fish out

1.  Also, fish up. Discover and retrieve something from a pile or store. For example, She finally fished out the right letter from the files, or He fished up a scandal for the paper to run in the early edition. This usage likens pulling fish from the sea to finding something. [Mid-1600s]
2.  Deplete the fish in a body of water by fishing, as in This stream is completely fished out.