TY  - BOOK
AU  - Amarasinghe, U.S.
TI  - Fish Yields of Some Down-Stream Reservoirs of the Mahaweli Basin 
PY  - 1989///,
CY  - Sri Lanka
N2  - Fish yields and fishing pressure in down-stream reserveirs 
©f the Mahaweli basin vary considerably from each other. In 
Parakrama Samudra, where the fish yield was recorded to be one 
of the highest (376 kg ha , yr ) in the South East Asian region, 
the annual fish yield in 1985 was ^6 kg/ha. This declining trend 
is due to over-fishing. High fish yields (^1 kg ha , yr in 
1985) were recorded in Pimburettewa where the fishery is optimally 
exploited.
Indigenous fish species such as Labeo dussumieri and Barbus 
sarana which have been recorded to be contributed considerably to 
the commercial catches during rainy seasons, are presently 
insignificant in the landings. Tor khudree longispines has almost 
entirely disappeared in the reservoir fish catches. This could 
possibly be due to the river damming which would interrupt 
reproductive strategies of indigenous riverine species.
Although the major constituent in the Sri Lankan reservoir 
fishery is Oreochromis mossambicus, in some down-stream reservoirs 
of the Mahaweli basin, 0. niloticus appears to become dominant.
After intensive stocking ©f 0. niloticus fingerlings, the conditions 
were probably more favourable in these reservoirs due to the receipt 
of water from the Mahaweli river diversion project. Future research 
needs on the reservoir ecosystems in relation to fisheries 
management are discussed

ER  -