Edexcel IGCSE Geography 复习笔记 2.2.3 Threats to Coastal Ecosystems

The Value of Coastal Ecosystems

• All ecosystems offer people a range of opportunities – goods and services
  • Goods – a material resource that can be extracted and used
  • Services – general benefits and advantages
• Coastal ecosystems can provide the following:

Industrial Threats

• Threats to Coral Reefs
  • Coral reefs are easily stressed by human action, if the stress persists, then the death of the reef soon follows
  • Pollution, overfishing and quarrying of coral for building stone
  • Industrialisation is responsible for rising sea temperatures and sea-level rise, putting coral reefs under threat
  • Rising sea temperatures increase levels of coral bleaching
• Threats to Mangroves
  • Pollution, overfishing and deforestation for aquaculture
  • Clearance for land development particularly in developing countries
• Threats to Sand Dunes
  • Least threatened at a global level due to value being mainly tourism and leisure
  • Local level the biggest threat is sand mining
• Threats to Salt Marsh
  • Industrial pollution
  • Ideal sites for nuclear power stations
  • Clearance for development - commercial and private
  • Development can lead to increased noise and light pollution which may affect wildlife behaviour and nesting

• Threats to Coral Reefs
  • Overfishing reduces the number of grazing fish that keep coral clear of algae
  • Fishing using explosives damage coral reefs
  • Commercial farming
  • Fertiliser runoff
  • Pesticide overspray
• Threats to Mangroves
  • Aquaculture - intense fish and shrimp farms
  • Pesticide use
  • Antibiotics used in aquaculture practices
  • Clearance for farm development particularly in developing countries
• Threats to Sand Dunes
  • Destabilisation due to grazing animals on dunes
• Threats to Salt Marsh
  • Drained and cleared for farming
  • Eutrophication through heavy use of fertilisers
  • Pollution from pesticides and herbicides
  • Slurry run-off from cattle

• Threats to Coral Reefs
  • Tourism is the biggest threat globally and locally to coral reefs
  • 58% of all coral reefs are at threat from human activity
  • Any contact with the human body is likely to kill coral immediately around the point of contact
  • Propellers and anchors directly damaging corals from boat tours
  • Pollution through diesel spills
• Threats to Mangroves
  • Clearance of mangroves to build hotels and other tourist attractions
  • Diversion of fresh water to hotels etc
  • Disturbance of habitats
  • Collection of souvenirs by tourist
  • Tours in waterways and pollution through spills of boat fuel
• Threats to Sand Dunes
  • Largest threat to sand dunes due to trampling of delicate, unfixed dunes
  • Driving using 4x4 or quadbikes over sand dunes
  • Sporting events - sand surfing etc
  • Collecting shells and driftwood
  • Pollution from rubbish left by tourists
  • Car parks
  • Sand mining for building hotels
  • Development of seaside towns
• Threats to Salt Marshes
  • Tourism is limited to the local level and nature reserves
  • Roads have divided salt marshes cutting off parts of it
  • Trampling by visitors
  • Dog walkers letting dogs roam and disturb the wildlife
  • Noise from local tourist areas may disturb the wildlife

• Threats to Coral Reefs
  • Clearance of coastal forests and mangroves disturbs natural flows of water and nutrients leading to stress and coral bleaching
  • Removal of coral reef for stone building or tourist sales
  • Any destruction of coral reef leaves the coastline open to coastal flooding and storm surges
• Threats to Mangroves
  • Removal of the trees leads to the collapse of the ecosystem
  • Leaves the coast open to storms, flooding and coastal retreat
  • Mangrove wood is used for timber and fuel
  • Cleared to reduce malaria - unsupported evidence that this works
• Threats to Sand Dunes
  • Removal of trees destroys the mature dunes and allows for dune migration
  • Leaves coast open to storms and flooding
• Threats to Salt Marshes
  • Real threat is through industrialisation and agriculture

转载自savemyexams