CORAL REEF

CORAL REEF

The coral reefs can be defined as a ridge or mound of limestone, the upper surface of which is near the surface of the sea and which is formed by calcium carbonate through the actions of organisms, chiefly corals.

Corals are marine invertebrates or animals that do not possess a spine. They are the largest living structures on the planet. Each coral is called a polyp, and thousands of such polyps live together to form a colony, which grows when polyps multiply to make copies of themselves.

Formation:

• Larva settlement: Coral reef formation begins with free-swimming coral larvae attaching to submerged rocks or other hard surfaces along the edges of islands or continents.
• Growth stage: As these corals grow and expand, they take the form of reefs as fringing, barrier, or atoll types.
• Ideal Conditions for Coral Growth:
  • Stable climatic conditions: With the presence of sunlight.
  • Perpetually warm waters: Around 20°C (Ideal: 23°C to 25°C).
  • Shallow water: 45 to 55 meters below sea surface.
  • Clear saltwater: With salinity between 27% to 40%.
  • Abundant plankton: For nutrient supply.
  • No pollution: Corals are sensitive to pollution and sediments.

Importance:

1. Environmental:

• Maintain quality of coastal: Coral reefs support a wide range of species and maintain the quality of the coastal biosphere.
• Carbon sequestration: Corals control the level of carbon dioxide in the water by converting it into a limestone shell.
• Habitation: Corals provide habitats and shelter for many marine organisms and are the source of nitrogen and other essentials.
  • For example: About 25% of the ocean’s fish depend on healthy coral reefs.
• Nutrient recycling: Nutrients for marine food chains, assisting in carbon and nitrogen fixation.
• Climate change record: Coral reefs are climatologically important because they provide an accurate long-term record of climate change, helping extend our knowledge of seasonal climate variability in remote tropical oceans.
• Clean nearby water: Most corals and sponges consume particulate matter suspended in the water column, contributing to enhanced quality and clarity of nearshore waters.

1. Economic:

• Medicinal value: Many drugs are being developed from coral reef animals and plants as possible cures for cancer, arthritis, bacterial infections, viruses, and other diseases.
• Fishing industry: The fishing industry depends on coral reefs because many fish spawn there, and juvenile fish spend time there before heading into the open sea.
  • For example: The Great Barrier Reef generates more than $1.5 billion every year for the Australian economy from fishing and tourism.
• Tourism: In Australia, the Barrier Reef, in pre-COVID times, generated $4.6 billion annually through tourism and employed over 60,000 people, including divers and guides.
• Livelihood: Local economies receive billions of dollars from visitors to reefs through diving tours, recreational fishing trips, hotels, restaurants, and other businesses based near reef ecosystems.
• For example: A study estimated the value of coral reefs at $10 billion and direct economic benefits of $360 million per year.

1. Geographic:

• Protect Coastal Areas: Protect coastlines from the damaging effects of wave action and tropical storms.
  • For example: During the IOR tsunami of December 2004, some coastlines were protected from severe damage because of healthy reefs.
• Monsoon forecasting: According to the Indian Institute of Meteorology, coral reefs can provide insight into the monsoon system.

Location:

Coral Reefs in India:

• Gulf of Kutch: Fringing reefs.
• Lakshadweep: Coral atolls.
• Gulf of Mannar: Fringing reefs.
• Andaman and Nicobar Islands: Fringing reefs.

Coral Triangle:

• Triangular area of the tropical marine waters of Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands, and Timor.

Threat Factors:

1. Environmental:
   • Ocean acidification: Change in the pH of ocean water starts coral bleaching.
   • Extreme climatic conditions: Extreme climatic conditions make corals hostile, increasing the chances of bleaching.
   • Solar radiation and ultraviolet radiation: Changes in tropical weather patterns result in less cloud cover and more radiation, which induces coral bleaching.
   • Water pollution and surface runoff: Decreases the clarity of water, which restricts the formation of corals.
   • Rise in temperature: High temperature of water leads to the decline of these corals as they cannot survive in high temperature.

1. Geographical:
   • Subaerial Exposure: Sudden exposure of reef flat corals to the atmosphere during events such as extreme low tides, ENSO-related sea level drops, or tectonic uplift can potentially induce bleaching.
   • Fresh Water Dilution: Rapid dilution of reef waters from storm-generated precipitation and runoff has been demonstrated to cause coral bleaching.
   • Infectious Diseases: Penetration of bacterium like Vibrio shiloi inhibits photosynthesis of zooxanthellae. These bacteria become more potent with elevated sea temperatures.
2. Anthropogenic:
   • Coastal development: Development of coastal infrastructure and tourist resorts on or near these coral reefs causes significant damage.
   • Sedimentation: Construction along the coasts and islands leads to soil erosion, increasing sediments in the river. This can smother corals by depriving them of light needed to survive.
   • Pollution: Toxic pollutants dumped directly into the ocean can poison coral reefs by increasing the nitrogen level of seawater, leading to an overgrowth of algae.
   • Overfishing: It is a major concern as it leads to an ecological imbalance of coral reefs.
   • Blast fishing: Use of explosives destroys coral reefs indiscriminately.
   • Bottom Trawling: This destroys the corals at the bottom and margins of continents and islands.
   • Recreational activities: Physical damage to coral reefs can occur through contact from careless swimmers, divers, and poorly placed boat anchors.
   • Plastic pollution: 8 million tons of plastic rubbish enter the world’s oceans every year. Many discarded plastics break down into what are known as microplastics, which are mistaken by coral polyps as food and ingested.

