Sulzkarsee is the only lake situated within Gesäuse National Park, Austria. The national park is home to precipitous limestone peaks and the river Enns; a southern tributary of the Danube. Before reaching the Danube, the river Enns descends 1,497m in altitude!
Sulzkarsee lake was stocked during the 1970s with salmonids (Salvelinus fontinalis, Oncorhynchus mykiss) and minnows (Phoxinus phoxinus) for hobby fishing until 2006. Intensive fishing in 2016 to reduce fish numbers allowed for successful spawning of the common toad (Bufo bufo) and alpine newt (Ichthyosaura alpestris).
The lake is situated within an area that is still used as alpine pasture for summer grazing. Animal access to the lake for drinking water has been restricted in an attempt to reduce excessive nutrient input. The lake has only one inlet and one outlet. However, there are a few sinkholes on one side of the lake.