Bauna-Vista Coral Reef: 'Little Sinharaja' at the bottom of the sea

What do you know about coral reefs? You sure must have heard about the Great Barrier Reef of Australia, one of the most famous coral reefs in the world, and the Hikkaduwa Coral Reef, one of our Sri Lankan treasures. Coral reefs add beauty to the sea world and are also a blessing in disguise for the islands, because these reefs slow down the ocean waves, minimising coastal erosion.

Today, we are featuring one of the most beautiful coral reefs in Sri Lanka, the Bauna-Vista Coral Reef, which is situated a few miles away from the Galle town. The name 'Bona Vist', which means 'beautiful scenery' was given by the Portuguese, but later, according to the Latin pronunciation it had changed to 'Bauna-Vista'.

When you stand by this coral reef, you get a magnificent view of the Galle Fort and Harbour.According to the Ramayana, Luxmana, Rama's brother had been injured by an arrow shot by Rawana. So, Rawana himself had arranged a doctor for him.

This ayurvedic doctor had wanted a herb called 'Sanjeewani' to heal the wound. Hanumantha was sent here to find and bring this herb to Himalaya, but he was not exactly sure what the herb was. So, he had uprooted part of the mountain containing the herb and taken it with him. On his way, two pieces of the mountain fell off; one is said to be at Ritigala and the other at Unawatuna. The latter mountain is located close to the Bauna-Vista.

The reef slopes down randomly and opens to the sea. It is home for several varieties of small fish as well as some bigger ones. According to studies done before 1998, this was rated as the most beautiful coral reef in Sri Lanka, because of its shape, position and the bio-diversity. The geographical difference around the reef adds to its beauty.

The value of a coral reef is usually measured by its bio-diversity. The area it covers, number of coral varieties and number of fish varieties are some of the other factors. The number of butterfly-fish varieties in a reef is especially considered as a measure because these fish have their own eating habits and natural habitats. If there are more butterfly-fish varieties, this means there is more variation in the habitat. The Bauna-Vista Reef has 29 butterfly-fish varieties out of 36 varieties found all over the country.

Another measurement of a coral reef is the percentage of the live coral covering. At Bauna-Vista, this was almost 70 per cent before 1998. At that time, there were 183 coral varieties in Sri Lanka. At the beginning of 1998, an Australian scientist found four new coral varieties from Sri Lankan reefs. Three out of this were from Bauna-Vista, and aren't seen anywhere else in the world.

Tragedy in 1998

We mentioned that there were 183 coral varieties before 1998. So, what happened in 1998? This was the most unfortunate year for Sri Lanka's coral reefs.

Because of the 'El-nino effect', warm surges, which started from Seychelles and Diego Garcia Island around Madagascar came towards our South and Western coral reefs. The usual temperature of the sea water, which was 27-28 degrees Celsius, rose up to 36 degrees.

As a result, the algae, main food of the coral, started to die. Within four days, the corals also started dying without food. It was like a snow fall at the bottom of the sea. Because of this, the coverage of coral reefs declined at Unawatuna, from 80 per cent to two per cent.

At Hikkaduwa, it declined from 35 per cent to five per cent. The reefs at Kabalana and Akurala were fully destroyed and at Bauna-Vista, it came down to 20 per cent from 70 per cent. The remaining part of the Bauna-Vista is still very precious. Today, the corals are growing again, with the reef at Bauna-Vista now having grown up to 40 per cent. The percentage of fish and other vertebrates have also increased.

This coral reef is growing faster, when compared to other reefs. According to sources, this is the best coral reef that they can use to spread new coral reefs around the island.

How corals are formed

There are two major types of corals named 'Zooxanthellate' and 'Azooxanthellate'. Corals are made by a creature called coral polyp. They may vary in size from 1 mm to 8 inches. These polyps live together, but the bigger ones live alone.

Algae live inside the cells of the coral polyps. They absorb the carbon dioxide in the water and produce oxygen and food for coral polyps. So, the coral polyps have no worries about looking for food, and have the ability of growing.

The colour and the growth rate of the reef depend on the algae that combine with the coral polyps. No matter how big the coral reef is, the live coral comprise just a thin layer. The rest are all skeletons left by dead corals.

Compiled by Janani Amarasekara.