Considered to be one of the island’s most productive and dynamic coastlines, this unique area in which several types of marine ecosystems converge, is of national importance. Enjoying high levels of biodiversity due to its geographical location, this coastline is dotted with a chain of islands to the west and protected forest sanctuaries to the north and south, thereby forming a single flourishing ecosystem which is home to a mesmerising cast of animals.
Akin to a jigsaw puzzle coming together to make one holistic picture, the Wilpattu National Park’s (WNP) marine influence zone comprises of a multitude of thriving ecosystems. Riverine forests, mangroves, seagrass meadows, islands that vary in size due to monsoonal weather patterns, shallow water coral reefs, deep water sandstone habitats and a pelagic zone, lie side by side in contiguity to make up this marine zone which has been proposed to be declared as the ‘Wilpattu Marine Wildlife Sanctuary’. This Marine Protected Area (MPA) status will provide further protection to this area of biological importance.
Of particular significance is the population of the locally endangered Dugong, which in days gone by has been documented within the extensive seagrass meadows, north of the Kalpitiya peninsula. The presence of a small pod of Indo-Pacific Humpback Dolphins is also noteworthy, given their limited distribution around the island. Yet, in recent years, with population pressures on this ecosystem on the rise, sightings of both marine cetaceans have diminished.
This nutrient-rich landscape is frequented by numerous varieties of aquatic birds in addition to migratory birds. Being the southernmost land mass along the Central Asian Flyway and the final destination for many migratory species exiting the eastern and western Indian flyways, birding in this area can be a very fruitful activity.
Bar Reef Marine Sanctuary
Designated as a Protected Area (PA) in 1992, the Bar Reef Marine Sanctuary (BRMS) at 30,670ha is one of the island’s largest MPAs. Located within the WNP’s marine influence zone, the BRMS is a complex of offshore continental shelf patch reefs that form one of the largest coral reef systems in the country. This area located offshore from the Puttalam lagoon encompasses the Dutch and Portugal bays, including shallow coral reefs and sandstone habitats.
During surveys of this area, it has been recorded that the BRMS is home to approximately 122 species of stony corals belonging to 54 genera present on the reef, while a further 400 species of reef and reef-associated fish, have also been documented. The surveys carried out in the BRMS indicated that this habitat supports a year-round species richness of marine mammals, suggesting that the northern and central areas may be considered as a cetacean ‘hotspot’.
Coral Reefs
The BRMS contains one of the most extensive coral reef systems in Sri Lanka. Coral reefs within this area are classified as patch reefs, consisting of corals growing on raised humps of hard substrate, some distance away from the shoreline. Within the BRMS, these reefs occur in shallow water in depths between 1m and 10m. Individual coral patches in the BRMS are relatively large compared to other reefs in Sri Lanka, with some coral patches reaching several acres in size. They are dominated by branching and table corals while large dome corals are found at depths of around 10m. Parrotfish, surgeonfish, rabbitfish, wrasses and damselfish are some of the most abundant fish groups. Unfortunately, coral reefs in the area have been significantly impacted by coral bleaching caused by warming oceans and are currently in a degraded state. However, coral reefs within the BRMS have shown a capacity to recover from similar events in the past, providing some hope for the future.
Sandstone Reefs
Sandstone reefs are located further offshore at depths of 20 to 30m, and consist of sandstone ridges running parallel to the shoreline. The rocky ridges contain significant coral communities growing on them along with soft corals, sponges and sea anemones. Sandstone reefs within the BRMS provide an important habitat for larger fish species such as groupers, moray eels, snappers and emperors. They are also home to the globally endangered Humphead Wrasse. Although they have less coral growth than on coral reefs, research has shown them to have a higher diversity of both corals and reef fish species compared to shallow coral reefs within the BRMS. Along with their biological diversity, sandstone reefs are also important for fisheries, and support large numbers of fishery-targeted species.
Deep Sea
The deep sea is the area beyond the continental shelf’s edge, ranging in depth from a several hundred to more than a several thousand metres. Off Kalpitiya, the continental shelf increases in depth very gradually until a depth of approximately 20m, after which it drops significantly into deeper waters. Deeper waters are home to many pelagic fish species such as tuna, Spanish mackerel, sharks and rays. This includes several species of deep-water sharks that are known to live several hundred metres below the surface. The edge of the continental shelf is prone to upwelling, a process by which deep nutrient-rich waters are pushed up towards the surface, creating an abundance of plankton. As a result, this area is an important feeding ground for many fish species as well as marine mammals such as dolphins and whales that congregate along the shelf edge to feed.
Threats to the Wilpattu National Park’s Marine Influence Zone
With population pressure on the rise, much of the richness that once was abundant in this area, has slowly disappeared. Accounts from the past speak of dugongs being commonplace. Sadly in recent years, the only signs of the presence of these gentle giants have been recorded via dead animals; victims of dynamite fishing or as a result of entanglement in nets. Destructive fishing practises such as bottom trawling, dynamite fishing, ‘Laila’ netting (use of purse seines) and overfishing have severely depleted the nutrient-rich waters. Despite ‘Laila’ netting being banned in 2016 and bottom trawling in 2017, a lack of enforcement has led to these illegal practises continuing. Inland water pollution and marine debris have also affected these aquatic habitats negatively. Unregulated and unsustainable tourism practises exert further pressure on this delicately balanced ecosystem.
Guidelines for Safely Enjoying Natural Habitats
Use reusable bottles and bags to cut plastic waste. Opt for glass bottles or cans instead of plastic when buying sodas. Say no to plastic straws and bags, and bring a reusable bag when shopping.
Avoid bush-meat like wild boar and venison to prevent harm to wildlife. The methods used for capture are illegal and destructive, often harming unintended animals like leopards and fishing cats in snares.
Respect the animals and their habitat. Allowing our natural environment to remain the way it is with minimal disturbance will only make for better sightings and experiences in the wild.
Follow these guidelines and spread the word to friends and family. Engage with your local community and speak out about environmental issues. Your actions can drive real change—don't hesitate to speak up!
