The amount of eggs produced by a fish stock over its lifespan under a specific fishing regime, relative to the spawn that would have been produced over the fish stock’s lifespan if there were no fishing. It is a measure of the impact that fishing has on the ability of a fish stock to contribute to spawning. Often expressed as a percentage. For example, SPR50% means that under the specified fishing mortality rate, a recruit will, on average, produce half the eggs in its lifetime that it would have produced without fishing.
