Stock density calculator

Fish shorter than 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 catches some sizes more than others, says little about the pond.

Length categories (stock, quality, preferred, memorable, trophy) follow Gabelhouse (1984), as compiled in Anderson and Neumann, Fisheries Techniques (1996). The four boxes are the four categories from stock length up for the species you chose. Fish shorter than stock length are left out of both the top and bottom of the ratio.

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 pond crowded with bass, with many small bass and few small bluegill. The reverse points to one crowded with bluegill, with few bass and stunted bluegill, and stocking more bass helps there. Once the pond reads balanced, the harvest planner gives the yearly take that keeps it there. Practitioner discussion: Pond Boss forum thread Fish Population and Size Analysis.