Abstract:
Sri Lanka has a coastline of approximately 1700 km, along which many varieties of marine
algae are found. There are nearly 260 species of seaweeds growing along the coastal line.
Out of these only a few species of Chiorophyceae, Rhodophyceae and Phaeophyceae are
common as economically important. Although there is a good potential for development
of the seaweed industry in Sri Lanka the currently available data is insufficient for
determining the abundance of seaweed resources available in the country. To improve this
industry NARA has conducted a field survey to determine the distribution and abundance—
of standing population of the presently available seaweed in Sri Lanka. Main objectives
of this survey are to determine the standing biomass and cover of economically imported
seaweeds in Southern coastal belt and identification of the sites in the southern coastal
belt for culturing the economically important seaweed species. Ten sampling points were
randomly selected from six sampling sites using 0.25m2 quadrant. Percentage coverage
of different seaweed species at each sampling site were used for further analysis. There
were twenty five seaweed species including ten green algae species, twelve red algae
species and three brown algae species. The highest seaweed coverage (85%) is recorded
from Tangalle while the lowest coverage (18.5%) recorded from Polhena. Galle shows the
highest total dry weight (744g/m2) and Midigama shows the lowest total dry weight (233.6
g/m2) of seagrass. Sargassum spps was more abundant in Southern coastal area and there
is a potential for culturing. Velonia species was collected from all sites and Ulva lactuca
was collected from Midigama, Mirissa and Polhena sites and it reveals that, seawater in
the area was polluted because Ulva lactuca is an indicator of determining the level of
pollution of sea water.
