This definition seems correct, but more explanation could be very helpful. As it is, this is nothing more than a glossary (or is this the glossary?)
It should be added in the beginning of the definition that this applies to the use of the word in population genetics. In other contexts and in common language, the word obviously has other meanings too.
If an article is composed around the definition, then the population genetic consequences of a bottleneck could be discussed, such as genetic drift or fixation of genes. Examples could be added to illustrate the concepts. Restrict the page to those elements that a (broadly interested) coastal manager should want to know about this subject, e.g. relating to near-extinction of populations, maintenance of viable populations, minimum sizes for MPA's etc. Consider referring to a Wikipedia page for more details than needed in the context of this Coastal Wiki.