Impact of Seasonal Water Quality Variations on the Distribution of Gulfam (Cyprinus carpio), Rohu (Labeo rohita), and Tilapia (Oreochromis niloticus) in the Irrigation Canals of District Larkana, Sindh, Pakistan

Abstract

The present study was examined the impact of seasonal water quality conditions on the distribution of three commercially important freshwater fishes namely Gulfam (Cyprinus carpio), Rohu (Labeo rohita) and Tilapia (Oreochromis niloticus), in the irrigation canals in District Larkana, Sindh, Pakistan). The research was carried out at five canal sites at three seasons: winter, summer and monsoon seasons. On the selected parameters of physicochemical parameters, the water samples were analyzed in terms of temperature, pH, dissolved oxygen (DO), turbidity, electrical conductivity (EC), and total dissolved solids (TDS). Measures of abundance and diversity of fish were done once they had been plotted using the standardized netting and visual census approach with the use of nets to catch the plentiful fish and then their counts were visually enumerated.

The result meant that this revealed that there were certain seasonal preferences among the target species. Gulfam was highest during the winter season, which is likely to occur due to its preference of low temperature and cool water. Rohu was the most common during the monsoon season when water movement and connection of the habitat was rife at this time. In summer, Tilapia was the dominant species and this happens to mean that it does not perish due to the high temperatures, or rather low levels of DO. The most important parameter in the water quality parameters was the DO and temperature whereby the DO was positively related to species richness. The results may be compared to the ecological trends of the region but at the same time it indicates the local specific differences that are also needed in the localized fisheries management. The paper sheds some light on the importance of the water quality and species-specific ecological measures, which have to be monitored in an ecological systems of canals. The current study provides a viable background information on planning and conservation of aquaculture sustainability in the semi-arid land of the Pakistani region where the irrigation canals could serve the purpose of providing sources of agricultural life as well as aquatic life in the area.