Fishing should be even MORE of a mindfucking mystery, not less of one.
As it is IRL we barely know what the fuck we're doing today, fucking running fish into extinction because we have no idea what their numbers are.
Right! but lets make the waterbody-related system. so in central SG's half of em would be extinct already, making frontier SG's subject to a world fish-rush.
i'd also add an ability to introduce spieces into water bodies, if they were extinct there, by dropping unbutchered fishes into lakes.(And not catching them(leting em go immidiately) for some time to let them breed.(and killing any poacher who dares to drain your lake

And given more fish recieps suggested here viewtopic.php?f=5&t=19913 , it would be even more sufficient and fun.