000			nam a22 7a 4500
999			_c9506 _d9506
003			OSt
005			20181227093638.0
008			181214b xxu||||| |||| 00| 0 eng d
040			_cNARA
100			_917727 _aDe Silva, M.W.R.N.
245			_aSeagrass Beds of the Negombo Lagoon
260			_c1987, _aSri Lanka, _bNARA,
300			_a14p.
520			_aSeagrass beds are high productive ecosystems which occur in the sea, in lagoons and in estuaries. They are prominent features of many sand and reef flats in the coastal waters of Sri Lanka, Although well represented throughout the island, there is little information on their distribution and ecology. Salm in 1981 has indicated the locations of the seagrass beds in the Kokkilai lagoon, Puttalam and Dutch Bays, Jaffna and Mannar Districts as well as in the Negombo Lagoon. Some information is also available on the taxonomy of seagrasses, but there appears to be some confusion even with respect to the genera that have been recorded for Sri Lanka. Abeywickrema (pers. comm.) records 12 species divided among 9 genera for Sri Lanka based on previous records. }The genera Halodule. Zostera and Thalassiodendron recorded for its Sri Lanka by Samarakoon in 1986 in a draft Technical Report of a Workshop on Critical Habitats in the Coastal Zone (CCD/USAID/URI) if they are truely present, have not been included in Abeywickrema's records. The present investigation has indicated the presence of extensive beds of seagrasses in the Negombo Lagoon. In areal extent the cover by seagrass beds exceed that of the mangroves of the Negombo Lagoon at least by three times. It is possible that the highly productive seagrass beds in the Negombo Lagoon play a major and a more important role in the fisheries productivity than the mangroves. Further research need to be geared to determining the the contribution of the seagrass beds to • * particularly the productive prawn fishery of the Negombo Lagoon. The following seagrasses were recorded in the lagoon during the present investigation; i) Halophila ovalis ii) Halophila beccarii iii) Halophila sp. iv) Ruppia sp. v) Syringodium isoetifolium vi) Halodule ? Further, during the investigation, several activities that could stress the seagrass beds were observed. Among them were; (i) The use of drag nets for fishing. (ii) The disturbance to seagrass beds by the collection of polychaete worms to be used as a feed in the shrimp hatcheries that have developed recently in the Negombo area.
700			_917737 _aRanatunge, R.A.S.
942			_cRP _2ddc