Prior posts have noted the various strategies for assuring the recovery of depleted fish stocks, particularly the creation of no-fish zones. A recent study has found that in terms of restoring caviar-producing sturgeon the key is saving grown females, not supplementing the population with hatchery fish.
Using data from the Ural River, researchers found that females should not be harvested until they are at least 31 years old in order to assure that they have a sufficient chance to produce eggs. This strategy was found to be ten-times more effective than supplementing the population with hatchery fish.
The study can be found at http://www3.interscience.wiley.com/journal/123299992/abstract?CRETRY=1&SRETRY=0.