Comparative transcriptomics of Atlantic Salmo salar, chum Oncorhynchus keta and pink salmon O. gorbuscha during infections with salmon lice Lepeophtheirus salmonis.

PubMed

Sutherland, Ben J G; Koczka, Kim W; Yasuike, Motoshige; Jantzen, Stuart G; Yazawa, Ryosuke; Koop, Ben F; Jones, Simon R M

2014-03-15

Salmon species vary in susceptibility to infections with the salmon louse (Lepeophtheirus salmonis). Comparing mechanisms underlying responses in susceptible and resistant species is important for estimating impacts of infections on wild salmon, selective breeding of farmed salmon, and expanding our knowledge of fish immune responses to ectoparasites. Herein we report three L. salmonis experimental infection trials of co-habited Atlantic Salmo salar, chum Oncorhynchus keta and pink salmon O. gorbuscha, profiling hematocrit, blood cortisol concentrations, and transcriptomic responses of the anterior kidney and skin to the infection. In all trials, infection densities (lice per host weight (g)) were consistently highest on chum salmon, followed by Atlantic salmon, and lowest in pink salmon. At 43 days post-exposure, all lice had developed to motile stages, and infection density was uniformly low among species. Hematocrit was reduced in infected Atlantic and chum salmon, and cortisol was elevated in infected chum salmon. Systemic transcriptomic responses were profiled in all species and large differences in response functions were identified between Atlantic and Pacific (chum and pink) salmon. Pink and chum salmon up-regulated acute phase response genes, including complement and coagulation components, and down-regulated antiviral immune genes. The pink salmon response involved the largest and most diverse iron sequestration and homeostasis mechanisms. Pattern recognition receptors were up-regulated in all species but the active components were often species-specific. C-type lectin domain family 4 member M and acidic mammalian chitinase were specifically up-regulated in the resistant pink salmon. Experimental exposures consistently indicated increased susceptibility in chum and Atlantic salmon, and resistance in pink salmon, with differences in infection density occurring within the first three days of infection. Transcriptomic analysis suggested candidate resistance

Multivariate evaluation of the effectiveness of treatment efficacy of cypermethrin against sea lice (Lepeophtheirus salmonis) in Atlantic salmon (Salmo salar)

PubMed Central

2013-01-01

Background The sea louse Lepeophtheirus salmonis is the most important ectoparasite of farmed Atlantic salmon (Salmo salar) in Norwegian aquaculture. Control of sea lice is primarily dependent on the use of delousing chemotherapeutants, which are both expensive and toxic to other wildlife. The method most commonly used for monitoring treatment effectiveness relies on measuring the percentage reduction in the mobile stages of Lepeophtheirus salmonis only. However, this does not account for changes in the other sea lice stages and may result in misleading or incomplete interpretation regarding the effectiveness of treatment. With the aim of improving the evaluation of delousing treatments, we explored multivariate analyses of bath treatments using the topical pyrethroid, cypermethrin, in salmon pens at five Norwegian production sites. Results Conventional univariate analysis indicated reductions of over 90% in mobile stages at all sites. In contrast, multivariate analyses indicated differing treatment effectiveness between sites (p-value < 0.01) based on changes in the proportion and abundance of the chalimus and PAAM (pre-adult and adult males) stages. Low water temperatures and shortened intervals between sampling after treatment may account for the differences in the composition of chalimus and PAAM stage groups following treatment. Using multivariate analysis, such factors could be separated from those which were attributable to inadequate treatment or chemotherapeutant failure. Conclusions Multivariate analyses for evaluation of treatment effectiveness against multiple life cycle stages of L. salmonis yield additional information beyond that derivable from univariate methods. This can aid in the identification of causes of apparent treatment failure in salmon aquaculture. PMID:24354936

Increased susceptibility to infectious salmon anemia virus (ISAv) in Lepeophtheirus salmonis – infected Atlantic salmon

USDA-ARS?s Scientific Manuscript database

The salmon louse and infectious salmon anemia virus (ISAv) are the two most significant pathogens of concern to the Atlantic salmon (Salmo salar) aquaculture industry. However, the interactions between sea lice and ISAv, as well as the impact of a prior sea lice infection on the susceptibility of th...

Maternal inheritance of deltamethrin resistance in the salmon louse Lepeophtheirus salmonis (Krøyer) is associated with unique mtDNA haplotypes

PubMed Central

Carmona-Antoñanzas, Greta; Bekaert, Michaël; Humble, Joseph L.; Boyd, Sally; Roy, William; Bassett, David I.; Houston, Ross D.; Gharbi, Karim

2017-01-01

Parasitic infections by the salmon louse, Lepeophtheirus salmonis (Krøyer), cause huge economic damage in salmon farming in the northern hemisphere, with combined treatment costs and production losses in 2014 having been estimated at US$ 350 million for Norway (annual production 1.25 million tonnes). The control of L. salmonis relies significantly on medicinal treatments, supplemented by non-pharmacological approaches. However, efficacy losses have been reported for several delousing agents, including the pyrethroid deltamethrin. The aim of the present study was to analyse the genetic basis of deltamethrin resistance in L. salmonis. Deltamethrin median effective concentrations (EC50) were 0.28 μg L-1 in the drug susceptible L. salmonis strain IoA-00 and 40.1 μg L-1 in the pyrethroid resistant strain IoA-02. IoA-00 and IoA-02 were crossed to produce families spanning one parental and three filial generations (P0, F1-F3). In three families derived from P0 crosses between an IoA-00 sire and an IoA-02 dam, 98.8% of F2 parasites (n = 173) were resistant, i.e. remained unaffected after exposure to 2.0 μg L-1 deltamethrin. F3 parasites from these crosses showed a deltamethrin EC50 of 9.66 μg L-1. In two families of the inverse orientation at P0 (IoA-02 sire x IoA-00 dam), 16.7% of F2 parasites were resistant (n = 84), while the deltamethrin EC50 in F3 animals was 0.26 μg L-1. The results revealed a predominantly maternal inheritance of deltamethrin resistance. The 15,947-nt mitochondrial genome was sequenced and compared among six unrelated L. salmonis strains and parasites sampled from wild salmon in 2010. IoA-02 and three further deltamethrin resistant strains, established from isolates originating from different regions of Scotland, showed almost identical mitochondrial haplotypes. In contrast, the mitochondrial genome was variable among susceptible strains and L. salmonis from wild hosts. Deltamethrin caused toxicity and depletion of whole body ATP levels in Io

Sea lice and salmon population dynamics: effects of exposure time for migratory fish.

PubMed

Krkosek, Martin; Morton, Alexandra; Volpe, John P; Lewis, Mark A

2009-08-07

The ecological impact of parasite transmission from fish farms is probably mediated by the migration of wild fishes, which determines the period of exposure to parasites. For Pacific salmon and the parasitic sea louse, Lepeophtheirus salmonis, analysis of the exposure period may resolve conflicting observations of epizootic mortality in field studies and parasite rejection in experiments. This is because exposure periods can differ by 2-3 orders of magnitude, ranging from months in the field to hours in experiments. We developed a mathematical model of salmon-louse population dynamics, parametrized by a study that monitored naturally infected juvenile salmon held in ocean enclosures. Analysis of replicated trials indicates that lice suffer high mortality, particularly during pre-adult stages. The model suggests louse populations rapidly decline following brief exposure of juvenile salmon, similar to laboratory study designs and data. However, when the exposure period lasts for several weeks, as occurs when juvenile salmon migrate past salmon farms, the model predicts that lice accumulate to abundances that can elevate salmon mortality and depress salmon populations. The duration of parasite exposure is probably critical to salmon-louse population dynamics, and should therefore be accommodated in coastal planning and management where fish farms are situated on wild fish migration routes.

Genetic dissection of MHC-associated susceptibility to Lepeophtheirus salmonis in Atlantic salmon

PubMed Central

Gharbi, Karim; Glover, Kevin A; Stone, Louise C; MacDonald, Elizabeth S; Matthews, Louise; Grimholt, Unni; Stear, Michael J

2009-01-01

Background Genetic variation has been shown to play a significant role in determining susceptibility to the salmon louse, Lepeophtheirus salmonis. However, the mechanisms involved in differential response to infection remain poorly understood. Recent findings in Atlantic salmon (Salmo salar) have provided evidence for a potential link between marker variation at the major histocompatibility complex (MHC) and differences in lice abundance among infected siblings, suggesting that MHC genes can modulate susceptibility to the parasite. In this study, we used quantitative trait locus (QTL) analysis to test the effect of genomic regions linked to MHC class I and II on linkage groups (LG) 15 and 6, respectively. Results Significant QTL effects were detected on both LG 6 and LG 15 in sire-based analysis but the QTL regions remained unresolved due to a lack of recombination between markers. In dam-based analysis, a significant QTL was identified on LG 6, which accounted for 12.9% of within-family variance in lice abundance. However, the QTL was located at the opposite end of DAA, with no significant overlap with the MHC class II region. Interestingly, QTL modelling also revealed evidence of sex-linked differences in lice abundance, indicating that males and females may have different susceptibility to infection. Conclusion Overall, QTL analysis provided relatively weak support for a proximal effect of classical MHC regions on lice abundance, which can partly be explained by linkage to other genes controlling susceptibility to L. salmonis on the same chromosome. PMID:19397823

Effects of the vertically transmitted microsporidian Facilispora margolisi and the parasiticide emamectin benzoate on salmon lice (Lepeophtheirus salmonis).

PubMed

Poley, Jordan D; Sutherland, Ben J G; Fast, Mark D; Koop, Ben F; Jones, Simon R M

2017-08-17

Microsporidia are highly specialized, parasitic fungi that infect a wide range of eukaryotic hosts from all major taxa. Infections cause a variety of damaging effects on host physiology from increased stress to death. The microsporidian Facilispora margolisi infects the Pacific salmon louse (Lepeophtheirus salmonis oncorhynchi), an economically and ecologically important ectoparasitic copepod that can impact wild and cultured salmonids. Vertical transmission of F. margolisi was demonstrated by using PCR and in situ hybridization to identify and localize microsporidia in female L. salmonis and their offspring. Spores and developmental structures of F. margolisi were identified in 77% of F 1 generation copepods derived from infected females while offspring from uninfected females all tested negative for the microsporidia. The transcriptomic response of the salmon louse to F. margolisi was profiled at both the copepodid larval stage and the pre-adult stage using microarray technology. Infected copepodids differentially expressed 577 transcripts related to stress, ATP generation and structural components of muscle and cuticle. The infection also impacted the response of the copepodid to the parasiticide emamectin benzoate (EMB) at a low dose of 1.0 ppb for 24 h. A set of 48 transcripts putatively involved in feeding and host immunomodulation were up to 8-fold underexpressed in the F. margolisi infected copepodids treated with EMB compared with controls or either stressor alone. Additionally, these infected lice treated with EMB also overexpressed 101 transcripts involved in stress resistance and signalling compared to the other groups. In contrast, infected pre-adult lice did not display a stress response, suggesting a decrease in microsporidian virulence associated with lice maturity. Furthermore, copepodid infectivity and moulting was not affected by the microsporidian infection. This study demonstrated that F. margolisi is transmitted vertically between salmon

Iron metabolism modulation in Atlantic salmon infested with the sea lice Lepeophtheirus salmonis and Caligus rogercresseyi: A matter of nutritional immunity?

PubMed

Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

2017-01-01

Sea lice are copepodid ectoparasites that produce high economic losses and environmental issues, thus impacting the salmon aquaculture worldwide. Atlantic salmon (Salmo salar) from Northern and Southern Hemispheres are primarily parasitized by Lepeophtheirus salmonis and Caligus rogercresseyi, respectively. To cope L. salmonis infestation, studies suggest that Atlantic salmon can restrict iron availability as a mechanism of nutritional immunity. However, no molecular studies of iron regulation from salmonids infected with C. rogercresseyi have been reported. The aim of this study was to determine if there are differences in the regulation of iron metabolism in Atlantic salmon infested with L. salmonis or C. rogercresseyi. For comparisons, skin and head kidney were profiled using qPCR of 15 genes related to iron regulation in Atlantic salmons infected with each sea louse species in Norway and Chile, respectively. Prior to infestation, no significant differences were observed between fish group. However, genes involved in iron transport and Heme biosynthesis were highly upregulated in Atlantic salmon infested with L. salmonis. Interestingly, hepcidin and Heme oxygenase, a component of the Heme degradation pathway, were upregulated during C. rogercresseyi infestation. Oxidative stress related genes were also evaluated, showing higher transcription activity in the head kidney than in the skin of Atlantic salmon infested with L. salmonis. These comparative results suggest pathogen-specific responses in infected Atlantic salmon, where iron metabolism is primarily regulated during the infestation with L. salmonis than C. rogercresseyi. Feeding behavior, for instance haematophagy, of the infesting sea lice species in relation to iron modulation is discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Physiology and immunology of Lepeophtheirus salmonis infections of salmonids.

PubMed

Wagner, Glenn N; Fast, Mark D; Johnson, Stewart C

2008-04-01

'Sea lice' is a common name for a large number of species of marine ectoparasitic copepods, many of which are widespread and important disease-causing agents that infect both cultured and wild fish. Of these copepods, the salmon louse Lepeophtheirus salmonis is the most extensively studied because of its economic impact on the salmonid aquaculture industry and its possible impacts on wild salmonid populations. Different levels of infection by this parasite can affect the long-term survival and viability of its hosts. In this article, we review the nature of the interactions between L. salmonis and it hosts to identify crucial areas that warrant further research to aid understanding of the impact of infection with L. salmonis.

Local and systemic gene expression responses of Atlantic salmon (Salmo salar L.) to infection with the salmon louse (Lepeophtheirus salmonis)

PubMed Central

Skugor, Stanko; Glover, Kevin Alan; Nilsen, Frank; Krasnov, Aleksei

2008-01-01

Background The salmon louse (SL) is an ectoparasitic caligid crustacean infecting salmonid fishes in the marine environment. SL represents one of the major challenges for farming of salmonids, and veterinary intervention is necessary to combat infection. This study addressed gene expression responses of Atlantic salmon infected with SL, which may account for its high susceptibility. Results The effects of SL infection on gene expression in Atlantic salmon were studied throughout the infection period from copepodids at 3 days post infection (dpi) to adult lice (33 dpi). Gene expression was analyzed at three developmental stages in damaged and intact skin, spleen, head kidney and liver, using real-time qPCR and a salmonid cDNA microarray (SFA2). Rapid detection of parasites was indicated by the up-regulation of immunoglobulins in the spleen and head kidney and IL-1 receptor type 1, CD4, beta-2-microglobulin, IL-12β, CD8α and arginase 1 in the intact skin of infected fish. Most immune responses decreased at 22 dpi, however, a second activation was observed at 33 dpi. The observed pattern of gene expression in damaged skin suggested the development of inflammation with signs of Th2-like responses. Involvement of T cells in responses to SL was witnessed with up-regulation of CD4, CD8α and programmed death ligand 1. Signs of hyporesponsive immune cells were seen. Cellular stress was prevalent in damaged skin as seen by highly significant up-regulation of heat shock proteins, other chaperones and mitochondrial proteins. Induction of the major components of extracellular matrix, TGF-β and IL-10 was observed only at the adult stage of SL. Taken together with up-regulation of matrix metalloproteinases (MMP), this classifies the wounds afflicted by SL as chronic. Overall, the gene expression changes suggest a combination of chronic stress, impaired healing and immunomodulation. Steady increase of MMP expression in all tissues except liver was a remarkable feature of SL

Can reduced predation offset negative effects of sea louse parasites on chum salmon?

PubMed Central

Peacock, Stephanie J.; Connors, Brendan M.; Krkošek, Martin; Irvine, James R.; Lewis, Mark A.

2014-01-01

The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host–parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations. PMID:24352951

Can reduced predation offset negative effects of sea louse parasites on chum salmon?

PubMed

Peacock, Stephanie J; Connors, Brendan M; Krkosek, Martin; Irvine, James R; Lewis, Mark A

2014-02-07

The impact of parasites on hosts is invariably negative when considered in isolation, but may be complex and unexpected in nature. For example, if parasites make hosts less desirable to predators then gains from reduced predation may offset direct costs of being parasitized. We explore these ideas in the context of sea louse infestations on salmon. In Pacific Canada, sea lice can spread from farmed salmon to migrating juvenile wild salmon. Low numbers of sea lice can cause mortality of juvenile pink and chum salmon. For pink salmon, this has resulted in reduced productivity of river populations exposed to salmon farming. However, for chum salmon, we did not find an effect of sea louse infestations on productivity, despite high statistical power. Motivated by this unexpected result, we used a mathematical model to show how a parasite-induced shift in predation pressure from chum salmon to pink salmon could offset negative direct impacts of sea lice on chum salmon. This shift in predation is proposed to occur because predators show an innate preference for pink salmon prey. This preference may be more easily expressed when sea lice compromise juvenile salmon hosts, making them easier to catch. Our results indicate how the ecological context of host-parasite interactions may dampen, or even reverse, the expected impact of parasites on host populations.

A 200K SNP chip reveals a novel Pacific salmon louse genotype linked to differential efficacy of emamectin benzoate.

PubMed

Messmer, Amber M; Leong, Jong S; Rondeau, Eric B; Mueller, Anita; Despins, Cody A; Minkley, David R; Kent, Matthew P; Lien, Sigbjørn; Boyce, Brad; Morrison, Diane; Fast, Mark D; Norman, Joseph D; Danzmann, Roy G; Koop, Ben F

2018-04-16

Antiparasitic drugs such as emamectin benzoate (EMB) are relied upon to reduce the parasite load, particularly of the sea louse Lepeophtheirus salmonis, on farmed salmon. The decline in EMB treatment efficacy for this purpose is an important issue for salmon producers around the world, and particularly for those in the Atlantic Ocean where widespread EMB tolerance in sea lice is recognized as a significant problem. Salmon farms in the Northeast Pacific Ocean have not historically experienced the same issues with treatment efficacy, possibly due to the relatively large population of endemic salmonid hosts that serve to both redistribute surviving lice and dilute populations potentially under selection by introducing naïve lice to farms. Frequent migration of lice among farmed and wild hosts should limit the effect of farm-specific selection pressures on changes to the overall allele frequencies of sea lice in the Pacific Ocean. A previous study using microsatellites examined L. salmonis oncorhynchi from 10 Pacific locations from wild and farmed hosts and found no population structure. Recently however, a farm population of sea lice was detected where EMB bioassay exposure tolerance was abnormally elevated. In response, we have developed a Pacific louse draft genome that complements the previously-released Atlantic louse sequence. These genomes were combined with whole-genome re-sequencing data to design a highly sensitive 201,279 marker SNP array applicable for both subspecies (90,827 validated Pacific loci; 153,569 validated Atlantic loci). Notably, kmer spectrum analysis of the re-sequenced samples indicated that Pacific lice exhibit a large within-individual heterozygosity rate (average of 1 in every 72 bases) that is markedly higher than that of Atlantic individuals (1 in every 173 bases). The SNP chip was used to produce a high-density map for Atlantic sea louse linkage group 5 that was previously shown to be associated with EMB tolerance in Atlantic lice

Salmon lice – impact on wild salmonids and salmon aquaculture

PubMed Central

Torrissen, O; Jones, S; Asche, F; Guttormsen, A; Skilbrei, O T; Nilsen, F; Horsberg, T E; Jackson, D

2013-01-01

Salmon lice, Lepeophtheirus salmonis, are naturally occurring parasites of salmon in sea water. Intensive salmon farming provides better conditions for parasite growth and transmission compared with natural conditions, creating problems for both the salmon farming industry and, under certain conditions, wild salmonids. Salmon lice originating from farms negatively impact wild stocks of salmonids, although the extent of the impact is a matter of debate. Estimates from Ireland and Norway indicate an odds ratio of 1.1:1-1.2:1 for sea lice treated Atlantic salmon smolt to survive sea migration compared to untreated smolts. This is considered to have a moderate population regulatory effect. The development of resistance against drugs most commonly used to treat salmon lice is a serious concern for both wild and farmed fish. Several large initiatives have been taken to encourage the development of new strategies, such as vaccines and novel drugs, for the treatment or removal of salmon lice from farmed fish. The newly sequenced salmon louse genome will be an important tool in this work. The use of cleaner fish has emerged as a robust method for controlling salmon lice, and aquaculture production of wrasse is important towards this aim. Salmon lice have large economic consequences for the salmon industry, both as direct costs for the prevention and treatment, but also indirectly through negative public opinion. PMID:23311858

Transcriptomics of coping strategies in free-swimming Lepeophtheirus salmonis (Copepoda) larvae responding to abiotic stress.

PubMed

Sutherland, Ben J G; Jantzen, Stuart G; Yasuike, Motoshige; Sanderson, Dan S; Koop, Ben F; Jones, Simon R M

2012-12-01

The salmon louse Lepeophtheirus salmonis is a marine ectoparasite of wild and farmed salmon in the Northern Hemisphere. Infections of farmed salmon are of economic and ecological concern. Nauplius and copepodid salmon lice larvae are free-swimming and disperse in the water column until they encounter a host. In this study, we characterized the sublethal stress responses of L. salmonis copepodid larvae by applying a 38K oligonucleotide microarray to profile transcriptomes following 24 h exposures to suboptimal salinity (30-10 parts per thousand (‰)) or temperature (16-4 °C) environments. Hyposalinity exposure resulted in large-scale gene expression changes relative to those elicited by a thermal gradient. Subsequently, transcriptome responses to a more finely resolved salinity gradient between 30 ‰ and 25 ‰ were profiled. Minimal changes occurred at 29 ‰ or 28 ‰, a threshold of response was identified at 27 ‰, and the largest response was at 25 ‰. Differentially expressed genes were clustered by pattern of expression, and clusters were characterized by functional enrichment analysis. Results indicate larval copepods adopt two distinct coping strategies in response to short-term hyposaline stress: a primary response using molecular chaperones and catabolic processes at 27 ‰; and a secondary response up-regulating ion pumps, transporters, a different suite of chaperones and apoptosis-related transcripts at 26 ‰ and 25 ‰. The results further our understanding of the tolerances of L. salmonis copepodids to salinity and temperature gradients and may assist in the development of salmon louse management strategies. © 2012 Blackwell Publishing Ltd.

Sea Louse Infection of Juvenile Sockeye Salmon in Relation to Marine Salmon Farms on Canada's West Coast

PubMed Central

Price, Michael H. H.; Proboszcz, Stan L.; Routledge, Rick D.; Gottesfeld, Allen S.; Orr, Craig; Reynolds, John D.

2011-01-01

Background Pathogens are growing threats to wildlife. The rapid growth of marine salmon farms over the past two decades has increased host abundance for pathogenic sea lice in coastal waters, and wild juvenile salmon swimming past farms are frequently infected with lice. Here we report the first investigation of the potential role of salmon farms in transmitting sea lice to juvenile sockeye salmon (Oncorhynchus nerka). Methodology/Principal Findings We used genetic analyses to determine the origin of sockeye from Canada's two most important salmon rivers, the Fraser and Skeena; Fraser sockeye migrate through a region with salmon farms, and Skeena sockeye do not. We compared lice levels between Fraser and Skeena juvenile sockeye, and within the salmon farm region we compared lice levels on wild fish either before or after migration past farms. We matched the latter data on wild juveniles with sea lice data concurrently gathered on farms. Fraser River sockeye migrating through a region with salmon farms hosted an order of magnitude more sea lice than Skeena River populations, where there are no farms. Lice abundances on juvenile sockeye in the salmon farm region were substantially higher downstream of farms than upstream of farms for the two common species of lice: Caligus clemensi and Lepeophtheirus salmonis, and changes in their proportions between two years matched changes on the fish farms. Mixed-effects models show that position relative to salmon farms best explained C. clemensi abundance on sockeye, while migration year combined with position relative to salmon farms and temperature was one of two top models to explain L. salmonis abundance. Conclusions/Significance This is the first study to demonstrate a potential role of salmon farms in sea lice transmission to juvenile sockeye salmon during their critical early marine migration. Moreover, it demonstrates a major migration corridor past farms for sockeye that originated in the Fraser River, a complex of

Sea louse infection of juvenile sockeye salmon in relation to marine salmon farms on Canada's west coast.

PubMed

Price, Michael H H; Proboszcz, Stan L; Routledge, Rick D; Gottesfeld, Allen S; Orr, Craig; Reynolds, John D

2011-02-09

Pathogens are growing threats to wildlife. The rapid growth of marine salmon farms over the past two decades has increased host abundance for pathogenic sea lice in coastal waters, and wild juvenile salmon swimming past farms are frequently infected with lice. Here we report the first investigation of the potential role of salmon farms in transmitting sea lice to juvenile sockeye salmon (Oncorhynchus nerka). We used genetic analyses to determine the origin of sockeye from Canada's two most important salmon rivers, the Fraser and Skeena; Fraser sockeye migrate through a region with salmon farms, and Skeena sockeye do not. We compared lice levels between Fraser and Skeena juvenile sockeye, and within the salmon farm region we compared lice levels on wild fish either before or after migration past farms. We matched the latter data on wild juveniles with sea lice data concurrently gathered on farms. Fraser River sockeye migrating through a region with salmon farms hosted an order of magnitude more sea lice than Skeena River populations, where there are no farms. Lice abundances on juvenile sockeye in the salmon farm region were substantially higher downstream of farms than upstream of farms for the two common species of lice: Caligus clemensi and Lepeophtheirus salmonis, and changes in their proportions between two years matched changes on the fish farms. Mixed-effects models show that position relative to salmon farms best explained C. clemensi abundance on sockeye, while migration year combined with position relative to salmon farms and temperature was one of two top models to explain L. salmonis abundance. This is the first study to demonstrate a potential role of salmon farms in sea lice transmission to juvenile sockeye salmon during their critical early marine migration. Moreover, it demonstrates a major migration corridor past farms for sockeye that originated in the Fraser River, a complex of populations that are the subject of conservation concern.

Fish farms, parasites, and predators: implications for salmon population dynamics.

PubMed

Krkosek, Martin; Connors, Brendan M; Ford, Helen; Peacock, Stephanie; Mages, Paul; Ford, Jennifer S; Morton, Alexandra; Volpe, John P; Hilborn, Ray; Dill, Lawrence M; Lewis, Mark A

2011-04-01

For some salmon populations, the individual and population effects of sea lice (Lepeophtheirus salmonis) transmission from sea cage salmon farms is probably mediated by predation, which is a primary natural source of mortality of juvenile salmon. We examined how sea lice infestation affects predation risk and mortality of juvenile pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon, and developed a mathematical model to assess the implications for population dynamics and conservation. A risk-taking experiment indicated that infected juvenile pink salmon accept a higher predation risk in order to obtain foraging opportunities. In a schooling experiment with juvenile chum salmon, infected individuals had increased nearest-neighbor distances and occupied peripheral positions in the school. Prey selection experiments with cutthroat trout (O. clarkii) predators indicated that infection reduces the ability of juvenile pink salmon to evade a predatory strike. Group predation experiments with coho salmon (O. kisutch) feeding on juvenile pink or chum salmon indicated that predators selectively consume infected prey. The experimental results indicate that lice may increase the rate of prey capture but not the handling time of a predator. Based on this result, we developed a mathematical model of sea lice and salmon population dynamics in which parasitism affects the attack rate in a type II functional response. Analysis of the model indicates that: (1) the estimated mortality of wild juvenile salmon due to sea lice infestation is probably higher than previously thought; (2) predation can cause a simultaneous decline in sea louse abundance on wild fish and salmon productivity that could mislead managers and regulators; and (3) compensatory mortality occurs in the saturation region of the type II functional response where prey are abundant because predators increase mortality of parasites but not overall predation rates. These findings indicate that predation is an

Salmon lice (Lepeophtheirus salmonis) showing varying emamectin benzoate susceptibilities differ in neuronal acetylcholine receptor and GABA-gated chloride channel mRNA expression.

