| Popis: |
Ongoing degradation of this wetland has resulted in biodiversity losses and alterations of fish and bird communities. Fish were represented by 14 species until 1980, five of which were introduced species; nowadays, there are six species left (three of them introduced) in the years when water quality was slightly improved. Habitat destruction, water availability and water pollution are the main processes threatening fish biodiversity in this wetland; toxic algae, cyanide and gill malfunctioning related with eutrophication were responsible for mass mortality of fish. Waterfowl are strongly dependent upon flooding areas, with this wetland acting as an ecological refuge for waterfowl living in nearby, temporary wetlands when these had dried up. Breeding numbers of aquatic birds were related to the spring flooding area. Impaired water quality, with its side effect of diminishing transparency, has resulted in the disappearance of most diving ducks. This chapter will review long-term patterns (1970–2007) of fish and bird communities as related to man-made impacts in the wetland. Some data on passerine species are also provided. |
