Abstract:
The coastal region of the Ampara district
of Sri Lanka has a considerable number of perineal and
seasonal estuaries which are poorly used for
aquaculture. The reason they are not being used in
aquaculture is the lack of awareness and inadequate
information on the water quality parameters of these
estuaries. Thus, the research has focused on
investigating the water quality parameters of brackish
waters in the Ampara district of Sri Lanka, with
particular emphasis on their suitability for aquaculture.
Water temperature, dissolved oxygen (DO), water and
soil pH, salinity, conductivity, and total dissolved solids
of the available estuaries or coastal wetlands in the
Ampara district were investigated to assess the sites
suitable for aquaculture for a full year from January to
December 2018. Ambient temperature and
precipitation were also recorded over the course of the
year. The annual differences between the maximum and
minimum level of water temperature, salinity, pH,
specific conductivity, total dissolved solids, DO, and soil
pH were 24.2 - 36.2ºC, 0.9- 38.2 ppt, 6.2 - 8.9, 55.5 - 62870
µs/cm, 35.5 - 37800 mg/L, 3.2 - 13.4 mg/L, and 4.0 - 7.2
respectively for the whole year of 2018. The water
quality parameters investigated in the full year indicate
that the culture of brackish water shrimps would be
suitable in Arugam lagoon (salinity, 17.1±3.3ppt) and
Komari river mouth area (salinity, 21.4±8.4ppt), and
culture of freshwater fish would be better in Oluvil
(5.3±3.5ppt), Addalaichenai- Konawatte and River
mouth (4.1±1.2ppt), Periyamuhathuwaram
(3.2±1.2ppt), and Urani lagoon (5.1±3.0ppt) in all year
long. As the seasonal lagoon of Sainthamaruthu
(9.8±2.6) is unpredictable and recorded with highly
variable water quality parameters, it would be very
risky to culture the shrimps and may be suitable for
euryhaline fish culture. The Sinnamuhathuwaram
lagoon (9.3±3.9 ppt) is suitable for euryhaline fish
farming during the period between November and
March, while it is suitable for shrimp cultivation from
April to October. Pottuvil Lagoon in Kottukkal would
be suitable for freshwater fish farming from November
to April, and for shrimp farming from April to October.
Our study concluded that the lagoons of Komari- II and
Arugambay are the ideal sites for culturing shrimp in all
year long.
