Abstract:
The species composition, abundance and the distribution of different seagrass
beds of Puttalam lagoon have been investigated. Eight species belonging to six
genera were recorded during the investigation i.e., Enhalus acroida (I. F..)Royle
Thalassia hemprichif (Ehrenb.) Aschers., HaIodule uninervis (Forsk.) Aschers in
Bossiser, Syringodium isoetifolium (Aschers.) Dandy, Cymodocea rotundata
Ehernb. et Hempr. ex Aschers., Cymodocea serrulata(R. Br.) Aschers, and Magnus,
Halophila ovalis (R. Br.) Hook. F. and Halophila decipiens Ostenfeld. Two
varieties of Halodule uninervis (narrow and wide) were also recorded during this
investigation. The distribution pattern of the different species of seagrass beds
showed a close association with different salinity values of the lagoon. It was
found that the narrow variety of Halodule uninervis covered 75% of the potential
areas of the lagoon. It was also observed that Enhalus acroides, Cymodocea
serrulata and Thalassia hemprichii play a major role as substrata lor many
important epiphytic forms of macro and micro algae. It was also discussed thai
traditionalfishing methods prevailing in this lagoon show til great threat to the
'survival of the seagrass communities.