Yellow Island Aquaculture Ltd.

Campbell River, Canada

Yellow Island Aquaculture Ltd.

Campbell River, Canada
SEARCH FILTERS
Time filter
Source Type

Shrimpton J.M.,University of Northern British Columbia | Heath J.W.,Yellow Island Aquaculture Ltd. | Devlin R.H.,Center for Aquaculture and Environmental Research | Heath D.D.,University of Windsor
Aquaculture | Year: 2012

The use of triploid salmon for aquaculture is attractive as they do not mature sexually, limiting losses associated with poor flesh quality in mature fish and posing less genetic risk to wild stocks if they escape. Inconsistent survival and growth performance in triploid fish, however, has limited their implementation. In our study, ocean-type Chinook salmon (Oncorhynchus tshawytscha) were bred using replicated 3×3 factorial mating designs to create 18 families to test whether triploidization resulted in changes in growth and ionoregulation performance in freshwater and seawater. Eggs were pressure shocked after fertilization to create triploid offspring in a subset of each family. In spring, freshwater fish were sampled for size and gill Na +, K +-ATPase activity. Plasma chloride and cortisol were measured following a 24-h saltwater challenge. Growth performance was monitored for a further four months following transfer to sea water. We found significant effects of ploidy and sire (paternal effect) on smolt weight, as well as on gill Na +, K +-ATPase activity, although the latter did not correspond with performance in a 24-h saltwater challenge. Following four months of ocean growth, diploid animals were consistently larger, with greater circulating levels of insulin-like growth factor-1 than triploid sibs, although specific growth rates did not differ. Conversely, gill Na +, K +-ATPase activity at that time was significantly higher in triploid than diploid fish. When the phenotypic variance for the various traits was partitioned, triploids exhibited significantly greater additive genetic variance and maternal effects across all traits relative to diploid fish - indicating that gene dosage effects were primarily additive. The strong family effect indicates that genotype has a substantial role in determining the effects of ploidy manipulation on ionoregulatory and growth performance in Chinook salmon. © 2011 Elsevier B.V.


Shields J.L.,University of Windsor | Heath J.W.,Yellow Island Aquaculture Ltd. | Heath D.D.,University of Windsor
Marine Ecology Progress Series | Year: 2010

Adult marine mussels are sessile, but their highly dispersive planktonic larval stage plays a critical role in shaping population structure. However, shoreline geography and oceanographic currents can modify the dispersal pattern of pelagic larvae. On Vancouver Island (VI), British Columbia, 3 species of blue mussels (native Mytilus trossulus and introduced M. galloprovincialis and M. edulis) form a localized hybrid zone. Here we genetically mapped the distribution of Mytilus species and populations along VI and the surrounding islands. Using diagnostic species markers and microsatellite loci, we estimated the extent of the Mytilus hybrid zone on VI and measured population differentiation among the observed sites in 2005 and 2006. We predicted that the distribution of non-native genotypes would be mirrored by the microsatellite allelic patterns, which correspond to oceanographic features that reflect barriers to gene flow in the Strait of Georgia. Generally, non-native genotypes were restricted to southern VI and strong microsatellite population structure was detected. The distribution of non-native genotypes reflected patterns of microsatellite allele frequency in the Strait of Georgia. Using a landscape genetics approach, we identified 2 genetic discontinuities, which correspond to oceanographic and hydrographic features of the Strait of Georgia. Thus, physical dispersal barriers likely limit the spread of the VI Mytilus hybrid zone; however, additional biological barriers to dispersal must also exist. The VI Mytilus hybrid zone provides an excellent example of complex dispersal patterns in a non-equilibrium system. © 2010 Inter-Research.


Lehnert S.J.,University of Windsor | Heath J.W.,Yellow Island Aquaculture Ltd | Heath D.D.,University of Windsor
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2013

Escapes from aquaculture sites may threaten wild populations through ecological risks such as reproductive interference and genetic risks through successful hybridization. Mating studies examining wild-farmed interactions should quantify fertilization and reproductive success separately through genotyping of eggs and fry, respectively, to estimate ecological and genetic risks. We examined fertilization and reproductive success (fry survival to 158 and 201 days) of farmed (XY and XX males) and wild Chinook salmon (Oncorhynchus tshawytscha) males in competitive seminatural spawning channels with farmed females. XY and XX farmed males did not differ in fertilization and reproductive success. Farmed and wild males exhibited no difference in fertilization success; however, farmed males experienced significantly lower reproductive success relative to wild owing to differences in egg-to-fry survival because of competition with wild-sired offspring. Therefore, farmed males pose ecological risk to wild populations by removing reproductive opportunities from wild males, potentially reducing wild salmon productivity. However, low survival of farm-sired offspring will reduce further opportunities for interbreeding between wild and farm-raised fish. Nevertheless, research is needed to further quantify these genetic impacts.


