Recently, the Mumbai civic body received the green signal from the Principal Chief Conservator of Forests (Wildlife), Nagpur, for translocating the corals off the coast of Mumbai for the Rs 12,700-crore Mumbai Coastal Road Project.
What are ‘corals’?
- Corals exhibit characteristics of plants, but are marine animals that are related to jellyfish and anemones.
- Coral polyps are tiny, soft-bodied organisms. At their base is a hard, protective limestone skeleton called a calcite, which forms the structure of coral reefs.
- Reefs begin when a polyp attaches itself to a rock on the seafloor, then divides, or buds, into thousands of clones. The polyp calcites connect to one another, creating a colony that acts as a single organism.
- As colonies grow over hundreds and thousands of years, they join with other colonies, and become reefs.
- There are soft corals as well, which are non-reef-building, and resemble bushes, grasses, trees.
Corals in Mumbai
- The Mumbai coast hosts a tiny population of corals. The corals found across rocky patches along the Mumbai coastline are mostly fast-growing and non-reef building corals. Small coral colonies have been documented off Marine Drive, Geeta Nagar in Colaba, Haji Ali, and Worli.
How are corals translocated?
- In a three-year-long project in Sindhudurg, corals were cultivated — fragments of corals were taken and attached to concrete frames with the help of nylon threads — and then left on ocean beds at a depth suitable for their growth.
- In a project at the Andaman islands, ReefWatch Marine Conservation has transplanted coral fragments on to nine artificial structures, totalling a 20-square-metre area. The project has been on since 2017.
Significance of coral reefs
- Coral reefs are like underwater cities that support marine life. According to the UN Environment programme, they provide at least half a billion people around the world with food security and livelihoods.
- Coral reefs also act as ‘wave breaks’ between the sea and the coastline and minimise the impact of sea erosion. In India, they are protected in the same way as the tiger or elephant, under Schedule I of the Wildlife Protection Act (WPA), 1972.
Threat to coral reefs
- Climate change remains one of the biggest threats to corals.
- Around the world, this threat has been visible in the “bleaching” of corals — is a process during which corals, under stress from warm weather, expel the algae that give corals their brilliant colours and live in their tissues and produce their food.
- The Great Barrier Reef off the coast of Australia, a UNESCO World Heritage site and home to one of the largest collections of coral reefs on the planet, has suffered six mass bleaching events due to warmer than normal ocean temperatures: in 1998, 2002, 2006, 2016, 2017, and now 2020.
- Experts have documented bleaching of the corals along Mumbai’s coastline as well.