Inland Fisheries

1.2.1. Distribution of natural waters

Fishes and other aquatic resources are captured from a great variety of freshwater ecosystems, most of which are natural. Natural aquatic ecosystems include lakes , swamps and floodplains , collectively called standing waters, and rivers and streams , collectively called running waters.

The distribution pattern of natural freshwaters among the continents is uneven which has important implications for aquatic production (inland capture fisheries and aquaculture). For example, the greatest occurrence of standing waters is in the relatively unproductive northern areas of the Northern Hemisphere. In contrast, the distribution of running waters in the form of perennial rivers is more homogeneous, with the exceptions of the great deserts of North and Southwest Africa, the Arabian Peninsula and Australia.

The status and trends of aquatic ecosystems, both natural and modified , are closely linked to the condition of adjacent terrestrial ecosystems. Therefore, it is essential to view each inland aquatic ecosystem in terms of the watershed , or basin , in which it occurs. This applies particularly to the multiple use aspects of inland systems that require integrated watershed development , integrated watershed management and a framework within which to assess the environmental impacts of land-based activities on inland aquatic ecosystems.

Globally, lakes, reservoirs and wetlands important for inland fisheries cover a total area of about 7.8 million km². Relatively high proportions of land area are covered with surface waters in Southeast Asia, North America, east and central West Africa, the northern part of Asia, Europe and South America.

Distribution by continent of major surface freshwater resources

	Surface area								Share of total (%)
	Lakes	Reservoirs	Rivers	Floodplain	Flooded forest (Km)	Peat land	Intermittent wetland	Total
Asia	898000	8000	141000	1292000	57000	491000	357000	3316000	42
South America	90000	47000	108000	422000	860000	--	2800	1529800	20
North America	861000	69000	58000	18000	57000	205000	26000	1294000	17
Africa	223000	34000	45000	694000	179000	--	187000	1362000	17
Europe	101000	14000	5000	53000	--	13000	500	186500	2
Australia	8000	4000	500	--	--	--	112000	124500	2
Oceania	5000	1000	1000	6000	--	--	100	13100	0
Total	2186000	249000	358500	248500	1153000	709000	685400	7825900	100