Abstract:
Bundala National Park (BNP) is the first Ramsar wetland in Sri Lanka. Present study aimed to
investigate ecological aspects o f Malala lagoon, Embillakala lagoon and Bundala Lewaya in
BNP. This study also focused on some sociological aspects in BNP. Physico-chemical
parameters and biological parameters o f selected lagoons were probed in random, spatial and
temporal scale. Diversity and feeding preferences o f fish fauna inhabiting these lagoons were
examined. Birds associated with lagoons were investigated with a special reference to their
habitat preferences and abundance. Ecological importance o f pondweed beds o f Embillakala
lagoon was analyzed. The association between neighboring human community and BNP was
also investigated. Morphological features and hydrological characters o f each lagoon differed.
Present study identified important phytoplankton, zooplankton and benthic assemblages in
each lagoon. Seasonal variation o f physicochemical parameters and biological parameters o f
three lagoons were described. Data indicated the spatial and temporal changes o f
physico-chemical parameters and key zooplankton species in Malala lagoon. Salinity
fluctuations accompanied with changing nutrient levels seemed to play a key role in designing
the biological environment o f the lagoons. Thirty-two fish species were recorded from three
lagoons. They were categorized into dermersal, pelagic, bentho-pelagic and reef associated
guilds. Fish stomach content analysis highlighted the important food items in lagoons. Fishes were classified as piscivorous, zooplanktonivorous and omnivorous depending on their feeding
preferences. Analysis o f bird communities revealed that each lagoon performed as a specific
habitat for birds. Lagoon area and salinity strongly correlated with bird abundance. The
reduction o f abundance o f migratory waterfowls and resident water birds taxa were noted.
The difference o f physico-chemical parameters and biological parameters between pond weed
beds and adjacent weed free localities revealed that they perform as an important
micro-ecosystem. A significant density o f phytoplankton, zooplankton, and benthos inhabited
the pondweed beds in contrast to the non-weedy localities. Overall data indicated that studied
lagoons are delicate and extremely dynamic ecosystems. Poor education level associated with
underprivileged living condition was common in the studied human community. Occupational
practices such as fishing, land use practices, utilization o f other park resources have profound
effects on the health o f the Park environment. Freshwater discharge into lagoons and
anthropogenic desiccation o f lagoons were identified as key factors affecting lagoon hydrology
and biology. This study stresses the importance o f long term monitoring programs in Bundala
lagoons. Action plans and management plans should be designed in accordance with the
dynamic nature o f lagoons and stakeholder perceptions. Investigation o f ecological
characteristics more precisely can strengthen sustainable utilization o f resources and
conservation efforts.