PubMed

Carmichael, Stephen N; Bron, James E; Taggart, John B; Ireland, Jacqueline H; Bekaert, Michaël; Burgess, Stewart Tg; Skuce, Philip J; Nisbet, Alasdair J; Gharbi, Karim; Sturm, Armin

2013-06-18

Caligid copepods, also called sea lice, are fish ectoparasites, some species of which cause significant problems in the mariculture of salmon, where the annual cost of infection is in excess of €300 million globally. At present, caligid control on farms is mainly achieved using medicinal treatments. However, the continued use of a restricted number of medicine actives potentially favours the development of drug resistance. Here, we report transcriptional changes in a laboratory strain of the caligid Lepeophtheirus salmonis (Krøyer, 1837) that is moderately (~7-fold) resistant to the avermectin compound emamectin benzoate (EMB), a component of the anti-salmon louse agent SLICE® (Merck Animal Health). Suppression subtractive hybridisation (SSH) was used to enrich transcripts differentially expressed between EMB-resistant (PT) and drug-susceptible (S) laboratory strains of L. salmonis. SSH libraries were subjected to 454 sequencing. Further L. salmonis transcript sequences were available as expressed sequence tags (EST) from GenBank. Contiguous sequences were generated from both SSH and EST sequences and annotated. Transcriptional responses in PT and S salmon lice were investigated using custom 15 K oligonucleotide microarrays designed using the above sequence resources. In the absence of EMB exposure, 359 targets differed in transcript abundance between the two strains, these genes being enriched for functions such as calcium ion binding, chitin metabolism and muscle structure. γ-aminobutyric acid (GABA)-gated chloride channel (GABA-Cl) and neuronal acetylcholine receptor (nAChR) subunits showed significantly lower transcript levels in PT lice compared to S lice. Using RT-qPCR, the decrease in mRNA levels was estimated at ~1.4-fold for GABA-Cl and ~2.8-fold for nAChR. Salmon lice from the PT strain showed few transcriptional responses following acute exposure (1 or 3 h) to 200 μg L-1 of EMB, a drug concentration tolerated by PT lice, but toxic for S lice

Desmozoon lepeophtherii n. gen., n. sp., (Microsporidia: Enterocytozoonidae) infecting the salmon louse Lepeophtheirus salmonis (Copepoda: Caligidae)

PubMed Central

2009-01-01

Background A microsporidian was previously reported to infect the crustacean parasite, Lepeophtheirus salmonis (Krøyer, 1837) (Copepoda, Caligidae), on farmed Atlantic salmon (Salmo salar L.) in Scotland. The microsporidian was shown to be a novel species with a molecular phylogenetic relationship to Nucleospora (Enterocytozoonidae), but the original report did not assign it to a genus or species. Further studies examined the development of the microsporidian in L. salmonis using electron microscopy and re-evaluated the molecular findings using new sequence data available for the group. Here we report a full description for the microsporidian and assign it to a new genus and species. Results The microsporidian infects subcuticular cells that lie on the innermost region of the epidermal tissue layer beneath the cuticle and along the internal haemocoelic divisions. The mature spores are sub-spherical with a single nucleus and an isofilar polar filament with 5-8 turns in a double coil. The entire development is in direct contact with the host cell cytoplasm and is polysporous. During early merogony, a diplokaryotic nuclear arrangement exists which is absent throughout the rest of the developmental cycle. Large merogonial plasmodia form which divide to form single uninucleate sporonts. Sporogonial plasmodia were not observed; instead, binucleate sporonts divide to form two sporoblasts. Prior to final division, there is a precocious development of the polar filament extrusion apparatus which is associated with large electron lucent inclusions (ELIs). Analyses of DNA sequences reveal that the microsporidian is robustly supported in a clade with other members of the Enterocytozoonidae and confirms a close phylogenetic relationship with Nucleospora. Conclusion The ultrastructural findings of the precocious development of the polar filament and the presence of ELIs are consistent with those of the Enterocytozoonidae. However, the confirmed presence of an early

Modulation of Atlantic salmon miRNome response to sea louse infestation.

PubMed

Valenzuela-Muñoz, Valentina; Novoa, Beatriz; Figueras, Antonio; Gallardo-Escárate, Cristian

2017-11-01

MicroRNAs are non-coding RNA that plays a crucial role in post-transcriptional regulation and immune system regulation. On other hand, sea lice are prevalent parasites that affect salmon farming, generating different degrees of immune suppression depending on the salmon and sea louse species. Caligus rogercresseyi for example, which affects the salmon industry in Chile, decreases Th1 response, macrophage activation, TLR-mediated response and iron regulation in infected fish. In this study, we explore Atlantic salmon miRNome during infestation by C. rogercresseyi. Using small RNA sequencing, we annotated 1718 miRNAs for skin and head kidney from infected Atlantic salmon. The most abundant families identified were mir-10, mir-21, mir-30, mir-181 and let7. Significant differences were found between tissue, with 1404 annotated miRNA in head kidney and 529 in skin. Differential analysis of transcript expression indicated that at an early stage of infestation miRNA expression was higher in head kidney than in skin tissue, revealing tissue-specific expression patterns. In parallel, miRNA target prediction using 3'UTRs from highly regulated immune-related genes and iron metabolism showed that mir-140-4 and mir-181a-2-5 modulate the expression of TLR22 and Aminolevulinic acid synthase, respectively. This study contributes knowledge about the immune response of Atlantic salmon during infestation with sea lice. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-throughput SNP discovery and transcriptome expression profiles from the salmon louse Caligus rogercresseyi (Copepoda: Caligidae).

PubMed

Nuñez-Acuña, Gustavo; Valenzuela-Muñoz, Valentina; Gallardo-Escárate, Cristian

2014-06-01

The salmon louse Caligus rogercresseyi is the dominant ectoparasite species affecting the salmon aquaculture industry in the Southern hemisphere, and it is currently the main cause for economic losses in Chilean aquaculture. However, despite the great concern over Caligus infestations, genomic information on this louse is still scarce, even while the need to develop high-resolution molecular markers is growing. This study provides the first deep transcriptome survey to identify thousands of SNP markers from C. rogercresseyi, with a total of 69,466 SNPs identified using the MiSeq platform (Illumina®), 30,605 (52%) of which were found in contigs successfully annotated against known protein databases. Furthermore, in silico gene expression profiles associated with SNP variants were evaluated, and the results evidenced a wide array of genes that were down- and upregulated throughout the developmental stages of C. rogercresseyi. Interestingly, putative KEGG pathways involved in resistance to antiparasitic agents were also identified, where ten pathways were associated with the nervous system and one was related to ABC transporters. Taken together, this information could be highly useful for investigating the molecular underpinnings involved in the susceptibility or resistance of salmon lice to chemical treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

Differences in Lepeophtheirus salmonis abundance levels on Atlantic salmon farms in the Broughton Archipelago, British Columbia, Canada.

PubMed

Saksida, S; Karreman, G A; Constantine, J; Donald, A

2007-06-01

Sea lice data collected from Atlantic salmon farms in the Broughton Archipelago between 2003 and 2005 were examined for inter-regional differences in mobile Lepeophtheirus salmonis (Krøyer) abundance using the generalized linear model procedure. Factors such as age of the salmon populations, location of farms and time of year had a significant effect on the abundance of the mobile stages of L. salmonis whereas water temperature and salinity did not. Separate evaluation of SLICE treatment data found no significant difference in treatment frequency among the areas but did show that there were significantly lower numbers of farm treatments during the summer months when compared with other seasons. The role of environment and wild fish in influencing sea lice abundance on the farmed salmon is discussed. The findings suggest that effective management programmes for sea lice should not only be based on geographical location but should take into account other factors which could influence lice abundance levels.

Identification and Molecular Characterization of Two Acetylcholinesterases from the Salmon Louse, Lepeophtheirus salmonis

PubMed Central

Kaur, Kiranpreet; Bakke, Marit Jørgensen; Nilsen, Frank; Horsberg, Tor Einar

2015-01-01

Acetylcholinesterase (AChE) is an important enzyme in cholinergic synapses. Most arthropods have two genes (ace1 and ace2), but only one encodes the predominant synaptic AChE, the main target for organophosphates. Resistance towards organophosphates is widespread in the marine arthropod Lepeophtheirus salmonis. To understand this trait, it is essential to characterize the gene(s) coding for AChE(s). The full length cDNA sequences encoding two AChEs in L. salmonis were molecularly characterized in this study. The two ace genes were highly similar (83.5% similarity at protein level). Alignment to the L. salmonis genome revealed that both genes were located close to each other (separated by just 26.4 kbp on the L. salmonis genome), resulting from a recent gene duplication. Both proteins had all the typical features of functional AChE and clustered together with AChE-type 1 proteins in other species, an observation that has not been described in other arthropods. We therefore concluded the presence of two versions of ace1 gene in L. salmonis, named ace1a and ace1b. Ace1a was predominantly expressed in different developmental stages compared to ace1b and was possibly active in the cephalothorax, indicating that ace1a is more likely to play the major role in cholinergic synaptic transmission. The study is essential to understand the role of AChEs in resistance against organophosphates in L. salmonis. PMID:25938836

Salmon lice (Lepeophtheirus salmonis) showing varying emamectin benzoate susceptibilities differ in neuronal acetylcholine receptor and GABA-gated chloride channel mRNA expression

PubMed Central

2013-01-01

Background Caligid copepods, also called sea lice, are fish ectoparasites, some species of which cause significant problems in the mariculture of salmon, where the annual cost of infection is in excess of €300 million globally. At present, caligid control on farms is mainly achieved using medicinal treatments. However, the continued use of a restricted number of medicine actives potentially favours the development of drug resistance. Here, we report transcriptional changes in a laboratory strain of the caligid Lepeophtheirus salmonis (Krøyer, 1837) that is moderately (~7-fold) resistant to the avermectin compound emamectin benzoate (EMB), a component of the anti-salmon louse agent SLICE® (Merck Animal Health). Results Suppression subtractive hybridisation (SSH) was used to enrich transcripts differentially expressed between EMB-resistant (PT) and drug-susceptible (S) laboratory strains of L. salmonis. SSH libraries were subjected to 454 sequencing. Further L. salmonis transcript sequences were available as expressed sequence tags (EST) from GenBank. Contiguous sequences were generated from both SSH and EST sequences and annotated. Transcriptional responses in PT and S salmon lice were investigated using custom 15 K oligonucleotide microarrays designed using the above sequence resources. In the absence of EMB exposure, 359 targets differed in transcript abundance between the two strains, these genes being enriched for functions such as calcium ion binding, chitin metabolism and muscle structure. γ-aminobutyric acid (GABA)-gated chloride channel (GABA-Cl) and neuronal acetylcholine receptor (nAChR) subunits showed significantly lower transcript levels in PT lice compared to S lice. Using RT-qPCR, the decrease in mRNA levels was estimated at ~1.4-fold for GABA-Cl and ~2.8-fold for nAChR. Salmon lice from the PT strain showed few transcriptional responses following acute exposure (1 or 3 h) to 200 μg L-1 of EMB, a drug concentration tolerated by PT lice, but

Discovery of sex-related genes through high-throughput transcriptome sequencing from the salmon louse Caligus rogercresseyi.

PubMed

Farlora, Rodolfo; Araya-Garay, José; Gallardo-Escárate, Cristian

2014-06-01

Understanding the molecular underpinnings involved in the reproduction of the salmon louse is critical for designing novel strategies of pest management for this ectoparasite. However, genomic information on sex-related genes is still limited. In the present work, sex-specific gene transcription was revealed in the salmon louse Caligus rogercresseyi using high-throughput Illumina sequencing. A total of 30,191,914 and 32,292,250 high quality reads were generated for females and males, and these were de novo assembled into 32,173 and 38,177 contigs, respectively. Gene ontology analysis showed a pattern of higher expression in the female as compared to the male transcriptome. Based on our sequence analysis and known sex-related proteins, several genes putatively involved in sex differentiation, including Dmrt3, FOXL2, VASA, and FEM1, and other potentially significant candidate genes in C. rogercresseyi, were identified for the first time. In addition, the occurrence of SNPs in several differentially expressed contigs annotating for sex-related genes was found. This transcriptome dataset provides a useful resource for future functional analyses, opening new opportunities for sea lice pest control. Copyright © 2014 Elsevier B.V. All rights reserved.

Sea lice, Lepeophtheirus salmonis, transfer between wild sympatric adult and juvenile salmon on the north coast of British Columbia, Canada.

PubMed

Gottesfeld, A S; Proctor, B; Rolston, L D; Carr-Harris, C

2009-01-01

We examine sea lice, Lepeophtheirus salmonis, on juvenile and adult salmon from the north coast of British Columbia between 2004 and 2006 in an area that does not at present contain salmon farms. There is a pronounced zonation in the abundance of L. salmonis on juvenile pink salmon, Oncorhynchus gorbuscha, in the Skeena and Nass estuaries. Abundances in the proximal and distal zones of these estuaries are 0.01 and 0.05 respectively. The outer zones serve as feeding and staging areas for the pink salmon smolts. Returning Chinook, Oncorhynchus tshawytscha, and coho salmon, Oncorhynchus kisutch, concentrate in these areas. We collected data in 2006 to examine whether L. salmonis on returning adult salmon are an important source of the sea lice that appear on juvenile pink salmon. Nearly all (99%) of the sea lice on returning Chinook and over 80% on coho salmon were L. salmonis. Most of the L. salmonis were motile stages including many ovigerous females. There was a sharp increase in the abundance of sea lice on juvenile pink salmon smolts between May and July 2006 near the sites of adult captures. As there are no salmon farms on the north coast, few sticklebacks, Gasterosteus aculeatus, and very few resident salmonids until later in the summer, it seems that the most important reservoir of L. salmonis under natural conditions is returning adult salmon. This natural source of sea lice results in levels of abundance that are one or two orders of magnitude lower than those observed on juvenile pink salmon in areas with salmon farms such as the Broughton Archipelago.

RNA-Seq Analysis Using De Novo Transcriptome Assembly as a Reference for the Salmon Louse Caligus rogercresseyi

PubMed Central

Gallardo-Escárate, Cristian; Valenzuela-Muñoz, Valentina; Nuñez-Acuña, Gustavo

2014-01-01

Despite the economic and environmental impacts that sea lice infestations have on salmon farming worldwide, genomic data generated by high-throughput transcriptome sequencing for different developmental stages, sexes, and strains of sea lice is still limited or unknown. In this study, RNA-seq analysis was performed using de novo transcriptome assembly as a reference for evidenced transcriptional changes from six developmental stages of the salmon louse Caligus rogercresseyi. EST-datasets were generated from the nauplius I, nauplius II, copepodid and chalimus stages and from female and male adults using MiSeq Illumina sequencing. A total of 151,788,682 transcripts were yielded, which were assembled into 83,444 high quality contigs and subsequently annotated into roughly 24,000 genes based on known proteins. To identify differential transcription patterns among salmon louse stages, cluster analyses were performed using normalized gene expression values. Herein, four clusters were differentially expressed between nauplius I–II and copepodid stages (604 transcripts), five clusters between copepodid and chalimus stages (2,426 transcripts), and six clusters between female and male adults (2,478 transcripts). Gene ontology analysis revealed that the nauplius I–II, copepodid and chalimus stages are mainly annotated to aminoacid transfer/repair/breakdown, metabolism, molting cycle, and nervous system development. Additionally, genes showing differential transcription in female and male adults were highly related to cytoskeletal and contractile elements, reproduction, cell development, morphogenesis, and transcription-translation processes. The data presented in this study provides the most comprehensive transcriptome resource available for C. rogercresseyi, which should be used for future genomic studies linked to host-parasite interactions. PMID:24691066

RNA-Seq analysis using de novo transcriptome assembly as a reference for the salmon louse Caligus rogercresseyi.

PubMed

Gallardo-Escárate, Cristian; Valenzuela-Muñoz, Valentina; Nuñez-Acuña, Gustavo

2014-01-01

Despite the economic and environmental impacts that sea lice infestations have on salmon farming worldwide, genomic data generated by high-throughput transcriptome sequencing for different developmental stages, sexes, and strains of sea lice is still limited or unknown. In this study, RNA-seq analysis was performed using de novo transcriptome assembly as a reference for evidenced transcriptional changes from six developmental stages of the salmon louse Caligus rogercresseyi. EST-datasets were generated from the nauplius I, nauplius II, copepodid and chalimus stages and from female and male adults using MiSeq Illumina sequencing. A total of 151,788,682 transcripts were yielded, which were assembled into 83,444 high quality contigs and subsequently annotated into roughly 24,000 genes based on known proteins. To identify differential transcription patterns among salmon louse stages, cluster analyses were performed using normalized gene expression values. Herein, four clusters were differentially expressed between nauplius I-II and copepodid stages (604 transcripts), five clusters between copepodid and chalimus stages (2,426 transcripts), and six clusters between female and male adults (2,478 transcripts). Gene ontology analysis revealed that the nauplius I-II, copepodid and chalimus stages are mainly annotated to aminoacid transfer/repair/breakdown, metabolism, molting cycle, and nervous system development. Additionally, genes showing differential transcription in female and male adults were highly related to cytoskeletal and contractile elements, reproduction, cell development, morphogenesis, and transcription-translation processes. The data presented in this study provides the most comprehensive transcriptome resource available for C. rogercresseyi, which should be used for future genomic studies linked to host-parasite interactions.

Using Agent-Based Modelling to Predict the Role of Wild Refugia in the Evolution of Resistance of Sea Lice to Chemotherapeutants.

PubMed

McEwan, Gregor F; Groner, Maya L; Fast, Mark D; Gettinby, George; Revie, Crawford W

2015-01-01

A major challenge for Atlantic salmon farming in the northern hemisphere is infestation by the sea louse parasite Lepeophtheirus salmonis. The most frequent method of controlling these sea louse infestations is through the use of chemical treatments. However, most major salmon farming areas have observed resistance to common chemotherapeutants. In terrestrial environments, many strategies employed to manage the evolution of resistance involve the use of refugia, where a portion of the population is left untreated to maintain susceptibility. While refugia have not been deliberately used in Atlantic salmon farming, wild salmon populations that migrate close to salmon farms may act as natural refugia. In this paper we describe an agent-based model that explores the influence of different sizes of wild salmon populations on resistance evolution in sea lice on a salmon farm. Using the model, we demonstrate that wild salmon populations can act as refugia that limit the evolution of resistance in the sea louse populations. Additionally, we demonstrate that an increase in the size of the population of wild salmon results in an increased effect in slowing the evolution of resistance. We explore the effect of a population fitness cost associated with resistance, finding that in some cases it substantially reduces the speed of evolution to chemical treatments.

Using Agent-Based Modelling to Predict the Role of Wild Refugia in the Evolution of Resistance of Sea Lice to Chemotherapeutants

PubMed Central

McEwan, Gregor F.; Groner, Maya L.; Fast, Mark D.; Revie, Crawford W.

2015-01-01

A major challenge for Atlantic salmon farming in the northern hemisphere is infestation by the sea louse parasite Lepeophtheirus salmonis. The most frequent method of controlling these sea louse infestations is through the use of chemical treatments. However, most major salmon farming areas have observed resistance to common chemotherapeutants. In terrestrial environments, many strategies employed to manage the evolution of resistance involve the use of refugia, where a portion of the population is left untreated to maintain susceptibility. While refugia have not been deliberately used in Atlantic salmon farming, wild salmon populations that migrate close to salmon farms may act as natural refugia. In this paper we describe an agent-based model that explores the influence of different sizes of wild salmon populations on resistance evolution in sea lice on a salmon farm. Using the model, we demonstrate that wild salmon populations can act as refugia that limit the evolution of resistance in the sea louse populations. Additionally, we demonstrate that an increase in the size of the population of wild salmon results in an increased effect in slowing the evolution of resistance. We explore the effect of a population fitness cost associated with resistance, finding that in some cases it substantially reduces the speed of evolution to chemical treatments. PMID:26485023

Transcriptomic responses to emamectin benzoate in Pacific and Atlantic Canada salmon lice Lepeophtheirus salmonis with differing levels of drug resistance.

PubMed

Sutherland, Ben J G; Poley, Jordan D; Igboeli, Okechukwu O; Jantzen, Johanna R; Fast, Mark D; Koop, Ben F; Jones, Simon R M

2015-02-01

Salmon lice Lepeophtheirus salmonis are an ecologically and economically important parasite of wild and farmed salmon. In Scotland, Norway, and Eastern Canada, L. salmonis have developed resistance to emamectin benzoate (EMB), one of the few parasiticides available for salmon lice. Drug resistance mechanisms can be complex, potentially differing among populations and involving multiple genes with additive effects (i.e., polygenic resistance). Indicators of resistance development may enable early detection and countermeasures to avoid the spread of resistance. Here, we collect sensitive Pacific L. salmonis and sensitive and resistant Atlantic L. salmonis from salmon farms, propagate in laboratory (F1), expose to EMB in bioassays, and evaluate either baseline (Atlantic only) or induced transcriptomic differences between populations. In all populations, induced responses were minor and a cellular stress response was not identified. Pacific lice did not upregulate any genes in response to EMB, but downregulated degradative enzymes and transport proteins at 50 ppb EMB. Baseline differences between sensitive and now resistant Atlantic lice were much greater than responses to exposures. All resistant lice overexpressed degradative enzymes, and resistant males, the most resistant group, overexpressed collagenases to the greatest extent. These results indicate an accumulation of baseline expression differences related to resistance.

Transcriptomic responses to emamectin benzoate in Pacific and Atlantic Canada salmon lice Lepeophtheirus salmonis with differing levels of drug resistance

PubMed Central

Sutherland, Ben J G; Poley, Jordan D; Igboeli, Okechukwu O; Jantzen, Johanna R; Fast, Mark D; Koop, Ben F; Jones, Simon R M

2015-01-01

Salmon lice Lepeophtheirus salmonis are an ecologically and economically important parasite of wild and farmed salmon. In Scotland, Norway, and Eastern Canada, L. salmonis have developed resistance to emamectin benzoate (EMB), one of the few parasiticides available for salmon lice. Drug resistance mechanisms can be complex, potentially differing among populations and involving multiple genes with additive effects (i.e., polygenic resistance). Indicators of resistance development may enable early detection and countermeasures to avoid the spread of resistance. Here, we collect sensitive Pacific L. salmonis and sensitive and resistant Atlantic L. salmonis from salmon farms, propagate in laboratory (F1), expose to EMB in bioassays, and evaluate either baseline (Atlantic only) or induced transcriptomic differences between populations. In all populations, induced responses were minor and a cellular stress response was not identified. Pacific lice did not upregulate any genes in response to EMB, but downregulated degradative enzymes and transport proteins at 50 ppb EMB. Baseline differences between sensitive and now resistant Atlantic lice were much greater than responses to exposures. All resistant lice overexpressed degradative enzymes, and resistant males, the most resistant group, overexpressed collagenases to the greatest extent. These results indicate an accumulation of baseline expression differences related to resistance. PMID:25685190

Mechanism behind Resistance against the Organophosphate Azamethiphos in Salmon Lice (Lepeophtheirus salmonis)

PubMed Central

Kaur, Kiranpreet; Helgesen, Kari Olli; Bakke, Marit Jørgensen; Horsberg, Tor Einar

2015-01-01

Acetylcholinesterase (AChE) is the primary target for organophosphates (OP). Several mutations have been reported in AChE to be associated with the reduced sensitivity against OP in various arthropods. However, to the best of our knowledge, no such reports are available for Lepeophtheirus salmonis. Hence, in the present study, we aimed to determine the association of AChE(s) gene(s) with resistance against OP. We screened the AChE genes (L. salmonis ace1a and ace1b) in two salmon lice populations: one sensitive (n=5) and the other resistant (n=5) for azamethiphos, a commonly used OP in salmon farming. The screening led to the identification of a missense mutation Phe362Tyr in L. salmonis ace1a, (corresponding to Phe331 in Torpedo californica AChE) in all the samples of the resistant population. We confirmed the potential role of the mutation, with reduced sensitivity against azamethiphos in L. salmonis, by screening for Phe362Tyr in 2 sensitive and 5 resistant strains. The significantly higher frequency of the mutant allele (362Tyr) in the resistant strains clearly indicated the possible association of Phe362Tyr mutation in L. salmonis ace1a with resistance towards azamethiphos. The 3D modelling, short term survival experiments and enzymatic assays further supported the imperative role of Phe362Tyr in reduced sensitivity of L. salmonis for azamethiphos. Based on all these observations, the present study, for the first time, presents the mechanism of resistance in L. salmonis against azamethiphos. In addition, we developed a rapid diagnostic tool for the high throughput screening of Phe362Tyr mutation using High Resolution Melt analysis. PMID:25893248

High level efficacy of lufenuron against sea lice (Lepeophtheirus salmonis) linked to rapid impact on moulting processes.

PubMed

Poley, Jordan D; Braden, Laura M; Messmer, Amber M; Igboeli, Okechukwu O; Whyte, Shona K; Macdonald, Alicia; Rodriguez, Jose; Gameiro, Marta; Rufener, Lucien; Bouvier, Jacques; Wadowska, Dorota W; Koop, Ben F; Hosking, Barry C; Fast, Mark D

2018-03-13

Drug resistance in the salmon louse Lepeophtheirus salmonis is a global issue for Atlantic salmon aquaculture. Multiple resistance has been described across most available compound classes with the exception of the benzoylureas. To target this gap in effective management of L. salmonis and other species of sea lice (e.g. Caligus spp.), Elanco Animal Health is developing an in-feed treatment containing lufenuron (a benzoylurea) to be administered prior to seawater transfer of salmon smolts and to provide long-term protection of salmon against sea lice infestations. Benzoylureas disrupt chitin synthesis, formation, and deposition during all moulting events. However, the mechanism(s) of action are not yet fully understood and most research completed to date has focused on insects. We exposed the first parasitic stage of L. salmonis to 700 ppb lufenuron for three hours and observed over 90% reduction in survival to the chalimus II life stage on the host, as compared to vehicle controls. This agrees with a follow up in vivo administration study on the host, which showed >95% reduction by the chalimus I stage. Transcriptomic responses of salmon lice exposed to lufenuron included genes related to moulting, epithelial differentiation, solute transport, and general developmental processes. Global metabolite profiles also suggest that membrane stability and fluidity is impacted in treated lice. These molecular signals are likely the underpinnings of an abnormal moulting process and cuticle formation observed ultrastructurally using transmission electron microscopy. Treated nauplii-staged lice exhibited multiple abnormalities in the integument, suggesting that the coordinated assembly of the epi- and procuticle is impaired. In all cases, treatment with lufenuron had rapid impacts on L. salmonis development. We describe multiple experiments to characterize the efficacy of lufenuron on eggs, larvae, and parasitic stages of L. salmonis, and provide the most comprehensive

Sex-biased gene expression and sequence conservation in Atlantic and Pacific salmon lice (Lepeophtheirus salmonis).

PubMed

Poley, Jordan D; Sutherland, Ben J G; Jones, Simon R M; Koop, Ben F; Fast, Mark D

2016-07-04

Salmon lice, Lepeophtheirus salmonis (Copepoda: Caligidae), are highly important ectoparasites of farmed and wild salmonids, and cause multi-million dollar losses to the salmon aquaculture industry annually. Salmon lice display extensive sexual dimorphism in ontogeny, morphology, physiology, behavior, and more. Therefore, the identification of transcripts with differential expression between males and females (sex-biased transcripts) may help elucidate the relationship between sexual selection and sexually dimorphic characteristics. Sex-biased transcripts were identified from transcriptome analyses of three L. salmonis populations, including both Atlantic and Pacific subspecies. A total of 35-43 % of all quality-filtered transcripts were sex-biased in L. salmonis, with male-biased transcripts exhibiting higher fold change than female-biased transcripts. For Gene Ontology and functional analyses, a consensus-based approach was used to identify concordantly differentially expressed sex-biased transcripts across the three populations. A total of 127 male-specific transcripts (i.e. those without detectable expression in any female) were identified, and were enriched with reproductive functions (e.g. seminal fluid and male accessory gland proteins). Other sex-biased transcripts involved in morphogenesis, feeding, energy generation, and sensory and immune system development and function were also identified. Interestingly, as observed in model systems, male-biased L. salmonis transcripts were more frequently without annotation compared to female-biased or unbiased transcripts, suggesting higher rates of sequence divergence in male-biased transcripts. Transcriptome differences between male and female L. salmonis described here provide key insights into the molecular mechanisms controlling sexual dimorphism in L. salmonis. This analysis offers targets for parasite control and provides a foundation for further analyses exploring critical topics such as the interaction

Managing aquatic parasites for reduced drug resistance: lessons from the land.

PubMed

McEwan, Gregor F; Groner, Maya L; Burnett, Danielle L; Fast, Mark D; Revie, Crawford W

2016-12-01

Atlantic salmon farming is one of the largest aquaculture industries in the world. A major problem in salmon farms is the sea louse ectoparasite Lepeophtheirus salmonis, which can cause stress, secondary infection and sometimes mortality in the salmon host. Sea lice have substantial impacts on farm economics and potentially nearby wild salmonid populations. The most common method of controlling sea louse infestations is application of chemicals. However, most farming regions worldwide have observed resistance to the small set of treatment chemicals that are available. Despite this, there has been little investigation of treatment strategies for managing resistance in aquaculture. In this article, we compare four archetypical treatment strategies inspired by agriculture, where the topic has a rich history of study, and add a fifth strategy common in aquaculture. We use an agent-based model (ABM) to simulate these strategies and their varying applications of chemicals over time and space. We analyse the ABM output to compare how the strategies perform in controlling louse abundance, number of treatments required and levels of resistance in the sea louse population. Our results indicated that among the approaches considered applying chemicals in combination was the most effective over the long term. © 2016 The Author(s).

'Snorkel' lice barrier technology reduced two co- occurring parasites, the salmon louse (Lepeophtheirus salmonis) and the amoebic gill disease causing agent (Neoparamoeba perurans), in commercial salmon sea-cages.

PubMed

Wright, D W; Stien, L H; Dempster, T; Vågseth, T; Nola, V; Fosseidengen, J-E; Oppedal, F

2017-05-01

Diverse chemical-free parasite controls are gaining status in Atlantic salmon sea-cage farming. Yet, the intricacies of their use at commercial scale, including effects on co-occurring parasites, are seldom reported. A new salmon lice prevention method involves installing a deep net roof and 'snorkel' lice barrier in cages to shelter salmon from free-living infective larvae which concentrate at shallow depths, and allows salmon to jump and re- inflate their buoyancy-regulating swim bladder by swallowing air. We document use of snorkel cages (10m deep barrier) in commercial farms, where their effects on salmon lice levels, amoebic gill disease (AGD)-related gill scores, the cage environment, fish welfare and farm management practices were compared to standard cages. During an autumn-winter study involving only snorkel cages, high AGD-related gill scores were observed to decline when freshwater was pumped into snorkels, creating a freshwater surface layer for salmon to enter for self-treatment. In a spring-summer study incorporating snorkel and standard cages, snorkel cages were found to reduce new lice infestations by 84%. The deployment of snorkels and intermittent oxygen depletion detected within them in the spring-summer study did not alter fish welfare parameters. Overall, the results suggest snorkel technology has a place in the toolkit of commercial salmon sea-cage farmers co-managing salmon lice and amoebic gill disease outbreaks - two principal parasite issues facing the industry. Copyright © 2017 Elsevier B.V. All rights reserved.

