Management of Coral Reefs (DP IB Geography)

Coral reef Characteristics

Characteristics of coral reefs 

• Coral reefs are productive environments

• Warm coral reefs are located in tropical and subtropical waters (above 18°C)

• Cold tropical reefs are located in deep, dark waters (4–12°C)

• Coral reefs are also fragile environments

• Any slight change in a coral reef environment can have devastating effects 

• Coral reefs form by small coral larvae (polyps) attaching themselves to rocks 

  • Polyps secrete calcium carbonate, creating a hard skeleton. Other polyps can then connect to this skeleton

  • Polyps can divide (clone) themselves. These clones connect, forming a large organism

  • These organisms connect further over time, forming large coral reefs

• There are three differing structures of a coral reef:

  • Fringing reefs 

    • The most common form of coral reef

    • Exist close to coastlines, like a border

  • Barrier reefs

    • Barrier reefs also exist on coastlines, but a deep lagoon separates the shore and the reef

    • Can form as fringing reefs grow and connect with each other

    • Very rare forms of coral reef

  • Atoll reefs 

    • As a volcanic island sinks beneath sea level and a fringing reef encircles it, atoll reefs form

    • They are circular shaped, with a lagoon in the middle

    • Found in the middle of the ocean

Formation of three coral reef structures 

Coral Reefs Uses & Value

Uses and value of coral reefs 

• Coral reefs are valuable ecosystems

• Stakeholders value and use coral reefs differently

• Coral reefs are also dangerously under threat

• All stakeholders must work together to reduce threats to coral reef environments

• Coastal protection

  • Coral reefs reduce the impact of strong storm waves, helping to reduce the erosion of the coastline

  • They protect coastal landscapes (e.g. mangrove swamps) and local communities 

  • Coral reefs are valuable to local residents and environmentalists 

• Resource use

  • Fish are abundant in coral reef environments. This provides food and livelihoods for local residents

  • Both commercial and subsistence fishing occur in coral reef environments

  • Coral reefs help to develop medicine. The biodiversity of reef systems provides treatments for diseases including cancer, asthma and other bacterial or viral diseases

  • Coral reefs are valuable to fishing industries and science development

• Tourism and the economy

  • Coastal areas with coral reefs attract millions of tourists each year

  • Divers and beach lovers alike bring vital tourism to coastal areas

  • Coral reefs boost the economy by providing jobs and bringing tourism to the area

  • From accommodation to boat crews, income from tourism is important for coastal communities

  • Coral reefs are valuable to tourists and the tourist economy

• Species habitat

  • Coral reefs are home to all types of species; they are incredibly biodiverse

  • From fish to mammals, coral reefs provide food, shelter and nursery for an estimated 25% of all marine life

  • Coral reefs are valuable to marine life and environmentalists

Threats

• Development

  • Coastline development for commercial and non-commercial practices puts pressure on coral reefs

  • Activities like quarrying, dredging, boating practices and recreation can damage coral reefs 

• Overfishing and harvesting 

  • Overfishing of coral reef environments can be disastrous for the food web

  • Coral reefs need fish to remove dangerous algae

  • Blast fishing can damage coral reefs’ structure

  • Harvesting coral reefs for the jewellery/souvenir industry can damage biodiversity and cause habitat destruction

• Pollution

  • Increased sediment (from development, agriculture, deforestation etc.) can choke coral reefs

  • Coral reefs require very little nutrients to function. More nutrients enter the coral reef environment from fertilisers, sewage and animal waste 

  • Algae growth increases with higher nutrient densities and uses vital oxygen and blocks sunlight

  • More harmful bacteria also grow with higher nutrient densities

  • Diseases enter coral reef environments from sewage, storm runoff and industrial and agricultural runoff 

  • Rubbish and microplastics also damage coral reef ecosystems

• Acidification and bleaching

  • Algae gives coral reefs their colour

  • As sea waters warm, coral reefs get rid of this algae, causing coral reefs to lose colour. 

