A study reveals that coral reefs in the Gulf of Eilat experienced a 3,000-year growth shutdown due to global cooling but have since naturally recovered from deeper waters.

Recovery of Corals in the Gulf of Eilat

• Resilience to Environmental Shifts: Despite exposure to sea-level changes and cooling events, corals demonstrated adaptability. The reef ecosystem gradually restored itself without external intervention.
• Lessons for Conservation: Historical recovery highlights coral resilience, but modern threats like climate change and pollution are more severe. Urgent conservation efforts are needed to protect reefs from unprecedented challenges.

About the Gulf of Eilat

• Also Known As: Gulf of Aqaba.
• Location: It is a narrow extension of the Red Sea.
• Geographical Position: It is situated east of the Sinai Peninsula (Egypt) and west of the Arabian Peninsula.
• Connection to the Red Sea: The Gulf of Eilat is linked to the Red Sea through the Strait of Tiran.
• Geological Significance: It is an integral part of the East African Rift System.
• Bordering Countries: Egypt, Israel, Jordan, and Saudi Arabia.
• Strategic Importance: The cities of Eilat (Israel) and Aqaba (Jordan) are located along its shores, making it a key hub for trade and tourism.
• Depth Contrast : The Gulf of Eilat is much deeper (1,850 meters) compared to the Gulf of Suez (100 meters).
• Coral Ecosystem: The Gulf is home to one of the northernmost coral reef ecosystems in the world.
• NEOM Brine Pools: Salty underwater lakes known as NEOM Brine Pools have been discovered in the Gulf of Aqaba.

About Corals

• Nature of Corals: Corals are sessile animals, meaning they are permanently attached to the ocean floor.
• Appearance : Although corals resemble colorful plants, they are actually animals.
• Structure : Corals are made up of individual organisms called polyps.
• Skeletal Formation : Polyps extract calcium and carbonate ions from seawater to build their hard, cup-shaped skeletons made of calcium carbonate (limestone).

About Polyp

• Stomach Structure: Each polyp has a single-opening stomach.
• Tentacles: Surrounding the mouth, the tentacles help in defense, capturing food, and clearing debris.
• Feeding Process: Food enters through the mouth, and waste is expelled through the same opening.

Symbiotic Relationship

• Zooxanthellae : Corals share a symbiotic relationship with single-celled algae called zooxanthellae.
• Algae Contribution: Zooxanthellae provide corals with food and nutrients through photosynthesis.
• Coral Contribution: Corals offer shelter and nutrients to the algae.
• Coloration: A symbiotic relationship is responsible for the vibrant colors of corals.

Ideal Condition for Corals

• Temperature: Reef-building corals thrive in water temperatures between 23°–29°C (73°–84°F) but can tolerate short-term extremes from 18°C (64°F) to 40°C (104°F).
• Salinity: Corals require highly saline water, with salt levels between 32 to 42 parts per thousand.
• Light and Depth: They need clear, shallow water for maximum sunlight penetration, as they rely on symbiotic zooxanthellae for photosynthesis. Optimal growth occurs at depths shallower than 70m.
• Water Clarity: Turbid water reduces light penetration, affecting coral-algae symbiosis and food production.

Global Distribution of Coral Reef

• Global Distribution: Coral reefs are mainly found in tropical and subtropical waters between 30°N and 30°S latitudes, with the best growth in shallow, clear water.
  • Shallow tropical reefs in the Indian and Pacific Oceans boast the most coral species.
• Depth: Mesophotic coral ecosystems thrive at depths of 30-150 meters, where light is limited, but they still require light for zooxanthellae.
• Deep-sea corals grow at depths from 50m to over 3000m, often found on continental shelves and slopes, exhibiting high biodiversity.
• Coral Reef Distribution in India: India’s coral reefs are mainly found along its western and eastern coasts, with notable sites like the Lakshadweep Islands, Gulf of Mannar, Andaman and Nicobar Islands, and the Gulf of Kutch. 
  • These reefs are rich in biodiversity and vital for marine ecosystems.

Ecological Importance

• “Rainforests of the Sea”: Corals are referred to as the rainforests of the sea due to their high biodiversity and ecological significance.
  • Nearly half of the atmospheric oxygen comes from the ocean and Coral reefs are responsible for it.
• Marine Habitat: Coral reefs provide shelter and habitat for a vast range of marine organisms, including fish, invertebrates, and algae.

Factors Affecting Corals

• Coral Bleaching: A sustained increase in sea surface temperature (SST) causes the zooxanthellae to leave their coral hosts, resulting in coral bleaching.
• Impact: Without zooxanthellae, corals lose their pigmentation and their primary source of nutrients.

Protection of coral reef

• Laws protecting coral reef in India: All the hard corals i.e. Scleractinian coral species are protected under the Wildlife (Protection) Act, 1972 and listed in Schedule-I category which prevents collection of live and dead corals.
  • In addition, major coral reefs areas in the country have been declared as Protected Areas.
• International Law: Under CITES any trade or transport of corals requires an export permit.

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