The efficacy of emamectin benzoate against infestations of Lepeophtheirus salmonis on farmed Atlantic salmon (Salmo salar L) in Scotland, 2002-2006.

PubMed

Lees, Fiona; Baillie, Mark; Gettinby, George; Revie, Crawford W

2008-02-06

Infestations of the parasitic copepod Lepeophtheirus salmonis, commonly referred to as sea lice, represent a major challenge to commercial salmon aquaculture. Dependence on a limited number of theraputants to control such infestations has led to concerns of reduced sensitivity in some sea lice populations. This study investigates trends in the efficacy of the in-feed treatment emamectin benzoate in Scotland, the active ingredient most widely used across all salmon producing regions. Study data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. An epi-informatics approach was adopted whereby available farm records, descriptive epidemiological summaries and statistical linear modelling methods were used to identify factors that significantly affect sea lice abundance following treatment with emamectin benzoate (SLICE(R), Schering Plough Animal Health). The results show that although sea lice infestations are reduced following the application of emamectin benzoate, not all treatments are effective. Specifically there is evidence of variation across geographical regions and a reduction in efficacy over time. Reduced sensitivity and potential resistance to currently available medicines are constant threats to maintaining control of sea lice populations on Atlantic salmon farms. There is a need for on-going monitoring of emamectin benzoate treatment efficacy together with reasons for any apparent reduction in performance. In addition, strategic rotation of medicines should be encouraged and empirical evidence for the benefit of such strategies more fully evaluated.

Impact of early salmon louse, Lepeophtheirus salmonis, infestation and differences in survival and marine growth of sea-ranched Atlantic salmon, Salmo salar L., smolts 1997–2009

PubMed Central

Skilbrei, O T; Finstad, B; Urdal, K; Bakke, G; Kroglund, F; Strand, R

2013-01-01

The impact of salmon lice on the survival of migrating Atlantic salmon smolts was studied by comparing the adult returns of sea-ranched smolts treated for sea lice using emamectin benzoate or substance EX with untreated control groups in the River Dale in western Norway. A total of 143 500 smolts were released in 35 release groups in freshwater from 1997 to 2009 and in the fjord system from 2007 to 2009. The adult recaptures declined gradually with release year and reached minimum levels in 2007. This development corresponded with poor marine growth and increased age at maturity of ranched salmon and in three monitored salmon populations and indicated unfavourable conditions in the Norwegian Sea. The recapture rate of treated smolts was significantly higher than the controls in three of the releases performed: the only release in 1997, one of three in 2002 and the only group released in sea water in 2007. The effect of treating the smolts against salmon lice was smaller than the variability in return rates between release groups, and much smaller that variability between release years, but its overall contribution was still significant (P < 0.05) and equivalent to an odds ratio of the probability of being recaptured of 1.17 in favour of the treated smolts. Control fish also tended to be smaller as grilse (P = 0.057), possibly due to a sublethal effect of salmon lice. PMID:23311746

Immunostimulation of Salmo salar L., and its effect on Lepeophtheirus salmonis (Krøyer) P-glycoprotein mRNA expression following subsequent emamectin benzoate exposure.

PubMed

Igboeli, O O; Purcell, S L; Wotton, H; Poley, J; Burka, J F; Fast, M D

2013-03-01

Control of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar, relies heavily on chemotherapeutants. However, reduced efficacy of many treatments and need for integrated sea lice management plans require innovative strategies. Resistance to emamectin benzoate (EMB), a major sea lice parasiticide, has been linked with P-glycoprotein (P-gp) expression. We hypothesized that host immunostimulation would complement EMB treatment outcome. Lepeophtheirus salmonis-infected Atlantic salmon were fed immunostimulatory or control feeds. Sea lice were collected for 24-h EMB bioassays 1 and 2 weeks prior to commencement of EMB treatment of the fish. Two weeks after cessation of immunostimulant-treated feed, EMB was administered at 150 μg kg(-1) fish biomass for 7 days. The bioassay revealed stage, gender and immunostimulant-related differences in EMB EC(50) . Sea lice attached to salmon with a history of immunostimulation exhibited significantly greater survival than those on control feeds, despite similar levels of EMB in host tissues. Lepeophtheirus salmonis from salmon with a history of immunostimulation also exhibited higher P-gp mRNA expression as well as greater survivability compared to controls. Administration of immunostimulants prior to EMB treatment caused increased expression of P-gp mRNA which could have consequently caused decreased efficacy of the parasiticide. © 2013 Blackwell Publishing Ltd.

Lepeophtheirus salmonis: characterization of prostaglandin E(2) in secretory products of the salmon louse by RP-HPLC and mass spectrometry.

PubMed

Fast, M D; Ross, N W; Craft, C A; Locke, S J; MacKinnon, S L; Johnson, S C

2004-01-01

Lepeophtheirus salmonis is an ectoparasitic copepod that causes serious disease outbreaks in both wild and farmed salmonids. As the relationship between L. salmonis and its hosts is not well understood, the current investigation was undertaken to investigate whether any immunomodulatory compounds could be identified from secretions of L. salmonis. By incubating live L. salmonis adults with the neurotransmitter dopamine in seawater, we were able to obtain secretions from the parasite. These were analyzed by RP-HPLC column, as well as LC-MS. L. salmonis secretions contained a compound with the same retention time and mass of PGE(2). The identity of this compound as PGE(2) was confirmed by MS-in source dissociation. The concentrations of PGE(2) in L. salmonis secretions ranged from 0.2 to 12.3 ng/individual and varied with incubation temperature and time kept off the host. Prostaglandin E(2) is a potent vasodilator and thought to aid in parasite evasion from host immune responses. This is the first reported evidence of prostaglandin production in parasitic copepod secretions and its implications for the host-parasite relationship are discussed.

The Efficacy of Emamectin Benzoate against Infestations of Lepeophtheirus salmonis on Farmed Atlantic Salmon (Salmo salar L) in Scotland, 2002–2006

PubMed Central

Lees, Fiona; Baillie, Mark; Gettinby, George; Revie, Crawford W.

2008-01-01

Background Infestations of the parasitic copepod Lepeophtheirus salmonis, commonly referred to as sea lice, represent a major challenge to commercial salmon aquaculture. Dependence on a limited number of theraputants to control such infestations has led to concerns of reduced sensitivity in some sea lice populations. This study investigates trends in the efficacy of the in-feed treatment emamectin benzoate in Scotland, the active ingredient most widely used across all salmon producing regions. Methodology/Principal Findings Study data were drawn from over 50 commercial Atlantic salmon farms on the west coast of Scotland between 2002 and 2006. An epi-informatics approach was adopted whereby available farm records, descriptive epidemiological summaries and statistical linear modelling methods were used to identify factors that significantly affect sea lice abundance following treatment with emamectin benzoate (SLICE®, Schering Plough Animal Health). The results show that although sea lice infestations are reduced following the application of emamectin benzoate, not all treatments are effective. Specifically there is evidence of variation across geographical regions and a reduction in efficacy over time. Conclusions/Significance Reduced sensitivity and potential resistance to currently available medicines are constant threats to maintaining control of sea lice populations on Atlantic salmon farms. There is a need for on-going monitoring of emamectin benzoate treatment efficacy together with reasons for any apparent reduction in performance. In addition, strategic rotation of medicines should be encouraged and empirical evidence for the benefit of such strategies more fully evaluated. PMID:18253496

Effects of parasites from salmon farms on productivity of wild salmon

PubMed Central

Krkošek, Martin; Connors, Brendan M.; Morton, Alexandra; Lewis, Mark A.; Dill, Lawrence M.; Hilborn, Ray

2011-01-01

The ecological risks of salmon aquaculture have motivated changes to management and policy designed to protect wild salmon populations and habitats in several countries. In Canada, much attention has focused on outbreaks of parasitic copepods, sea lice (Lepeophtheirus salmonis), on farmed and wild salmon in the Broughton Archipelago, British Columbia. Several recent studies have reached contradictory conclusions on whether the spread of lice from salmon farms affects the productivity of sympatric wild salmon populations. We analyzed recently available sea lice data on farms and spawner–recruit data for pink (Oncorhynchus gorbuscha) and coho (Oncorhynchus kisutch) salmon populations in the Broughton Archipelago and nearby regions where farms are not present. Our results show that sea lice abundance on farms is negatively associated with productivity of both pink and coho salmon in the Broughton Archipelago. These results reconcile the contradictory findings of previous studies and suggest that management and policy measures designed to protect wild salmon from sea lice should yield conservation and fishery benefits. PMID:21873246

The caligid life cycle: new evidence from Lepeophtheirus elegans reconciles the cycles of Caligus and Lepeophtheirus (Copepoda: Caligidae)

PubMed Central

Venmathi Maran, Balu Alagar; Moon, Seong Yong; Ohtsuka, Susumu; Oh, Sung-Yong; Soh, Ho Young; Myoung, Jung-Goo; Iglikowska, Anna; Boxshall, Geoffrey Allan

2013-01-01

The developmental stages of the sea louse Lepeophtheirus elegans (Copepoda: Caligidae) are described from material collected from marine ranched Korean rockfish, Sebastes schlegelii. In L. elegans, setal number on the proximal segment of the antennule increases from 3 in the copepodid to 27 in the adult. Using the number of setae as a stage marker supports the inference that the post-naupliar phase of the life cycle comprises six stages: copepodid, chalimus I, chalimus II, pre-adult I, pre-adult II, and the adult. We observed variation in body length in both of the chalimus stages which we consider represents an early expression of sexual size dimorphism. We interpret the larger specimens of chalimus I as putative females, and the smaller as putative males; similarly with chalimus II, larger specimens are putative females and the smaller are males. Two patterns of life cycle are currently recognized within the Caligidae but the evidence presented here reconciles the two. We conclude that the typical caligid life cycle comprises only eight stages: two naupliar, one copepodid, and four chalimus stages preceding the adult in Caligus, but with the four chalimus stages represented by two chalimus and two pre-adult stages in Lepeophtheirus. This is a profound change with significant implications for the aquaculture industry, given that lice monitoring protocols include counts of chalimus stages and use temperature to predict when they will moult into the more pathogenic, mobile pre-adults. Lice management strategies must be tailored to the precise life cycle of the parasite. PMID:23647664

The complete genome sequence of CrRV-Ch01, a new member of the family Rhabdoviridae in the parasitic copepod Caligus rogercresseyi present on farmed Atlantic salmon (Salmo salar) in Chile.

PubMed

Økland, Arnfinn Lodden; Skoge, Renate Hvidsten; Nylund, Are

2018-06-01

We have determined the complete genome sequence of a new rhabdovirus, tentatively named Caligus rogercresseyi rhabdovirus Ch01 (CrRV-Ch01), which was found in the parasite Caligus rogercresseyi, present on farmed Atlantic salmon (Salmo salar) in Chile. The genome encodes the five canonical rhabdovirus proteins in addition to an unknown protein, in the order N-P-M-U (unknown)-G-L. Phylogenetic analysis showed that the virus clusters with two rhabdoviruses (Lepeophtheirus salmonis rhabdovirus No9 and Lepeophtheirus salmonis rhabdovirus No127) obtained from another parasitic caligid, Lepeophtheirus salmonis, present on farmed Atlantic salmon on the west coast of Norway.

Sea louse control in Scotland, past and present.

PubMed

Rae, Gordon H

2002-06-01

Methods for farming the Atlantic salmon (Salmo salar L) in Scotland were developed at the Unilever Research Laboratory facility at Lochailort on the west coast of Scotland in the late 1960s. By the spring of 1972 a fledgling commercial company had been set up and Marine Harvest, as it was known, received its first year class of smolts at Lochailort. Sea lice (Lepeophtheirus salmonis Krøyer) from passing wild fish infected the smolts but did not cause any significant damage until the summer of 1976 when intervention was required. The Scottish industry has since grown to become a vital source of employment for fragile rural economies and produced about 130,000 tonnes of salmon in 2000. This paper gives an overview of how fish welfare has been maintained by the development of treatments and management strategies aimed at minimising the impact of sea lice.

Gene expression in Atlantic salmon skin in response to infection with the parasitic copepod Lepeophtheirus salmonis, cortisol implant, and their combination

PubMed Central

2012-01-01

Background The salmon louse is an ectoparasitic copepod that causes major economic losses in the aquaculture industry of Atlantic salmon. This host displays a high level of susceptibility to lice which can be accounted for by several factors including stress. In addition, the parasite itself acts as a potent stressor of the host, and outcomes of infection can depend on biotic and abiotic factors that stimulate production of cortisol. Consequently, examination of responses to infection with this parasite, in addition to stress hormone regulation in Atlantic salmon, is vital for better understanding of the host pathogen interaction. Results Atlantic salmon post smolts were organised into four experimental groups: lice + cortisol, lice + placebo, no lice + cortisol, no lice + placebo. Infection levels were equal in both treatments upon termination of the experiment. Gene expression changes in skin were assessed with 21 k oligonucleotide microarray and qPCR at the chalimus stage 18 days post infection at 9°C. The transcriptomic effects of hormone treatment were significantly greater than lice-infection induced changes. Cortisol stimulated expression of genes involved in metabolism of steroids and amino acids, chaperones, responses to oxidative stress and eicosanoid metabolism and suppressed genes related to antigen presentation, B and T cells, antiviral and inflammatory responses. Cortisol and lice equally down-regulated a large panel of motor proteins that can be important for wound contraction. Cortisol also suppressed multiple genes involved in wound healing, parts of which were activated by the parasite. Down-regulation of collagens and other structural proteins was in parallel with the induction of proteinases that degrade extracellular matrix (MMP9 and MMP13). Cortisol reduced expression of genes encoding proteins involved in formation of various tissue structures, regulators of cell differentiation and growth factors. Conclusions These results suggest that

How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere

PubMed Central

Costello, Mark J.

2009-01-01

Fishes farmed in sea pens may become infested by parasites from wild fishes and in turn become point sources for parasites. Sea lice, copepods of the family Caligidae, are the best-studied example of this risk. Sea lice are the most significant parasitic pathogen in salmon farming in Europe and the Americas, are estimated to cost the world industry €300 million a year and may also be pathogenic to wild fishes under natural conditions. Epizootics, characteristically dominated by juvenile (copepodite and chalimus) stages, have repeatedly occurred on juvenile wild salmonids in areas where farms have sea lice infestations, but have not been recorded elsewhere. This paper synthesizes the literature, including modelling studies, to provide an understanding of how one species, the salmon louse, Lepeophtheirus salmonis, can infest wild salmonids from farm sources. Three-dimensional hydrographic models predicted the distribution of the planktonic salmon lice larvae best when they accounted for wind-driven surface currents and larval behaviour. Caligus species can also cause problems on farms and transfer from farms to wild fishes, and this genus is cosmopolitan. Sea lice thus threaten finfish farming worldwide, but with the possible exception of L. salmonis, their host relationships and transmission adaptations are unknown. The increasing evidence that lice from farms can be a significant cause of mortality on nearby wild fish populations provides an additional challenge to controlling lice on the farms and also raises conservation, economic and political issues about how to balance aquaculture and fisheries resource management. PMID:19586950

Two novel male-associated peroxinectin genes are downregulated by exposure to delousing drugs in Caligus rogercresseyi.

PubMed

Núñez-Acuña, Gustavo; Gallardo-Escárate, Cristian

2015-02-15

Peroxinectin (PX) is a protein involved in cell adhesion, peroxidase activities, and the encapsulation of invaders in diverse species, including parasitic copepods. Recently, a transcript denoted peroxinectin-like was identified in the salmon louse Lepeophtheirus salmonis, and this was significantly correlated with the immune response of host fish. Thus, the PX gene is a potential candidate to evaluate host-parasite interactions, as well as to analyze responses to delousing drugs used in the salmon aquaculture industry worldwide. The objective of this study was to identify Peroxinectin transcripts in the Chilean salmon louse Caligus rogercresseyi, and to determine expression levels after exposition to the antiparasitics deltamethrin and azamethiphos. Two novel transcript homologs to peroxinectins were identified from a transcriptomic library of C. rogercresseyi. Moreover, in silico gene transcription levels were evaluated through RNA-seq analyses based on unique gene read levels in transcriptomic libraries that were constructed from sea lice exposed to delousing drugs. The identified transcripts were named Peroxinectin-Cr1 and Peroxinectin-Cr2, which, respectively, had lengths of 2543 and 2555 base pairs. Both PX transcripts were highly associated with male adults, and transcription levels were significantly reduced by deltamethrin and azamethiphos. This result suggests a modulation of peroxinectin in response to delousing drugs. Copyright © 2014 Elsevier B.V. All rights reserved.

Commercial trials using emamectin benzoate to control sea lice Lepeophtheirus salmonis infestations in Atlantic salmon Salmo salar.

PubMed

Stone, J; Sutherland, I H; Sommerville, C; Richards, R H; Varma, K J

2000-06-19

Two trials were conducted at commercial salmon farms to evaluate the efficacy of emamectin benzoate (Slice, 0.2% aquaculture pre-mix, Schering-Plough Animal Health) as a treatment for sea lice Lepeophtheirus salmonis (Krøyer) and Caligus elongatus Nordmann infestations in Atlantic salmon Salmo salar L. Trials were carried out in 15 m2 commercial sea pens, at temperatures of 5.5 to 7.5 degrees C and 10.8 to 13.8 degrees C. Each pen was stocked with 14,000 to 17,500 fish with mean weights of 0.44 to 0.74 and 1.33 to 1.83 kg. Fish were naturally infested with sea lice at the start of each trial. At Day -1, samples of 10 or 15 fish were taken from each pen to determine pre-treatment numbers of lice. Emamectin benzoate was administered in feed, to 4 replicate pens, at a dose of 50 micrograms kg-1 biomass d-1 for 7 consecutive days (Days 0 to 6). Sea lice were counted again, between Days 7 and 77, and comparisons made with untreated control fish. Despite adverse weather conditions, wide variations in fish weights and exposure to new infestations, treatment was effective against chalimus and motile stages of L. salmonis. In the autumn trial, efficacy at Day 27 was 89%, and lice numbers remained lower on treated fish than on control fish 64 d from the start of treatment. In the winter trial, reductions in lice numbers at low temperatures were slower but good efficacy was achieved by Day 35. Although control fish had to be treated with hydrogen peroxide at Day 21, fish treated only with emamectin benzoate on Days 0 to 6 still had 89% fewer lice than control fish at Day 35. There were very few C. elongatus present, but at the end of both trials numbers were lower on treated fish. No adverse effects were associated with treatment of fish with emamectin benzoate.

The infection dynamicsof sea lice on sentinel Atlantic salmon in Cobscook Bay, ME

USDA-ARS?s Scientific Manuscript database

This study set out to understand the infection dynamics of sea lice, Lepeophtheirus salmonis an ectoparasite of Atlantic salmon in Cobscook Bay, Maine. Spatial and temporal patterns of parasite settlement were investigated between June 2013 and June 2015. The infective pressure was assessed on a mon...

Transcription expression of immune-related genes from Caligus rogercresseyi evidences host-dependent patterns on Atlantic and coho salmon.

PubMed

Vera-Bizama, Fredy; Valenzuela-Muñoz, Valentina; Gonçalves, Ana Teresa; Marambio, Jorge Pino; Hawes, Christopher; Wadsworth, Simon; Gallardo-Escárate, Cristian

2015-12-01

The transcriptomic response of the sea louse Caligus rogercresseyi during the infestation on Atlantic salmon (Salmo salar) and coho salmon (Oncorhynchus kisutch) was evaluated using 27 genes related to immune response, antioxidant system and secretome. Results showed early responses of TLR/IMD signaling pathway in sea lice infesting Atlantic salmon. Overall, genes associated with oxidative stress responses were upregulated in both host species. This pattern suggests that reactive oxygen species emitted by the host as a response to the infestation, could modulate the sea louse antioxidant system. Secretome-related transcripts evidenced upregulation of trypsins and serpins, mainly associated to Atlantic salmon than coho salmon. Interestingly, cathepsins and trypsin2 were downregulated at 7 days post-infection (dpi) in coho salmon. The principal component analysis revealed an inverse time-dependent pattern based on the different responses of C. rogercresseyi infecting both salmon species. Here, Atlantic salmon strongly modulates the transcriptome responses at earlier infection stages; meanwhile coho salmon reveals a less marked modulation, increasing the transcription activity during the infection process. This study evidences transcriptome differences between two salmon host species and provides pivotal knowledge towards elaborating future control strategies. Copyright © 2015 Elsevier Ltd. All rights reserved.

A fixed-dose approach to conducting emamectin benzoate tolerance assessments on field-collected sea lice, Lepeophtheirus salmonis.

PubMed

Whyte, S K; Westcott, J D; Elmoslemany, A; Hammell, K L; Revie, C W

2013-03-01

In New Brunswick, Canada, the sea louse, Lepeophtheirus salmonis, poses an on-going management challenge to the health and productivity of commercially cultured Atlantic salmon, Salmo salar. While the in-feed medication, emamectin benzoate (SLICE® ; Merck), has been highly effective for many years, evidence of increased tolerance has been observed in the field since late 2008. Although bioassays on motile stages are a common tool to monitor sea lice sensitivity to emamectin benzoate in field-collected sea lice, they require the collection of large numbers of sea lice due to inherent natural variability in the gender and stage response to chemotherapeutants. In addition, sensitive instruments such as EC(50) analysis may be unnecessarily complex to characterize susceptibility subsequent to a significant observed decline in efficacy. This study proposes an adaptation of the traditional, dose-response format bioassay to a fixed-dose method. Analysis of 657 bioassays on preadult and adult stages of sea lice over the period 2008-2011 indicated a population of sea lice in New Brunswick with varying degrees of susceptibility to emamectin benzoate. A seasonal and spatial effect was observed in the robustness of genders and stages of sea lice, which suggest that mixing different genders and stages of lice within a single bioassay may result in pertinent information being overlooked. Poor survival of adult female lice in bioassays, particularly during May/June, indicates it may be prudent to consider excluding this stage from bioassays conducted at certain times of the year. This work demonstrates that fixed-dose bioassays can be a valuable technique in detecting reduced sensitivity in sea lice populations with varying degrees of susceptibility to emamectin benzoate treatments. © 2013 Blackwell Publishing Ltd.

Ectoparasite Caligus rogercresseyi modifies the lactate response in Atlantic salmon (Salmo salar) and Coho salmon (Oncorhynchus kisutch).

PubMed

Vargas-Chacoff, L; Muñoz, J L P; Hawes, C; Oyarzún, R; Pontigo, J P; Saravia, J; González, M P; Mardones, O; Labbé, B S; Morera, F J; Bertrán, C; Pino, J; Wadsworth, S; Yáñez, A

2017-08-30

Although Caligus rogercresseyi negatively impacts Chilean salmon farming, the metabolic effects of infection by this sea louse have never been completely characterized. Therefore, this study analyzed lactate responses in the plasma, as well as the liver/muscle lactate dehydrogenase (LDH) activity and gene expression, in Salmo salar and Oncorhynchus kisutch infested by C. rogercresseyi. The lactate responses of Atlantic and Coho salmon were modified by the ectoparasite. Both salmon species showed increasing in plasma levels, whereas enzymatic activity increased in the muscle but decreased in the liver. Gene expression was overexpressed in both Coho salmon tissues but only in the liver for Atlantic salmon. These results suggest that salmonids need more energy to adapt to infection, resulting in increased gene expression, plasma levels, and enzyme activity in the muscles. The responses differed between both salmon species and over the course of infection, suggesting potential species-specific responses to sea-lice infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Detection of emamectin benzoate tolerance emergence in different life stages of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar L.

PubMed

Jones, P G; Hammell, K L; Gettinby, G; Revie, C W

2013-03-01

Emamectin benzoate has been used to treat sea lice, Lepeophtheirus salmonis, infestations on farmed Atlantic salmon, Salmo salar. Recent evidence suggests a reduction in effectiveness in some locations. A major challenge in the detection of tolerance emergence can be the typically low proportion of resistant individuals in a population during the early phases. The objectives of this study were to develop a method for determining differences in temporal development of tolerance between sea lice life stages and to explore how these differences might be used to improve the monitoring of treatment effectiveness in a clinical setting. This study examined two data sets based on records of sea lice abundance following emamectin benzoate treatments from the west coast of Scotland (2002-2006) and from New Brunswick, Canada (2004-2008). Life stages were categorized into two groups (adult females and the remaining mobile stages) to examine the trends in mean abundance and treatment effectiveness. Differences in emamectin benzoate effectiveness were found between the two groups by year and location, suggesting that an important part of monitoring drug resistance development in aquatic ectoparasites may be the need to focus on key life stages. © 2013 Blackwell Publishing Ltd.

Cessation of a salmon decline with control of parasites.

PubMed

Peacock, Stephanie J; Krkosek, Martin; Proboszcz, Stan; Orr, Craig; Lewis, Mark A

2013-04-01

The resilience of coastal social-ecological systems may depend on adaptive responses to aquaculture disease outbreaks that can threaten wild and farm fish. A nine-year study of parasitic sea lice (Lepeophtheirus salmonis) and pink salmon (Oncorhynchus gorbuscha) from Pacific Canada indicates that adaptive changes in parasite management on salmon farms have yielded positive conservation outcomes. After four years of sea lice epizootics and wild salmon population decline, parasiticide application on salmon farms was adapted to the timing of wild salmon migrations. Winter treatment of farm fish with parasiticides, prior to the out-migration of wild juvenile salmon, has reduced epizootics of wild salmon without significantly increasing the annual number of treatments. Levels of parasites on wild juvenile salmon significantly influence the growth rate of affected salmon populations, suggesting that these changes in management have had positive outcomes for wild salmon populations. These adaptive changes have not occurred through formal adaptive management, but rather, through multi-stakeholder processes arising from a contentious scientific and public debate. Despite the apparent success of parasite control on salmon farms in the study region, there remain concerns about the long-term sustainability of this approach because of the unknown ecological effects of parasticides and the potential for parasite resistance to chemical treatments.

Ectoparasitic sea lice (Lepeophtheirus salmonis) affect behavior and brain serotonergic activity in Atlantic salmon (Salmo salar L.): Perspectives on animal welfare.

PubMed

Øverli, Øyvind; Nordgreen, Janicke; Mejdell, Cecilie M; Janczak, Andrew M; Kittilsen, Silje; Johansen, Ida B; Horsberg, Tor E

2014-06-10

Scientific research and public debate on the welfare of animals in human custody is increasing at present. Fish are in this context mentioned with particular attention to the high numbers of individuals reared in aquaculture. Research on fish has also contributed to the understanding of individual variation in the ability to cope with stress and disease. One mediator of such variation is the brain serotonergic (5-hydroxytryptamine, 5-HT) system, which conveys physiological and behavioral responses to stress and sub-optimal rearing conditions. Here we study links between the 5-HT response, melanin-based skin pigmentation, and behavior in laboratory-reared Atlantic salmon (Salmo salar) experimentally infested with ectoparasitic sea lice (Lepeophtheirus salmonis). Lice numbers were more variable in less pigmented fish, while the neurochemical response to ectoparastic lice-increased levels of the main 5-HT catabolite 5-HIAA in the brain stem-did not differ between pigmentation groups. A strong depression of growth and locomotor activity was seen in all infested fish but less pigmented fish grew better than fish with more skin melanization regardless of infestation status. The observed combination of neurochemical and behavioral effects clearly suggest that animal welfare concerns can be added to the list of negative effects of ectoparasitic sea lice. Copyright © 2014 Elsevier Inc. All rights reserved.

Association between sea lice (Lepeophtheirus salmonis) infestation on Atlantic salmon farms and wild Pacific salmon in Muchalat Inlet, Canada.

PubMed

Nekouei, Omid; Vanderstichel, Raphael; Thakur, Krishna; Arriagada, Gabriel; Patanasatienkul, Thitiwan; Whittaker, Patrick; Milligan, Barry; Stewardson, Lance; Revie, Crawford W

2018-03-05

Growth in salmon aquaculture over the past two decades has raised concerns regarding the potential impacts of the industry on neighboring ecosystems and wild fish productivity. Despite limited evidence, sea lice have been identified as a major cause for the decline in some wild Pacific salmon populations on the west coast of Canada. We used sea lice count and management data from farmed and wild salmon, collected over 10 years (2007-2016) in the Muchalat Inlet region of Canada, to evaluate the association between sea lice recorded on salmon farms with the infestation levels on wild out-migrating Chum salmon. Our analyses indicated a significant positive association between the sea lice abundance on farms and the likelihood that wild fish would be infested. However, increased abundance of lice on farms was not significantly associated with the levels of infestation observed on the wild salmon. Our results suggest that Atlantic salmon farms may be an important source for the introduction of sea lice to wild Pacific salmon populations, but that the absence of a dose response relationship indicates that any estimate of farm impact requires more careful evaluation of causal inference than is typically seen in the extant scientific literature.

Increasing transcriptome response of serpins during the ontogenetic stages in the salmon louse Caligus rogercresseyi (Copepoda: Caligidae).

