The beach carnival at Hikkaduwa ends todaywith this picturesque coastal town attracting tens of thousands of fun-loving people for this annual event, that lasted four days. But beyond the flamboyance of the shows on the beach, a dark story was unfolding beneath the blue waters. It was the story of Hikkaduwa’s once-famous coral gardens.
Coral reefs are known as rainforests of the sea because of their high level of biodiversity. Being a tropical island, Sri Lanka has many coral reefs, but the most popular is the one at Hikkaduwa. Those who take a ride on a glass-bottom boat can still see many corals in Hikkaduwa, but the truth is that they are looking at dead corals.
Watching the vibrant-coloured fish through the glass-bottom of the boat in the past was an experience in itself. But today, most of the fish colonies consist of one or two species. The health of the Hikkaduwa reef is fast degenerating.
The world famous Hikkaduwa reef started loosing its glory in the late 1990s. The first to attack the reef was invasive algae. This attack in 1997 reduced the live coral percentage. Then came the infamous coral bleaching event. This happened due to a warm ocean current generated by the global climatic phenomena called El-Nino in 1998. The temperature of the Hikkaduwa waters rose by 5 degrees Celsius. As a result, the friendly algae that not only brought colours to the corals but also protected them from the sun’s ultra violet rays started dying. It is said that no coral can survive without a friendly-algae coat.
Coral bleaching reduced the live coral cover of Hikkaduwa to an unbelievable 5% with some coral species, which were common in Hikkaduwa becoming extinct.The reefs could have been salvaged if they had been left undisturbed, but human activities continued to harass the sensitive eco-system.
The latest threat comes from a harbour development project that overlooked the ecology of the reef area. The tsunami-damaged Hikkaduwa fisheries harbour was reconstructed with an extended breakwater just north of the reef.
Hikkaduwa has an ocean current that goes parallel to the shore and moves the sand northward. It is believed that this breakwater stopped this natural phenomenon and sand started accumulating around the reef area, posing a major threat to the reef. Sand-filling has already covered the sea grass beds and disturbs the recovery of the reef. Some experts fear that the reef will be fully buried in sand in the next few years.
“The average depth of the water in the reef area is about two metres, but sand accumulation has reduced it to one metre,” says Terney Pradeep Kumara of the Ruhuna Univestity’s Department of Oceanography and Marine Geology.
Sea anemon with Clown Fish
It appears that the hydrological survey for the fisheries harbour project was not done properly. Since the harbour project cannot be undone, there is an urgent need to find a solution to save the reef.
Some marine experts suggest pumping of the accumulated sand to the deep oceans. They say this can be done by setting up a sand-pumping station at the breakwater. Though this station also could have some environmental impact, at least it will give a chance for the Hikkaduwa reef to recover.
Being a marine expert who works in the area, Terney also believes that tourism-related activities also contribute to the death of the Hikkaduwa reef. Glass-bottom boat rides and visitor activities delay the recovery of the reef, he says.
“Each time a visitor steps on a coral, he causes damage to the delicate structure that had taken years to grow,” Terney says stressing the need for zoning the Hikkaduwa coral reef area by way of an urgent solution. “This will provide a separate area for visitor activities like swimming, glass-bottom boat rides, research etc. It is like keeping buffer zones in national parks. Boat movements too have to be regulated,” he says.
Prasanna Weerakkody, a marine naturalist who is involved in the restoration work at the adjacent Rumassala reef says coral transplanting which can expedite the recovery of the corals can also be tried by way of a solution.
He points out that most of the corals that are growing in Hikkaduwa after the bleaching are ‘opportunistic’ coral species that spread fast and do not add much diversity to the reef. “They are like weeds which grow fast like trees at a rainforest after they are cut. The reef may recover on its own if it is left undisturbed, but still it will be painfully slow. One way to quicken the recovery is bringing corals from outside. But this is not an easy task. Any attempt to restore a reef must start with a good background knowledge on the needs of each coral species,” Weerakkody says.
There were several attempts at coral transplanting aimed at restoring the Hikkaduwa reef. Before the disasters struck, some 40 percent of the Hikkaduwa reef consisted of Acropora formosa – stag horn-type of corals. But they had become extinct, especially after the bleaching in 1998.
A team from University of Colombo brought a live coral colony of Stag Horn type from Kapparathota reef in 2000. This type of coral hastens the recovery as even the broken corals can continue to propagate themselves. The reintroduced colony grew successfully, but unfortunately a tube worm colony started growing on them destroying the newly hatched. Another invasive species -- the black sponge -- also attacked the new corals, but despite several reminders, the research team was unable to remedy the situation.
This experiment shows that coral transplanting can be used, but it requires a clear plan and a long-term commitment.
The Hikkaduwa reef comes under the protection of the Department of Wildlife Conservation (DWC) since it was declared as the first Marine Sanctuary in 1979. Its status is uplifted to a Marine National Park in 2002. But despite being a reserve in law, it is very difficult to control visitors because Hikkaduwa is one of the key tourist areas.
Tourism-related and other human activities continue on the 1.35 km beach front extending from the rocky islets near the Coral Gardens Hotels to the southern breakwater of the fisheries harbour. However, the DWC’s presence has stopped only the fishing in the area.
The task of protecting Hikkaduwa should not solely be the responsibility of the DWC. Every stakeholder, including the National Aquatic Resources Research and Development Agency (NARA), fisheries harbour authorities, the police, hoteliers, guides and even tourists, should take part in a proper long-term management plan to save the Hikkaduwa reef and the corals and bring back Hikkaduwa’s past glory.
What is a coral reef?
The primary organism responsible for the structure of a forest is the tree. Likewise, a coral reef is an underwater ecosystem comprising thousands of life forms. But like the tree in a forest, the coral reef is built by colonies of tiny reef animals known as coral polyps.
Individually, coral polyps are small and rarely grow bigger than a centimetre across. The coral animals usually live in colonies and each polyp builds a limestone skeleton which links with the skeletons of all other members of the colony over generations to form the structures we readily recognize as a coral.
Thousands of tiny coral polyps form coral colonies. An aggregation of thousands of coral colonies of many different species form coral reefs. There are 183 different coral species found in Sri Lankan reefs.
The reefs serve many purposes in the coastline – they are important centres of bio-diversity, fisheries production and nursery grounds, aesthetics, tourism, coastal stabilization and barriers against coastal erosion. Most coral reefs like Hikkaduwa are located close to the shore and easily accessible. Thus, they are often subject to the brunt of pollution, human impacts and extreme weather conditions.
Use of destructive fishing methods, removal of reef corals for lime trade, unregulated tourism, collection of marine organisms for souvenirs, unplanned coastal development, boat and anchor damage, pollution, global warming and invasive species are some of the threats to Sri Lanka’s corals.
Hikkaduwa, Pigeon Island and Kalpitiya have beendeclared as marine protected areas in Sri Lanka, but all these coral reefs face many conservation issues.
Source: Reef Help Guide –
Nature Conservation Group.