Stock density calculator
Fish under stock length are not counted. PSD describes the size structure of one species from one sample; a sample of fewer than 50 stock-length fish, or one taken with gear that selects for a size, says little about the pond.
Balance check
Method and sources
RSD-P and RSD-M = the same, for preferred and memorable length
Length categories (stock, quality, preferred, memorable, trophy) follow Gabelhouse (1984), as compiled in Anderson and Neumann, Fisheries Techniques (1996). The bins on this page are the four stock-and-over categories for the chosen species; fish shorter than stock length are left out of both the numerator and the denominator.
Balance targets for bass and bluegill ponds come from Anderson (1985) and Willis et al. (1993): largemouth bass PSD 40 to 70 with RSD-P 10 to 40, bluegill PSD 20 to 60 with RSD-P 5 to 20. A low bass PSD with a high bluegill PSD points to a bass-crowded pond; the reverse points to a bluegill-crowded pond. Practitioner discussion: Pond Boss forum thread Fish Population and Size Analysis.