the reefs and associated life form to adapt. Coral bleaching occurs whereby the coral turns completely white or be bleached. This occurs when higher sea temperature result in the loss of algae.
What are mangrove ecosystem?
Mangrove species are salt-tolerant tropical or subtropical plants which grow in conditions that most plants are unable to . They grow on tidal mud on sheltered coasts. They are home to their own unique communities of plants and animals
State the adaptations of mangrove.
Avicennia and Sonneratia have pencil-like aerial breathing roots that take in oxygen during parts of the day when they are not submerged.
Rhizophora have prop roots to anchor the trees firmly in the soft, muddy ground which ensure that trees will not be uprooted or swept away by the strong waves.
Bruguiera have kneed roots to trap soil between their roots, which is essential for plant growth.
Mangroves have javelin shaped fruit to pierce the soft mud to germinate and grow into a sapling immediately. Mangrove have buoyant fruit that float away and germinate in other coastal areas. This increase their chances of survival.
Mangroves are salt tolerant and have developed ways to secrete excess salt. Some species do this through the underside of the leaf.
Explain the value of mangrove.
Mangrove play a key role in stabilising shoreline. Their dense network of roots can absorb energy of waves, thus slowing flow of water.
The dense network of mangrove roots and the build-up of sedimensts can help protect coastal areas from erosion by tides, storm waves and tsunamis. Mangroves absorb the forces of storms due to their dense root system. As the storm waves approach the coast, their speed is reduced due to friction, hence reducing the impacts of storms on coasts.
The mangrove environment is also a breeding ground and habitat for a range of marine creatures. Barnacles, oysters and sponges anchor on the hard surface of the aerial roots; shrimps, crabs and lobsters forage for food in the muddy sediment between mangrove roots; and a variety of fish breed in nearby waters.
A United Nations Environment Programme report in 2006 estimated that the annual value of mangroves to an economy was between US$200,000 and US$900,000 per square kilometre. These figure include the value of mangrove that protect beaches and fish, provide building material, improve water quality and even contribute to tourism and recreational activities.
With reference to specific examples, explain the pressure on mangroves.
In Indonesia, mangroves are cleared for fuel and charcoal, particularly in regions with low technology and low income economies. Fish breeding grounds are reduced. Coasts are more open to storm waves.
In Vietnam and Thailand, thousands of hectares of the flat, well-watered mangroves are converted into paddy fields and shrimp farms. Mangroves are cleared and coasts become more vulnerable.
In Caribbean islands, land is reclaimed for housing, industry and recreational uses. Mangroves largely disappear from the environment. Coastal waters are polluted as a result of human activities
In Gulf of Thailand, Rising sea levels and extreme storm activity will occur if climate change accelerates. Mangroves will have trouble colonising areas further inland despite sea level rise as they will be in competition with human activities such as farming and the construction of sea defences
