The Fish Market
You didn't think you will end up holding all that fish did you? :), Fish processing is here, and it brings up some cool things. The tea market has been extended with new places, go visit.

The fish will not last forever, so you better hurry. The fresh fish will last about 2 hours before its spoiled, so hurry to the fish market to monetize it then plan your timing right on future fishing.

For the current fish you hold, you have 48 hours to do something with it, or it will spoil just like the new fish from now on.