PubMed

Maldonado-Aguayo, W; Gallardo-Escárate, C

2014-06-01

Serine protease inhibitors, or serpins, target serine proteases, and are important regulators of intra- and extracellular proteolysis. For parasite survival, parasite-derived protease inhibitors have been suggested to play essential roles in evading the host's immune system and protecting against exogenous host proteases. The aim of this work was to identify serpins via high throughput transcriptome sequencing and elucidate their potential functions during the lifecycle of the salmon louse Caligus rogercresseyi. Eleven putative, partial serpin sequences in the C. rogercresseyi transcriptome were identified and denoted as Cr-serpins 1 to 11. Comparative analysis of the deduced serpin-like amino acid sequences revealed a highly conserved reactive center loop region. Interestingly, P1 residues suggest putative functions involved with the trypsin/subtilisin, elastase, or subtilisin inhibitors, which evidenced increasing gene expression profiles from the copepodid to adult stage in C. rogercresseyi. Concerning this, Cr-serpin 10 was mainly expressed in the copepodid stage, while Cr-serpins 3, 4, 5, and 11 were mostly expressed in chalimus and adult stages. These results suggest that serpins could be involved in evading the immune response of the host fish. The identification of these serpins furthers the understanding of the immune system in this important ectoparasite species. Copyright © 2014 Elsevier B.V. All rights reserved.

Next-Generation Transcriptome Profiling of the Salmon Louse Caligus rogercresseyi Exposed to Deltamethrin (AlphaMax™): Discovery of Relevant Genes and Sex-Related Differences.

PubMed

Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

2015-12-01

Sea lice are one of the main parasites affecting the salmon aquaculture industry, causing significant economic losses worldwide. Increased resistance to traditional chemical treatments has created the need to find alternative control methods. Therefore, the objective of this study was to identify the transcriptome response of the salmon louse Caligus rogercresseyi to the delousing drug deltamethrin (AlphaMax™). Through bioassays with different concentrations of deltamethrin, adult salmon lice transcriptomes were sequenced from cDNA libraries in the MiSeq Illumina platform. A total of 78 million reads for females and males were assembled in 30,212 and 38,536 contigs, respectively. De novo assembly yielded 86,878 high-quality contigs and, based on published data, it was possible to annotate and identify relevant genes involved in several biological processes. RNA-seq analysis in conjunction with heatmap hierarchical clustering evidenced that pyrethroids modify the ectoparasitic transcriptome in adults, affecting molecular processes associated with the nervous system, cuticle formation, oxidative stress, reproduction, and metabolism, among others. Furthermore, sex-related transcriptome differences were evidenced. Specifically, 534 and 1033 exclusive transcripts were identified for males and females, respectively, and 154 were shared between sexes. For males, estradiol 17-beta-dehydrogenase, sphingolipid delta4-desaturase DES1, ketosamine-3-kinase, and arylsulfatase A, among others, were discovered, while for females, vitellogenin 1, glycoprotein G, transaldolase, and nitric oxide synthase were among those identified. The shared transcripts included annotations for tropomyosin, γ-crystallin A, glutamate receptor-metabotropic, glutathione S-transferase, and carboxipeptidase B. The present study reveals that deltamethrin generates a complex transcriptome response in C. rogercresseyi, thus providing valuable genomic information for developing new delousing drugs.

Evaluation of emamectin benzoate and substance EX against salmon lice in sea-ranched Atlantic salmon smolts.

PubMed

Skilbrei, Ove Tommy; Espedal, Per Gunnar; Nilsen, Frank; Garcia, Enrique Perez; Glover, Kevin A

2015-04-08

Experimental releases of Atlantic salmon smolts treated with emamectin benzoate (EB) against salmon lice have previously been used to estimate the significance of salmon lice on the survival of migrating smolts. In recent years, the salmon louse has developed reduced sensitivity to EB, which may influence the results of such release experiments. We therefore tested the use of 2 anti-lice drugs: EB was administered to salmon smolts in high doses by intra-peritoneal injection and the prophylactic substance EX (SubEX) was administered by bathing. A third, untreated control group was also established. Salmon were challenged with copepodids of 2 strains of salmon lice (1 EB-sensitive strain and 1 with reduced EB-sensitivity) in mixed-group experimental tanks. At 31 d post-challenge, the numbers of pre-adult lice on treated fish were around 20% compared with the control fish, with minor or no differences between the 2 treatments and lice strains. Both treatments therefore appeared to give the smolts a high degree of protection against infestation of copepodids of salmon lice. However, significantly lower growth of the EB-treatment group indicates that bathing the fish in SubEX is less stressful for smolts than intra-peritoneal injection of EB.

Effectiveness of emamectin benzoate for treatment of Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, Canada.

PubMed

Jones, Patti G; Hammell, K Larry; Dohoo, Ian R; Revie, Crawford W

2012-12-03

Emamectin benzoate (an avermectin chemotherapeutant administered to fish as an in-feed treatment) has been used to treat infestations of sea lice Lepeophtheirus salmonis on farmed Atlantic salmon Salmo salar in the Bay of Fundy, New Brunswick, Canada, since 1999. This retrospective study examined the effectiveness of 114 emamectin benzoate treatment episodes from 2004 to 2008 across 54 farms. Study objectives were to establish whether changes in the effectiveness of emamectin benzoate were present for this period, examine factors associated with treatment outcome, and determine variables that influenced differences in L. salmonis abundance after treatment. The analysis was carried out in 2 parts: first, trends in treatment effectiveness and L. salmonis abundance were explored, and second, statistical modelling (linear and logistic regression) was used to examine the effects of multiple variables on post-treatment abundance and treatment outcome. Post-treatment sea lice abundance increased in the later years examined. Mean abundance differed between locations in the Bay of Fundy, and higher numbers were found at farms closer to the mainland and lower levels were found in the areas around Grand Manan Island. Treatment effectiveness varied by geographical region and decreased over time. There was an increased risk for unsuccessful treatments in 2008, and treatments applied during autumn months were more likely to be ineffective than those applied during summer months.

Transcriptome analysis of the couch potato (CPO) protein reveals an expression pattern associated with early development in the salmon louse Caligus rogercresseyi.

PubMed

Gallardo-Escárate, Cristian; Valenzuela-Muñoz, Valentina; Nuñez-Acuña, Gustavo; Chávez-Mardones, Jacqueline; Maldonado-Aguayo, Waleska

2014-02-15

The couch potato (CPO) protein is a key biomolecule involved in regulating diapause through the RNA-binding process of the peripheral and central nervous systems in insects and also recently discovered in a few crustacean species. As such, ectoparasitic copepods are interesting model species that have no evidence of developmental arrest. The present study is the first to report on the cloning of a putative CPO gene from the salmon louse Caligus rogercresseyi (CrCPO), as identified by high-throughput transcriptome sequencing. In addition, the transcription expression in larvae and adults was evaluated using quantitative real-time PCR. The CrCPO cDNA sequence showed 3261 base pairs (bp), consisting of 713bp of 5' UTR, 1741bp of 3' UTR, and an open reading frame of 807bp encoding for 268 amino acids. The highly conserved RNA binding regions RNP2 (LFVSGL) and RNP1 (SPVGFVTF), as well the dimerization site (LEF), were also found. Furthermore, eight single nucleotide polymorphisms located in the untranslated regions and one located in the coding region were detected. Gene transcription analysis revealed that CrCPO has ubiquitous expression across larval stages and in adult individuals, with the highest expression from nauplius to copepodid stages. The present study suggests a putative biological function of CrCPO associated with the development of the nervous system in salmon lice and contributes molecular evidence for candidate genes related to host-parasite interactions. Copyright © 2013 Elsevier B.V. All rights reserved.

Transmission dynamics of parasitic sea lice from farm to wild salmon.

PubMed

Krkosek, Martin; Lewis, Mark A; Volpe, John P

2005-04-07

Marine salmon farming has been correlated with parasitic sea lice infestations and concurrent declines of wild salmonids. Here, we report a quantitative analysis of how a single salmon farm altered the natural transmission dynamics of sea lice to juvenile Pacific salmon. We studied infections of sea lice (Lepeophtheirus salmonis and Caligus clemensi) on juvenile pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) as they passed an isolated salmon farm during their seaward migration down two long and narrow corridors. Our calculations suggest the infection pressure imposed by the farm was four orders of magnitude greater than ambient levels, resulting in a maximum infection pressure near the farm that was 73 times greater than ambient levels and exceeded ambient levels for 30 km along the two wild salmon migration corridors. The farm-produced cohort of lice parasitizing the wild juvenile hosts reached reproductive maturity and produced a second generation of lice that re-infected the juvenile salmon. This raises the infection pressure from the farm by an additional order of magnitude, with a composite infection pressure that exceeds ambient levels for 75 km of the two migration routes. Amplified sea lice infestations due to salmon farms are a potential limiting factor to wild salmonid conservation.

Transmission dynamics of parasitic sea lice from farm to wild salmon

PubMed Central

Krkošek, Martin; Lewis, Mark A; Volpe, John P

2005-01-01

Marine salmon farming has been correlated with parasitic sea lice infestations and concurrent declines of wild salmonids. Here, we report a quantitative analysis of how a single salmon farm altered the natural transmission dynamics of sea lice to juvenile Pacific salmon. We studied infections of sea lice (Lepeophtheirus salmonis and Caligus clemensi ) on juvenile pink salmon (Oncorhynchus gorbuscha) and chum salmon (Oncorhynchus keta) as they passed an isolated salmon farm during their seaward migration down two long and narrow corridors. Our calculations suggest the infection pressure imposed by the farm was four orders of magnitude greater than ambient levels, resulting in a maximum infection pressure near the farm that was 73 times greater than ambient levels and exceeded ambient levels for 30 km along the two wild salmon migration corridors. The farm-produced cohort of lice parasitizing the wild juvenile hosts reached reproductive maturity and produced a second generation of lice that re-infected the juvenile salmon. This raises the infection pressure from the farm by an additional order of magnitude, with a composite infection pressure that exceeds ambient levels for 75 km of the two migration routes. Amplified sea lice infestations due to salmon farms are a potential limiting factor to wild salmonid conservation. PMID:15870031

Effects of host migration, diversity and aquaculture on sea lice threats to Pacific salmon populations.

PubMed

Krkosek, Martin; Gottesfeld, Allen; Proctor, Bart; Rolston, Dave; Carr-Harris, Charmaine; Lewis, Mark A

2007-12-22

Animal migrations can affect disease dynamics. One consequence of migration common to marine fish and invertebrates is migratory allopatry-a period of spatial separation between adult and juvenile hosts, which is caused by host migration and which prevents parasite transmission from adult to juvenile hosts. We studied this characteristic for sea lice (Lepeophtheirus salmonis and Caligus clemensi) and pink salmon (Oncorhynchus gorbuscha) from one of the Canada's largest salmon stocks. Migratory allopatry protects juvenile salmon from L. salmonis for two to three months of early marine life (2-3% prevalence). In contrast, host diversity facilitates access for C. clemensi to juvenile salmon (8-20% prevalence) but infections appear ephemeral. Aquaculture can augment host abundance and diversity and increase parasite exposure of wild juvenile fish. An empirically parametrized model shows high sensitivity of salmon populations to increased L. salmonis exposure, predicting population collapse at one to five motile L. salmonis per juvenile pink salmon. These results characterize parasite threats of salmon aquaculture to wild salmon populations and show how host migration and diversity are important factors affecting parasite transmission in the oceans.

MicroRNA biogenesis pathway from the salmon louse (Caligus rogercresseyi): emerging role in delousing drug response.

PubMed

Valenzuela-Miranda, Diego; Nuñez-Acuña, Gustavo; Valenzuela-Muñoz, Valentina; Asgari, Sassan; Gallardo-Escárate, Cristian

2015-01-25

Despite the increasing evidence of the importance of microRNAs (miRNAs) in the regulation of multiple biological processes, the molecular bases supporting this regulation are still barely understood in crustaceans. Therefore, the molecular characterization and transcriptome modulation of the miRNA biogenesis pathway were evaluated in the salmon louse Caligus rogercresseyi, an ectoparasite that constitutes one of the biggest concerns for salmonid aquaculture industry. Hence, RNA-Seq analysis was conducted from six different developmental stages, and also after bioassays with delousing drugs Deltamethrin and Azamethiphos using adult individuals. In silico analysis evidenced 24 putative genes involved in the miRNA pathway such as biogenesis, transport, maturation and miRNA-target interaction. Moreover, 243 putative single nucleotide polymorphisms (SNPs) were identified, 15 of which showed non-synonym mutations. RNA-Seq analysis revealed that CCR4-Not complex subunit 3 (CNOT3) was upregulated at earlier developmental stages (nauplius I-II and copepodid), and also after the exposure to Azamethiphos, but not to Deltamethrin. In contrast, the subunit 7 (CNOT7) showed an inverse expression pattern. Different Argonaute transcripts were associated to chalimus and adult stages, revealing specific expression patterns in response to antiparasitic drugs. Our results suggest novel insights into the regulatory network of the post-transcriptional gene regulation in C. rogercresseyi mediated by miRNAs, evidencing a putative role during the ontogeny and drug response. Copyright © 2014 Elsevier B.V. All rights reserved.

A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis.

PubMed

Ljungfeldt, Lina Eva Robin; Espedal, Per Gunnar; Nilsen, Frank; Skern-Mauritzen, Mette; Glover, Kevin Alan

2014-05-19

The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing. With the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure. To our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance development and other

A common-garden experiment to quantify evolutionary processes in copepods: the case of emamectin benzoate resistance in the parasitic sea louse Lepeophtheirus salmonis

PubMed Central

2014-01-01

Background The development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing. Results With the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure. Conclusions To our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance

The sea louse Lepeophtheirus acutus (Caligidae, Siphonostomatoida, Copepoda) as a pathogen of aquarium-held elasmobranchs.

PubMed

Kik, M J L; Janse, M; Benz, G W

2011-10-01

Lepeophtheirus acutus Heegaard, 1943 (Caligidae, Siphonostomatoida, Copepoda), was collected from or observed on four of six elasmobranch species held at Burgers' Zoo (Arnhem, The Netherlands). Circumstantial evidence suggested that a zebra shark, Stegostoma fasciatum (Hermann), from the wild carried the infection into the facility, where copepods reproduced and colonized additional hosts. Copepods typically attached on and about the eyes, in the mouth and occasionally about the cloaca and on the claspers. Severe ocular lesions were associated with infections on zebra sharks, a grey reef shark, Carcharhinus amblyrhynchos (Bleeker), whitetip reef sharks, Triaenodon obesus (Rüppell), and giant shovelnose ray, Rhinobatos typus Bennett, while blacktip reef sharks, Carcharhinus melanopterus (Quoy & Gaimard), and blacktip sharks, Carcharhinus limbatus (Valenciennes), living in infested aquaria showed no sign of infection. Water treatments using trichlorfon were considered primarily responsible for the eradication of copepods from hosts and infested aquaria. This case is the first report of a copepod infection being closely associated with disease and death of an aquarium-held elasmobranch. Given its ability to infect a wide variety of elasmobranchs and promote life-threatening lesions on some hosts, L. acutus should be considered a dangerous pathogen of captive elasmobranchs. © 2011 Blackwell Publishing Ltd.

Simulated environmental transport distances of Lepeophtheirus salmonis in Loch Linnhe, Scotland, for informing aquaculture area management structures.

PubMed

Salama, N K G; Murray, A G; Rabe, B

2016-04-01

In the majority of salmon farming countries, production occurs in zones where practices are coordinated to manage disease agents such as Lepeophtheirus salmonis. To inform the structure of zones in specific systems, models have been developed accounting for parasite biology and system hydrodynamics. These models provide individual system farm relationships, and as such, it may be beneficial to produce more generalized principles for informing structures. Here, we use six different forcing scenarios to provide simulations from a previously described model of the Loch Linnhe system, Scotland, to assess the maximum dispersal distance of lice particles released from 12 sites transported over 19 day. Results indicate that the median distance travelled is 6.1 km from release site with <2.5% transported beyond 15 km, which occurs from particles originating from half of the release sites, with an absolute simulated distance of 36 km observed. This provides information suggesting that the disease management areas developed for infectious salmon anaemia control may also have properties appropriate for salmon lice management in Scottish coastal waters. Additionally, general numerical descriptors of the simulated relative lice abundance reduction with increased distance from release location are proposed. © 2015 Crown copyright. © 2015 John Wiley & Sons Ltd.

Phylogenomic and functional analyses of salmon lice aquaporins uncover the molecular diversity of the superfamily in Arthropoda.

PubMed

Stavang, Jon Anders; Chauvigné, Francois; Kongshaug, Heidi; Cerdà, Joan; Nilsen, Frank; Finn, Roderick Nigel

2015-08-19

An emerging field in biomedical research is focusing on the roles of aquaporin water channels in parasites that cause debilitating or lethal diseases to their vertebrate hosts. The primary vectorial agents are hematophagous arthropods, including mosquitoes, flies, ticks and lice, however very little is known concerning the functional diversity of aquaporins in non-insect members of the Arthropoda. Here we conducted phylogenomic and functional analyses of aquaporins in the salmon louse, a marine ectoparasitic copepod that feeds on the skin and body fluids of salmonids, and used the primary structures of the isolated channels to uncover the genomic repertoires in Arthropoda. Genomic screening identified 7 aquaporin paralogs in the louse in contrast to 42 in its host the Atlantic salmon. Phylogenetic inference of the louse nucleotides and proteins in relation to orthologs identified in Chelicerata, Myriapoda, Crustacea and Hexapoda revealed that the arthropod aquaporin superfamily can be classified into three major grades (1) classical aquaporins including Big brain (Bib) and Prip-like (PripL) channels (2) aquaglyceroporins (Glp) and (3) unorthodox aquaporins (Aqp12-like). In Hexapoda, two additional subfamilies exist as Drip and a recently classified entomoglyceroporin (Eglp) group. Cloning and remapping the louse cDNAs to the genomic DNA revealed that they are encoded by 1-7 exons, with two of the Glps being expressed as N-terminal splice variants (Glp1_v1, -1_v2, -3_v1, -3_v2). Heterologous expression of the cRNAs in amphibian oocytes demonstrated that PripL transports water and urea, while Bib does not. Glp1_v1, -2, -3_v1 and -3_v2 each transport water, glycerol and urea, while Glp1_v2 and the Aqp12-like channels were retained intracellularly. Transcript abundance analyses revealed expression of each louse paralog at all developmental stages, except for glp1_v1, which is specific to preadult and adult males. Our data suggest that the aquaporin repertoires of

[Louse-borne typhus potential and new technologies in prediction of epidemic louse-borne typhus outburst].

PubMed

Boev, B V; Lobanov, A V; Khudobin, V V

2008-01-01

Features of louse-borne typhus in Russia in the middle of 20th century are considered. Study of the infection source, blood serum in patient after epidemic louse-borne typhus (ELBT) and agent (louse) was performed on territory with high morbidity of pediculosis and ELBT in the years of 2nd world war. New materials of seroimmunological examinations are represented. Priority data of lice morphology based on morphometrical data of lice, collected in Russia and world collection in Berlin are shown. Methods of ELBT prediction are given, special attention is paid to development of mathematic prognostic models based on new technologies.

Hey! A Louse Bit Me!

MedlinePlus

... Staying Safe Videos for Educators Search English Español Hey! A Louse Bit Me! KidsHealth / For Kids / Hey! A Louse Bit Me! Print en español ¡Ay! ¡ ... topic for: Kids Lice Aren't So Nice Hey! A Gnat Bit Me! Hey! A Flea Bit ...

Space-time cluster analysis of sea lice infestation (Caligus clemensi and Lepeophtheirus salmonis) on wild juvenile Pacific salmon in the Broughton Archipelago of Canada.

PubMed

Patanasatienkul, Thitiwan; Sanchez, Javier; Rees, Erin E; Pfeiffer, Dirk; Revie, Crawford W

2015-06-15

Sea lice infestation levels on wild chum and pink salmon in the Broughton Archipelago region are known to vary spatially and temporally; however, the locations of areas associated with a high infestation level had not been investigated yet. In the present study, the multivariate spatial scan statistic based on a Poisson model was used to assess spatial clustering of elevated sea lice (Caligus clemensi and Lepeophtheirus salmonis) infestation levels on wild chum and pink salmon sampled between March and July of 2004 to 2012 in the Broughton Archipelago and Knight Inlet regions of British Columbia, Canada. Three covariates, seine type (beach and purse seining), fish size, and year effect, were used to provide adjustment within the analyses. The analyses were carried out across the five months/datasets and between two fish species to assess the consistency of the identified clusters. Sea lice stages were explored separately for the early life stages (non-motile) and the late life stages of sea lice (motile). Spatial patterns in fish migration were also explored using monthly plots showing the average number of each fish species captured per sampling site. The results revealed three clusters for non-motile C. clemensi, two clusters for non-motile L. salmonis, and one cluster for the motile stage in each of the sea lice species. In general, the location and timing of clusters detected for both fish species were similar. Early in the season, the clusters of elevated sea lice infestation levels on wild fish are detected in areas closer to the rivers, with decreasing relative risks as the season progresses. Clusters were detected further from the estuaries later in the season, accompanied by increasing relative risks. In addition, the plots for fish migration exhibit similar patterns for both fish species in that, as expected, the juveniles move from the rivers toward the open ocean as the season progresses The identification of space-time clustering of infestation on wild

Transcriptome mining: Multigene panel to test delousing drug response in the sea louse Caligus rogercresseyi.

PubMed

Valenzuela-Muñoz, V; Gallardo-Escárate, C

2016-02-01

Controlling infestations of copepodid ectoparasites in the salmon industry is increasingly problematic given higher instances of drug resistance or loss of sensitivity. Despite the importance of this issue, the molecular mechanisms and genes implicated in resistance/susceptibility are only scarcely understood. The objective of the present study was to identify and evaluate the expression levels of candidate genes associated with delousing drug response in the sea louse Caligus rogercresseyi. From RNA-seq data obtained for adult male and female sea lice, 62.48 M reads were assembled in 70,349 high-quality contigs. BLASTX analysis against UniprotKB/Swiss-Prot and the ESTs available for crustaceans in the NCBI database identified 870 transcripts previously related to genes associated with delousing drug response. Furthermore, 14 candidate genes were validated through RT-qPCR and were evaluated with deltamethrin and azamethiphos bioassays. The results evidenced an overregulation of genes involved in ion transport in salmon lice treated with deltamethrin, while those treated with azamethiphos evidenced an overregulation of genes such as cytochrome P450, Carboxylesterase, and acetylcholine receptors. The present study provides a multigene panel to test delousing drug response to pyrethroids and organophosphates in a highly prevalent pathogen of the Chilean salmon industry. Copyright © 2015 Elsevier B.V. All rights reserved.

Wild juvenile salmonids in Muchalat Inlet, British Columbia, Canada: factors associated with sea lice prevalence.

PubMed

Elmoslemany, Ahmed; Revie, Crawford W; Milligan, Barry; Stewardson, Lance; Vanderstichel, Raphael

2015-12-09

The Muchalat Inlet, British Columbia, is among the most westerly points at which aquaculture is practiced in Canada. In this paper, we summarise data from over 18000 wild fish sampled at 16 sites over an 8 yr period, between 2004 and 2011. The most prevalent wild species was chum salmon Oncorhynchus keta (82.4%), followed by Chinook O. tshawytscha (10%) and coho O. kisutch (4.3%). However, inter-annual and seasonal variation was evident, and smaller numbers of other Pacific salmon and stickleback species were sporadically observed. A high percentage of wild salmon (~95%) had no sea lice parasites present, with less than 1% of the fish hosting a mobile-stage sea louse. Of the data for which sea lice species were recorded, just over 96% of samples were identified as Lepeophtheirus salmonis. Logistic regression models assessed the association between the presence of lice and a range of independent variables. These models indicated a significant degree of spatial variation, much of which could be explained in terms of salinity levels. There were also important variations through time, both over the season within a year and across years. In addition, coho salmon were significantly more likely (odds ratio = 1.65; 95% CI = 1.20-2.3) to be infected than chum salmon. The protective effect of low salinity was most clearly seen at values lower than 15 psu, although this was dependent on fish species.

Reduced growth in wild juvenile sockeye salmon Oncorhynchus nerka infected with sea lice.

PubMed

Godwin, S C; Dill, L M; Krkošek, M; Price, M H H; Reynolds, J D

2017-07-01

Daily growth rings were examined in the otoliths of wild juvenile sockeye salmon Oncorhynchus nerka to determine whether infection by ectoparasitic sea lice Caligus clemensi and Lepeophtheirus salmonis was associated with reduced host body growth, an important determinant of survival. Over 98% of the sea lice proved to be C. clemensi and the fish that were highly infected grew more slowly than uninfected individuals. Larger fish also grew faster than smaller fish. Finally, there was evidence of an interaction between body size and infection status, indicating the potential for parasite-mediated growth divergence. © 2017 The Fisheries Society of the British Isles.

Combinatorial effects of administration of immunostimulatory compounds in feed and follow-up administration of triple-dose SLICE® (emamectin benzoate) on Atlantic salmon, Salmo salar L., infection with Lepeophtheirus salmonis.

PubMed

Poley, J; Purcell, S L; Igboeli, O O; Donkin, A; Wotton, H; Fast, M D

2013-03-01

Several immunostimulatory feed additives have shown the ability to induce protective responses in Atlantic salmon to infection with Lepeophtheirus salmonis. However, even the most encouraging results rarely surpass a 50% protective index in the host. That fact coupled with the well-documented limitations of single-therapy strategies in the effective management of parasitic infections generally make it imperative to identify therapies that can be combined in an integrated pest management approach for sea lice. With this in mind, we hypothesized that immunostimulatory feeds could enhance the protection provided by SLICE® emamectin benzoate (EMB). To test this hypothesis, Atlantic salmon were fed one of two different immunostimulatory feeds (CpG ODN or Aquate®) for c. 7 weeks, challenged with L. salmonis copepodids early within that immunostimulatory feed period and then placed on a triple-dose (150 μg kg(-1) ) feed of SLICE® for 1 week following the completion of the immunostimulatory feeding period. CpG ODN (2 mg kg(-1) ) and the commercial yeast extract (Aquate® 0.2%) inclusion in feeds were able to successfully induce inflammatory gene expression (interleukin-1β) in the head kidneys of infected fish at 13 and 26 days post-exposure (DPE), and 13 DPE, respectively. Lice burdens were lower on fish fed CpG ODN (18%) or Aquate® (19%) diets; however, due to variability, these were not statistically significant over time. Despite no statistically significant reductions in lice numbers, by 33 DPE fish on immunostimulatory feeds had significantly reduced cortisol levels when compared to infected fish on control diet. Cortisol levels in fish receiving an immunostimulatory diet were no different from initial baseline levels prior to infection, whereas the levels in control diet fish were significantly elevated from all other time points. Despite the positive effects on infection of fish fed immunostimulatory feeds, no synergism was observed with follow-up treatment

Impact of parasites on salmon recruitment in the Northeast Atlantic Ocean

PubMed Central

Krkošek, Martin; Revie, Crawford W.; Gargan, Patrick G.; Skilbrei, Ove T.; Finstad, Bengt; Todd, Christopher D.

2013-01-01

Parasites may have large effects on host population dynamics, marine fisheries and conservation, but a clear elucidation of their impact is limited by a lack of ecosystem-scale experimental data. We conducted a meta-analysis of replicated manipulative field experiments concerning the influence of parasitism by crustaceans on the marine survival of Atlantic salmon (Salmo salar L.). The data include 24 trials in which tagged smolts (totalling 283 347 fish; 1996–2008) were released as paired control and parasiticide-treated groups into 10 areas of Ireland and Norway. All experimental fish were infection-free when released into freshwater, and a proportion of each group was recovered as adult recruits returning to coastal waters 1 or more years later. Treatment had a significant positive effect on survival to recruitment, with an overall effect size (odds ratio) of 1.29 that corresponds to an estimated loss of 39 per cent (95% CI: 18–55%) of adult salmon recruitment. The parasitic crustaceans were probably acquired during early marine migration in areas that host large aquaculture populations of domesticated salmon, which elevate local abundances of ectoparasitic copepods—particularly Lepeophtheirus salmonis. These results provide experimental evidence from a large marine ecosystem that parasites can have large impacts on fish recruitment, fisheries and conservation. PMID:23135680

Essential oils in the management of the donkey louse, Bovicola ocellatus.

PubMed

Ellse, L; Sands, B; Burden, F A; Wall, R

2016-05-01

Chewing lice are widespread and clinically compromising parasites of livestock and equids. Their management is complicated by growing levels of resistance to commonly applied insecticides. Hence, the development of novel approaches to their control is of major clinical interest. To assess the effects of incorporating the essential oils of tea tree and lavender into a grooming programme for populations of donkeys with natural infestations of Bovicola ocellatus in the UK and Ireland when louse populations were at their winter seasonal peak. In vivo field trial. Suspensions of 5% (v/v) tea tree or lavender oil or an excipient only control were groomed into the coats of winter-housed donkeys (n = 198) on 2 occasions, 2 weeks apart. Louse counts were conducted before each application and 2 weeks later. After 2 applications, the groups groomed with lavender or tea tree oil suspensions had a significant reduction in louse intensity, with a mean decline in louse abundance of 78% (95% confidence interval 76-80%). Louse numbers in the groups groomed with excipient only either did not change or increased significantly. Donkey hair length had no effect on the decline in louse numbers. These results demonstrate that the inclusion of essential oil suspensions during grooming can be used to manage louse populations successfully. © 2015 EVJ Ltd.