Some examples:

• The Great Barrier Reef: According to the 2014 report of the Government of Australia’s Great Barrier Reef Marine Park Authority, climate change is the most significant environmental threat to the Great Barrier Reef.
• The Lakshadweep Islands: Bombay Natural History Society and Wildlife Institute of India (WII) recorded that coral reefs in the Lakshadweep Islands are undergoing recurring bleaching and dying.

Government and Global Initiatives:

Government Initiatives

The protection of coral reefs has been stressed under:

• Wildlife Protection Act, 1972
• Environmental Protection Act, 1986
• Corals are included in Schedule I of the Wildlife Protection Act, 1972

• Integrated Coastal and Marine Area Management: Aims at integrating the management of coastal and marine areas and has prepared model plans for the Gulf of Kutch.

• Coastal Regulation Zone notification, and Island Protection Zone notification: Corals are sought to be protected by regulating developmental activities along the sea coast.
• National Coastal Zone Management Authority (NCZMA) and State Coastal Zone Management Authority: India has created mechanisms such authority for the protection of coastal and marine areas.
• Ministry of Environment and Forests (MoEF): India has included studies on coral reefs under the Coastal Zone Studies (CZS).
• Coral Bleaching Alert System (initiated by INCOIS): This model uses satellite-derived Sea Surface Temperature (SST) to assess the thermal stress accumulated in coral environments.
• National Coral Reef Research Centre: Established at Port Blair. Database Network and Website on Coral Reefs has also been established.

Global Initiatives

1. International Coral Reefs Initiative: It is an informal partnership between Nations and organizations that aims to preserve coral reefs and related ecosystems worldwide.
2. Global Coral Reef monitoring network: It is a network under ICRI that works to provide scientific information and communication on the status of coral reef ecosystems to increase conservation and management of coral reefs.
3. International Coral Reef Action Network: It is a strategic alliance of private and public organizations that acts worldwide to address the management of coral reef ecosystems and the needs of the communities that depend upon them.
4. United Nations Environment Programme (UNEP): Has included coral reef conservation and restoration as an ecosystem-based adaptation measure (EBA) for coastal protection.
5. Global warming measures: Adopting UNFCCC and IPCC protocols.
6. CITES: Corals are protected under CITES, which manages their trade activities.

Best Practices

• Project REGENERATE: Maldivian coral reefs have shown great capacity for resilience in the past, with coral recovery being among the best recorded in the Indian Ocean.
• A Mumbai-based NGO: Reef Watch India has taken up two projects — Re(ef)Build and Re(ef)Grow — to conserve the reefs.

Measures to be taken (Mitigating measures):

1. Environment:
   • Regeneration of lost biodiversity.
   • Preservation and regeneration of an important source of food for the village depends on it.
   • Reservation of marine ecosystems and endemic and endangered species.
   • Decreasing greenhouse gases and adopting the Paris Agreement in spirit.
   • Checking polluted water disposal in the sea.
   • Banning of bottom trawling and blast fishing.
2. Social:
   • Empowering the sustainable management of their environment.
   • Social cohesion and food sovereignty.

1. Economic:
   • Creating a sustainable environment for fishing.
   • Increasing and diversifying income.
   • Complementary activities: Corals contribute to the regeneration of the biomass, which allows the development of sustainable fisheries for the village.
   • Potential development of activities such as eco-tourism is also a tool to raise awareness of marine conservation for tourists.
2. Methods of coral restoration:
   • Biorock Technology: It is a method to restore coral reefs using bio-rock or mineral accretion.
   • Biological restoration: Uses various methods involving coral growth and transplanting to assist the restoration of a coral reef. It includes:
     • Asexual propagation: Involves transplanting coral fragments or larger colonies from a donor reef site to a reef of choice, most commonly a degraded reef.
     • Coral Gardening: Collecting, growing, and reattaching coral fragments at a degraded reef site.
   • Structural restoration: Involves the construction of artificial reefs, sinking of wrecks, or relocation of rocks/dead coral heads.
   • Physical restoration: Addresses conditions in which the corals are growing to improve their health, growth rates, or reproductive ability.

Way forward

• Awareness: Community awareness and education programs are required to educate and inform the public, policymakers, and other stakeholders of the ecological and socio-economic values of coral reef ecosystems.
• Climate action: It is important to undertake immediate actions to address climate change under the Paris Agreement’s goal of limiting global average temperature increase to 1.5°C.
• Coral restoration programs: Can play an important role in conserving coral reefs.
  • For example: The innovative Force Blue project is training retired Special Forces soldiers to transplant endangered coral species.
• Marine Park: Establish marine parks with the help of legislation: Marine National Park at Krusadi Island in the Gulf of Mannar.
• Satellite Oceanography: A feasible cost-effective technology to address the mapping and monitoring aspects of coral reefs.
• Scientific knowledge: Improved scientific knowledge is required to inform an effective response to threats to coral reefs.
• Fishing regulation: Fishing in nearby areas must be regulated, and heavy fishing in coral reef areas should be controlled.
• Invasive species: The massive destruction of corals on coral reefs in the Great Barrier Reef and some parts of the Tropical West Pacific region due to the feeding activities of the starfish has been observed. Such patterns need to be monitored.

Coral reefs are an important part of the ecosystem. They have not only ecological significance but also serve as an important indicator of environmental health. The recent rise in coral bleaching has raised various concerns, and efforts have been made to restore coral reefs. However, despite these efforts, a dedicated coral protection program is lacking in India, affecting the coral protection programs conducted by concerned state governments.