Aykanat T.,University of Windsor | Heath J.W.,Yellow Island Aquaculture Ltd. | Dixon B.,University of Windsor | Dixon B.,University of Waterloo | Heath D.D.,University of Windsor
Immunogenetics | Year: 2012

Estimation of quantitative genetic parameters is important for improving salmonid broodstock management in commercial and government hatcheries. Using a replicated 2×2 factorial breeding design (48 families and 192 individuals), we partitioned early immune response transcription variation into additive genetic, non-additive genetic, and maternal components in juvenile Chinook salmon (Oncorhynchus tshawytscha). Transcription of four cytokine genes (IL1, TNF-α, IL-8, IL8-R) and two control genes (IgM and RPS-11) was measured relative to an endogenous control (EF1a) before and 24 h after immune stimulation with Vibrio vaccine. Additive genetic variation was not significant for cytokine transcription and heritability ranged from 0.44 (in pre-challenge IL1) to 0.04 (in post-challenge TNF-α). Non-additive genetic variance was significant in postchallenge IL1 (18 %) and TNF-α (12 %) while maternal effects contributed to pre-challenge cytokine transcription. Cytokine transcription co-expressed within but not between pre- and post-challenge states. The lack of additive genetic effects indicates that cytokine transcription is not a likely candidate for selection programs to improve immune function in Chinook salmon. Our results add to the growing evidence that non-additivity in salmon is common and contributes to our understanding of the genetic architecture of transcription. This indicates that transcription variation may act to maintain genetic variation and facilitate rapid adaptive response in salmonids. © Springer-Verlag 2012.


Madison B.N.,University of Guelph | Heath J.W.,Yellow Island Aquaculture Ltd | Heath D.D.,University of Windsor | Bernier N.J.,University of Guelph
Journal of Fish Biology | Year: 2013

To assess whether parental mate choice and early rearing in a semi-natural spawning channel may benefit the culture of Chinook salmon Oncorhynchus tshawytscha, 90day growth trials were conducted using hatchery O. tshawytscha (hatchery), mate choice O. tshawytscha (i.e. the offspring of parents allowed to choose their own mate) that spent 6months in a spawning channel prior to hatchery rearing (channel) and mate choice O. tshawytscha transferred to the hatchery as fertilized eggs (transfer). During the growth trials, all O. tshawytscha stocks were reared separately or in either mixed channel and hatchery or transfer and hatchery groups for comparison of performance to traditional practices. After 60days in fresh water, all O. tshawytscha were transferred to seawater for an additional 30days. Reared separately, all stocks grew c. 4·5 fold over 90days but specific growth rate (G) and food conversion efficiency were higher in fresh water than after seawater transfer on day 60. In contrast, hatchery O. tshawytscha from mixed hatchery and channel and hatchery and transfer growth trials had a larger mass and length gain than their counterparts on day 60, but reduced G in seawater. In general, plasma levels of growth hormone, insulin-like growth factor I and cortisol did not differ among any O. tshawytscha groups in either the separate or mixed growth trials. Despite some differences in gill Na+,K+-ATPase activity, all O. tshawytscha had a high degree of seawater tolerance and experienced virtually no perturbation in plasma chloride following seawater transfer. Overall, all O. tshawytscha exhibited similar growth and seawater performance under traditional hatchery conditions and any benefit derived from either parental mate choice or semi-natural early rearing environment was only observed in the presence of mutual competition with hatchery O. tshawytscha. © 2013 The Author. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.


Ching B.,University of Windsor | Jamieson S.,University of Windsor | Heath J.W.,Yellow Island Aquaculture Ltd. | Heath D.D.,University of Windsor | Hubberstey A.,University of Windsor
Heredity | Year: 2010

Understanding how organisms function at the level of gene expression is becoming increasingly important for both ecological and evolutionary studies. It is evident that the diversity and complexity of organisms are not dependent solely on their number of genes, but also the variability in gene expression and gene interactions. Furthermore, slight differences in transcription control can fundamentally affect the fitness of the organism in a variable environment or during development. In this study, triploid and diploid Chinook salmon (Oncorhynchus tshawytscha) were used to examine the effects of polyploidy on specific and genome-wide gene expression response using quantitative real-time PCR (qRT-PCR) and microarray technology after an immune challenge with the pathogen Vibrio anguillarum. Although triploid and diploid fish had significant differences in mortality, qRT-PCR revealed no differences in cytokine gene expression response (interleukin-8, interleukin-1, interleukin-8 receptor and tumor necrosis factor), whereas differences were observed in constitutively expressed genes, (immunoglobulin (Ig) M, major histocompatibility complex (MHC) -II and β-actin) upon live Vibrio anguillarum exposure. Genome-wide microarray analysis revealed that, overall, triploid gene expression is similar to diploids, consistent with their similar phenotypes. This pattern, however, can subtly be altered under stress (for example, handling, V. anguillarum challenge) as we have observed at some housekeeping genes. Our results are the first report of dosage effect on gene transcription in a vertebrate, and they support the observation that diploid and triploid salmon are generally phenotypically indistinguishable, except under stress, when triploids show reduced performance. © 2010 Macmillan Publishers Limited. All rights reserved.


