According to the Natural History Museum definition, coral reefs have an estimated global value of £ 6 trillion each year, owing to their contribution to fishing, tourism industries, and coastal protection.
More than 500 million people worldwide depend on reefs for food, jobs, and coastal defence. The ridges in coral reefs act as barriers and can reduce wave energy by up to 97%, providing crucial protection from threats such as tsunamis. They help protect areas such as mangrove forests and seagrass beds, which act as nurseries for marine animals as well as human coastal populations.
Considered the ocean’s forests and marine ecosystem engineers, coral reefs provide economic and environmental benefits to Sri Lanka. With several studies indicating the rapid depletion of a vital element of the ocean, the Government, International Non-Governmental Organisations (INGOs), and private sector companies have carried out several initiatives to restore the coral reefs around Sri Lanka using various methods.
As a country that fuels its economy through fisheries and tourism, safeguarding the ecosystems that nurture aquatic life around Sri Lanka is essential. However, as scientists have continued to report over the years, the marine ecosystem has been facing threats of destruction, with the coral reef population decimated to 10% by 2019.
Positive signs
However, recent initiatives have returned positive outcomes, indicating the possibilities of restoring or rehabilitating coral reef colonies around Sri Lanka. This was pointed out by Arulananthan et al in their research findings in 2021, which recorded an increase in the diversity index of coral cover on the northern coast against the depleting coral cover in other parts of Sri Lanka.
The study recorded 113 species of scleractinian corals, representing 16 families and 39 genera, as well as seven soft coral genera, among which 36 of the scleractinian coral species were identified for the first time in the area.
While there was a massive destruction of the coastal environment caused by the land reclamation for Colombo Port City, in June this year, The Pearl Protectors – a marine environment conservation organisation – shared an image of the wave breaker built surrounding Port City, which had provided ground for a coral reef colony to thrive.
“The most probable reason for fast growth in coral around the Port City is that no excessive nutrients are entering the area. Excessive nutrients cause algal blooms, which hampers the growth of corals. The protective barrier around the Port City limits ocean pollution entering the area and stops strong ocean currents from harming the growth,” The Pearl Protectors Coordinator Muditha Katuwawala observed.
Reef restoration
Furthermore, in 2022, Marine Researcher and Ocean Restoration Steward Samara Polwatta commenced an initiative titled ‘School Meets the Reef’ by teaming up with four environmental activists who managed to breathe life back into the reef in Kalkudah, located south of the Kayankerni Marine Sanctuary on the east coast of Sri Lanka.
“The former jetty served as a natural harbour during British rule and is home to the endemic parrotfish. It is also a hatching area for the endangered turtle species Chelonia mydas and Lepidochelys olivacea. Endowed with more than 210 reef fish species, as well as several coral species including Acropora, Montipora, Porites, and Pocillopora, the site was in urgent need of restoration to protect its rich biodiversity,” Polwatta explained.
“After testing several parameters such as salinity, water quality, depth, and pH, we found the site suitable for restoration through coral recruitment. The team along with several volunteers from EarthLanka, the Marine Environment Protection Authority (MEPA), and area anglers deployed three reef balls into the site with around 50 fragments of Acropora and Porites attached to them,” Polwatta stated.
Since the initial deployment, Polwatta and her team continuously monitored the site with the assistance of divers from among the EarthLanka volunteers.
“Based on these sessions, we found our methods to be both successful and replicable. Acropora had grown by 3-5 millimetres as measured from the last monitoring session in January. Although monitoring was difficult during the offseason due to strong winds and turbid water, we could still observe the growth of these coral fragments,” she said.
Challenges for conservation
Polwatta further noted that although the reef was resilient, it also faced many threats from human activity: “For instance, coral mining to produce quicklime for construction purposes causes sedimentation, which is a growing threat as nutrients from rivers are washed into the ocean, causing algal blooms. Other threats to the reef include harmful fishing activities such as dynamite fishing, the use of ghost nets, and damage from anchorage. It has always been my passion to bring the reef back to health by raising awareness amongst communities and encouraging active coral rehabilitation.”
While reef restoration efforts applied to small areas of a reef appear to be successful, International Union for Conservation of Nature (IUCN) Coastal and Marine Programme Coordinator Arjan Rajasuriya is of the view that it is not practical if applied on a larger scale.
Sharing an experience of a coral transplanting effort gone wrong, Rajasuriya noted that the efforts could be unsuccessful if the new corals were not closely monitored: “In 2000, the coral restoration project that was initiated in Hikkaduwa failed as it was not carefully monitored. An invasive marine creature species ended up destroying the newly-transplanted corals. Therefore, the corals chosen to be transplanted should be compatible with the marine environment as they are sensitive to the oceanic climate and should be resilient to invasive species.”
All attempts made to contact the National Aquatic Resources Research and Development Agency (NARA) for comment on the efforts taken to preserve coral reefs and conduct further research proved futile.