HomeAboutActivitiesMapsPhotosPublicationsNews
 
Home >> Vital Water Graphics 2 >> Fish diversity in freshwater systems
File type Download Size Language
.jpg .jpg Download 88 kb -
.eps .eps Download 937 kb -
Uploaded on Thursday 16 Feb 2012 by GRID-Arendal

Fish diversity in freshwater systems

Year: 2009
From collection: Vital Water Graphics 2
Author: Philippe Rekacewicz
Description:
Although freshwater ecosystems such as rivers, lakes and wetlands occupy less than 2% of the earth’s total land surface, they provide a wide range of habitats for a significant proportion of the world’s plant and animal species. Many are yet to be discovered, but the number of freshwater species worldwide is estimated at between 9,000 and 25,000 (Cosgrove and Rijsberman, 2000). However, this number is rapidly decreasing due to human interference. Physical alteration, habitat degradation, excessive water withdrawal and pollution have contributed directly or indirectly to the decline in freshwater species. Other factors that reduce freshwater biodiversity include the incursion of non-native species and the mismanagement of inland fisheries. Today, an estimated 20% of the world’s freshwater fish is vulnerable, endangered or extinct (Revenga et al., 1998).
Views: 839     Downloads: 186     Rating: 4
Suspended sediment discharge
Planet index 2007 for marine species population
Who will not reach the water and sanitation millennium development goal?
Industrial areas and seasonal zones of oxygen depleted waters
Nitrate levels: concentrations at river mouths
Renewable surface water produced internally
Total population: access to an improved water source
Water Scarcity Index