ABSTRACT
Stocking measures are often used to enhance or maintain pike populations. Stocking of pike, and piscivores in general, can also be used as a biomanipulation tool, example to restore turbid, eutrophic lakes into lakes with clearer water and well-developed macrophyte cover. If the stocked pike survive long enough to increase the density of older, larger pike, stocking may result in increased predation pressure on larger benthivorous fish, thereby reducing possible macrophyte uprooting and resuspension of fine particles. A pike stocking for lake restoration should result in clear changes in the trophic structure of the lake, that is, reduced density of zooplanktivores, higher abundance of especially larger sized zooplankton species, less phytoplankton, and ultimately a higher water visibility and increased abundance of submerged macrophytes. Pike stocking in lakes containing pike at equilibrium densities are unlikely to result in permanent, or even transitional, increases in pike population densities, and therefore unlikely to significantly affect trophic composition, at least in the long term.