Pharmacokinetics and transcriptional effects of the anti-salmon lice drug emamectin benzoate in Atlantic salmon (Salmo salar L.)

PubMed Central

Olsvik, Pål A; Lie, Kai K; Mykkeltvedt, Eva; Samuelsen, Ole B; Petersen, Kjell; Stavrum, Anne-Kristin; Lunestad, Bjørn T

2008-01-01

Background Emamectin benzoate (EB) is a dominating pharmaceutical drug used for the treatment and control of infections by sea lice (Lepeophtheirus salmonis) on Atlantic salmon (Salmo salar L). Fish with an initial mean weight of 132 g were experimentally medicated by a standard seven-day EB treatment, and the concentrations of drug in liver, muscle and skin were examined. To investigate how EB affects Atlantic salmon transcription in liver, tissues were assessed by microarray and qPCR at 7, 14 and 35 days after the initiation of medication. Results The pharmacokinetic examination revealed highest EB concentrations in all three tissues at day 14, seven days after the end of the medication period. Only modest effects were seen on the transcriptional levels in liver, with small fold-change alterations in transcription throughout the experimental period. Gene set enrichment analysis (GSEA) indicated that EB treatment induced oxidative stress at day 7 and inflammation at day 14. The qPCR examinations showed that medication by EB significantly increased the transcription of both HSP70 and glutathione-S-transferase (GST) in liver during a period of 35 days, compared to un-treated fish, possibly via activation of enzymes involved in phase II conjugation of metabolism in the liver. Conclusion This study has shown that a standard seven-day EB treatment has only a modest effect on the transcription of genes in liver of Atlantic salmon. Based on GSEA, the medication seems to have produced a temporary oxidative stress response that might have affected protein stability and folding, followed by a secondary inflammatory response. PMID:18786259

Pharmacokinetics and transcriptional effects of the anti-salmon lice drug emamectin benzoate in Atlantic salmon (Salmo salar L.).

PubMed

Olsvik, Pål A; Lie, Kai K; Mykkeltvedt, Eva; Samuelsen, Ole B; Petersen, Kjell; Stavrum, Anne-Kristin; Lunestad, Bjørn T

2008-09-11

Emamectin benzoate (EB) is a dominating pharmaceutical drug used for the treatment and control of infections by sea lice (Lepeophtheirus salmonis) on Atlantic salmon (Salmo salar L). Fish with an initial mean weight of 132 g were experimentally medicated by a standard seven-day EB treatment, and the concentrations of drug in liver, muscle and skin were examined. To investigate how EB affects Atlantic salmon transcription in liver, tissues were assessed by microarray and qPCR at 7, 14 and 35 days after the initiation of medication. The pharmacokinetic examination revealed highest EB concentrations in all three tissues at day 14, seven days after the end of the medication period. Only modest effects were seen on the transcriptional levels in liver, with small fold-change alterations in transcription throughout the experimental period. Gene set enrichment analysis (GSEA) indicated that EB treatment induced oxidative stress at day 7 and inflammation at day 14. The qPCR examinations showed that medication by EB significantly increased the transcription of both HSP70 and glutathione-S-transferase (GST) in liver during a period of 35 days, compared to un-treated fish, possibly via activation of enzymes involved in phase II conjugation of metabolism in the liver. This study has shown that a standard seven-day EB treatment has only a modest effect on the transcription of genes in liver of Atlantic salmon. Based on GSEA, the medication seems to have produced a temporary oxidative stress response that might have affected protein stability and folding, followed by a secondary inflammatory response.

The diversity of sea lice (Copepoda: Caligidae) parasitic on threespine stickleback (Gasterosteus aculeatus) in coastal British Columbia.

PubMed

Jones, Simon R M; Prosperi-Porta, Gina

2011-06-01

The prevalence, intensity, and abundance of sea lice belonging to Lepeophtheirus or Caligus clemensi are reported from threespine stickleback (Gasterosteus aculeatus) collected from the Broughton Archipelago region of coastal British Columbia, Canada, between 2005 and 2008. In total, 25,130 sea lice were collected from 7,684 sticklebacks. The prevalence of Lepeophtheirus ranged from 51% in 2005 to 11% in 2008 and that of C. clemensi from 56% in 2007 to 24% in 2008. Chalimus stages accounted for approximately 69% of all Lepeophtheirus and 88% of Caligus specimens. Cytochrome c oxidase subunit 1 (COI) gene sequences, useful in distinguishing reference specimens belonging to 8 species of Lepeophtheirus, Caligus, and Bomolochus, were used to identify the Lepeophtheirus specimens from stickleback as L. salmonis (71%) and L. cuneifer (29%). A COI phylogenetic analysis confirmed a monophylogenetic origin of Lepeophtheirus but not of Caligus. Two genotypes were resolved in L. cuneifer, i.e., genotype A occurred twice as often as genotype B. Virtually all immature Lepeophtheirus specimens from juvenile salmon were L. salmonis. The results emphasized the need to accurately identify immature sea lice as a prerequisite to understanding sea lice ecology. The threespine stickleback may be a useful sentinel species for the abundance and diversity of the sea lice that are also parasites of wild and farmed salmon in coastal ecosystems in British Columbia.

Sea lice infestations on farmed Atlantic salmon in Scotland and the use of ectoparasitic treatments.

PubMed

Revie, C W; Gettinby, G; Treasurer, J W; Grant, A N; Reid, S W J

A recently compiled national database on sea lice infestations on farmed Atlantic salmon, contains detailed records for the period 1996 to 2000 from over 30 commercial sites on the west coast of Scotland. The data indicate that the two prevalent species of lice, Lepeophtheirus salmonis and Caligus elongatus, have different trends in abundance and distinctive seasonal patterns of infestation on farmed salmon. For the economically important species L salmonis, its abundance on fish varies with the time of the production cycle, the time of year and the particular year. Weekly fluctuations in sea lice counts indicate that treatment can be very effective in controlling infestations but that the counts recover rapidly and regular treatments are necessary to ensure control. A comparison of sites using medium or large numbers of treatments suggests that they do not reduce sea lice infestations to the same levels. There is also evidence that sites using treatments based on different chemical constituents had significantly different levels of infestation.

Gene silencing reveals multiple functions of Na+/K+-ATPase in the salmon louse (Lepeophtheirus salmonis).

PubMed

Komisarczuk, Anna Z; Kongshaug, Heidi; Nilsen, Frank

2018-02-01

Na + /K + -ATPase has a key function in a variety of physiological processes including membrane excitability, osmoregulation, regulation of cell volume, and transport of nutrients. While knowledge about Na + /K + -ATPase function in osmoregulation in crustaceans is extensive, the role of this enzyme in other physiological and developmental processes is scarce. Here, we report characterization, transcriptional distribution and likely functions of the newly identified L. salmonis Na + /K + -ATPase (LsalNa + /K + -ATPase) α subunit in various developmental stages. The complete mRNA sequence was identified, with 3003 bp open reading frame encoding a putative protein of 1001 amino acids. Putative protein sequence of LsalNa + /K + -ATPase revealed all typical features of Na + /K + -ATPase and demonstrated high sequence identity to other invertebrate and vertebrate species. Quantitative RT-PCR analysis revealed higher LsalNa + /K + -ATPase transcript level in free-living stages in comparison to parasitic stages. In situ hybridization analysis of copepodids and adult lice revealed LsalNa + /K + -ATPase transcript localization in a wide variety of tissues such as nervous system, intestine, reproductive system, and subcuticular and glandular tissue. RNAi mediated knock-down of LsalNa + /K + -ATPase caused locomotion impairment, and affected reproduction and feeding. Morphological analysis of dsRNA treated animals revealed muscle degeneration in larval stages, severe changes in the oocyte formation and maturation in females and abnormalities in tegmental glands. Thus, the study represents an important foundation for further functional investigation and identification of physiological pathways in which Na + /K + -ATPase is directly or indirectly involved. Copyright © 2018 Elsevier Inc. All rights reserved.

Sea lice infestations on juvenile chum and pink salmon in the Broughton Archipelago, Canada, from 2003 to 2012.

PubMed

Patanasatienkul, Thitiwan; Sanchez, Javier; Rees, Erin E; Krkosek, Martin; Jones, Simon R M; Revie, Crawford W

2013-07-22

Juvenile pink salmon Oncorhynchus gorbuscha and chum salmon O. keta were sampled by beach or purse seine to assess levels of sea lice infestation in the Knight Inlet and Broughton Archipelago regions of coastal British Columbia, Canada, during the months of March to July from 2003 to 2012. Beach seine data were analyzed for sea lice infestation that was described in terms of prevalence, abundance, intensity, and intensity per unit length. The median annual prevalence for chum was 30%, ranging from 14% (in 2008 and 2009) to 73% (in 2004), while for pink salmon, the median was 27% and ranged from 10% (in 2011) to 68% (in 2004). Annual abundance varied from 0.2 to 5 sea lice per fish with a median of 0.47 for chum and from 0.1 to 3 lice (median 0.42) for pink salmon. Annual infestation followed broadly similar trends for both chum and pink salmon. However, the abundance and intensity of Lepeophtheirus salmonis and Caligus clemensi, the 2 main sea lice species of interest, were significantly greater on chum than on pink salmon in around half of the years studied. Logistic regression with random effect was used to model prevalence of sea lice infestation for the combined beach and purse seine data. The model suggested inter-annual variation as well as a spatial clustering effect on the prevalence of sea lice infestation in both chum and pink salmon. Fish length had an effect on prevalence, although the nature of this effect differed according to host species.

The body louse as a vector of reemerging human diseases.

PubMed

Raoult, D; Roux, V

1999-10-01

The body louse, Pediculus humanus humanus, is a strict human parasite, living and multiplying in clothing. Louse infestation is associated with cold weather and a lack of hygiene. Three pathogenic bacteria are transmitted by the body louse. Borrelia recurrentis is a spirochete, the agent of relapsing fever, recently cultured on axenic medium. Historically, massive outbreaks have occurred in Eurasia and Africa, but currently the disease is found only in Ethiopia and neighboring countries. Bartonella quintana is now recognized as an agent of bacillary angiomatosis bacteremia, trench fever, endocarditis, and chronic lymphadenopathy among the homeless. Rickettsia prowazekii is the agent of epidemic typhus. The most recent outbreak (and the largest since World War II) was observed in Burundi. A small outbreak was also reported in Russia in 1997. Louse infestation appears to become more prevalent worldwide, associated with a decline in social and hygienic conditions provoked by civil unrest and economic instability.

Transcriptomic insights on the ABC transporter gene family in the salmon louse Caligus rogercresseyi.

PubMed

Valenzuela-Muñoz, Valentina; Sturm, Armin; Gallardo-Escárate, Cristian

2015-04-09

ATP-binding cassette (ABC) protein family encode for membrane proteins involved in the transport of various biomolecules through the cellular membrane. These proteins have been identified in all taxa and present important physiological functions, including the process of insecticide detoxification in arthropods. For that reason the ectoparasite Caligus rogercresseyi represents a model species for understanding the molecular underpinnings involved in insecticide drug resistance. llumina sequencing was performed using sea lice exposed to 2 and 3 ppb of deltamethrin and azamethiphos. Contigs obtained from de novo assembly were annotated by Blastx. RNA-Seq analysis was performed and validated by qPCR analysis. From the transcriptome database of C. rogercresseyi, 57 putative members of ABC protein sequences were identified and phylogenetically classified into the eight subfamilies described for ABC transporters in arthropods. Transcriptomic profiles for ABC proteins subfamilies were evaluated throughout C. rogercresseyi development. Moreover, RNA-Seq analysis was performed for adult male and female salmon lice exposed to the delousing drugs azamethiphos and deltamethrin. High transcript levels of the ABCB and ABCC subfamilies were evidenced. Furthermore, SNPs mining was carried out for the ABC proteins sequences, revealing pivotal genomic information. The present study gives a comprehensive transcriptome analysis of ABC proteins from C. rogercresseyi, providing relevant information about transporter roles during ontogeny and in relation to delousing drug responses in salmon lice. This genomic information represents a valuable tool for pest management in the Chilean salmon aquaculture industry.

Uncovering iron regulation with species-specific transcriptome patterns in Atlantic and coho salmon during a Caligus rogercresseyi infestation.

PubMed

Valenzuela-Muñoz, V; Boltaña, S; Gallardo-Escárate, C

2017-09-01

Salmon species cultured in Chile evidence different levels of susceptibility to the sea louse Caligus rogercresseyi. These differences have mainly been associated with specific immune responses. Moreover, iron regulation seems to be an important mechanism to confer immunity during the host infestation. This response called nutritional immunity has been described in bacterial infections, despite that no comprehensive studies involving in marine ectoparasites infestation have been reported. With this aim, we analysed the transcriptome profiles of Atlantic and coho salmon infected with C. rogercresseyi to evidence modulation of the iron metabolism as a proxy of nutritional immune responses. Whole transcriptome sequencing was performed in samples of skin and head kidney from Atlantic and coho salmon infected with sea lice. RNA-seq analyses revealed significant upregulation of transcripts in both salmon species at 7 and 14 dpi in skin and head kidney, respectively. However, iron regulation transcripts were differentially modulated, evidencing species-specific expression profiles. Genes related to heme degradation and iron transport such as hepcidin, transferrin and haptoglobin were primary upregulated in Atlantic salmon; meanwhile, in coho salmon, genes associated with heme biosynthesis were strongly transcribed. In summary, Atlantic salmon, which are more susceptible to infestation, presented molecular mechanisms to deplete cellular iron availability, suggesting putative mechanisms of nutritional immunity. In contrast, resistant coho salmon were less affected by sea lice, mainly activating pro-inflammatory mechanisms to cope with infestation. © 2017 John Wiley & Sons Ltd.

Transcriptome immunomodulation of in-feed additives in Atlantic salmon Salmo salar infested with sea lice Caligus rogercresseyi.

PubMed

Núñez-Acuña, Gustavo; Gonçalves, Ana Teresa; Valenzuela-Muñoz, Valentina; Pino-Marambio, Jorge; Wadsworth, Simon; Gallardo-Escárate, Cristian

2015-11-01

One of the most significant threats to the Chilean salmon aquaculture industry is the ectoparasitic sea louse Caligus rogercresseyi. To cope with sea lice infestations, functional diets have become an important component in strengthening the host immune response. The aim of this study was to evaluate molecular mechanisms activated through immunostimulation by in-feed plant-derived additives in Atlantic salmon infected with sea lice. Herein, a transcriptome-wide sequencing analysis was performed from skin and head kidney tissues, evidencing that the immune response genes were the most variable after the challenge, especially in the head kidney, while other genes involved in metabolism were highly expressed individuals fed with the immunostimulants. Interestingly, defensive enzymes such as Cytochrome p450 and serpins were down-regulated in infested individuals, especially in skin tissue. Additionally, MHC-I and MHC-II genes were differentially expressed after the incorporation of the in-feed additives, giving some cues about the protection mechanisms of plant-derived compound as immunostimulants for infested salmons. This is the first published study that evaluates the transcriptomic response of sea lice-infested Atlantic salmon fed with in-feed additives. Copyright © 2015 Elsevier Ltd. All rights reserved.

Scratching an ancient itch: an Eocene bird louse fossil.

PubMed Central

Wappler, Torsten; Smith, Vincent S; Dalgleish, Robert C

2004-01-01

Out of the 30 extant orders of insects, all but one, the parasitic lice (Insecta: Phthiraptera), have a confirmed fossil record. Here, we report the discovery of what appears to be the first bird louse fossil: an exceptionally well-preserved specimen collected from the crater of the Eckfeld maar near Manderscheid, Germany. The 44-million-year-old specimen shows close phylogenetic affinities with modern feather louse ectoparasites of aquatic birds. Preservation of feather remnants in the specimen's foregut confirms its association as a bird ectoparasite. Based on a phylogenetic analysis of the specimen and palaeoecological data, we suggest that this louse was the parasite of a large ancestor to modern Anseriformes (swans, geese and ducks) or Charadriiformes (shorebirds). The crown group position of this fossil in the phylogeny of lice confirms the group's long coevolutionary history with birds and points to an early origin for lice, perhaps inherited from early-feathered theropod dinosaurs. PMID:15503987

Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle.

PubMed

Kirkness, Ewen F; Haas, Brian J; Sun, Weilin; Braig, Henk R; Perotti, M Alejandra; Clark, John M; Lee, Si Hyeock; Robertson, Hugh M; Kennedy, Ryan C; Elhaik, Eran; Gerlach, Daniel; Kriventseva, Evgenia V; Elsik, Christine G; Graur, Dan; Hill, Catherine A; Veenstra, Jan A; Walenz, Brian; Tubío, José Manuel C; Ribeiro, José M C; Rozas, Julio; Johnston, J Spencer; Reese, Justin T; Popadic, Aleksandar; Tojo, Marta; Raoult, Didier; Reed, David L; Tomoyasu, Yoshinori; Kraus, Emily; Krause, Emily; Mittapalli, Omprakash; Margam, Venu M; Li, Hong-Mei; Meyer, Jason M; Johnson, Reed M; Romero-Severson, Jeanne; Vanzee, Janice Pagel; Alvarez-Ponce, David; Vieira, Filipe G; Aguadé, Montserrat; Guirao-Rico, Sara; Anzola, Juan M; Yoon, Kyong S; Strycharz, Joseph P; Unger, Maria F; Christley, Scott; Lobo, Neil F; Seufferheld, Manfredo J; Wang, Naikuan; Dasch, Gregory A; Struchiner, Claudio J; Madey, Greg; Hannick, Linda I; Bidwell, Shelby; Joardar, Vinita; Caler, Elisabet; Shao, Renfu; Barker, Stephen C; Cameron, Stephen; Bruggner, Robert V; Regier, Allison; Johnson, Justin; Viswanathan, Lakshmi; Utterback, Terry R; Sutton, Granger G; Lawson, Daniel; Waterhouse, Robert M; Venter, J Craig; Strausberg, Robert L; Berenbaum, May R; Collins, Frank H; Zdobnov, Evgeny M; Pittendrigh, Barry R

2010-07-06

As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens.

Genome sequences of the human body louse and its primary endosymbiont provide insights into the permanent parasitic lifestyle

PubMed Central

Kirkness, Ewen F.; Haas, Brian J.; Sun, Weilin; Braig, Henk R.; Perotti, M. Alejandra; Clark, John M.; Lee, Si Hyeock; Robertson, Hugh M.; Kennedy, Ryan C.; Elhaik, Eran; Gerlach, Daniel; Kriventseva, Evgenia V.; Elsik, Christine G.; Graur, Dan; Hill, Catherine A.; Veenstra, Jan A.; Walenz, Brian; Tubío, José Manuel C.; Ribeiro, José M. C.; Rozas, Julio; Johnston, J. Spencer; Reese, Justin T.; Popadic, Aleksandar; Tojo, Marta; Raoult, Didier; Reed, David L.; Tomoyasu, Yoshinori; Kraus, Emily; Mittapalli, Omprakash; Margam, Venu M.; Li, Hong-Mei; Meyer, Jason M.; Johnson, Reed M.; Romero-Severson, Jeanne; VanZee, Janice Pagel; Alvarez-Ponce, David; Vieira, Filipe G.; Aguadé, Montserrat; Guirao-Rico, Sara; Anzola, Juan M.; Yoon, Kyong S.; Strycharz, Joseph P.; Unger, Maria F.; Christley, Scott; Lobo, Neil F.; Seufferheld, Manfredo J.; Wang, NaiKuan; Dasch, Gregory A.; Struchiner, Claudio J.; Madey, Greg; Hannick, Linda I.; Bidwell, Shelby; Joardar, Vinita; Caler, Elisabet; Shao, Renfu; Barker, Stephen C.; Cameron, Stephen; Bruggner, Robert V.; Regier, Allison; Johnson, Justin; Viswanathan, Lakshmi; Utterback, Terry R.; Sutton, Granger G.; Lawson, Daniel; Waterhouse, Robert M.; Venter, J. Craig; Strausberg, Robert L.; Collins, Frank H.; Zdobnov, Evgeny M.; Pittendrigh, Barry R.

2010-01-01

As an obligatory parasite of humans, the body louse (Pediculus humanus humanus) is an important vector for human diseases, including epidemic typhus, relapsing fever, and trench fever. Here, we present genome sequences of the body louse and its primary bacterial endosymbiont Candidatus Riesia pediculicola. The body louse has the smallest known insect genome, spanning 108 Mb. Despite its status as an obligate parasite, it retains a remarkably complete basal insect repertoire of 10,773 protein-coding genes and 57 microRNAs. Representing hemimetabolous insects, the genome of the body louse thus provides a reference for studies of holometabolous insects. Compared with other insect genomes, the body louse genome contains significantly fewer genes associated with environmental sensing and response, including odorant and gustatory receptors and detoxifying enzymes. The unique architecture of the 18 minicircular mitochondrial chromosomes of the body louse may be linked to the loss of the gene encoding the mitochondrial single-stranded DNA binding protein. The genome of the obligatory louse endosymbiont Candidatus Riesia pediculicola encodes less than 600 genes on a short, linear chromosome and a circular plasmid. The plasmid harbors a unique arrangement of genes required for the synthesis of pantothenate, an essential vitamin deficient in the louse diet. The human body louse, its primary endosymbiont, and the bacterial pathogens that it vectors all possess genomes reduced in size compared with their free-living close relatives. Thus, the body louse genome project offers unique information and tools to use in advancing understanding of coevolution among vectors, symbionts, and pathogens. PMID:20566863

Aquaporin family genes exhibit developmentally-regulated and host-dependent transcription patterns in the sea louse Caligus rogercresseyi.

PubMed

Farlora, Rodolfo; Valenzuela-Muñoz, Valentina; Chávez-Mardones, Jacqueline; Gallardo-Escárate, Cristian

2016-07-01

Aquaporins are small integral membrane proteins that function as pore channels for the transport of water and other small solutes across the cell membrane. Considering the important roles of these proteins in several biological processes, including host-parasite interactions, there has been increased research on aquaporin proteins recently. The present study expands on the knowledge of aquaporin family genes in parasitic copepods, examining diversity and expression during the ontogeny of the sea louse Caligus rogercresseyi. Furthermore, aquaporin expression was evaluated during the early infestation of Atlantic (Salmo salar) and Coho salmon (Oncorhynchus kisutch). Deep transcriptome sequencing data revealed eight full length and two partial open reading frames belonging to the aquaporin protein family. Clustering analyses with identified Caligidae sequences revealed three major clades of aquaglyceroporins (Cr-Glp), classical aquaporin channels (Cr-Bib and Cr-PripL), and unorthodox aquaporins (Cr-Aqp12-like). In silico analysis revealed differential expression of aquaporin genes between developmental stages and between sexes. Male-biased expression of Cr-Glp1_v1 and female-biased expression of Cr-Bib were further confirmed in adults by RT-qPCR. Additionally, gene expressions were measured for seven aquaporins during the early infestation stage. The majority of aquaporin genes showed significant differential transcription expressions between sea lice parasitizing different hosts, with Atlantic salmon sea lice exhibiting overall reduced expression as compared to Coho salmon. The observed differences in the regulation of aquaporin genes may reveal osmoregulatory adaptations associated with nutrient ingestion and metabolite waste export, exposing complex host-parasite relationships in C. rogercresseyi. Copyright © 2016 Elsevier B.V. All rights reserved.

Optimization and field use of a bioassay to monitor sea lice Lepeophtheirus salmonis sensitivity to emamectin benzoate.

PubMed

Westcott, Jillian D; Stryhn, Henrik; Burka, John F; Hammell, K Larry

2008-04-01

A bioassay for sea lice Lepeophtheirus salmonis sensitivity towards emamectin benzoate (EMB) was validated for field use. A probit regression model with natural responsiveness was used for the number of affected (moribund or dead) sea lice in bioassays involving different concentrations of EMB. Bioassay optimization included an evaluation of the inter-rater reliability of sea lice responsiveness to EMB and an evaluation of gender-related differences in susceptibility. Adoption of a set of bioassay response criteria improved the concordance (evaluated using the concordance correlation coefficient) between raters' assessments and the model estimation of EC50 values (the 'effective concentration' leading to a response of 50% of the lice not prone to natural response). An evaluation of gender-related differences in EMB susceptibility indicated that preadult stage female sea lice exhibited a significantly larger sensitivity towards EMB in 12 of 19 bioassays compared to preadult males. In order to evaluate sea lice sensitivity to EMB in eastern Canada, the intensive salmon farming area in the Bay of Fundy in southwestern New Brunswick was divided into 4 distinct regions based on industry health management practices and hydrographics. A total of 38 bioassays were completed from 2002 to 2005 using populations of preadult stage sea lice collected from Atlantic salmon Salmo salar farms within the 4 described regions. There was no significant overall effect of region or year on EC50 values; however, analysis of variance indicated a significant effect of time of year on EC50 values in 2002 and a potential effect in 2004 to 2005. Although the range of EC50 values obtained in this 3 yr study did not appear sufficient to affect current clinical success in the control of sea lice, the results suggest a seasonal- or temperature-associated variation in sensitivity to EMB. This will need to be considered if changes in EMB efficacy occur in the future.

Predicting the effectiveness of depth-based technologies to prevent salmon lice infection using a dispersal model.

PubMed

Samsing, Francisca; Johnsen, Ingrid; Stien, Lars Helge; Oppedal, Frode; Albretsen, Jon; Asplin, Lars; Dempster, Tim

2016-07-01

Salmon lice is one of the major parasitic problems affecting wild and farmed salmonid species. The planktonic larval stages of these marine parasites can survive for extended periods without a host and are transported long distances by water masses. Salmon lice larvae have limited swimming capacity, but can influence their horizontal transport by vertical positioning. Here, we adapted a coupled biological-physical model to calculate the distribution of farm-produced salmon lice (Lepeophtheirus salmonis) during winter in the southwest coast of Norway. We tested 4 model simulations to see which best represented empirical data from two sources: (1) observed lice infection levels reported by farms; and (2) experimental data from a vertical exposure experiment where fish were forced to swim at different depths with a lice-barrier technology. Model simulations tested were different development time to the infective stage (35 or 50°-days), with or without the presence of temperature-controlled vertical behaviour of lice early planktonic stages (naupliar stages). The best model fit occurred with a 35°-day development time to the infective stage, and temperature-controlled vertical behaviour. We applied this model to predict the effectiveness of depth-based preventive lice-barrier technologies. Both simulated and experimental data revealed that hindering fish from swimming close to the surface efficiently reduced lice infection. Moreover, while our model simulation predicted that this preventive technology is widely applicable, its effectiveness will depend on environmental conditions. Low salinity surface waters reduce the effectiveness of this technology because salmon lice avoid these conditions, and can encounter the fish as they sink deeper in the water column. Correctly parameterized and validated salmon lice dispersal models can predict the impact of preventive approaches to control this parasite and become an essential tool in lice management strategies. Copyright

The control of sea lice in Atlantic salmon by selective breeding.

PubMed

Gharbi, Karim; Matthews, Louise; Bron, James; Roberts, Ron; Tinch, Alan; Stear, Michael

2015-09-06

Sea lice threaten the welfare of farmed Atlantic salmon and the sustainability of fish farming across the world. Chemical treatments are the major method of control but drug resistance means that alternatives are urgently needed. Selective breeding can be a cheap and effective alternative. Here, we combine experimental trials and diagnostics to provide a practical protocol for quantifying resistance to sea lice. We then combined quantitative genetics with epidemiological modelling to make the first prediction of the response to selection, quantified in terms of reduced need for chemical treatments. We infected over 1400 young fish with Lepeophtheirus salmonis, the most important species in the Northern Hemisphere. Mechanisms of resistance were expressed early in infection. Consequently, the number of lice per fish and the ranking of families were very similar at 7 and 17 days post infection, providing a stable window for assessing susceptibility to infection. The heritability of lice numbers within this time window was moderately high at 0.3, confirming that selective breeding is viable. We combined an epidemiological model of sea lice infection and control on a salmon farm with genetic variation in susceptibility among individuals. We simulated 10 generations of selective breeding and examined the frequency of treatments needed to control infection. Our model predicted that substantially fewer chemical treatments are needed to control lice outbreaks in selected populations and chemical treatment could be unnecessary after 10 generations of selection. Selective breeding for sea lice resistance should reduce the impact of sea lice on fish health and thus substantially improve the sustainability of Atlantic salmon production. © 2015 The Author(s).

Deltamethrin resistance in the sea louse Caligus rogercresseyi (Boxhall and Bravo) in Chile: bioassay results and usage data for antiparasitic agents with references to Norwegian conditions.

PubMed

Helgesen, K O; Bravo, S; Sevatdal, S; Mendoza, J; Horsberg, T E

2014-10-01

The sea louse Caligus rogercresseyi is a major threat to Chilean salmonid farming. Pyrethroids have been used for anticaligus treatments since 2007, but have shown reduced effect, most likely due to resistance development. Pyrethroid resistance is also a known problem in Lepeophtheirus salmonis in the Northern Hemisphere. This study describes the development of deltamethrin resistance in C. rogercresseyi based on bioassays and usage data for pyrethroids in Chilean aquaculture. These results were compared to bioassays from L. salmonis from Norway and to Norwegian usage data. Available deltamethrin bioassay results from 2007 and 2008, as well as bioassays from Norway, were collected and remodelled. Bioassays were performed on field-collected sea lice in region X in Chile in 2012 and 2013. Bioassays from 2007 were performed prior to the introduction of pyrethroids to the Chilean market. Both the results from 2008 and 2012 showed an increased resistance. Increased pyrethroid resistance was also indicated by the increased use of pyrethroids in Chilean aquaculture compared with the production of salmonids. A similar trend was seen in the Norwegian usage data. The bioassay results from Chile from 2012 and 2013 also indicated a difference in the susceptibility to deltamethrin between male and female caligus. © 2014 John Wiley & Sons Ltd.

