Quantitative PCR analysis used to characterize physiological changes in brain tissue of senescent sockeye salmon.

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Quantitative PCR analysis used to characterize physiological changes in brain tissue of senescent sockeye salmon.

Biogerontology. 2013 Aug 15;

Authors: Storer CS, Quinn TP, Roberts SB

Abstract
Senescence varies considerably among fishes, and understanding the evolutionary basis for this diversity has become an important area of study. For rapidly senescing species such as Pacific salmon, senescence is a complex process as these fish are initiating anorexia while migrating to natal spawning grounds, and die within days of reproduction. To better understand senescence in Pacific salmon we examined expression patterns for a suite of genes in brain tissue of pre-senescent and senescent sockeye salmon. Interestingly, a significant increase in expression of genes involved in telomere repair and immune activity was observed in senescent salmon. These data provide insight into physiological changes in salmon undergoing senescence and the factors contributing to variation in observed senescence rates among individuals and populations.

PMID: 23948798 [PubMed – as supplied by publisher]

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Reproductive success of captively bred and naturally spawned Chinook salmon colonizing newly accessible habitat.

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Reproductive success of captively bred and naturally spawned Chinook salmon colonizing newly accessible habitat.

Evol Appl. 2013 Feb;6(2):165-79

Authors: Anderson JH, Faulds PL, Atlas WI, Quinn TP

Abstract
Captively reared animals can provide an immediate demographic boost in reintroduction programs, but may also reduce the fitness of colonizing populations. Construction of a fish passage facility at Landsburg Diversion Dam on the Cedar River, WA, USA, provided a unique opportunity to explore this trade-off. We thoroughly sampled adult Chinook salmon () at the onset of colonization (2003-2009), constructed a pedigree from genotypes at 10 microsatellite loci, and calculated reproductive success (RS) as the total number of returning adult offspring. Hatchery males were consistently but not significantly less productive than naturally spawned males (range in relative RS: 0.70-0.90), but the pattern for females varied between years. The sex ratio was heavily biased toward males; therefore, inclusion of the hatchery males increased the risk of a genetic fitness cost with little demographic benefit. Measurements of natural selection indicated that larger salmon had higher RS than smaller fish. Fish that arrived early to the spawning grounds tended to be more productive than later fish, although in some years, RS was maximized at intermediate dates. Our results underscore the importance of natural and sexual selection in promoting adaptation during reintroductions.

PMID: 23467446 [PubMed – in process]

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Summer emigration and resource acquisition within a shared nursery lake by sockeye salmon (Oncorhynchus nerka) from historically discrete rearing environments

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Summer emigration and resource acquisition within a shared nursery lake by sockeye salmon (Oncorhynchus nerka) from historically discrete rearing environments

R.K. Simmons,* T.P. Quinn, L.W. Seeb, D.E. Schindler, and R. Hilborn. School of Aquatic and Fishery Sciences, Box 355020, University of Washington, Seattle, WA 98195, USA.

Abstract
Many fish species disperse broadly during juvenile life history stages. While this may enable persistence in variable environments, it may also produce novel competitive interactions in recipient habitats that contain conspecifics from other populations. Here we used genetics techniques to study the stock-specific movement and performance of juvenile sockeye salmon (Oncorhynchus nerka) between July and August of 2008 in an ecosystem characterized by extensive juvenile migration and environmental change: the Chignik Lake system, Alaska. Genetic composition of juvenile sockeye salmon in the lower nursery lake based on 45 single nucleotide polymorphism markers indicated that 2008 was characterized by earlier timing and larger magnitude of emigrations from the upper lake, where rearing conditions have become increasingly unstable in recent decades. However, the larger size of emigrants did not confer a clear advantage in foraging based on comparisons of growth and body condition with juveniles native to the lower lake. These results highlight how shifting environmental conditions may exert pressures on evolved behavior patterns and increase interactions between sympatric populations, a theme of increasing importance where ecological uncertainty is high.

Can. J. Fish. Aquat. Sci. 70: 57–63 (2013) dx.doi.org/10.1139/cjfas-2012-0159 Published at www.nrcresearchpress.com/cjfas on 8 November 2012.

Resource polymorphism and diversity of Arctic charr

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Resource polymorphism and diversity of Arctic charr
Salvelinus alpinus in a series of isolated lakes

P. J. Woods*†‡§, D. Young, S. Sk´ ulason*, S. S. Snorrason†
and T. P. Quinn‡

*H´olar University College, H´aeyri 1, 551 Sauð´arkr´okur, Iceland, †University of Iceland, Sturlugata 7, Askja, 101 Reykjavík, Iceland, ‡University of  Washington, Box 355020, Seattle, Washington 98195, U.S.A. and National Park Service, Lake Clark National Park and Preserve, Port Alsworth, AK 99653, U.S.A.

