In order to legally fish in Karsińskie Lake, it is necessary to obtain a permit (prices vary depending on the type of fishing you plan to undertake.) A permit, which is valid together with a fishing card, can be bought at the Fisherman's Farm in Charzykowy, as well as at nearby fishing shops in Chojnice, Brusay, in the centers in Drzewicz and in Charzykowy.
In the lake, also thanks to the fact that it is fed by two rivers, there is really a lot of fish. You can catch, among others bream, perch, roach, zander, pike, as well as carp, rudd and eel. The positions where Brda flows into the lake should be of particular interest to anglers.
Check the list of lakes and the price list of permits: http://charzykowy-ryby.pl/wykaz-jezior-i-cennik-zezwolen.php
Rules of fishing in the National Park: http://www.pnbt.com.pl/wedkarstwo-368