I worked in Austria as a fellow at the Konrad Lorenz Institute during the summer of 2005. On 1st May (the day after I arrived), I went for a long walk around the village of Altenberg. Here there is a lake which was once a stretch of the River Danube before the river was diverted and dammed when the power station at Greifenstein was built in the early 1980s. In that lake - the Altarm - one could see large fish. I was able to take the picture below - which has been manipulated a bit to make the fish more prominent. I know nothing about the different species of fish but I suspect that this may be a trout – which brings to mind Schubert's quintet. [Listen]