[The mathematical modelling of the possible morbidity from epidemic louse-borne typhus under current conditions].

PubMed

Lukin, E P; Mikhaĭlov, V V; Oleĭchik, V L; Solodiankin, A I

1996-01-01

On the basis of their earlier formula for modeling the possible development of the epidemic process of louse-borne exanthematous typhus the authors have calculated the probability of the development of such process for high indices (10 -- 12 % of convalescents with louse contamination rate among them reaching 20 -- 40 %) characterizing this process. The number of sources of this infection (primary patients), as well as the rate of increase and scale of louse contamination of the population, are of prime importance for the prognostication of the development of the epidemic.

Treatment of Phthiriasis Palpebrarum and Crab Louse: Petrolatum Jelly and 1% Permethrin Shampoo

PubMed Central

Karabela, Yunus; Yardimci, Gurkan; Yildirim, Isik; Karabela, Semsi Nur

2015-01-01

Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area. PMID:26451147

Treatment of Phthiriasis Palpebrarum and Crab Louse: Petrolatum Jelly and 1% Permethrin Shampoo.

PubMed

Karabela, Yunus; Yardimci, Gurkan; Yildirim, Isik; Atalay, Eray; Karabela, Semsi Nur

2015-01-01

Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. A 45-year-old man presented with conjunctival hyperaemia and moderate itching associated with irritation, and crusty excretions of the eyelashes in the left eye. Careful slit-lamp examination revealed many lice and nits in left eye and mild conjunctival hyperaemia. No abnormality was found in the right eye. On dermatologic examination, only one louse was found at the pubic area. The patient was treated effectively with petrolatum jelly (Vaseline) and 1% permethrin shampoo (Kwellada 1% shampoo). At the end of the first week no louse or nit was present on eyelashes and pubic area.

The mitochondrial genome of the chimpanzee louse, Pediculus schaeffi: insights into the process of mitochondrial genome fragmentation in the blood-sucking lice of great apes.

PubMed

Herd, Kate E; Barker, Stephen C; Shao, Renfu

2015-09-03

Blood-sucking lice in the genera Pediculus and Pthirus are obligate ectoparasites of great apes. Unlike most bilateral animals, which have 37 mitochondrial (mt) genes on a single circular chromosome, the sucking lice of humans have extensively fragmented mt genomes. The head louse, Pediculus capitis, and the body louse, Pe. humanus, have their 37 mt genes on 20 minichromosomes. The pubic louse, Pthirus pubis, has its 34 mt genes known on 14 minichromosomes. To understand the process of mt genome fragmentation in the sucking lice of great apes, we sequenced the mt genome of the chimpanzee louse, Pe. schaeffi, and compared it with the three human lice. We identified all of the 37 mt genes typical of bilateral animals in the chimpanzee louse; these genes are on 18 types of minichromosomes. Seventeen of the 18 minichromosomes of the chimpanzee louse have the same gene content and gene arrangement as their counterparts in the human head louse and the human body louse. However, five genes, cob, trnS 1 , trnN, trnE and trnM, which are on three minichromosomes in the human head louse and the human body louse, are together on one minichromosome in the chimpanzee louse. Using the human pubic louse, Pt. pubis, as an outgroup for comparison, we infer that a single minichromosome has fragmented into three in the lineage leading to the human head louse and the human body louse since this lineage diverged from the chimpanzee louse ~6 million years ago. Our results provide insights into the process of mt genome fragmentation in the sucking lice in a relatively fine evolutionary scale.

Genotyping of human lice suggests multiple emergencies of body lice from local head louse populations.

PubMed

Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L; Pittendrigh, Barry; Raoult, Didier

2010-03-23

Genetic analyses of human lice have shown that the current taxonomic classification of head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus) does not reflect their phylogenetic organization. Three phylotypes of head lice A, B and C exist but body lice have been observed only in phylotype A. Head and body lice have different behaviours and only the latter have been involved in outbreaks of infectious diseases including epidemic typhus, trench fever and louse borne recurrent fever. Recent studies suggest that body lice arose several times from head louse populations. By introducing a new genotyping technique, sequencing variable intergenic spacers which were selected from louse genomic sequence, we were able to evaluate the genotypic distribution of 207 human lice. Sequence variation of two intergenic spacers, S2 and S5, discriminated the 207 lice into 148 genotypes and sequence variation of another two intergenic spacers, PM1 and PM2, discriminated 174 lice into 77 genotypes. Concatenation of the four intergenic spacers discriminated a panel of 97 lice into 96 genotypes. These intergenic spacer sequence types were relatively specific geographically, and enabled us to identify two clusters in France, one cluster in Central Africa (where a large body louse outbreak has been observed) and one cluster in Russia. Interestingly, head and body lice were not genetically differentiated. We propose a hypothesis for the emergence of body lice, and suggest that humans with both low hygiene and head louse infestations provide an opportunity for head louse variants, able to ingest a larger blood meal (a required characteristic of body lice), to colonize clothing. If this hypothesis is ultimately supported, it would help to explain why poor human hygiene often coincides with outbreaks of body lice. Additionally, if head lice act as a reservoir for body lice, and that any social degradation in human populations may allow the formation of new populations of

Genotyping of Human Lice Suggests Multiple Emergences of Body Lice from Local Head Louse Populations

PubMed Central

Li, Wenjun; Ortiz, Gabriel; Fournier, Pierre-Edouard; Gimenez, Gregory; Reed, David L.; Pittendrigh, Barry; Raoult, Didier

2010-01-01

Background Genetic analyses of human lice have shown that the current taxonomic classification of head lice (Pediculus humanus capitis) and body lice (Pediculus humanus humanus) does not reflect their phylogenetic organization. Three phylotypes of head lice A, B and C exist but body lice have been observed only in phylotype A. Head and body lice have different behaviours and only the latter have been involved in outbreaks of infectious diseases including epidemic typhus, trench fever and louse borne recurrent fever. Recent studies suggest that body lice arose several times from head louse populations. Methods and Findings By introducing a new genotyping technique, sequencing variable intergenic spacers which were selected from louse genomic sequence, we were able to evaluate the genotypic distribution of 207 human lice. Sequence variation of two intergenic spacers, S2 and S5, discriminated the 207 lice into 148 genotypes and sequence variation of another two intergenic spacers, PM1 and PM2, discriminated 174 lice into 77 genotypes. Concatenation of the four intergenic spacers discriminated a panel of 97 lice into 96 genotypes. These intergenic spacer sequence types were relatively specific geographically, and enabled us to identify two clusters in France, one cluster in Central Africa (where a large body louse outbreak has been observed) and one cluster in Russia. Interestingly, head and body lice were not genetically differentiated. Conclusions We propose a hypothesis for the emergence of body lice, and suggest that humans with both low hygiene and head louse infestations provide an opportunity for head louse variants, able to ingest a larger blood meal (a required characteristic of body lice), to colonize clothing. If this hypothesis is ultimately supported, it would help to explain why poor human hygiene often coincides with outbreaks of body lice. Additionally, if head lice act as a reservoir for body lice, and that any social degradation in human populations

Human louse-transmitted infectious diseases.

PubMed

Badiaga, S; Brouqui, P

2012-04-01

Several of the infectious diseases associated with human lice are life-threatening, including epidemic typhus, relapsing fever, and trench fever, which are caused by Rickettsia prowazekii, Borrelia recurrentis, and Bartonella quintana, respectively. Although these diseases have been known for several centuries, they remain a major public health concern in populations living in poor-hygiene conditions because of war, social disruption, severe poverty, or gaps in public health management. Poor-hygiene conditions favour a higher prevalence of body lice, which are the main vectors for these diseases. Trench fever has been reported in both developing and developed countries in populations living in poor conditions, such as homeless individuals. In contrast, outbreaks of epidemic typhus and epidemic relapsing fever have occurred in jails and refugee camps in developing countries. However, reports of a significantly high seroprevalence for epidemic typhus and epidemic relapsing fever in the homeless populations of developed countries suggest that these populations remain at high risk for outbreaks of these diseases. Additionally, experimental laboratory studies have demonstrated that the body louse can transmit other emerging or re-emerging pathogens, such as Acinetobacter baumannii and Yersinia pestis. Therefore, a strict survey of louse-borne diseases and the implementation of efficient delousing strategies in these populations should be public health priorities. © 2012 The Authors. Clinical Microbiology and Infection © 2012 European Society of Clinical Microbiology and Infectious Diseases.

Field efficacy of eprinomectin against the sucking louse Haematopinus asini on naturally infested donkeys.

PubMed

Veneziano, Vincenzo; Galietti, Alfredo; Mariani, Ugo; Di Loria, Antonio; Piantedosi, Diego; Neola, Benedetto; Guccione, Jacopo; Gokbulut, Cengiz

2013-08-01

A trial was conducted to assess the efficacy of eprinomectin (EPR) against the sucking louse Haematopinus asini on naturally infested donkeys. Parasitological investigations were performed on fifteen animals. On day 0, donkeys received EPR pour-on at the manufacturer's recommended cattle dose. Louse counts were performed on days -1, 7, 14, 21, 28, 35, 42, 49 and 56 at seven predilection sites on the skin of each donkey. EPR was completely effective (100%) from day 7, until the end of the study. Clinically no adverse reactions were observed in any of donkeys treated. EPR was considered to be 100% effective against H. asini. This is the first trial to evaluate the efficacy of EPR against a natural louse infestation in donkeys. Copyright © 2013 Elsevier Ltd. All rights reserved.

Using observed load distributions with a simple model to analyse the epidemiology of sea lice (Lepeophtheirus salmonis) on sea trout (Salmo trutta).

PubMed

Murray, Alexander G

2002-06-01

Sea lice are ectoparasites of salmonids that have been associated with the recent decline in sea trout numbers in north-west Europe. Observed patterns of louse load distribution between sea trout in the seas surrounding the UK, Ireland and Norway and a simple model have been used to analyse the epidemiology of lice. Loads are aggregated and deviate strongly from the Poisson distribution, although less than is observed with many other parasites. The louse numbers on fish from offshore sites are slightly less variable than for fish from coastal sites with comparable mean loads. Analysis of louse development stages and sexes shows that selection between hosts by sea lice plays a limited role. If host selection is absent, then associated poor condition would be caused by, not the cause of, high louse burdens; however the absence of such selection is not proved. Scenarios with infection that is patchy in space and time best generate the aggregated load patterns observed; these patches accord with observed swarms of copepodids. Prevalence patterns may indicate the movement of trout between environments. Control of copepodids in infection 'hot spots', either directly or through control of louse egg production in their catchment, may reduce louse loads on wild sea trout and, in particular, extreme and damaging loads.

Disease Resistance in Atlantic Salmon (Salmo salar): Coinfection of the Intracellular Bacterial Pathogen Piscirickettsia salmonis and the Sea Louse Caligus rogercresseyi

PubMed Central

Lhorente, Jean Paul; Gallardo, José A.; Villanueva, Beatriz; Carabaño, María J.; Neira, Roberto

2014-01-01

Background Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1) coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2) coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. Methodology In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI) of P. salmonis (primary pathogen) or coinfection with C. rogercresseyi (secondary pathogen). Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish). Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. Main Findings C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545). Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h 2 SI = 0.23±0.07; h 2 LC = 0.17±0.08; h 2 HC = 0.24±0.07). A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99±0.01) but not between the single and coinfection treatments (rg SI-LC = −0.14±0.33; rg SI-HC = 0.32±0.34). Conclusions/Significance C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future research on

Disease resistance in Atlantic salmon (Salmo salar): coinfection of the intracellular bacterial pathogen Piscirickettsia salmonis and the sea louse Caligus rogercresseyi.

PubMed

Lhorente, Jean Paul; Gallardo, José A; Villanueva, Beatriz; Carabaño, María J; Neira, Roberto

2014-01-01

Naturally occurring coinfections of pathogens have been reported in salmonids, but their consequences on disease resistance are unclear. We hypothesized that 1) coinfection of Caligus rogercresseyi reduces the resistance of Atlantic salmon to Piscirickettsia salmonis; and 2) coinfection resistance is a heritable trait that does not correlate with resistance to a single infection. In total, 1,634 pedigreed Atlantic salmon were exposed to a single infection (SI) of P. salmonis (primary pathogen) or coinfection with C. rogercresseyi (secondary pathogen). Low and high level of coinfection were evaluated (LC = 44 copepodites per fish; HC = 88 copepodites per fish). Survival and quantitative genetic analyses were performed to determine the resistance to the single infection and coinfections. C. rogercresseyi significantly increased the mortality in fish infected with P. salmonis (SI mortality = 251/545; LC mortality = 544/544 and HC mortality = 545/545). Heritability estimates for resistance to P. salmonis were similar and of medium magnitude in all treatments (h2SI = 0.23 ± 0.07; h2LC = 0.17 ± 0.08; h2HC = 0.24 ± 0.07). A large and significant genetic correlation with regard to resistance was observed between coinfection treatments (rg LC-HC = 0.99 ± 0.01) but not between the single and coinfection treatments (rg SI-LC = -0.14 ± 0.33; rg SI-HC = 0.32 ± 0.34). C. rogercresseyi, as a secondary pathogen, reduces the resistance of Atlantic salmon to the pathogen P. salmonis. Resistance to coinfection of Piscirickettsia salmonis and Caligus rogercresseyi in Atlantic salmon is a heritable trait. The absence of a genetic correlation between resistance to a single infection and resistance to coinfection indicates that different genes control these processes. Coinfection of different pathogens and resistance to coinfection needs to be considered in future research on salmon farming, selective breeding and conservation.

Seasonal dynamics and variation among sheep in densities of the sheep biting louse, Bovicola ovis.

PubMed

James, P J; Moon, R D; Brown, D R

1998-02-01

Cyclic patterns and variations among sheep in numbers of Bovicola ovis are described in Polypay and Columbia ewes that were initially infested with equal numbers of lice and penned indoors continuously for 2 years. Bovicola ovis populations were censused at 3-4-week intervals at 69 body sites on each animal. In the second year of the study, the ewes were reinfested and half were mated. Louse populations were monitored on the resulting lambs from birth until 25 weeks of age. Strong seasonal cycles in louse numbers were observed on the ewes, with peaks in spring and troughs in summer. These cycles occurred in the absence of shearing, direct solar radiation or rainfall. Populations began to decline when daily mean and maximum temperatures were 11.5 degrees C and 15 degrees C, respectively, well below temperatures thought to cause warm season decline. Louse densities on Polypay ewes were approximately 10 times higher than on Columbias at most inspections. There were also large differences among sheep within breeds and sheep counts were highly correlated among dates, both within and between years. One third of the ewes failed to become infested despite having lice applied on five separate occasions and being penned together with other infested sheep. Pregnancy and lactation did not significantly affect louse numbers on the ewes. There was a significant negative correlation between louse counts and weight gains in the lambs, and lamb counts were significantly correlated with those of their dams up until, but not after, weaning. It is suggested that sheep may exert regulatory influences on lice which contribute to cycles in B. ovis populations.

Host specificity and genealogy of the louse Polyplax serrata on field mice, Apodemus species: a case of parasite duplication or colonisation?

PubMed

Stefka, Jan; Hypsa, Václav

2008-05-01

The genealogy, population structure and population dynamics of the sucking louse Polyplax serrata were analysed across four host species of the genus Apodemus. An analysis of 126 sequences of cytochrome c oxidase subunit I using phylogenetic approaches and haplotype networking revealed a clear structure of European samples, forming three distinct and genetically distant clades with different host specificities. Although a clear connection was detected between the host and parasite genealogies/phylogenies, a uniform pattern of co-speciation was not found. For example, a dramatic shift in the degree of host specificity was demonstrated for two related louse lineages living in sympatry and sharing one of their host species. While one of the louse lineages frequently parasitised two different host taxa (Apodemus sylvaticus and Apodemus flavicollis), the other louse lineage was strictly specific to A. flavicollis. The estimate of divergence time between the two louse lineages indicates that they may have arisen due to parasite duplication on A. flavicollis.

Comparative analysis of long non-coding RNAs in Atlantic and Coho salmon reveals divergent transcriptome responses associated with immunity and tissue repair during sea lice infestation.

PubMed

Valenzuela-Muñoz, Valentina; Valenzuela-Miranda, Diego; Gallardo-Escárate, Cristian

2018-05-24

The increasing capacity of transcriptomic analysis by high throughput sequencing has highlighted the presence of a large proportion of transcripts that do not encode proteins. In particular, long non-coding RNAs (lncRNAs) are sequences with low coding potential and conservation among species. Moreover, cumulative evidence has revealed important roles in post-transcriptional gene modulation in several taxa. In fish, the role of lncRNAs has been scarcely studied and even less so during the immune response against sea lice. In the present study we mined for lncRNAs in Atlantic salmon (Salmo salar) and Coho salmon (Oncorhynkus kisutch), which are affected by the sea louse Caligus rogercresseyi, evaluating the degree of sequence conservation between these two fish species and their putative roles during the infection process. Herein, Atlantic and Coho salmon were infected with 35 lice/fish and evaluated after 7 and 14 days post-infestation (dpi). For RNA sequencing, samples from skin and head kidney were collected. A total of 5658/4140 and 3678/2123 lncRNAs were identified in uninfected/infected Atlantic and Coho salmon transcriptomes, respectively. Species-specific transcription patterns were observed in exclusive lncRNAs according to the tissue analyzed. Furthermore, neighbor gene GO enrichment analysis of the top 100 highly regulated lncRNAs in Atlantic salmon showed that lncRNAs were localized near genes related to the immune response. On the other hand, in Coho salmon the highly regulated lncRNAs were localized near genes involved in tissue repair processes. This study revealed high regulation of lncRNAs closely localized to immune and tissue repair-related genes in Atlantic and Coho salmon, respectively, suggesting putative roles for lncRNAs in salmon against sea lice infestation. Copyright © 2018 Elsevier Ltd. All rights reserved.

Origin, acquisition and diversification of heritable bacterial endosymbionts in louse flies and bat flies.

PubMed

Duron, Olivier; Schneppat, Ulrich E; Berthomieu, Arnaud; Goodman, Steven M; Droz, Boris; Paupy, Christophe; Nkoghe, Judicaël Obame; Rahola, Nil; Tortosa, Pablo

2014-04-01

The γ-proteobacterium Arsenophonus and its close relatives (Arsenophonus and like organisms, ALOs) are emerging as a novel clade of endosymbionts, which are exceptionally widespread in insects. The biology of ALOs is, however, in most cases entirely unknown, and it is unclear how these endosymbionts spread across insect populations. Here, we investigate this aspect through the examination of the presence, the diversity and the evolutionary history of ALOs in 25 related species of blood-feeding flies: tsetse flies (Glossinidae), louse flies (Hippoboscidae) and bat flies (Nycteribiidae and Streblidae). While these endosymbionts were not found in tsetse flies, we identify louse flies and bat flies as harbouring the highest diversity of ALO strains reported to date, including a novel ALO clade, as well as Arsenophonus and the recently described Candidatus Aschnera chinzeii. We further show that the origin of ALO endosymbioses extends deep into the evolutionary past of louse flies and bat flies, and that it probably played a major role in the ecological specialization of their hosts. The evolutionary history of ALOs is notably complex and was shaped by both vertical transmission and horizontal transfers with frequent host turnover and apparent symbiont replacement in host lineages. In particular, ALOs have evolved repeatedly and independently close relationships with diverse groups of louse flies and bat flies, as well as phylogenetically more distant insect families, suggesting that ALO endosymbioses are exceptionally dynamic systems. © 2014 John Wiley & Sons Ltd.

THE EXPERIMENTAL INFECTION OF THE HUMAN BODY LOUSE, PEDICULUS HUMANUS CORPORIS, WITH MURINE AND EPIDEMIC LOUSE-BORNE TYPHUS STRAINS

PubMed Central

Snyder, J. C.; Wheeler, C. M.

1945-01-01

Experiments are described which demonstrate that human body lice (Pediculus humanus corporis), were infected experimentally with murine and epidemic louse-borne strains of typhus fever by feeding on suitably prepared rabbits. Details of the two methods of infection, the "bleb technique" and the "I.V. technique," are presented. It is concluded that the experimental infection of human lice with typhus can be accomplished very easily and rapidly with these methods. The possible applications of the method are discussed. PMID:19871482

Efficacy of the LouseBuster, a new medical device for treating head lice (Anoplura:Pediculidae).

PubMed

Bush, Sarah E; Rock, Alex N; Jones, Sherri L; Malenke, Jael R; Clayton, Dale H

2011-01-01

Human head lice (Pediculus humanus capitis De Geer) occur worldwide and infest millions of children and adults every year. Head lice infestations, which are known as pediculosis capitis, are psychologically stressful, physically irritating, and are one of the leading causes of K-6 school absence. The prevalence of head lice in many countries is increasing rapidly because of resistance to chemicals used in many head lice treatments. We tested the efficacy of an alternative method for controlling head lice, the LouseBuster, a custom-built medical device designed to kill head lice and their eggs using controlled, heated air. A total of 56 infested subjects was treated with the LouseBuster, and the efficacy of the treatment was evaluated by comparing the viability of lice and eggs on randomly assigned pre- and posttreatment sides of each subject's scalp. We evaluate treatment efficacy in the hands of novice versus experienced operators. We also evaluate treatment efficacy on different hair types and at different ambient humidities. Overall mortality of lice and eggs was 94.8% after treatment by experienced operators. Novice operators also achieved good results after a short training session; their results did not differ significantly from those of experienced operators. No adverse events were associated with the LouseBuster treatment. The LouseBuster is efficacious for killing head lice and their eggs. The use of heated air is appealing because it is a fast, safe, nonchemical treatment. Head lice are also unlikely to evolve resistance to desiccation, which is the apparent mode of action.

Treatment of head louse infestation with 4% dimeticone lotion: randomised controlled equivalence trial

PubMed Central

Burgess, Ian F; Brown, Christine M; Lee, Peter N

2005-01-01

Objective To evaluate the efficacy and safety of 4% dimeticone lotion for treatment of head louse infestation. Design Randomised controlled equivalence trial. Setting Community, with home visits. Participants 214 young people aged 4 to 18 years and 39 adults with active head louse infestation. Interventions Two applications seven days apart of either 4.0% dimeticone lotion, applied for eight hours or overnight, or 0.5% phenothrin liquid, applied for 12 hours or overnight. Outcome measures Cure of infestation (no evidence of head lice after second treatment) or reinfestation after cure. Results Cure or reinfestation after cure occurred in 89 of 127 (70%) participants treated with dimeticone and 94 of 125 (75%) treated with phenothrin (difference -5%, 95% confidence interval -16% to 6%). Per protocol analysis showed that 84 of 121 (69%) participants were cured with dimeticone and 90 of 116 (78%) were cured with phenothrin. Irritant reactions occurred significantly less with dimeticone (3/127, 2%) than with phenothrin (11/125, 9%; difference -6%, -12% to -1%). Per protocol this was 3 of 121 (3%) participants treated with dimeticone and 10 of 116 (9%) treated with phenothrin (difference -6%, -12% to -0.3%). Conclusion Dimeticone lotion cures head louse infestation. Dimeticone seems less irritant than existing treatments and has a physical action on lice that should not be affected by resistance to neurotoxic insecticides. PMID:15951310

Pyrethroid resistance in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis.

PubMed

Levot, G W; Johnson, P W; Hughes, P B; Powis, K J; Boray, J C; Dawson, K L

1995-01-01

Synthetic pyrethroid (SP) resistance has developed in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis. Laboratory bioassays were used to measure the susceptibility of lice to cypermethrin and the other registered SPs. Results of these bioassays indicated resistance to cypermethrin, deltamethrin, cyhalothrin and alphacypermethrin. So far, high-level resistance has been diagnosed in only a few strains. The toxicological responses of these strains were clearly separated from those of the majority of louse strains tested. Furthermore, these strains had survived immersion in commercial SP dips. The level of resistance described in some strains was sufficient to cause pour-on products to fail despite the fact that the LC50s of these strains fell within the normal range of field responses.

PACIFIC SALMON: LESSONS LEARNED FOR RECOVERING ATLANTIC SALMON

EPA Science Inventory

n evaluation of the history of efforts to reverse the long-term decline of Pacific Salmon provides instructive policy lessons for recovering Atlantic Salmon. From California to southern British Columbia, wild runs of Pacific salmon have universally declined and many have disappe...

Poached Salmon

MedlinePlus

... page: https://medlineplus.gov/recipe/poachedsalmon.html Poached Salmon To use the sharing features on this page, ... olive oil Ground black pepper, to taste For salmon: 4 salmon steaks, 5 oz each 3 cups ...

Relationship of farm salmon, sea lice, and wild salmon populations.

PubMed

Marty, Gary D; Saksida, Sonja M; Quinn, Terrance J

2010-12-28

Increased farm salmon production has heightened concerns about the association between disease on farm and wild fish. The controversy is particularly evident in the Broughton Archipelago of Western Canada, where a high prevalence of sea lice (ectoparasitic copepods) was first reported on juvenile wild pink salmon (Oncorhynchus gorbuscha) in 2001. Exposure to sea lice from farmed Atlantic salmon (Salmo salar) was thought to be the cause of the 97% population decline before these fish returned to spawn in 2002, although no diagnostic investigation was done to rule out other causes of mortality. To address the concern that sea lice from fish farms would cause population extinction of wild salmon, we analyzed 10-20 y of fish farm data and 60 y of pink salmon data. We show that the number of pink salmon returning to spawn in the fall predicts the number of female sea lice on farm fish the next spring, which, in turn, accounts for 98% of the annual variability in the prevalence of sea lice on outmigrating wild juvenile salmon. However, productivity of wild salmon is not negatively associated with either farm lice numbers or farm fish production, and all published field and laboratory data support the conclusion that something other than sea lice caused the population decline in 2002. We conclude that separating farm salmon from wild salmon--proposed through coordinated fallowing or closed containment--will not increase wild salmon productivity and that medical analysis can improve our understanding of complex issues related to aquaculture sustainability.

Bio-Ecology of the Louse, Upupicola upupae, Infesting the Common Hoopoe, Upupa epops

PubMed Central

Agarwal, G. P; Ahmad, Aftab; Rashmi, Archna; Arya, Gaurav; Bansal, Nayanci; Saxena, A.K.

2011-01-01

The population characteristics of the louse, Upupicola upupae (Shrank) (Mallophaga: Philopteridae: Ishnocera), infesting the Common Hoopae, Upupa epops L. (Aves: Upupiformes), were recorded during 2007–08 in District Rampur, Uttar Pradesh India. The pattern of frequency distribution of the louse conformed to the negative binomial model. The lice and its nits were reared in vitro at 35 ± 1° C, 75–82 % RH, on a feather diet. The data obtained was used to construct the life table and to determine the intrinsic rate of natural increase (0.035 female/day), the net reproductive rate was 3.67 female eggs/female, the generation time was 37 days, and the doubling time of the population was 19 days. The chaetotaxy of the three nymphal instars has also been noted to record their diagnostic characteristics. Information on egg morphology and antennal sensilla is also presented. PMID:21861650

Relationship of farm salmon, sea lice, and wild salmon populations

PubMed Central

Marty, Gary D.; Saksida, Sonja M.; Quinn, Terrance J.

2010-01-01

Increased farm salmon production has heightened concerns about the association between disease on farm and wild fish. The controversy is particularly evident in the Broughton Archipelago of Western Canada, where a high prevalence of sea lice (ectoparasitic copepods) was first reported on juvenile wild pink salmon (Oncorhynchus gorbuscha) in 2001. Exposure to sea lice from farmed Atlantic salmon (Salmo salar) was thought to be the cause of the 97% population decline before these fish returned to spawn in 2002, although no diagnostic investigation was done to rule out other causes of mortality. To address the concern that sea lice from fish farms would cause population extinction of wild salmon, we analyzed 10–20 y of fish farm data and 60 y of pink salmon data. We show that the number of pink salmon returning to spawn in the fall predicts the number of female sea lice on farm fish the next spring, which, in turn, accounts for 98% of the annual variability in the prevalence of sea lice on outmigrating wild juvenile salmon. However, productivity of wild salmon is not negatively associated with either farm lice numbers or farm fish production, and all published field and laboratory data support the conclusion that something other than sea lice caused the population decline in 2002. We conclude that separating farm salmon from wild salmon—proposed through coordinated fallowing or closed containment—will not increase wild salmon productivity and that medical analysis can improve our understanding of complex issues related to aquaculture sustainability. PMID:21149706

Identification and Functional Expression of a Glutamate- and Avermectin-Gated Chloride Channel from Caligus rogercresseyi, a Southern Hemisphere Sea Louse Affecting Farmed Fish

PubMed Central

Niemeyer, María Isabel; Marabolí, Vanessa; González-Nilo, F. Danilo; Teulon, Jacques; Sepúlveda, Francisco V.; Cid, L. Pablo

2014-01-01

Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC50 value of around 200 nM, being cooperative (nH = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient

Identification and functional expression of a glutamate- and avermectin-gated chloride channel from Caligus rogercresseyi, a southern Hemisphere sea louse affecting farmed fish.

