It is only possible to fish from the daybreak till the twilight.
How to reach Dobbiaco/Toblach: https://www.drei-zinnen.info/en/dobbiaco/dobbiaco/contact-and-service/arrival-mobility.html
From Dobbiaco in southern direction. The lake is located on the right side.
Parking places are available.
Also accessible by public transport. The timetables are available on www.sii.bz.it.