The Puttalam lagoon is one of the largest lagoons of Sri Lanka which extends over 327.5 km². It is one of the most productive lagoons in the country and has been economically important in terms of fisheries, tourism, agriculture and industries. On the other hand, this sensitive coastal ecosystem is an asset of Sri Lankan biodiversity as it harbours a large number of flora and fauna species in many distinct habitats such as mangroves, coral reefs, salt marshes, etc. This study presentsan assessment of the socio-economical and ecological status of the mangrove ecosystem in the Puttalam lagoon area in Sri Lanka.

A total of 512 species of flora, including 406 native species, nine endemic, eight threatened species, 108 exotic and 13 invasive alien species; and a total of 308 faunal species belonging to 112 families with seven endemic and 12 nationally threatened species were identified in the Puttalam lagoon area. Mangrove habitat is the most extensively distributed habitat in the Puttalam lagoon area. A total of 13 true mangrove species and 18 mangrove-associated species were reported from Puttalam Lagoon and associate islands.

Mangroves are closely linked with many household activities and small industries in the Puttalam lagoon. Some of the wide uses of mangroves are fuel-wood, and fodder for livestock, for small industries and also for extracting food. During the past two decades the mangrove cover of the Lagoon is extensively being cleared due to the rapid expansion of shrimp farms, salterns and tourism industry. Water pollution due to the use of fertilizers and agrochemicals in upstream agriculture and downstream shrimp farming is another threat. 

Climate change is an emerging threat to the environment, economy and the communities associated with the Lagoon and the surrounding area. A 7% decrease in average rainfall has been reported in the Puttalam area between 1961 and1990 as compared to 1931-1960. Moreover, there has been an increasing trend in the average air temperature of 0.016 ºC per year within 1961-1990, with a maximum rate of an increase of 0.02 ºC per year. These changes along with the rising sea-level may also affect the mangrove ecosystem and the associated environmental services.

Adopting sustainable land use practices and alternate income generating activities and, improving natural resources governance have been identified as the necessary responses to improve the socio-economical and ecological condition of the area.