|
1. Summary |
From
the year 1997 to 2005 there were -in the Laguna Blanca National Park-
monthly censuses of the aquatic birds communities in different points of
the NP. The aquatic principal environment – the Laguna Blanca - suffered
in the years 1942, 1964 and 1975 the introduction of exotic fishes in
environments where fishes did not exist. As a result of these illegal
introductions, in the year 1986 one amphibian Atelognathus
patagoniucs became extinct of the main body water (the Laguna
Blanca), persisting in neighboring lagoons where fishes were not
introduced. As a consequence, there began to see a decrease in several
species of aquatic birds - especially the black neck swan, bird that
forms a part of the emblem of the National Park, accompanied by
modifications in the trophic structure and in the quality of the of the
Lagoon´s water. From the year 2005 and 2006 there began a process of
restoration of the lagoon by means of activities of traditional
fishing. The information on censuses of birds constitutes a variable of
real interest to be able to study the effects of the introduction of
fishes in environments where they did not exist and monitoring the
effects of the fish extraction on the recovery of the lagoon. The data
base development will also be extended to many other census information
in the National Parks Administration and in the country |
