Main Page | See live article | Alphabetical index In fisheries science, maximum sustainable yield or MSY is the largest long-term average yield/catch that can be taken from a stock of fish without depressing the species' ability to reproduce. A typical MSY is about 80% of the total population biomass of the mature fish capable of reproduction. The maximum sustainable yield is usually higher than the optimum sustainable yield. This article is a stub. You can help Wikipedia by fixing it. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.