Assessing the effects of catch and release regulations on a quality adfluvial brook trout population using a computer based age-structure model

North American Journal of Fisheries Management
By:  and 

Links

Abstract

Assessing the Effects of Catch-and-Release Regulations on a Brook Trout Population Using an Age-Structured Model: North American Journal of Fisheries Management: Vol 30, No 6

As populations of wild brook trout Salvelinus fontinalis decline across the species' native range in North America, angling regulations such as fly-fishing only and catch and release are being used by management agencies to conserve fish while maintaining angling opportunities. Postrelease (hooking) mortality may significantly shift the age structure and size structure of populations. To assess the possible influence of catch-and-release fishing on brook trout population structure, we applied data from several sources to build a deterministic population model that included age-classes up to age 5. To assess the potential effect of fishing, we examined the changes in population density and age structure at varying levels of angler effort (0–400 angler-hours·ha−1·year−1) and hooking mortality rates (0–14%). Assuming a low (5%) hooking mortality rate, trophy brook trout density (ages 4 and 5) decreased by 50% at an angling intensity of 160 angler-hours·ha−1·year−1. As angling effort increased, the proportion of older fish (ages 3–5) declined further. At very high levels of angling effort (>300 angler-hours·ha−1·year−1), age-4 and age-5 fish were eliminated from the population. Increases in postrelease mortality rates resulted in similar declines for older age-classes. The results of this simulation indicate that hooking mortality rates as might be common in catch-and-release fisheries may significantly shift the age structure of a population, thus reducing trophy angling potential.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Assessing the effects of catch and release regulations on a quality adfluvial brook trout population using a computer based age-structure model
Series title North American Journal of Fisheries Management
DOI 10.1577/M09-158.1
Volume 30
Issue 6
Year Published 2011
Language English
Publisher American Fisheries Society
Contributing office(s) Coop Res Unit Leetown
Description 11 p.
First page 1434
Last page 1444