Nigel P. Lester

Canada's Recreational Fisheries: The Invisible Collapse?

Abstract Fishing for recreation is a popular activity in many parts of the world and this activity has led to the development of a sector of substantial social and economic value worldwide. The maintenance of this sector depends on the ability of aquatic ecosystems to provide fishery harvest. We are currently witnessing the collapse of many commercial marine fisheries due to over-exploitation. Recreational fisheries are typically viewed as different from commercial fisheries in that they are self-sustaining and not controlled by the social and economic forces of the open market that have driven many commercial fisheries to collapse. Here we reject the view that recreational and commercial fisheries are inherently different and demonstrate several mechanisms that can lead to the collapse of recreational fisheries. Data from four high profile Canadian recreational fisheries show dramatic declines over the last several decades yet these declines have gone largely unnoticed by fishery scientists, managers, an...

Patterns of Food Chain Length in Lakes: A Stable Isotope Study

Food web structure is paramount in regulating a variety of ecologic patterns and processes, although food web studies are limited by poor empirical descriptions of inherently complex systems. In this study, stable isotope ratios (δ15N and δ13C) were used to quantify trophic relationships and food chain length (measured as a continuous variable) in 14 Ontario and Quebec lakes. All lakes contained lake trout as the top predator, although lakes differed in the presumed number of trophic levels leading to this species. The presumed number of trophic levels was correlated with food chain length and explained 40% of the among‐lake variation. Food chain length was most closely related to fish species richness ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

The effects of regional angling effort, angler behavior, and harvesting efficiency on landscape patterns of overfishing

r^{2}=0.69

Light and Temperature: Key Factors Affecting Walleye Abundance and Production

\end{document} ) and lake area ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape

Food web expansion and contraction in response to changing environmental conditions

r^{2}=0.50

Life-history plasticity and sustainable exploitation: a theory of growth compensation applied to walleye management

\end{document} ). However, the two largest study lakes had shorter food chains than lakes of intermediate size and species richness, producing hump‐shaped relationships with food chain length. Lake productivity was not a powerful predictor of food chain length ( \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape