Abstract:
Bundala National Park (BNP) of Sri Lanka has been designated as a Ramsar
wetland in 1993. Present study (year 2009) has investigated tht physicochemical
parameters and zooplankton diversity in the aquatic environments of northern
and southern periphery of Bundala lagoon with reference to the data collected in
a study conducted in this area during 2001-2003. In this study relatively high
salinity levels (42.5 to 10 ppt) were recorded in northern periphery of Bundala
lagoon when compared to the salinity levels (46 to 13.6 ppt) reported during
2001-2003. Highest dissolved nitrate concentrations were 5.46 mg/1 in Bundala
lagoon while it was 1.2 mg/1 during 2001-2003. The pH value of the study area
was lower than that of reported during 2001-2003. Gammarus pulex, Limnaea
franculata, Cyclops spp. and Candona Candida were the major zooplankton taxa
reported in this study while calanoid copepods, rotiferans i.e; Brachionus
plicatilis, Brachionus urceolaris and ostracods i.e.; Cypriodopsis spp. were the
major zooplankton recorded during 2001-2003. Change of zooplankton
composition when compared to the previous study might be a result of the
decreased salinity levels (Mann Whitney Test W=49, P=0.011), enhanced
aquatic nitrates (Mann Whitney Test W= 27, P=0.033) and reduced pH (Mann
Whitney Test W=21, P=0.025) levels.
