EDITORIAL: Toward Darwinian fisheries management

Erin S Dunlop,Katja Enberg,Christian Jørgensen,Mikko Heino

doi:10.1111/j.1752-4571.2009.00087.x

Abstract

There is increasing evidence that fishing may cause rapid contemporary evolution in freshwater and marine fish populations. This has led to growing concern about the possible consequences such evolutionary change might have for aquatic ecosystems and the utility of those ecosystems to society. This special issue contains contributions from a symposium on fisheries-induced evolution held at the American Fisheries Society Annual Meeting in August 2008. Contributions include primary studies and reviews of field-based and experimental evidence, and several theoretical modeling studies advancing life-history theory and investigating potential management options. In this introduction we review the state of research in the field, discuss current controversies, and identify contributions made by the papers in this issue to the knowledge of fisheries-induced evolution. We end by suggesting directions for future research.

Highlights

When Charles Darwin made his argument that life was evolving he began by showing the potency of artificial selection to modify domesticated species, and how quickly animal breeders were able to create new varieties—he cited examples of talented farmers who created new races of livestock within their own lifetime (Darwin 1859)
Thereafter, it took almost a century before these patterns were clearly identified in data, sparked by Ricker’s (1981) study of declining sizes of Pacific salmon Oncorhynchus spp. returning to spawn; patterns he could not explain by any concurrent environmental trend but that were consistent with evolutionary change driven by the size-selective fishery
Some contentious issues have been the relative role and importance of evolution when there have been simultaneous ecological changes (Browman et al 2008; Jørgensen et al 2008b), limitations to field evidence for evolving life-history traits because of strong physiological and environmental influences (Dieckmann and Heino 2007; Marshall and Browman 2007; Heino et al 2008; Swain 2008), whether the strong selection applied in experiments can shed light on evolutionary processes in the wild (Conover 2007; Hilborn 2006, 2007a; Brown et al 2008), and whether observed phenotypic change can be attributed to evolution when no parallel changes in gene frequencies have a 2009 The Authors Journal compilation a 2009 Blackwell Publishing Ltd 2 (2009) 245–259

Summary

Introduction

When Charles Darwin made his argument that life was evolving he began by showing the potency of artificial selection to modify domesticated species, and how quickly animal breeders were able to create new varieties—he cited examples of talented farmers who created new races of livestock within their own lifetime (Darwin 1859). This has advantages for comparisons across numerous studies, for example the meta-analysis of phenotypic change by Sharpe and Hendry (2009) In their analyses, Sharpe and Hendry (2009) observed trends toward younger ages and smaller sizes at maturation, and the rate of change for length at 50% maturity and the PMRN was significantly correlated with the intensity of fishing. Growth rate and behavior may be difficult to quantify in the field or from routine surveys, but there is a possibility that such differences are correlated with physiological characteristics Appreciating that such physiological indicators could be helpful when assessing the impact of fishing, Cooke et al (2009) studied whether physiological traits (plasma ions and metabolites, cortisol, gill Na+/K+-ATPase, energetic status) were correlated with vulnerability to fishing in sockeye salmon Oncorhynchus nerka. Both experiments and theoretical models have contributed to the body of evidence for fisheries-induced evolution and we discuss some of their contributions here

Experiments

Conclusions

Findings

Literature cited