Effects of introduced salmonids on amphibian distribution and abundance in Retezat National Park Dragoş Cocoş CBM CBM CBM CBM MASTER THESES SERIES MASTER THESES SERIES MASTER THESES SERIES MASTER THESES SERIES International Master Programme at the Swedish Biodiversity Centre Master theses

Torbjörn Ebenhard, Călin Hodor
2007 unpublished
A total of 105 ponds and lakes across the alpine area of Retezat National Park were surveyed in order to find if the introductions of nonnative fish species have a negative influence on the distribution and abundance of local amphibian populations. Surveys conducted over two summer months in 2006 were used to identify the lakes where the introduced fish species still occur and to note the status of amphibian populations. Experiments performed at two sites revealed that the fish species found in
more » ... sh species found in the area are capable of heavily preying on and drastically reducing the number of tadpoles. The results of the study also show that the remaining amphibian populations are very fragmented and missing from several sites that were stocked with fish which have later disappeared. Restoration of amphibian populations in some of the lakes is required and a good long term monitoring program should be set up to support the amphibian recovery process.