i think it is a great idea to be added in a couple months into the game. In terms of lore possibly something to do with a less abundant supply of fish traveling down the streams and more fish have been inhabiting the lake, within the lake could be rarer fish that provide possible buffs? something along these lines would make fishing a little more significant. Along with one among many reason for quick access to distant tribes for trade among many other things. Why not have water transportation if taming is meant to be added in early on in prelude for land transportation. possibly add them together even.