A recent research breakthrough has identified for the first time that specialized immune cells, specifically phagocytic cells, exist in certain varieties of sea corals and anemones. This discovery can play a crucial role in enhancing our understanding of how reef-building corals and other reef animals shield themselves from foreign invaders like bacteria and viruses found in and around coral reefs.
Understanding Phagocytosis
Phagocytosis is the process by which certain living cells, known as phagocytes, ingest or engulf other cells or particles. It’s a method seen in free-living one-celled organisms such as an amoeba, or body cells, like a white blood cell. Phagocytosis serves as a primary feeding mechanism for organisms like amoebas and sponges. In higher animals, it is predominantly a defensive reaction against infection and invasion of the body by foreign substances, also known as antigens.
Facts about Sea Anemones
Often referred to as the ‘flowers of the sea’, sea anemones are actually beautiful animals. They are closely related to coral and jellyfish and are the marine, predatory animals of the order Actiniaria. They inhabit every ocean, ranging from the tidal zone to depths of over 10,000 meters.
Coral Characteristics and Types
Corals consist of genetically identical organisms called polyps. Inside these polyps, reside microscopic algae known as zooxanthellae. Corals and zooxanthellae have a mutualistic relationship; while corals provide the necessary compounds for photosynthesis to zooxanthellae, they, in return, supply corals with organic products of photosynthesis, which corals utilize for synthesizing their calcium carbonate skeletons.
Corals can be broadly divided into two types: hard, shallow-water corals that form reefs and soft corals and deepwater corals that live in dark, cold waters.
Benefits and Threats to Coral Ecosystem
Coral provides habitat to over a million diverse aquatic species, including thousands of fish species. Its global estimated value stands at USD 2.7 trillion per year or 2.2% of all global ecosystem service values. This includes income from tourism and food production. Coral reefs also play a vital role in coastal protection by reducing shoreline erosion, facilitating potential medical treatments, and more.
On the other hand, these crucial ecosystems face threats like overfishing, destructive fishing, unregulated recreational activities, detrimental coastal development, pollution, and climate change which causes coral bleaching and ocean acidification.
Protection Initiatives for Corals
To safeguard these valuable ecosystems, numerous initiatives have been launched both at global and national levels. Global efforts include the International Coral Reef Initiative, Global Coral Reef Monitoring Network (GCRMN), Global Coral Reef Alliance (GCRA), and The Global Coral Reef R&D Accelerator Platform.
India too is committed to protecting its coral reefs. Studies on coral reefs are included under the Coastal Zone Studies (CZS). The Zoological Survey of India (ZSI) collaborates with Gujarat’s forest department to restore coral reefs using “biorock” or mineral accretion technology. Furthermore, the National Coastal Mission Programme aims to protect and sustain coral reefs in the country. Major locations of corals in India include the Gulf of Kutch, Gulf of Mannar, Andaman & Nicobar, Lakshadweep Islands, and Malvan.