Optimizing the Allocation of Hatchery-Produced Fish among Multiple Stocking Sites

Abstract

We describe a two‐stage procedure to increase recreational angler use through optimal allocation of hatchery‐produced fish among sites. In stage 1, data on historical fish stocking, angler‐days, and attributes of individual fishing sites are used to formulate a regression equation that shows the relation between angler‐days and the number of fish stocked (stocking elasticity). In stage 2, this stocking elasticity is used in conjunction with data on the hatchery supply of rainbow trout Oncorhynchus mykiss to formulate a reallocation of fish among fishing sites. The algorithm allocates the limited production of hatchery rainbow trout among receiving sites to maximize total angler‐days by equalizing the potential gain in angler‐days from stocking one additional fish at each site. Application of the procedure to selected fishing sites in New Mexico suggests that total angler‐days could be increased by 16% with no increase in budget or other resources. An optimized fish stocking program would produce several benefits: (1) increased angler‐days by the fishing public, (2) a fish stocking schedule that is easily updated any time hatchery supply or on‐site facilities change, and (3) an objective and defensible stocking program that meets the demands of rigorous public scrutiny.

How ecological processes shape the outcomes of stock enhancement and harvest regulations in recreational fisheries

“…Monetary stocking costs may not be of great concern if only a few lakes close to urban areas are stocked to satisfy anglers (Cole andWard 1994, Post andParkinson 2012), or for angling clubs in Germany or elsewhere in central Europe that have few stocks to manage, high license income and little alternative uses for the income than stocking. But costs may be a problem for North American agencies charged with managing hundreds if not thousands of stocks among which they must allocate a limited budget (Cowley et al 2003). In this context, our research suggests that low stocking rates of adults may be cost-effective in many situations, not only in put-and-take urban lakes.…”

“…But costs may be a problem for North American agencies charged with managing hundreds if not thousands of stocks among which they must allocate a limited budget (Cowley et al. ). In this context, our research suggests that low stocking rates of adults may be cost‐effective in many situations, not only in put‐and‐take urban lakes.…”

“…Such information can inform the allocation of stocking resources within the landscape of lakes, with and without natural fish populations, to maximize the benefits the angling community receives while avoiding incurring unneeded costs (Cowley et al. ).…”

“…), and managers must figure out how to allocate limited stocking resources optimally within the landscape (Cowley et al. ). Hence, our work should be extended to broader spatial scales to investigate the optimal policy mixes in a landscape of diverse fisheries and diverse angler populations.…”

“…Our results are in agreement with other stocking models (Lorenzen 2005, Rogers et al 2010) that reported stocking was much more advisable in culture-based situations compared to stock-enhancement scenarios. Such information can inform the allocation of stocking resources within the landscape of lakes, with and without natural fish populations, to maximize the benefits the angling community receives while avoiding incurring unneeded costs (Cowley et al 2003).…”