Munoz N.J.,University of Western Ontario | Farrell A.P.,University of British Columbia | Heath J.W.,Yellow Island Aquaculture Ltd | Neff B.D.,University of Western Ontario
Nature Climate Change | Year: 2015

Pacific salmon provide critical sustenance for millions of people worldwide and have far-reaching impacts on the productivity of ecosystems. Rising temperatures now threaten the persistence of these important fishes, yet it remains unknown whether populations can adapt. Here, we provide the first evidence that a Pacific salmon has both physiological and genetic capacities to increase its thermal tolerance in response to rising temperatures. In juvenile chinook salmon (Oncorhynchus tshawytscha), a 4°C increase in developmental temperature was associated with a 2°C increase in key measures of the thermal performance of cardiac function. Moreover, additive genetic effects significantly influenced several measures of cardiac capacity, indicative of heritable variation on which selection can act. However, a lack of both plasticity and genetic variation was found for the arrhythmic temperature of the heart, constraining this upper thermal limit to a maximum of 24.5 ± 2.2 °C. Linking this constraint on thermal tolerance with present-day river temperatures and projected warming scenarios, we predict a 17% chance ofrio. Climate change mitigation is thus necessary to ensure the future viability of Pacific salmon populations. © Macmillan Publishers Limited. All rights reserved.


Munoz N.J.,University of Western Ontario | Anttila K.,University of British Columbia | Chen Z.,University of British Columbia | Heath J.W.,Yellow Island Aquaculture Ltd | And 2 more authors.
Proceedings of the Royal Society B: Biological Sciences | Year: 2014

With global temperatures projected to surpass the limits of thermal tolerance for many species, evaluating the heritable variation underlying thermal tolerance is critical for understanding the potential for adaptation to climate change. We examined the evolutionary potential of thermal tolerance within a population of chinook salmon (Oncorhynchus tshawytscha) by conducting a full-factorial breeding design and measuring the thermal performance of cardiac function and the critical thermal maximum (CTmax) of offspring from each family. Additive genetic variation in offspring phenotype was mostly negligible, although these direct genetic effects explained 53% of the variation in resting heart rate (fH). Conversely, maternal effects had a significant influence on resting fH, scope for fH, cardiac arrhythmia temperature and CTmax. These maternal effects were associated with egg size, as indicated by strong relationships between the mean egg diameter of mothers and offspring thermal tolerance. Because egg size can be highly heritable in chinook salmon, our finding indicates that the maternal effects of egg size constitute an indirect genetic effect contributing to thermal tolerance. Such indirect genetic effects could accelerate evolutionary responses to the selection imposed by rising temperatures and could contribute to the population-specific thermal tolerance that has recently been uncovered among Pacific salmon populations. © 2014 The Author(s) Published by the Royal Society. All rights reserved.


Munoz N.J.,University of Western Ontario | Anttila K.,University of British Columbia | Chen Z.,University of British Columbia | Heath J.W.,Yellow Island Aquaculture Ltd | And 2 more authors.
Proceedings. Biological sciences / The Royal Society | Year: 2014

With global temperatures projected to surpass the limits of thermal tolerance for many species, evaluating the heritable variation underlying thermal tolerance is critical for understanding the potential for adaptation to climate change. We examined the evolutionary potential of thermal tolerance within a population of chinook salmon (Oncorhynchus tshawytscha) by conducting a full-factorial breeding design and measuring the thermal performance of cardiac function and the critical thermal maximum (CTmax) of offspring from each family. Additive genetic variation in offspring phenotype was mostly negligible, although these direct genetic effects explained 53% of the variation in resting heart rate (fH). Conversely, maternal effects had a significant influence on resting fH, scope for fH, cardiac arrhythmia temperature and CTmax. These maternal effects were associated with egg size, as indicated by strong relationships between the mean egg diameter of mothers and offspring thermal tolerance. Because egg size can be highly heritable in chinook salmon, our finding indicates that the maternal effects of egg size constitute an indirect genetic effect contributing to thermal tolerance. Such indirect genetic effects could accelerate evolutionary responses to the selection imposed by rising temperatures and could contribute to the population-specific thermal tolerance that has recently been uncovered among Pacific salmon populations. © 2014 The Author(s) Published by the Royal Society. All rights reserved.


Garner S.R.,University of Western Ontario | Heath J.W.,Yellow Island Aquaculture Ltd | Neff B.D.,University of Western Ontario
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2010

Armstrong has questioned the biological relevance of the feeding observations that we presented in the study "Egg consumption in mature Pacific salmon (Oncorhynchus spp.)" (Can. J. Fish. Aquat. Sci. 66(9): 1546-1553). Here we discuss his arguments and show that feeding can provide substantial energetic gains, which would, for example, allow feeding salmon to maintain body condition for up to an additional 23 days. Many consequences of feeding by mature Pacific salmon remain to be explored, but our study shows that these fish do feed in fresh water and that the benefits can be substantial.

Loading Yellow Island Aquaculture Ltd. collaborators
Loading Yellow Island Aquaculture Ltd. collaborators