PubMed

Cornejo, Isabel; Andrini, Olga; Niemeyer, María Isabel; Marabolí, Vanessa; González-Nilo, F Danilo; Teulon, Jacques; Sepúlveda, Francisco V; Cid, L Pablo

2014-09-01

Parasitic sea lice represent a major sanitary threat to marine salmonid aquaculture, an industry accounting for 7% of world fish production. Caligus rogercresseyi is the principal sea louse species infesting farmed salmon and trout in the southern hemisphere. Most effective control of Caligus has been obtained with macrocyclic lactones (MLs) ivermectin and emamectin. These drugs target glutamate-gated chloride channels (GluCl) and act as irreversible non-competitive agonists causing neuronal inhibition, paralysis and death of the parasite. Here we report the cloning of a full-length CrGluClα receptor from Caligus rogercresseyi. Expression in Xenopus oocytes and electrophysiological assays show that CrGluClα is activated by glutamate and mediates chloride currents blocked by the ligand-gated anion channel inhibitor picrotoxin. Both ivermectin and emamectin activate CrGluClα in the absence of glutamate. The effects are irreversible and occur with an EC(50) value of around 200 nM, being cooperative (n(H) = 2) for ivermectin but not for emamectin. Using the three-dimensional structure of a GluClα from Caenorabditis elegans, the only available for any eukaryotic ligand-gated anion channel, we have constructed a homology model for CrGluClα. Docking and molecular dynamics calculations reveal the way in which ivermectin and emamectin interact with CrGluClα. Both drugs intercalate between transmembrane domains M1 and M3 of neighbouring subunits of a pentameric structure. The structure displays three H-bonds involved in this interaction, but despite similarity in structure only of two these are conserved from the C. elegans crystal binding site. Our data strongly suggest that CrGluClα is an important target for avermectins used in the treatment of sea louse infestation in farmed salmonids and open the way for ascertaining a possible mechanism of increasing resistance to MLs in aquaculture industry. Molecular modeling could help in the design of new, more efficient

Relative resistance of Pacific salmon to infectious salmon anaemia virus

USGS Publications Warehouse

Rolland, J.B.; Winton, J.R.

2003-01-01

Infectious salmon anaemia (ISA) is a major disease of Atlantic salmon, Salmo salar, caused by an orthomyxovirus (ISAV). Increases in global aqua culture and the international movement of fish made it important to determine if Pacific salmon are at risk. Steelhead trout, Oncorhynchus mykiss, and chum, O. keta, Chinook, O. tshawytscha, coho, O. kisutch, and Atlantic salmon were injected intraperitoneally with a high, medium, or low dose of a Norwegian strain of ISAV. In a second challenge, the same species, except chum salmon, were injected with a high dose of either a Canadian or the Norwegian strain. Average cumulative mortality of Atlantic salmon in trial 1 was 12% in the high dose group, 20% in the medium dose group and 16% in the low dose group. The average cumulative mortality of Atlantic salmon in trial 2 was 98%. No signs typical of ISA and no ISAV-related mortality occurred among any of the groups of Oncorhynchus spp. in either experiment, although ISAV was reisolated from some fish sampled at intervals post-challenge. The results indicate that while Oncorhynchus spp. are quite resistant to ISAV relative to Atlantic salmon, the potential for ISAV to adapt to Oncorhynchus spp. should not be ignored.

An experimental model of human body louse infection with Rickettsia typhi.

PubMed

Houhamdi, Linda; Fournier, Pierre-Edouard; Fang, Rong; Raoult, Didier

2003-06-01

Murine (endemic) typhus caused by Rickettsia typhi, one of the most widely distributed arthropod-borne diseases, is transmitted to humans mainly by the oriental rat flea. The human body louse, Pediculus humanus corporis, has been suspected to have a role in the transmission of R. typhi to humans. To evaluate the potential role of Pediculus humanus corporis as a vector of murine typhus, we used R. typhi in an experimental model of human body louse infection previously used with R. prowazekii. A rabbit was made bacteremic by inoculating it with 2 x 10(6) plaque-forming units of R. typhi; it remained bacteremic for at least 59 hours. Two hundred body lice infected by feeding on the bacteremic rabbit were compared to 200 uninfected control lice. Each louse population was fed once a day on the abdomen of a seronegative rabbit. On day 8 post-infection, as a result of disruption of the gut cells and leakage of the blood meal into the hemolymph, four infected lice became bright red and died within four hours. The life span of infected lice was 20 days less than that of the controls. Infected lice did not transmit R. typhi to their progeny (eggs and larvae) as demonstrated by PCR amplification and cell culture. With an immunofluorescence assay, R. typhi was detected in feces from day 7 post-infection, and the organism remained viable in feces for up to 80 days as demonstrated by cell culture. From the 21st day post-infection, the rabbit used to feed the R. typhi-infected lice developed an immunoglobulin response with a titer of 1:50 increasing to 1:200 at the 42nd day post-infection. It showed no clinical signs of infection. The rabbit that was used to feed uninfected lice remained seronegative. Although body lice are not clearly identified vectors of R. typhi, it seems that under certain circumstances they could transmit R. typhi.

Transcriptome identification of putative genes involved in protein catabolism and innate immune response in human body louse (Pediculicidae: Pediculus humanus).

PubMed

Pedra, Joao H F; Brandt, Amanda; Li, Hong-Mei; Westerman, Rick; Romero-Severson, Jeanne; Pollack, Richard J; Murdock, Larry L; Pittendrigh, Barry R

2003-11-01

Genomics information relating to human body lice is surprisingly scarce, and this has constrained studies of their physiology, immunology and vector biology. To identify novel body louse genes, we used engorged adult lice to generate a cDNA library. Initially, 1152 clones were screened for inserts, edited for removal of vector sequences and base pairs of poor quality, and viewed for splicing variations, gene families and polymorphism. Computational methods identified 506 inferred open reading frames including the first predicted louse defensin. The inferred defensin aligns well with other insect defensins and has highly conserved cysteine residues, as are known for other defensin sequences. Two cysteine and five serine proteinases were categorized according to their inferred catalytic sites. We also discovered seven putative ubiquitin-pathway genes and four iron metabolizing deduced enzymes. Finally, glutathione-S-transferases and cytochrome P450 genes were among the detoxification enzymes found. Results from this first systematic effort to discover human body louse genes should promote further studies in Phthiraptera and lice.

Coinfection takes its toll: Sea lice override the protective effects of vaccination against a bacterial pathogen in Atlantic salmon.

PubMed

Figueroa, Carolina; Bustos, Paulina; Torrealba, Débora; Dixon, Brian; Soto, Carlos; Conejeros, Pablo; Gallardo, José A

2017-12-19

Vaccination is considered crucial for disease prevention and fish health in the global salmon farming industry. Nevertheless, some aspects, such as the efficacy of vaccines, can be largely circumvented during natural coinfections. Sea lice are ectoparasitic copepods that can occur with a high prevalence in the field, are frequently found in co-infection with other pathogens, and are highly detrimental to fish health. The aim of this case-control study was to evaluate the interaction between the detrimental effects of coinfection and the protective effects of vaccination in fish. We used the interaction between the sea louse Caligus rogercresseyi, the bacterial pathogen Piscirickettsia salmonis, and their host, the Atlantic salmon Salmo salar, as a study model. Our results showed that coinfection decreased the accumulated survival (AS) and specific growth rate (SGR) of vaccinated fish (AS = 5.2 ± 0.6%; SGR = -0.05 ± 0.39%) compared to a single infection of P. salmonis (AS = 42.7 ± 1.3%; SGR = 0.21 ± 0.22%). Concomitantly, the bacterial load and clinical signs of disease were significantly increased in coinfected fish. Coinfection may explain the reduced efficacy of vaccines in sea cages and highlights the need to test fish vaccines in more diverse conditions rather than with a single infection.

Evidence for louse-transmitted diseases in soldiers of Napoleon's Grand Army in Vilnius.

PubMed

Raoult, Didier; Dutour, Olivier; Houhamdi, Linda; Jankauskas, Rimantas; Fournier, Pierre-Edouard; Ardagna, Yann; Drancourt, Michel; Signoli, Michel; La, Vu Dang; Macia, Yves; Aboudharam, Gerard

2006-01-01

Many soldiers in Napoleon's Grand Army died of infectious diseases during its retreat from Russia. Because soldiers were commonly infested with body lice, it has been speculated that louse-borne infectious diseases, such as epidemic typhus (caused by Rickettsia prowazekii), were common. We investigated this possibility during recent excavations of a mass grave of Napoleon's soldiers in Vilnius, Lithuania. Segments of 5 body lice, identified morphologically and by polymerase chain reaction (PCR) amplification and sequencing, were found in earth from the grave that also contained fragments of soldiers' uniforms. DNA of Bartonella quintana (the agent of trench fever) was identified by PCR and sequencing in 3 of the lice. Similarly, PCR and sequencing of dental pulp from the remains of 35 soldiers revealed DNA of B. quintana in 7 soldiers and DNA of R. prowazekii in 3 other soldiers. Our results show that louse-borne infectious diseases affected nearly one-third of Napoleon's soldiers buried in Vilnius and indicate that these diseases might have been a major factor in the French retreat from Russia.

Serodiagnosis of Louse-Borne Relapsing Fever with Glycerophosphodiester Phosphodiesterase (GlpQ) from Borrelia recurrentis

PubMed Central

Porcella, Stephen F.; Raffel, Sandra J.; Schrumpf, Merry E.; Schriefer, Martin E.; Dennis, David T.; Schwan, Tom G.

2000-01-01

Human louse-borne relapsing fever occurs in sporadic outbreaks in central and eastern Africa that are characterized by significant morbidity and mortality. Isolates of the causative agent, Borrelia recurrentis, were obtained from the blood of four patients during a recent epidemic of the disease in southern Sudan. The glpQ gene, encoding glycerophosphodiester phosphodiesterase, from these isolates was sequenced and compared with the glpQ sequences obtained from other relapsing-fever spirochetes. Previously we showed that GlpQ of Borrelia hermsii is an immunogenic protein with utility as a serological test antigen for discriminating tick-borne relapsing fever from Lyme disease. In the present work, we cloned and expressed the glpQ gene from B. recurrentis and used recombinant GlpQ in serological tests. Acute- and convalescent-phase serum samples obtained from 42 patients with louse-borne relapsing fever were tested with an indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) that used whole cells of B. recurrentis and with immunoblotting to whole-cell lysates of the spirochete and Escherichia coli producing recombinant GlpQ. The geometric mean titers of the acute- and convalescent-phase serum samples measured by IFA were 1:83 and 1:575, respectively. The immunoblot analysis identified a high level of reactivity and seroconversion to GlpQ, and the assay was more sensitive than the whole-cell IFA and ELISA using purified, recombinant histidine-tagged GlpQ. Serum antibodies to GlpQ and other antigens persisted for 27 years in one patient. We conclude that assessment of anti-GlpQ antibodies will allow serological confirmation of louse-borne relapsing fever and determination of disease prevalence. PMID:11015364

Comment on "Declining wild salmon populations in relation to parasites from farm salmon".

PubMed

Riddell, Brian E; Beamish, Richard J; Richards, Laura J; Candy, John R

2008-12-19

Krkosek et al. (Reports, 14 December 2007, p. 1772) claimed that sea lice spread from salmon farms placed wild pink salmon populations "on a trajectory toward rapid local extinction." Their prediction is inconsistent with observed pink salmon returns and overstates the risks from sea lice and salmon farming.

The Mitochondrial Genome of the Guanaco Louse, Microthoracius praelongiceps: Insights into the Ancestral Mitochondrial Karyotype of Sucking Lice (Anoplura, Insecta)

PubMed Central

Li, Hu; Barker, Stephen C.

2017-01-01

Fragmented mitochondrial (mt) genomes have been reported in 11 species of sucking lice (suborder Anoplura) that infest humans, chimpanzees, pigs, horses, and rodents. There is substantial variation among these lice in mt karyotype: the number of minichromosomes of a species ranges from 9 to 20; the number of genes in a minichromosome ranges from 1 to 8; gene arrangement in a minichromosome differs between species, even in the same genus. We sequenced the mt genome of the guanaco louse, Microthoracius praelongiceps, to help establish the ancestral mt karyotype for sucking lice and understand how fragmented mt genomes evolved. The guanaco louse has 12 mt minichromosomes; each minichromosome has 2–5 genes and a non-coding region. The guanaco louse shares many features with rodent lice in mt karyotype, more than with other sucking lice. The guanaco louse, however, is more closely related phylogenetically to human lice, chimpanzee lice, pig lice, and horse lice than to rodent lice. By parsimony analysis of shared features in mt karyotype, we infer that the most recent common ancestor of sucking lice, which lived ∼75 Ma, had 11 minichromosomes; each minichromosome had 1–6 genes and a non-coding region. As sucking lice diverged, split of mt minichromosomes occurred many times in the lineages leading to the lice of humans, chimpanzees, and rodents whereas merger of minichromosomes occurred in the lineage leading to the lice of pigs and horses. Together, splits and mergers of minichromosomes created a very complex and dynamic mt genome organization in the sucking lice. PMID:28164215

The single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus.

PubMed

Shao, Renfu; Kirkness, Ewen F; Barker, Stephen C

2009-05-01

The mitochondrial (mt) genomes of animals typically consist of a single circular chromosome that is approximately 16-kb long and has 37 genes. Our analyses of the sequence reads from the Human Body Louse Genome Project and the patterns of gel electrophoresis and Southern hybridization revealed a novel type of mt genome in the sucking louse, Pediculus humanus. Instead of having all mt genes on a single chromosome, the 37 mt genes of this louse are on 18 minicircular chromosomes. Each minicircular chromosome is 3-4 kb long and has one to three genes. Minicircular mt chromosomes are also present in the four other species of sucking lice that we investigated, but not in chewing lice nor in the Psocoptera, to which sucking lice are most closely related. We also report unequivocal evidence for recombination between minicircular mt chromosomes in P. humanus and for sequence variation in mt genes generated by recombination. The advantages of a fragmented mt genome, if any, are currently unknown. Fragmentation of mt genome, however, has coevolved with blood feeding in the sucking lice. It will be of interest to explore whether or not life history features are associated with the evolution of fragmented chromosomes.

SALMON 2100 PROJECT: LIKELY SCENARIOS FOR WILD SALMON

EPA Science Inventory

The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and British Columbia. The Project does not support o...

Salmon habitat assessment for conservation planning in the lower White Salmon River, Washington

USGS Publications Warehouse

Hardiman, Jill M.; Allen, M. Brady

2015-01-01

In 2011, Condit Dam was removed from the White Salmon River, Washington. Since dam removal, there has been interest among scientists (State and Federal), Tribes, non-profit organizations, and the general public in assessing Pacific salmon habitat and use in the White Salmon River for conservation planning and potential fishery management actions. The study area extended from the lower 6 miles of the White Salmon River to the confluence with the Columbia River, including the former reservoir area. The Mid-Columbia Fisheries Enhancement Group received a grant to initiate efforts to plan for salmon habitat protection in the lower 6 river miles of the White Salmon River. As part of efforts by the Mid-Columbia Fisheries Enhancement Group to conduct conservation planning, the U.S. Geological Survey (USGS) used current and historical habitat information to assist in the planning process. The USGS compiled existing georeferenced habitat data into a Geographic Information System to identify areas of high quality habitat for salmon, potential areas for restoration/improvement, and areas that could be threatened. The primary sources of georeferenced data for this project include a lidar flight contracted by PacifiCorp, bathymetry from USGS, and fall Chinook salmon redd surveys from the U.S. Fish and Wildlife Service and Washington Department of Fish and Wildlife. Redd observations provided support that the study area is a migratory corridor for salmon and steelhead and that the lowest 2–3 miles had the highest concentration of documented fall Chinook salmon redds. The study area has potential for restoration/conservation areas to improve/conserve salmon habitat.

Discovering Alaska's Salmon: A Children's Activity Book.

ERIC Educational Resources Information Center

Devaney, Laurel

This children's activity book helps students discover Alaska's salmon. Information is provided about salmon and where they live. The salmon life cycle and food chains are also discussed. Different kinds of salmon such as Chum Salmon, Chinook Salmon, Coho Salmon, Sockeye Salmon, and Pink Salmon are introduced, and various activities on salmon are…

Evidence for competition at sea between Norton Sound chum salmon and Asian hatchery chum salmon

USGS Publications Warehouse

Ruggerone, Gregory T.; Agler, B.A.; Nielsen, Jennifer L.

2012-01-01

Increasing production of hatchery salmon over the past four decades has led to concerns about possible density-dependent effects on wild Pacific salmon populations in the North Pacific Ocean. The concern arises because salmon from distant regions overlap in the ocean, and wild salmon populations having low productivity may compete for food with abundant hatchery populations. We tested the hypothesis that adult length-at-age, age-at-maturation, productivity, and abundance of a Norton Sound, Alaska, chum salmon population were influenced by Asian hatchery chum salmon, which have become exceptionally abundant and surpassed the abundance of wild chum salmon in the North Pacific beginning in the early 1980s. We found that smaller adult length-at-age, delayed age-at-maturation, and reduced productivity and abundance of the Norton Sound salmon population were associated with greater production of Asian hatchery chum salmon since 1965. Modeling of the density-dependent relationship, while controlling for other influential variables, indicated that an increase in adult hatchery chum salmon abundance from 10 million to 80 million adult fish led to a 72% reduction in the abundance of the wild chum salmon population. These findings indicate that competition with hatchery chum salmon contributed to the low productivity and abundance of Norton Sound chum salmon, which includes several stocks that are classified as Stocks of Concern by the State of Alaska. This study provides new evidence indicating that large-scale hatchery production may influence body size, age-at-maturation, productivity and abundance of a distant wild salmon population.

Three new species of the sucking louse genus Hoplopleura (Phthiraptera: Anoplura: Hoplopleuridae) from rodents (Mammalia: Rodentia: Muridae) in northern Australia.

PubMed

Weaver, Haylee J

2017-03-23

Three new species of the rodent louse genus Hoplopleura (Anoplura: Hoplopleuridae) are described and illustrated from Australia: H. melomydis new species from Melomys burtoni (Muridae: Hydromyini, grassland melomys) and M. capensis (Muridae: Hydromyini, Cape York melomys) from Queensland; H. notomydis new species and H. setosa new species from Notomys alexis (Muridae: Hydromyini, spinifex hopping mouse) from the Northern Territory. These new louse species are the first lice recorded from each of the three host rodent species.

Utilization of smoked salmon trim in extruded smoked salmon jerky.

PubMed

Kong, J; Dougherty, M P; Perkins, L B; Camire, M E

2012-06-01

During smoked salmon processing, the dark meat along the lateral line is removed before packaging; this by-product currently has little economic value. In this study, the dark meat trim was incorporated into an extruded jerky. Three formulations were processed: 100% smoked trim, 75% : 25% smoked trim : fresh salmon fillet, and 50% : 50% smoked trim : fresh salmon blends (w/w basis). The base formulation contained salmon (approximately 83.5%), tapioca starch (8%), pregelatinized potato starch (3%), sucrose (4%), salt (1.5%), sodium nitrate (0.02%), and ascorbyl palmitate (0.02% of the lipid content). Blends were extruded in a laboratory-scale twin-screw extruder and then hot-smoked for 5 h. There were no significant differences among formulations in moisture, water activity, and pH. Protein was highest in the 50 : 50 blend jerky. Ash content was highest in the jerky made with 100% trim. Total lipids and salt were higher in the 100% trim jerky than in the 50 : 50 blend. Hot smoking did not adversely affect docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) content in lipids from 100% smoked trim jerky. Servings of salmon jerky made with 75% and 100% smoked trim provided at least 500 mg of EPA and DHA. The 50 : 50 formulation had the highest Intl. Commission on Illumination (CIE) L*, a*, and b* color values. Seventy consumers rated all sensory attributes as between "like slightly" and "like moderately." With some formulation and processing refinements, lateral line trim from smoked salmon processors has potential to be incorporated into acceptable, healthful snack products. Dark meat along the lateral line is typically discarded by smoked salmon processors. This omega-3 fatty acid rich by-product can be used to make a smoked salmon jerky that provides a convenient source of these healthful lipids for consumers. © 2012 Institute of Food Technologists®

Predation on Chinook Salmon parr by hatchery salmonids and Fallfish in the Salmon River, New York

USGS Publications Warehouse

Johnson, James H.; Nack, Christopher C.; Chalupnicki, Marc; Abbett, Ross; McKenna, James E.

2016-01-01

Naturally reproduced Chinook Salmon Oncorhynchus tshawytscha contribute substantially to the fishery in Lake Ontario. The Salmon River, a Lake Ontario tributary in New York, produces the largest numbers of naturally spawned Chinook Salmon, with parr abundance in the river often exceeding 10 million. In the spring of each year, large numbers of hatchery salmonid yearlings—potential predators of Chinook Salmon parr—are released into the Salmon River by the New York State Department of Environmental Conservation. We sought to examine predation on Chinook Salmon parr in the Salmon River during May and June prior to out-migration. Over the 4 years examined (2009–2012), annual consumption of Chinook Salmon parr by hatchery-released yearling steelhead O. mykiss and Coho Salmon O. kisutch ranged from 1.5 to 3.3 million and from 0.4 to 2.1 million, respectively. In 2009, Fallfish Semotilus corporalis were estimated to consume 2.9 million Chinook Salmon parr. Predation was higher in May, when the average TL of Chinook Salmon parr was 44.5 mm, than in June. Fallfish were also important predators of naturally reproduced steelhead subyearlings, consuming an estimated 800,000 steelhead in 2009. Hatchery-released yearling salmonids consumed 13.8–15.3% of the Chinook Salmon parr that were estimated to be present in the Salmon River during 2010–2012. Earlier releases of hatchery salmonid yearlings could reduce the riverine consumption of Chinook Salmon parr by facilitating the out-migration of yearlings prior to Chinook Salmon emergence.

Field trials in Norway with SLICE (0.2% emamectin benzoate) for the oral treatment of sea lice infestation in farmed Atlantic salmon Salmo salar.

PubMed

Ramstad, A; Colquhoun, D J; Nordmo, R; Sutherland, I H; Simmons, R

2002-06-21

Four commercial salmon farms on the West coast of Norway were recruited to a programme of field trials in which the efficacy of SLICE (0.2% emamectin benzoate; Schering-Plough Animal Health) was compared with a commercially available product, EKTOBANN (teflubenzuron 2 g kg(-1); Skretting A/S) in treating natural sea lice Lepeophtheirus salmonis infections in Atlantic salmon Salmo salmar L. At each test site, 3 fish pens were treated with each product. In total, nearly 1.2 million first-year-class fish were included in the trial, of which approximately 561,000 received emamectin benzoate at a dosage of 50 microg kg(-1) body wt d(-1), while approximately 610,000 received teflubenzuron at a dosage of 10 mg kg(-1) body wt d(-1). Medicated feed was provided at 0.5% body wt d(-1) over 7 consecutive days. Feed containing emamectin benzoate was generally well accepted by the fish and no problems were encountered in feeding the medicated diet at the desired dose. Lice numbers were counted 2 d before and 1, 7, 14 and 21 d after commencement of treatment. While treatment with both substances rapidly reduced lice numbers, pens treated with emamectin benzoate were found to harbour significantly fewer lice 14 and 21 d post-treatment. Twenty-one days following treatment with emamectin benzoate the lice abundance was reduced on average by 94%. Limited sampling outside the main study period indicated that emamectin benzoate protects against sea-lice infestation over longer periods.

Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.

USGS Publications Warehouse

Garver, Kyle A.; Marty, Gary D.; Cockburn, Sarah N.; Richard, Jon; Hawley, Laura M.; Müller, Anita; Thompson, Rachel L.; Purcell, Maureen K.; Saksida, Sonja M.

2015-01-01

A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon.

The single mitochondrial chromosome typical of animals has evolved into 18 minichromosomes in the human body louse, Pediculus humanus

PubMed Central

Shao, Renfu; Kirkness, Ewen F.; Barker, Stephen C.

2009-01-01

The mitochondrial (mt) genomes of animals typically consist of a single circular chromosome that is ∼16-kb long and has 37 genes. Our analyses of the sequence reads from the Human Body Louse Genome Project and the patterns of gel electrophoresis and Southern hybridization revealed a novel type of mt genome in the sucking louse, Pediculus humanus. Instead of having all mt genes on a single chromosome, the 37 mt genes of this louse are on 18 minicircular chromosomes. Each minicircular chromosome is 3–4 kb long and has one to three genes. Minicircular mt chromosomes are also present in the four other species of sucking lice that we investigated, but not in chewing lice nor in the Psocoptera, to which sucking lice are most closely related. We also report unequivocal evidence for recombination between minicircular mt chromosomes in P. humanus and for sequence variation in mt genes generated by recombination. The advantages of a fragmented mt genome, if any, are currently unknown. Fragmentation of mt genome, however, has coevolved with blood feeding in the sucking lice. It will be of interest to explore whether or not life history features are associated with the evolution of fragmented chromosomes. PMID:19336451

THE SALMON 2100 PROJECT -- AN ALTERNATIVES FUTURES PERSPECTIVE ON PACIFIC NORTHWEST SALMON RECOVERY

EPA Science Inventory

The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in the Pacific Northwest and California. Wild salmon recovery efforts in western North Americ...

Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.

PubMed

Garver, K A; Marty, G D; Cockburn, S N; Richard, J; Hawley, L M; Müller, A; Thompson, R L; Purcell, M K; Saksida, S

2016-02-01

A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of jaundiced Chinook Salmon; however, piscine reovirus (PRV) was identified via RT-rPCR in all 10 affected fish sampled. By histopathology, Jaundice Syndrome is an acute to peracute systemic disease, and the time from first clinical signs to death is likely <48 h; renal tubular epithelial cell necrosis is the most consistent lesion. In an infectivity trial, Chinook Salmon, Sockeye Salmon and Atlantic Salmon, intraperitoneally inoculated with a PRV-positive organ homogenate from jaundiced Chinook Salmon, developed no gross or microscopic evidence of jaundice despite persistence of PRV for the 5-month holding period. The results from this study demonstrate that the Jaundice Syndrome was not transmissible by injection of material from infected fish and that PRV was not the sole aetiological factor for the condition. Additionally, these findings showed the Pacific coast strain of PRV, while transmissible, was of low pathogenicity for Atlantic Salmon, Chinook Salmon and Sockeye Salmon. © 2015 John Wiley & Sons Ltd.

Plasmacytoid leukemia of chinook salmon.

PubMed

Kent, M L; Eaton, W D; Casey, J W

1997-04-01

Plasmacytoid leukemia is a common disease of seawater pen-reared chinook salmon (Oncorhynchus tshawytscha) in British Columbia, Canada, but has also been detected in wild salmon, in freshwater-reared salmon in United States, and in salmon from netpens in Chile. The disease can be transmitted under laboratory conditions, and is associated with a retrovirus, the salmon leukemia virus. However, the proliferating plasmablasts are often infected with the microsporean Enterocytozoon salmonis, which may be an important co-factor in the disease.

Calcitonin Salmon Injection

MedlinePlus

Calcitonin salmon injection is used to treat osteoporosis in postmenopausal women. Osteoporosis is a disease that causes bones to weaken and break more easily. Calcitonin salmon injection is also used to ...

Two Bacterial Genera, Sodalis and Rickettsia, Associated with the Seal Louse Proechinophthirus fluctus (Phthiraptera: Anoplura)

PubMed Central

Allen, Julie M.; Koga, Ryuichi; Fukatsu, Takema; Sweet, Andrew D.; Johnson, Kevin P.; Reed, David L.

2016-01-01

ABSTRACT Roughly 10% to 15% of insect species host heritable symbiotic bacteria known as endosymbionts. The lice parasitizing mammals rely on endosymbionts to provide essential vitamins absent in their blood meals. Here, we describe two bacterial associates from a louse, Proechinophthirus fluctus, which is an obligate ectoparasite of a marine mammal. One of these is a heritable endosymbiont that is not closely related to endosymbionts of other mammalian lice. Rather, it is more closely related to endosymbionts of the genus Sodalis associated with spittlebugs and feather-chewing bird lice. Localization and vertical transmission of this endosymbiont are also more similar to those of bird lice than to those of other mammalian lice. The endosymbiont genome appears to be degrading in symbiosis; however, it is considerably larger than the genomes of other mammalian louse endosymbionts. These patterns suggest the possibility that this Sodalis endosymbiont might be recently acquired, replacing a now-extinct, ancient endosymbiont. From the same lice, we also identified an abundant bacterium belonging to the genus Rickettsia that is closely related to Rickettsia ricketsii, a human pathogen vectored by ticks. No obvious masses of the Rickettsia bacterium were observed in louse tissues, nor did we find any evidence of vertical transmission, so the nature of its association remains unclear. IMPORTANCE Many insects are host to heritable symbiotic bacteria. These heritable bacteria have been identified from numerous species of parasitic lice. It appears that novel symbioses have formed between lice and bacteria many times, with new bacterial symbionts potentially replacing existing ones. However, little was known about the symbionts of lice parasitizing marine mammals. Here, we identified a heritable bacterial symbiont in lice parasitizing northern fur seals. This bacterial symbiont appears to have been recently acquired by the lice. The findings reported here provide insights

It's a Salmon's Life!