    • This is coral bleaching

    • This exposes the calcium carbonate and leaves corals under stress

  • As carbon dioxide in the atmosphere rises, so too do carbon dioxide levels in the ocean 

    • Carbonic acid increases, resulting in ocean acidification 

Case Study: The Great Barrier Reef

The Great Barrier Reef, Australia 

• The Great Barrier Reef is the largest coral reef environment in the world

• Located in the northeast of Australia, along the coastline of Queensland

• It is over 1250 miles long

Location of the Great Barrier Reef

Threats

• Climate change

  • Sea waters around the Great Barrier Reef are rising in temperature, resulting in coral bleaching

  • Fears of flooding and storm intensity are exacerbated by climate change

• Runoff

  • Increased runoff from agriculture is a large issue

  • This increases nutrients, sediment and pesticides in the water

• Development

  • Past, present and future development poses a threat to the reef

  • These are agriculture, mining, urbanisation, industrial development, port development, aquaculture and tourism development

• Fishing and poaching

  • Overfishing

  • Illegal fishing

  • Incidental catch 

• Scale 

  • The Great Barrier Reef is vast. It is difficult to find enough funding, resources and people to protect the area

• Invasive species

  • Crown-of-thorns starfish

  • Lionfish

Management 

• World Heritage Site and a Natural Wonder of the World – this provides lawful protection and global recognition 

• Legislations

  • Created for The Great Barrier Reef area, Queensland, The Commonwealth, and the International level

• Reef 2050 plan

  • Long-term plan for reef sustainability

  • Bringing together governments, local communities and industries

  • Assesses values and threats to the reef, guiding professionals to where management is most necessary

• Education

  • Education and training is important for people like tour guides

  • Presentations on reef protection regularly show at the Marine Park Authority Office 

  • Regular research is carried out to assess management strategies and their effectiveness

  • Universities in Queensland offer courses for coral research

• Tools 

  • Zoning plans

    • Guiding where activities and industry can and cannot take place 

    • Includes ‘No Take Zones’, ‘Scientific Research Zones’, ‘Green Zones’ for recreation, and ‘General Use Zones’

  • Permits – most activities require a permit, e.g. tourism, infrastructure construction, boating 

  • Policies – environmental, scientific and tourist government policies are set in place

• Balancing stakeholders

  • Tourism management

    • Balancing the importance of tourism while protecting the reef

    • Guidance on managing reef tourism 

    • Future plans for tourism to be ecological as well as respectful to the heritage of the area

  • Heritage management

    • Respecting Aboriginal ownership of land and knowledge of the area

    • Working with Aboriginals and Torres Strait Islanders to protect the reef together

    • Training, programs, mapping and action plans

  • Science management 

    • Using scientific evidence to guide management practices

• Monitoring

  • Fluker posts involve tourists in monitoring strategies

  • Tourists use these posts to take pictures of the reef

  • Photos are transferred to a site for professionals to examine

  • Cost-benefit – this saves money and time for workers

• Species protection and control

  • Some species have different levels of protection (international, national, state or local)

    • This means they have lawful protection 

  • Species are also separated into threatened, at-risk or iconic

  • Some species must be controlled due to their negative impact, such as crown-of-thorns starfish outbreaks

    • Professional divers inject starfish to kill them (without harming the environment) 

• Reef restoration

  • Planting vegetation in canals to reduce sediment

  • Coral IVF – growing baby corals outside of the reef and replacing them back into degrading areas

  • Coral fragments – taking fragments and planting them elsewhere (underwater or onshore in tanks)

  • Cryopreservation – freezing tissue in nitrogen for future preservation, reducing the risks of species extinction 

  • Photogrammetry – monitoring the growth of the coral reef

• Traditional management

  • Indigenous People are using traditional and modern tracking methods to track animals like turtles 

  • There is a priority for subsistence fishing, limiting overfishing

  • Some areas of the reef are taboo, increasing protection

  • Some areas of the reef belong to Indigenous Groups