Genetic and Evolutionary Considerations in Fishery Management: Research Needs for the Future

Abstract

Genetic methods have become indispensable for sound fishery management and will become even more so in the twenty-first century. Selectively neutral genetic markers are widely used in stock identification, mixed-stock fishery analysis, monitoring levels of genetic diversity within populations and levels of connectivity among populations, and for a range of other applications. We expect that future research will continue to provide incremental improvements in the number and type of genetic markers available, as well as in the methods for data analysis and the necessary computational resources. Topics that will merit special consideration include: (1) developing a better understanding of the various flavors of demographic independence and how genetic markers can provide relevant insights; (2) more powerful ways to deal with the low signal-to-noise ratio of population differentiation found in many marine species (the signal of genetic differences is small compared to various sources of random noise); (3) better integration of genetic information, biological information, and information about physical features of the habitat to provide a fuller picture of dynamic marine ecosystems; (4) whether the tiny effective size to census size ratios reported for some marine species are accurate, and if so what this means for conservation of large marine populations. In contrast to the situation with neutral genetic markers, evolutionary changes involving traits related to fitness have only recently attracted much attention in fishery management. In general, any changes to marine ecosystems alter the selective regimes that component species experience and hence can be expected to produce an evolutionary response. Three general topics are particularly important in this regard: harvest, artificial propagation, and climate change. One key challenge is to disentangle the effects of genetics versus environment in determining observed patterns of phenotypic change. Quantitative genetic and molecular genetic approaches can accomplish this, and our capabilities for examining functional parts of the genome are rapidly expanding. However, these methods are logistically challenging and resource-intensive, so in the near future will be feasible for only a fraction of the species of interest to fishery management. Therefore, in the short term, inferences about evolutionary changes in marine species will have to draw on information for model species and other better-studied aquatic organisms.