Inland Fisheries

1.2.1.1. Rivers of the world

Rivers are dynamic systems, with their courses and flows constantly changing due to natural and human responses. The world's main channel river length amounts to about 2,69,000 km, with the highest density of rivers located in South America and the least in Oceania. Globally, the reservoir storage is attained about seven times the standing of water in Rivers. Major river and floodplain systems are very important to Asian countries. Rivers play a substantial role for capture fisheries - their contribution to food security is often underestimated as statistics do not include the component consumed by fishers. Catch statistics from rivers are often of low quality because of the difficulty inherent in collecting data from fisheries which operate from many landings dispersed along a system that may traverse several countries. Extrapolating data from systems well-known to other river systems provides a comparison between the river channel length and catch for selected rivers of the world.

Multiple use of rivers - for transportation, power generation, agriculture and industry - and their abuse as a recipient of wastes and through channelization (especially in Europe, North America and Asia), has led to the loss of their original form and to the progressive loss of biological diversity. In China, the multitude of flood control and other hydraulic structures, together with river pollution, has caused a drastic decline in river fish stocks and fisheries, on which tens of thousands of people fully depended in the past. Although some mitigation measures have been introduced, these have resulted in only minor benefits for fish stocks. The deterioration of rivers on a global scale has led to calls for amelioration of negative impacts and, in some situations, to the reclamation of the natural habitat wherever possible.

The following table shows the longest rivers of the world with their source and outflow.

Rank	River	Source	Out flow	Length (km)
1	Nile (Egypt)	Tributaries of Lake Victoria, Africa	Mediterranean Sea	6,690
2	Amazon (Brazil)	Glacier-fed lakes, Peru	Atlantic Ocean	6,296
25	Brahmaputra	Himalayas	Ganges River	2,897
26	Indus	Himalayas	Arabian Sea	2,897
36	Ganges	Himalayas	Bay of Bengal	2,506