Inland Fisheries

9.3.3 Factors affecting fish diversity

With the rapid overall development of the country and owing to ever-increasing demand of fish as food, the aquatic ecosystems are under constant pressure of man-induced stresses to the detriment of the aquatic flora and fauna. Though the decline of individual fish species is very often related to more than one proximate factors, the various causes of imperilment of fishes in the aquatic ecosystems have been identified as

1. Physical habitat loss due to construction of dams and weirs across the rivers, soil erosion due to deforestation and excessive utilization of waters,
2. Chemical pollution due to industrial and municipal wastes
3. Over-exploitation and indiscriminate killing of juveniles and brood fishes
4. Competition from the introduced non-indigenous species.