Supply–demand equilibria and the size–number trade‐off in spatially structured recreational fisheries

• Published in: Ecological applications Vol. 26; no. 4; pp. 1086 - 1097
• Main Authors: Wilson, Kyle L, Ariane Cantin, Hillary G. M. Ward, Eric R. Newton, Jonathan A. Mee, Divya A. Varkey, Eric A. Parkinson, John R. Post
• Format: Journal Article
• Language: English
• Published: John Wiley & Sons, Ltd 2016
• Subjects: fish; fisheries; fishermen; foraging; lakes; landscapes; Oncorhynchus mykiss; predators; sport fishing; uncertainty; British Columbia
• ISSN: 1051-0761; 1939-5582

Recreational fishing effort varies across complex inland landscapes (e.g., lake‐districts) and appears influenced by both angler preferences and qualities of the fishery resource, like fish size and abundance. However, fish size and abundance have an ecological trade‐off within a population, thereby structuring equal‐quality isopleths expressing this trade‐off across the fishing landscape. Since expressed preferences of recreational anglers (i.e., site‐selection of high‐quality fishing opportunities among many lakes) can be analogous to optimal foraging strategies of natural predators, adopting such concepts can aid in understanding scale‐dependence in fish–angler interactions and impacts of fishing across broad landscapes. Here, we assumed a fish supply–angler demand equilibria and adapted a novel bivariate measure of fishing quality based on fish size and catch rates to assess how recreational anglers influence fishing quality among a complex inland landscape. We then applied this metric to evaluate (1) angler preferences for caught and released fish compared to harvested fish, (2) the nonlinear size–numbers trade‐off with uncertainty in both traits, and (3) the spatial‐scale of the equilibria across 62 lakes and four independent management regions in British Columbia's (BC) rainbow trout Oncorhynchus mykiss fishery. We found anglers had low preference for caught and released fish (