Fishing permit
To go fishing in Germany, you need to have a certificate of competence (fishing permit), though people whose permanent residence is outside Germany are exempt from this regulation. For more information, contact the fishing associations of the individual federal states. In addition to a fishing permit, you also need to have authorisation to fish in a particular stretch of water during a specific period. This can be purchased locally from the owner or leaseholder (generally a fishing club). Local tourist information offices can tell you where to do this.
There are exceptions: in Schleswig-Holstein's coastal waters, for instance, a fishing permit - or the exemption for non-residents - is sufficient and specific authorisation is not required.