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.

Results of recent studies in population genetics provide significant evidence that genetic changes may occur in many small, isolated, preserve populations. The primary phenomena producing these changes will be inbreeding, genetic drift, and the ‘founder’ and ‘bottleneck’ effects. A permanent reduction in population vigour and in genetic diversity may result from these processes.

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.

By 1973 the last populations of the Bush Elephant (Loxondonta africana africana) in the Republic of Rwanda comprised two small groups of ca 70 animals each. Both were surrounded by expanding human settlement which caused rising conflict between Elephants and Man. Eventually the elephants' removal became imperative. Adults (103) and unweaned immatures (3) were therefore shot.

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.