(Received 5 April 2012, Accepted 30 October 2012)

Abstract
Morphological, dietary and life-history variation in Arctic charr Salvelinus alpinus were characterized from three geographically proximate, but isolated lakes and one large lake into which they drain in south-western Alaska. Polymorphism was predicted to occur in the first three lakes because
S. alpinus tend to become polymorphic in deep, isolated lakes with few co-occurring species. Only one morph was evident in the large lake and two of the three isolated lakes. In the third isolated lake, Lower Tazimina Lake, small and large morphs were found, the latter including two forms differing in growth rate. The small morph additionally differed from the two large forms by having
more gill rakers and a deeper body than same-sized individuals of the large morph, consuming more limnetic and fewer benthic resources, having a greater gonado-somatic index and maturing at a smaller size. The two large forms consumed only slightly different foods (more terrestrial insects were consumed by the medium-growth form; more snails by the high-growth form). Trends
in consumption of resources with body shape also differed between lakes. Variability in life history of S. alpinus in these Alaskan lakes was as broad as that found elsewhere. This variability is important for understanding lake ecosystems of remote regions where this species is commonly dominant.

© 2013 The Authors
Journal of Fish Biology © 2013 The Fisheries Society of the British Isles

Journal of Fish Biology (2013) 82, 569–587
doi:10.1111/jfb.12011, available online at wileyonlinelibrary.com

Key words: divergence; intraspecific

Relationship between effective population size, inbreeding and adult fitness-related traits in a steelhead (Oncorhynchus mykiss) population released in the wild.

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Relationship between effective population size, inbreeding and adult fitness-related traits in a steelhead (Oncorhynchus mykiss) population released in the wild.

Mol Ecol. 2013 Feb 4;

Authors: Naish KA, Seamons TR, Dauer MB, Hauser L, Quinn TP

Abstract
Inbreeding is of concern in supportive breeding programmes in Pacific salmonids, Oncorhynchus spp, where the number of breeding adults is limited by rearing space or poor survival to adulthood, and large numbers are released to supplement wild stocks and fisheries. We reconstructed the pedigree of 6602 migratory hatchery steelhead (Oncorhynchus mykiss) over four generations, to determine the incidence and fitness consequences of inbreeding in a northwest USA programme. The hatchery maintained an effective population size, N˜e = 107.9 from F(0) to F(2) , despite an increasing census size (N), which resulted in a decreasing N(e) /N ratio (0.35 in F(0) to 0.08 in F(2) ). The reduced ratio was attributed to a small broodstock size, nonrandom transfers and high variance in reproductive success (particularly in males). We observed accumulation of inbreeding from the founder generation (in F(4) , percentage individuals with inbreeding coefficients Δf > 0 = 15.7%). Generalized linear mixed models showed that body length and weight decreased significantly with increasing Δf, and inbred fish returned later to spawn in a model that included father identity. However, there was no significant correlation between Δf and age at return, female fecundity or gonad weight. Similarly, there was no relationship between Δf and reproductive success of F(2) and F(3) individuals, which might be explained by the fact that reproductive success is partially controlled by hatchery mating protocols. This study is one of the first to show that small changes in inbreeding coefficient can affect some fitness-related traits in a monitored population propagated and released to the wild.

PMID: 23379933 [PubMed – as supplied by publisher]

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Can interbreeding of wild and artificially propagated animals be prevented by using broodstock selected for a divergent life history?

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Can interbreeding of wild and artificially propagated animals be prevented by using broodstock selected for a divergent life history?

Evol Appl. 2012 Nov;5(7):705-19

Authors: Seamons TR, Hauser L, Naish KA, Quinn TP

Abstract
TWO STRATEGIES HAVE BEEN PROPOSED TO AVOID NEGATIVE GENETIC EFFECTS OF ARTIFICIALLY PROPAGATED INDIVIDUALS ON WILD POPULATIONS: (i) integration of wild and captive populations to minimize domestication selection and (ii) segregation of released individuals from the wild population to minimize interbreeding. We tested the efficacy of the strategy of segregation by divergent life history in a steelhead trout, Oncorhynchus mykiss, system, where hatchery fish were selected to spawn months earlier than the indigenous wild population. The proportion of wild ancestry smolts and adults declined by 10-20% over the three generations since the hatchery program began. Up to 80% of the naturally produced steelhead in any given year were hatchery/wild hybrids. Regression model selection analysis showed that the proportion of hatchery ancestry smolts was lower in years when stream discharge was high, suggesting a negative effect of flow on reproductive success of early-spawning hatchery fish. Furthermore, proportions of hybrid smolts and adults were higher in years when the number of naturally spawning hatchery-produced adults was higher. Divergent life history failed to prevent interbreeding when physical isolation was ineffective, an inadequacy that is likely to prevail in many other situations.

PMID: 23144657 [PubMed – in process]

via pubmed: school of aquatic an… http://www.ncbi.nlm.nih.gov/PubMed/23144657?dopt=Abstract