Michigan Department of Natural Resources
Fisheries Research Report No.1856, 1977
Results of Attempts to Optimize Growth and Survival of Bluegills in Ponds By Yearly Population Manipulation
George B. Beyerle
Abstract.-For 5 consecutive years bluegill populations in three ponds (1. 0, 1. 8, and 2. 6 hectares) were manipulated to test the theory that optimum growth and survival would result if yearly survival of age-0 bluegills was restricted to less than 10, 000 per hectare, and if 50% of all other age groups was harvested each fall when the ponds were drained. Age-0 bluegills were manipulated as planned, but the anticipated 50% yearly harvest of other age groups was reduced to 0-25% in an attempt to maintain total standing crops of approximately 100 kg per hectare. Analysis and projection of the data obtained lead to the postulation that, although the 50% yearly harvest of age-I and older bluegills did not permit the standing crop (expressed in weight) to expand as anticipated, a continuation of the planned harvest would have resulted in optimum sustained yield of bluegills 15. 2 cm (6 inches) and larger.