Hello!
It wouldn't be the worst solution. Just think of the people who have been fishing since the beginning of the game. They probably already have 300 Fishbones. How will this affect Clams prices? Maybe not much, I just think too much. Either way, we already have plenty of places to get Clam.
My suggestion would be Fisherman's Chests, which can be crafted from various worthless items. Also, maybe a key? I leave that to the Game Designers.
If you have more ideas, let us know.
Have a nice day,
Sheen.