Michigan Department of Natural Resources
Fisheries Research Report No. 1795, 1973
Density Dependent Growth and Mortality of Yellow Perch in Ponds
James C. Schneider
Abstract.-Survival and growth of perch during their first 6 months of life were studied in relation to the density of older perch in replicated ponds at the Saline Fisheries Research Station from 1969 to 1972. Data on the growth and survival of older perch, and on the effects of pond types, were obtained also. In the spring of the year, the ponds were stocked with fertilized perch eggs and either no, low, or high numbers of fingerling (mostly yearling) perch. Stocking rates were selected so as to simulate densities, and produce growth rates, found in natural populations. In the fall of the year, the ponds were drained and the fish counted. I found that the number of young perch which survived was higher in the ponds rich in plankton than in the ponds with extensive stands of cattails, at all levels of fingerling density. In the cattail ponds, survival of young was reduced only at high fingerling densities, whereas in the plankton-rich ponds, even low numbers of fingerlings appeared to reduce survival of young. Growth of young compensated for abundance of young, with the result that cattail ponds produced 84 pounds of young per acre and the plankton ponds produced 108 pounds per acre, regardless of fingerling abundance. Growth of young was linearly related on a log-log scale to their own density. Competition with fingerlings did not affect growth of young until they reached a length of about 4.4 inches-a size not usually attained in natural populations in one year.
Between 10.9 and 52.9% of the planted fingerlings died of natural causes during each experiment. Survival was not related to density or pond type. Growth of individual fingerlings was inversely related to density; however, the ponds stocked at the highest rates produced the largest total standing crops.