Over the last twenty years, the population of Mountain Gorilla (Gorilla gorilla beringei) in the Virunga Volcanoes region of Rwanda, Uganda, and Zaire, has halved from an estimated 400–500 to fewer than 250. The major cause of this decline is loss of habitat through large-scale appropriation of National Park land in Rwanda for agriculture, and through encroachment by local people and their cattle which causes extensive damage to vegetation within the protected area.

The Spotted Tilapia, Tilapia mariae, apparently introduced to Dade County, Florida, between 1972 and 1974, has expanded its range dramatically. This exotic fish is now established in three counties (Broward, Collier, and Dade) in canals and lakes in an area encompassing approximately 2,000 km2.

The major carps such as Labeo rohita, Cirrhinus mrigala, Catla catla, and Labeo calbasu, which constitute important economic food-fishes in India, breed only in rivers, and consequently the spawn and fry of these fishes are collected from riverine resources for culture in ponds and tanks. The present paper describes our extensive survey of fish spawn-collection grounds in the River Ganges (from Barauni to Farakka, a stretch of about 256 km). In the course of these studies, active and major sites of spawning were located at Monghyr, Sultanganj, Akbarnagar, Sonbarsa, Bhagalpur, Colgong, Sahibganj, Rajmahal, Manikchak, and Farakka. Some of the environmental factors, such as water transparency, temperature, pH, dissolved oxygen, and meteorological conditions for spawning of fishes, were analysed.