Associate Professor, Aquatic & Fishery Sciences
knaish@u.washington.edu 206-221-6375

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quantitative and molecular genetics, genome mapping, conservation, aquaculture

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C. Naish

Our group’s research program focuses on the evolution, diversity and adaptation of aquatic organisms to their environments – and how environmental changes and human activities can impact and promote the long-term fitness of these animals. An understanding of the relationship between genetic diversity and fitness in a species is important in setting priorities in conservation and aquaculture, because a species’ continuing viability is related to its adaptability in a changing environment.

Conservation Genetics

Conservation efforts are directed towards minimizing extinction risks, and genetic approaches assist these efforts in a large number of ways. We are interested in many of the regional issues associated with conservation of aquatic organisms—the maintenance of small populations in the wild, captive breeding of threatened populations, and the consequences of supplementation programs to wild animals. We are using a number of approaches, incorporating both molecular and quantitative genetics, to investigating and quantifying the long-term demographic changes in salmon populations, the fitness consequences of maintaining small populations of salmon and abalone and the potential outcomes, if any, of introducing domesticated populations of both species to threatened wild populations.

Aquaculture Genetics

Many of the questions relevant to Conservation are also important in Aquaculture. Selective breeding in aquaculture seeks to enhance the number of favorable genotypes in a cultivated population – and to maintain these genotypes while minimizing the harmful effects from inbreeding. In the Pacific Northwest, aquaculture is also often used as a tool for maintaining captive populations destined for the restoration of depleted species, and for enhancing declining populations. In restoration aquaculture, inadvertent selection in a captive environment may lead to genetic change in the populations destined for re-introduction into the wild. We are developing lines of salmon in our hatchery aimed at testing the long-term effects of inbreeding and domestication selection in a captive population, and the consequences of cross-breeding unrelated individuals on fitness traits. We are also developing baseline information on population structure and captive breeding methods for restoration programs for abalone.

Genomics and Evolutionary Genetics

In the past, researchers in the field of Quantitative Genetics relied primarily on statistical approaches, large scale breeding projects and common-garden experiments to tease apart the genetic and environmental components of fitness traits. The field has expanded recently following the development of a wide range of molecular genetic tools (motivated to a large degree by advances in the human genome project) that can be used to locate the genetic loci underlying these traits. We are using genome mapping approaches to find markers linked to gene loci involved in fitness traits such as growth, age at maturity and disease resistance in Pacific salmon. We aim to use these markers as tools in understanding the genetic diversity underlying these adaptive traits in salmon populations—and in using predictive approaches to answering many of the questions raised above.

Select Publications

Naish, K. A., Taylor, J., Levin, P., Quinn, T. P., Winton, J. R., Huppert, D., and Hilborn, R. (2007). An evaluation of the effects of conservation and fishery enhancement hatcheries on wild populations of salmon. Advances in Marine Biology In press.

Eldridge, W. H., and Naish, K. A. (2007). Long term effects of translocation and release numbers on fine scale population structure among coho salmon (Onchorhynchus kisutch). Molecular Ecology 16, 2407-2421.

McClelland, E. K., and Naish, K. A. (2007). What is the fitness outcome of crossing unrelated fish populations? A meta-analysis and an evaluation of future research directions. Conservation Genetics 8, 397-416.