Fron the results obtained so far, the following tentative conclusions with regard to cagefish culture can be made.
Grass carp culture in cages is possible in all three lakes but, due to the greater abundance of grass, aquatic vegetation and other fodder, Begnas and Rupa Lakes have a greater potential. Furthermore, in all three lakes, there is less fodder in winter than during the rest of the year and alternative fodders (e.g. leaves of suitable trees) have to be used.
The best growth in silver carp has been recorded from Rupa Lake. Next comes Begnas Lake and the lowest growth has been in Phewa Lake. Even in Phewa Lake there are certain areas (e.g. Khapaudi), where there is an accumulation of plankton due to nutrients brought down by the Harpan Khola River and other runoff. Preliminary data on the growth rates of silver carp in Khapaudi have been encouraging. Similarly, differences in growth rates could be expected in different parts of the other two lakes as well.
A few Rohu (10–15) introduced into each cage have been found to be useful in cleaning the cage. As it is a column feeder, it helps to remove fouling organisms, thus providing better circulation of water. This also results in additional incidental production from the cage.
There is every indication that bighead carp will be successful in cage culture. Their culture could be expanded as more fingerlings become available.
Catla (Catla catla) is another species worth experimenting with. Being a plankton feeder, it is likely to be suitable as the other species referred to above in view of the negligible feed costs that would be involved in plankton rich waters.
In the Pokhara Lakes, Chinese carps grow faster than Indian or common carps. Therefore, culturing Chinese carps in cages is more profitable than common or Indian carps.
Cage fish culture could provide a more assured and more remunerative source to the fishermen than fishing in the lake.
A total of 100 t of fish could be produced by cagefish culture in the Pokhara Valley.
