Abstract:
Identification of abiotic variables that influence on biotic components in
the lagoon is one of the main challenges in ecology because biotic components show
variations in abundance as an adaptive response to changes in chemical, physical and
biological characteristics of the habitats. An important characteristic of the lagoon is its
biological diversity because physical, chemical (abiotic) measurements reflects water
quality at a given time while biological assessment reflects conditions that have exited
in a given environment over a long period of time. The present study investigated the
prevailing condition of water quality to identify possible abiotic factors that effect on
the biotic variables of the Batticaloa lagoon. In situ measurements of chemical, physical
parameters of the lagoons measured were measured routinely from 9th July 2008 to
22nd June 2009. Averages of the results indicated chemical parameters of dissolved
oxygen (3.65 } 0.40 to 13.99 } 0.64 mg/L), phosphorus (0.31 } 0.06 to 0.52 }
0.18mg/L), nitrate (1.07 } 0.32 to 3.98 } 0.22 mg/L), nitrite (58.33 } 9.27 to 72.08 }
6.90mg/L), and pH (8.01 } 0.02 to 8.16 } 0.05) and physical characteristics like salinity
(15.50 } 1.65 to 29.16 } 0.89 ppt), density (1.01 }0.00 to 1.02 }0.01 gcm-3), surface
water velocity (0.10 } 0.01 cms-l to 0.13 } 0.01 cms-1), turbidity (5.68 } 1.25 to 37.69
} 1.83FTU), temperature (31.58 } 0.60°C to 33.45 } 0.19°C) varied widely.
Simultaneously were collected existing biotic components (finfish, shellfish and jelly
fish) on the sampling points. Analysis elucidated the existing conditions were found to
have strong impact on biological parameters. Furthermore, seasonal changes and
anthropogenic influences also significantly affect the biotic components. This
information and observation of this study will be very crucial to the biological life of the
lagoon for formulating management policies (Master plan for Batticaloa lagoon) in
future with other sectors.
