Decades of conflict prevented fishing, allowing this lagoon ecosystem to recover. Post-war studies document how quickly fisheries collapsed when exploitation resumed, providing baseline data.
An Unintended Experiment
For nearly three decades, from 1983 until 2009, the lagoons around Mullaitivu were largely inaccessible due to the Sri Lankan Civil War. This prolonged period of conflict inadvertently created a protected zone where fishing and other human activities were severely restricted or brought to a standstill. The ecosystem, free from the pressures of exploitation, had a rare chance to recover. Fish, crustacean, and other aquatic populations flourished in the brackish waters, turning the lagoon into a natural, unmanaged reserve.
When the war ended in 2009, this period of quiet isolation came to an abrupt end. The region saw a rapid resumption of fishing, described by some as a "gold rush". Hundreds of fishing boats, many from outside the region, entered the lagoon, eager to exploit the recovered stocks. This sudden shift from a no-take zone to an intensely fished area presented a unique, if tragic, opportunity for scientists. It allowed them to collect baseline data on a relatively pristine estuarine ecosystem and then observe, in real-time, the effects of sudden, high-pressure exploitation. This kind of "natural experiment" is exceedingly rare in fisheries science, where most ecosystems are already heavily impacted before studies begin.
The Lagoon's Web of Life
The Mullaitivu lagoon system, which includes Nanthikadal and Kokkilai lagoons, is a habitat defined by its mangrove forests, seagrass beds, and mudflats. These ecosystems act as important nurseries for numerous species. Sri Lanka has about 28 identified mangrove species, with Avicennia marina being dominant in some areas of the Mullaitivu district. Mangroves are known to store significantly more carbon than terrestrial forests and provide an important buffer against coastal erosion and storm surges.
The lagoon's biodiversity supports a variety of aquatic life. Commercial species include the blue swimmer crab (Portunus pelagicus) and the mud crab (Scylla serrata). The blue swimmer crab's life cycle is heavily dependent on estuaries, where its larvae and juveniles grow and develop. The waters also host numerous finfish, with families like Cichlidae (tilapias), Clupeidae (herrings), and Leiognathidae (ponyfish) being particularly common. The area is also an important habitat for birds, with one study identifying 79 bird species around Nanthikadal Lagoon, 26 of which were migrants. The post-war fishing boom heavily targeted fish, crabs,, but also sea cucumbers, with species like Bohadschia vitiensis and Holothuria spinifera forming a significant part of the catch. The rapid depletion of these stocks demonstrated how quickly a seemingly resilient ecosystem can be overwhelmed.
💡Fun Facts
The female blue swimmer crab (*Portunus pelagicus*) can produce between 60,000 and nearly 2 million eggs in a single brood, depending on her size.
Mangrove forests are exceptionally efficient at carbon sequestration, storing up to four times more carbon per hectare than most terrestrial forests.
The life cycle of the blue swimmer crab involves four distinct larval stages (zoea) and a final megalopa stage before it metamorphoses into a recognizable crab.
The lagoons in the Mullaitivu district are part of a larger complex of over 200 freshwater tanks and a 78 km coastline, creating a diverse area for wildlife.
Open access, though local fishing activities are most prominent in the early morning.
Admission
Free
Accessibility
The lagoon is accessible via local roads from Mullaitivu town. The terrain around the lagoon is flat but can be muddy. Viewing is best done from roadsides or near local fishing landings.
Mullaitivu Lagoon Post-War RecoveryNorthern Province, Sri Lanka