What is fecundity in fishery?

In terms of reproduction, fecundity means the biological ability to have a particular quantity offspring. Fertility means the actual use of fecundity to produce the offspring. Both terms can be used either of an individual or a population.

In everyday speech, most people use the term "fertility" to cover both meanings. But when needing to distinguish the ability to have offspring from the actual use of the ability, "fertility" should be used for reproductive ability, and "fecundity" for actual number or rate of offspring.