ERIC Educational Resources Information Center

French, M. Jenice; Skochdopole, Laura Downey

1998-01-01

Describes an integrated science unit to help preservice teachers gain confidence in their abilities to learn and teach science. The teachers role played being salmon as they learned about the salmon's life cycle and the difficulties salmon encounter. The unit introduced the use of investigative activities that begin with questions and end with…

50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

Code of Federal Regulations, 2012 CFR

2012-10-01

... salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook... River salmon (except reaches above impassable natural falls, and Dworshak and Hells Canyon Dams...

50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

Code of Federal Regulations, 2013 CFR

2013-10-01

... salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook... River salmon (except reaches above impassable natural falls, and Dworshak and Hells Canyon Dams...

50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

Code of Federal Regulations, 2014 CFR

2014-10-01

... salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook... River salmon (except reaches above impassable natural falls, and Dworshak and Hells Canyon Dams...

50 CFR 226.205 - Critical habitat for Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River...

Code of Federal Regulations, 2010 CFR

2010-10-01

... salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. 226.205 Section... Snake River sockeye salmon, Snake River fall chinook salmon, and Snake River spring/summer chinook salmon. The following areas consisting of the water, waterway bottom, and adjacent riparian zone of...

Comparison of manual and semi-automatic DNA extraction protocols for the barcoding characterization of hematophagous louse flies (Diptera: Hippoboscidae).

PubMed

Gutiérrez-López, Rafael; Martínez-de la Puente, Josué; Gangoso, Laura; Soriguer, Ramón C; Figuerola, Jordi

2015-06-01

The barcoding of life initiative provides a universal molecular tool to distinguish animal species based on the amplification and sequencing of a fragment of the subunit 1 of the cytochrome oxidase (COI) gene. Obtaining good quality DNA for barcoding purposes is a limiting factor, especially in studies conducted on small-sized samples or those requiring the maintenance of the organism as a voucher. In this study, we compared the number of positive amplifications and the quality of the sequences obtained using DNA extraction methods that also differ in their economic costs and time requirements and we applied them for the genetic characterization of louse flies. Four DNA extraction methods were studied: chloroform/isoamyl alcohol, HotShot procedure, Qiagen DNeasy(®) Tissue and Blood Kit and DNA Kit Maxwell(®) 16LEV. All the louse flies were morphologically identified as Ornithophila gestroi and a single COI-based haplotype was identified. The number of positive amplifications did not differ significantly among DNA extraction procedures. However, the quality of the sequences was significantly lower for the case of the chloroform/isoamyl alcohol procedure with respect to the rest of methods tested here. These results may be useful for the genetic characterization of louse flies, leaving most of the remaining insect as a voucher. © 2015 The Society for Vector Ecology.

One Northwest community - People, salmon, rivers, and the sea: Towards sustainable salmon fisheries

USGS Publications Warehouse

MacDonald, Donald D.; Steward, Cleveland R.; Knudsen, E. Eric; Knudsen, E. Eric; Steward, Cleveland R.; MacDonald, Donald; Williams, Jack E.; Reiser, Dudley W.

1999-01-01

Pacific salmon management is in crisis. Throughout their range, salmon and steelhead populations are being adversely affected by human activities. Without coordinated, effective, and timely action, the future of the Pacific salmon resource is most certainly in doubt. To address the challenges that are currently facing salmon management, concerned citizens representing a diverse array of government agencies and non-governmental organizations have agreed to cooperate in the development of a Sustainable Fisheries Strategy for west coast salmon and steelhead populations. The Strategy builds on the contents of this book, resulting from the Sustainable Fisheries Conference and subsequent community- and watershed-based citizen forums. This chapter presents the key elements of the Strategy including a common vision for the future, a series of guiding principles, and specific strategies for supporting sustainable fisheries. As such, the Strategy embraces an ecosystem-based approach to managing human activities, rather than the traditional egocentric approach to managing salmonid populations and associated habitats. A system of community-based, watershed-oriented councils, including all stakeholders and agency representatives, is proposed for effective transition to ecosystem-based salmon and steelhead management. It is our hope that everyone involved in Pacific salmon management will embrace both the spirit and the specific elements of the Sustainable Fisheries Strategy as we face the difficult challenges ahead.

Louse-borne relapsing fever in a refugee from Somalia arriving in Belgium.

PubMed

Darcis, Gilles; Hayette, Marie-Pierre; Bontems, Sebastien; Sauvage, Anne-Sophie; Meuris, Christelle; Van Esbroeck, Marjan; Leonard, Philippe

2016-03-01

We report a case of louse-borne relapsing fever (LBRF) in a refugee from Somalia who had arrived in Belgium a few days earlier. He complained of myalgia and secondarily presented fever. Blood smears revealed spirochetes later identified as Borrelia recurrentis. LBRF should be considered in countries hosting refugees, particularly those who transit through endemic regions. © International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.

Asymmetric hybridization and introgression between pink salmon and chinook salmon in the Laurentian Great Lakes

USGS Publications Warehouse

Rosenfield, Jonathan A.; Todd, Thomas; Greil, Roger

2000-01-01

Among Pacific salmon collected in the St. Marys River, five natural hybrids of pink salmon Oncorhynchus gorbuscha and chinook salmon Oncorhynchus tshawytscha and one suspected backcross have been detected using morphologic, meristic, and color evidence. One allozyme (LDH, l-lactate dehydrogenase from muscle) and one nuclear DNA locus (growth hormone) for which species-specific fixed differences exist were analyzed to detect additional hybrids and to determine if introgression had occurred. Restriction fragment length polymorphism of mitochondrial DNA (mtDNA) was used to identify the maternal parent of each hybrid. Evidence of introgression was found among the five previously identified hybrids. All hybrid specimens had chinook salmon mtDNA, indicating that hybridization between chinook salmon and pink salmon in the St. Marys River is asymmetric and perhaps unidirectional. Ecological, physiological, and sexual selection forces may contribute to this asymmetric hybridization. Introgression between these highly differentiated species has implications for management, systematics, and conservation of Pacific salmon.

Lousy mums: patterns of vertical transmission of an amphibious louse.

PubMed

Leonardi, M S; Crespo, E A; Raga, J A; Aznar, F J

2013-09-01

In this study, we document patterns of vertical transmission of the amphibious louse Antarctophthirus microchir (Echinophthiriidae) in pups of South American sea lion, Otaria flavescens, from Patagonia. Vertical transmission is fundamental for the long-term stability of A. microchir populations because only pups stay long enough (1 month) on land for the louse to reproduce. A total of 72 pups ≤7 days old from a single rookery were captured and examined for lice. Infection parameters and population structure of A. microchir did not differ among pups collected at the beginning, middle, and end of the reproductive season, suggesting that patterns of early vertical transmission are not affected by the increase of rookery size during this period. Over 60% of 1-day-old pups were infected with A. microchir, and recruitment increased in pups up to 3 days old and then leveled off. In 1-day-old pups, significantly more adults than nymphs were found, but the pattern was reversed in older pups. The number of first-stage nymphs was significantly smaller than that of second- and third-stage nymphs, as it was the number of males vs. females, particularly in 1-day-old pups. Three non-exclusive hypotheses could account for these patterns, i.e., recruitment merely reflects the population structure of A. microchir is cows; the relative ability of lice to pass from cows onto pups increases in advanced instars; and/or natural selection favors transmission of adults, especially females, because they accrue greater fitness. The importance of latter hypothesis should not be underestimated in a species with a tight reproductive schedule.

Spot-on Treatments of Diflubenzuron and Permethrin to Control a Guinea Pig Louse, Gliricola Porcelli (Phthiraptera: Gyropidae)

USDA-ARS?s Scientific Manuscript database

Guinea pigs (Cavia porcellus (L.)) (Rodentia: Caviidae) are pets and laboratory animals. They can be infested by a chewing louse, Gliricola porcelli (Schrank) (Phthiraptera: Gyropidae), which is fairly common in some animal rearing facilities, pet stores, and on wild guinea pigs. Infestation with G....

The use of genomic information increases the accuracy of breeding value predictions for sea louse (Caligus rogercresseyi) resistance in Atlantic salmon (Salmo salar).

PubMed

Correa, Katharina; Bangera, Rama; Figueroa, René; Lhorente, Jean P; Yáñez, José M

2017-01-31

Sea lice infestations caused by Caligus rogercresseyi are a main concern to the salmon farming industry due to associated economic losses. Resistance to this parasite was shown to have low to moderate genetic variation and its genetic architecture was suggested to be polygenic. The aim of this study was to compare accuracies of breeding value predictions obtained with pedigree-based best linear unbiased prediction (P-BLUP) methodology against different genomic prediction approaches: genomic BLUP (G-BLUP), Bayesian Lasso, and Bayes C. To achieve this, 2404 individuals from 118 families were measured for C. rogercresseyi count after a challenge and genotyped using 37 K single nucleotide polymorphisms. Accuracies were assessed using fivefold cross-validation and SNP densities of 0.5, 1, 5, 10, 25 and 37 K. Accuracy of genomic predictions increased with increasing SNP density and was higher than pedigree-based BLUP predictions by up to 22%. Both Bayesian and G-BLUP methods can predict breeding values with higher accuracies than pedigree-based BLUP, however, G-BLUP may be the preferred method because of reduced computation time and ease of implementation. A relatively low marker density (i.e. 10 K) is sufficient for maximal increase in accuracy when using G-BLUP or Bayesian methods for genomic prediction of C. rogercresseyi resistance in Atlantic salmon.

Competition between Asian pink salmon (Oncorhynchus gorbuscha) and Alaskan sockeye salmon (O. nerka) in the North Pacific Ocean

USGS Publications Warehouse

Ruggerone, G.T.; Zimmermann, M.; Myers, K.W.; Nielsen, J.L.; Rogers, D.E.

2003-01-01

The importance of interspecific competition as a mechanism regulating population abundance in offshore marine communities is largely unknown. We evaluated offshore competition between Asian pink salmon and Bristol Bay (Alaska) sockeye salmon, which intermingle in the North Pacific Ocean and Bering Sea, using the unique biennial abundance cycle of Asian pink salmon from 1955 to 2000. Sockeye salmon growth during the second and third growing seasons at sea, as determined by scale measurements, declined significantly in odd-numbered years, corresponding to years when Asian pink salmon are most abundant. Bristol Bay sockeye salmon do not interact with Asian pink salmon during their first summer and fall seasons and no difference in first year scale growth was detected. The interaction with odd-year pink salmon led to significantly smaller size at age of adult sockeye salmon, especially among younger female salmon. Examination of sockeye salmon smolt to adult survival rates during 1977-97 indicated that smolts entering the ocean during even-numbered years and interacting with abundant odd-year pink salmon during the following year experienced 26% (age-2 smolt) to 45% (age-1 smolt) lower survival compared with smolts migrating during odd-numbered years. Adult sockeye salmon returning to Bristol Bay from even-year smolt migrations were 22% less abundant (reduced by 5.9 million fish per year) compared with returns from odd-year migrations. The greatest reduction in adult returns occurred among adults spending 2 compared with 3 years at sea. Our new evidence for interspecific competition highlights the need for multispecies, international management of salmon production, including salmon released from hatcheries into the ocean.

SALMON 2100 PROJECT

EPA Science Inventory

Twenty eight salmon scientists and policy experts have joined forces in an innovative project to identify ways that, if adopted, likely would restore and sustain wild salmon runs in California, Oregon, Washington, Idaho, and southern British Columbia.

Comparative diets of subyearling Atlantic salmon and subyearling coho salmon in Lake Ontario tributaries

USGS Publications Warehouse

Johnson, James H.; Ringler, Neil H.

2016-01-01

Restoration of Atlantic salmon (Salmo salar) in Lake Ontario could potentially be negatively affected by the presence of non-native salmonids that are naturalized in the basin. Coho salmon (Oncorhynchus kisutch) have been spawning successfully in Lake Ontario tributaries for over 40 years and their juveniles will reside in streams with juvenile Atlantic salmon for one year. This study sought to examine interspecific diet associations between these species, and to compare diets to the composition of the benthos and drift in three Lake Ontario tributaries. Aquatic insects, mainly ephemeropterans and chironomids were the major prey consumed by subyearling Atlantic salmon whereas terrestrial invertebrates made up only 3.7% of the diet. Ephemeropterans and chironomids were the primary aquatic taxa consumed by subyearling coho salmon but, as a group, terrestrial invertebrates (41.8%) were the major prey. In sympatry, Atlantic salmon fed more actively from the benthos whereas the diet of coho salmon was more similar to the drift. The different feeding pattern of each species resulted in low interspecific diet similarity. There is likely little competition between these species for food in Lake Ontario tributaries as juveniles.

Sockeye salmon evolution, ecology, and management

USGS Publications Warehouse

Woody, Carol Ann

2007-01-01

This collection of articles and photographs gives managers a good idea of recent research into what the sockeye salmon is and does, covering such topics as the vulnerability and value of sockeye salmon ecotypes, their homing ability, using new technologies to monitor reproduction, DNA and a founder event in the Lake Clark sockeye salmon, marine-derived nutrients, the exploitation of large prey, dynamic lake spawning migrations by females, variability of sockeye salmon residence, expression profiling using cDNA microarray technology, learning from stable isotropic records of native otolith hatcheries, the amount of data needed to manage sockeye salmon and estimating salmon "escapement." 

Predation by fallfish (Semotilus corporalis) on Pacific salmon eggs in the Salmon River, New York

USGS Publications Warehouse

Johnson, J. H.; Nack, C.C.; Chalupnicki, M.A.

2009-01-01

Fallfish (Semotilus corporalis) are the largest native cyprinid in the northeastern United States and are the most abundant native species in the Salmon River, New York. The Salmon River is a high-quality spawning and nursery river for Pacific salmon (Oncorhynchus spp.) migrating from Lake Ontario. Because of the large number of Pacific salmon spawning in the river in the fall extensive redd superimposition occurs resulting in salmonid eggs being available on the substrate. We examined the fall diet of 647 fallfish in 2007 and 2008 to determine the extent of predation on Pacific salmon eggs. The contribution of eggs in the diet significantly increased once fallfish attained a size of 100 mm total length. The largest size category of fallfish examined (≥150 mm) had the highest proportion (86.1%) of salmon eggs in their diet. The contribution of Zooplankton and chironomids in the diet of fallfish decreased with fish size. Except for the two largest groups of fallfish examined (i.e., 100–149 mm and ≥150 mm) diet overlap among size groups was low. The high contribution in the diet during the fall and high caloric value of Pacific salmon eggs could increase growth and survival of this species in the Salmon River.

The effect of exposure to farmed salmon on piscine orthoreovirus infection and fitness in wild Pacific salmon in British Columbia, Canada

PubMed Central

2017-01-01

The disease Heart and Skeletal Muscle Inflammation (HSMI) is causing substantial economic losses to the Norwegian salmon farming industry where the causative agent, piscine orthoreovirus (PRV), is reportedly spreading from farmed to wild Atlantic salmon (Salmo salar) with as yet undetermined impacts. To assess if PRV infection is epidemiologically linked between wild and farmed salmon in the eastern Pacific, wild Pacific salmon (Oncorhynchus sp.) from regions designated as high or low exposure to salmon farms and farmed Atlantic salmon reared in British Columbia (BC) were tested for PRV. The proportion of PRV infection in wild fish was related to exposure to salmon farms (p = 0.0097). PRV was detected in: 95% of farmed Atlantic salmon, 37–45% of wild salmon from regions highly exposed to salmon farms and 5% of wild salmon from the regions furthest from salmon farms. The proportion of PRV infection was also significantly lower (p = 0.0008) where wild salmon had been challenged by an arduous return migration into high-elevation spawning habitat. Inter-annual PRV infection declined in both wild and farmed salmon from 2012–2013 (p ≤ 0.002). These results suggest that PRV transfer is occurring from farmed Atlantic salmon to wild Pacific salmon, that infection in farmed salmon may be influencing infection rates in wild salmon, and that this may pose a risk of reduced fitness in wild salmon impacting their survival and reproduction. PMID:29236731

The effect of exposure to farmed salmon on piscine orthoreovirus infection and fitness in wild Pacific salmon in British Columbia, Canada.

PubMed

Morton, Alexandra; Routledge, Richard; Hrushowy, Stacey; Kibenge, Molly; Kibenge, Frederick

2017-01-01

The disease Heart and Skeletal Muscle Inflammation (HSMI) is causing substantial economic losses to the Norwegian salmon farming industry where the causative agent, piscine orthoreovirus (PRV), is reportedly spreading from farmed to wild Atlantic salmon (Salmo salar) with as yet undetermined impacts. To assess if PRV infection is epidemiologically linked between wild and farmed salmon in the eastern Pacific, wild Pacific salmon (Oncorhynchus sp.) from regions designated as high or low exposure to salmon farms and farmed Atlantic salmon reared in British Columbia (BC) were tested for PRV. The proportion of PRV infection in wild fish was related to exposure to salmon farms (p = 0.0097). PRV was detected in: 95% of farmed Atlantic salmon, 37-45% of wild salmon from regions highly exposed to salmon farms and 5% of wild salmon from the regions furthest from salmon farms. The proportion of PRV infection was also significantly lower (p = 0.0008) where wild salmon had been challenged by an arduous return migration into high-elevation spawning habitat. Inter-annual PRV infection declined in both wild and farmed salmon from 2012-2013 (p ≤ 0.002). These results suggest that PRV transfer is occurring from farmed Atlantic salmon to wild Pacific salmon, that infection in farmed salmon may be influencing infection rates in wild salmon, and that this may pose a risk of reduced fitness in wild salmon impacting their survival and reproduction.

Salmon-Eating Grizzly Bears Exposed to Elevated Levels of Marine Derived Persistent Organic Pollutants

NASA Astrophysics Data System (ADS)

Christensen, J. R.; Ross, P. S.; Whiticar, M. J.

2004-12-01

The coastal grizzly bears of British Columbia (BC, Canada) rely heavily on salmon returning from the Pacific Ocean, whereas interior bears do not have access to or readily utilize this marine-derived food source. Since salmon have been shown to accumulate persistent organic pollutants (POPs) from the North Pacific Ocean, we hypothesized that salmon consumption by grizzly bears would be reflected by an increase in the POP burden. To test this hypothesis we collected hair and fat tissue from grizzlies at various locations around BC to compare salmon-eating (coastal) grizzlies to non-salmon-eating (interior) grizzlies. We characterized the feeding habits for each bear sampled by measuring the stable carbon and nitrogen isotope signature of their hair. The positive relationship between 13C/12C and 15N/14N isotopic ratios suggests that the majority of the meat portion of the diet of coastal grizzlies is coming from salmon, rather than from terrestrial or freshwater sources. By contrast, stable isotope ratios revealed that interior bears have an almost exclusive vegetarian diet with no marine influence. As hypothesized, the coastal grizzly bears have significantly greater OC pesticide and lower-brominated PBDE congener body burden than the interior grizzlies. We also found a positive relationship between C and N isotope ratios and these same POP contaminants in bear tissue. Overall, these results demonstrate that Pacific salmon represents a significant vector delivering both OC pesticides and PBDEs to BC coastal grizzly bears.

Retrospective analysis of AYK Chinook salmon growth

USGS Publications Warehouse

Ruggerone, Gregory T.; Nielsen, Jennifer L.; Agler, B.A.

2007-01-01

Harvests of Yukon and Kuskokwim Chinook salmon declined significantly during 1998- 2002 in response to fewer returning salmon. Factors affecting the decline in Chinook salmon abundance are largely unknown. Growth of salmon in freshwater and the ocean is generally thought to influence salmon survival, therefore we examined historical Chinook salmon catch trends and developed growth indices of age-1.3 and age-1.4 Yukon and Kuskokwim Chinook salmon during each year and life stage in freshwater and the ocean, 1964-2004, using measurements of salmon scale growth. Availability of Yukon scales was greater than that of Kuskokwim scales during 1964-2004.Harvests of Yukon and Kuskokwim Chinook salmon rapidly increased in the mid-1970s, then rapidly declined in the late 1990s, apparently in response to the 1976/77 ocean regime shift and the 1997/98 El Nino event. Runs of Nushagak District Chinook salmon (Bristol Bay) also appeared to have been affected by these events in addition to the 1989 regime shift. The rapid responses of Chinook salmon abundance to climate change suggest late life stages were primarily affected, at least initially. Therefore, we searched for Chinook salmon growth patterns that might be related to changes in climate.

78 FR 62616 - Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 3730-005] Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer of Exemption 1. By letter filed September 23, 2013, Salmon Creek Hydroelectric Company informed the Commission that they have...

A model for studying isolation mechanisms in parasite populations: the genus Lepeophtheirus (Copepoda, Caligidae).

PubMed

De Meeus, T; Renaud, F; Gabrion, C

1990-05-01

In the Mediterranean, the parasitic copepod Lepeophtheirus thompsoni Baird, 1850 specifically infests turbot (Psetta maxima L., 1758), whereas L. europaensis Zeddam, Berrebi, Renaud, Raibaut, and Gabrion, 1988 infests brill (Scophthalmus rhombus L., 1758) and flounder (Platichthys flesus L., 1758). Experimental infestation of turbot by copepods from each of the three fish species showed an absence of any physiological incompatibility preventing natural development of the two parasite species, at least on one host species, i.e., the turbot. Moreover, interspecific hybrids were obtained experimentally, which implies that 1) there is no strict genetic barrier between the two species and 2) the natural prezygotic isolation results from a choice of the most favorable habitat. We discuss the origin and possible consequences of the presence, in the Mediterranean, of L. europaensis on brill and flounder, two hosts separated by their taxonomic status and ecobiology.

Isolation and identification of infectious salmon anaemia virus (ISAV) from Coho salmon in Chile.

PubMed

Kibenge, F S; Gárate, O N; Johnson, G; Arriagada, R; Kibenge, M J; Wadowska, D

2001-05-04

The isolation of infectious salmon anaemia virus (ISAV) from asymptomatic wild fish species including wild salmon, sea trout and eel established that wild fish can be a reservoir of ISAV for farmed Atlantic salmon. This report characterizes the biological properties of ISAV isolated from a disease outbreak in farmed Coho salmon in Chile and compares it with ISAV isolated from farmed Atlantic salmon in Canada and Europe. The virus that was isolated from Coho salmon tissues was initially detected with ISAV-specific RT-PCR (reverse transcription-polymerase chain reaction). The ability of the virus to grow in cell culture was poor, as cytopathology was not always conspicuous and isolation required passage in the presence of trypsin. Virus replication in cell culture was detected by RT-PCR and IFAT (indirect fluorescent antibody test), and the virus morphology was confirmed by positive staining electron microscopy. Further analysis of the Chilean virus revealed similarities to Canadian ISAV isolates in their ability to grow in the CHSE-214 cell line and in viral protein profile. Sequence analysis of genome segment 2, which encodes the viral RNA polymerase PB1, and segment 8, which encodes the nonstructural proteins NS1 and NS2, showed the Chilean virus to be very similar to Canadian strains of ISAV. This high sequence similarity of ISAV strains of geographically distinct origins illustrates the highly conserved nature of ISAV proteins PB1, NS1 and NS2 of ISAV. It is noteworthy that ISAV was associated with disease outbreaks in farmed Coho salmon in Chile without corresponding clinical disease in farmed Atlantic salmon. This outbreak, which produced high mortality in Coho salmon due to ISAV, is unique and may represent the introduction of the virus to a native wild fish population or a new strain of ISAV.

Presence and effects of the dog louse Trichodectes canis (Mallophaga, Trichodectidae) on wolves and coyotes from Minnesota and Wisconsin

USGS Publications Warehouse

Mech, L.D.; Thiel, R.P.; Fritts, S.H.; Berg, W.E.

1985-01-01

The dog louse was found on 19 wolves (Canis lupus) and six coyotes (C. latrans) from Minnesota and Wisconsin during the July-February, 1973 through 1983, period. No evidence was found that lice had any serious effect on wolf survival.

Basis of acoustic discrimination of Chinook salmon from other salmons by echolocating Orcinus orca.

PubMed

Au, Whitlow W L; Horne, John K; Jones, Christopher

2010-10-01

The "resident" ecotype of killer whales (Orcinus orca) in the waters of British Columbia and Washington State have a strong preference for Chinook salmon even in months when Chinook comprise less than about 10% of the salmon population. The foraging behavior of killer whales suggests that they depend on echolocation to detect and recognize their prey. In order to determine possible cues in echoes from salmon species, a series of backscatter measurements were made at the Applied Physics Laboratory (Univ. of Wash.) Facility on Lake Union, on three different salmon species using simulated killer whale echolocation signals. The fish were attached to a monofilament net panel and rotated while echoes were collected, digitized and stored on a laptop computer. Three transducer depths were used; same depth, 22° and 45° above the horizontal plane of the fish. Echoes were collected from five Chinook, three coho and one sockeye salmon. Radiograph images of all specimens were obtained to examine the swimbladder shape and orientation. The results show that echo structure from similar length but different species of salmon were different and probably recognizable by foraging killer whales.

PNW WILD SALMON IN 2100: AN ALTERNATIVE FUTURES PERSPECTIVE ON SALMON RECOVERY

EPA Science Inventory

The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project does not...

WILD SALMON RESTORATION: IS IT WORTH IT?

EPA Science Inventory

Salmon are categorized biologically into two groups: Pacific salmon and Atlantic salmon. Atlantic salmon are found on both sides of the North Atlantic Ocean, but have declined precipitously compared to the size of runs prior to the 1700s. The largest (though small by historic ...

Saving the Salmon

ERIC Educational Resources Information Center

Sprangers, Donald

2004-01-01

In November 2000, wild Atlantic salmon were placed under the protection of the Endangered Species Act of 1973. Washington Academy (WA) in Maine has played an integral role in the education and restoration of this species. Efforts to restore the salmon's dwindling population, enhance critical habitat areas, and educate and inform the public require…

Calcitonin Salmon Nasal Spray

MedlinePlus

Calcitonin salmon is used to treat osteoporosis in women who are at least 5 years past menopause and cannot ... a human hormone that is also found in salmon. It works by preventing bone breakdown and increasing ...

Sustainable fisheries management: Pacific salmon

USGS Publications Warehouse

Knudsen, E. Eric; Steward, Cleveland R.; MacDonald, Donald; Williams, Jack E.; Reiser, Dudley W.

1999-01-01

What has happened to the salmon resource in the Pacific Northwest? Who is responsible and what can be done to reverse the decline in salmon populations? The responsibly falls on everyone involved - fishermen, resource managers and concerned citizens alike - to take the steps necessary to ensure that salmon populations make a full recovery.This collection of papers examines the state of the salmon fisheries in the Pacific Northwest. They cover existing methods and supply model approaches for alternative solutions. The editors stress the importance of input from and cooperation with all parties involved to create a viable solution. Grass roots education and participation is the key to public support - and ultimately the success - of whatever management solutions are developed.A unique and valuable scientific publication, Sustainable Fisheries Management: Pacific Salmon clearly articulates the current state of the Pacific salmon resource, describes the key features of its management, and provides important guidance on how we can make the transition towards sustainable fisheries. The solutions presented in this book provide the basis of a strategy for sustainable fisheries, requiring society and governmental agencies to establish a shared vision, common policies, and a process for collaborative management.

Louse-borne relapsing fever in Finland in two asylum seekers from Somalia.

PubMed

Hytönen, Jukka; Khawaja, Tamim; Grönroos, Juha O; Jalava, Anna; Meri, Seppo; Oksi, Jarmo

2017-01-01

We report two cases of louse-borne relapsing fever (LBRF) in young Somali asylum seekers having recently arrived to Finland. They had sought medical attention for a febrile illness. Blood smears were examined for suspected malaria, but instead, spirochete shaped bacteria were observed. The bacteria were confirmed as Borrelia recurrentis by PCR and sequencing. The patients survived, but their treatment was complicated by Jarisch-Herxheimer reaction. We conclude that LBRF must be considered as a diagnostic option in febrile refugees also in the northernmost parts of Europe. © 2016 APMIS. Published by John Wiley & Sons Ltd.

Soya oil-based shampoo superior to 0.5% permethrin lotion for head louse infestation.

PubMed

Burgess, Ian F; Kay, Katrina; Burgess, Nazma A; Brunton, Elizabeth R

2011-01-01

This was a randomized, assessor-blind, controlled comparison of a soya oil- based medical device shampoo with a medicinal permethrin lotion in an alcohol vehicle for treatment of head louse infestation to generate data suitable for a regulatory submission to achieve reimbursable status for the shampoo product. We treated 91 children and adults, divided between two sites, on two occasions 9 days apart. Participants washed their hair and towel-dried it before treatment. The shampoo was used twice for 30 minutes each time. The lotion was used for 30 minutes followed by rinsing. Assessments were made by dry detection combing on days 2, 9, 11, and 14 after the first treatment. According to present knowledge, this combing technique does not influence the overall head louse populations or outcome of treatment. The soya oil shampoo was significantly (P < 0.01) more effective than the lotion for both intention to treat (62.2% versus 34.8% successful treatment) and per-protocol (74.3% versus 36.8% success) groups. Post-treatment assessments showed the necessity for repeat treatment, but that a 9-day interval was too long because if eggs hatched after the first treatment, the lice could grow old enough to lay eggs before the second treatment. The soya oil-based shampoo was more effective than the permethrin lotion, more cosmetically acceptable, and less irritant.

Soya oil-based shampoo superior to 0.5% permethrin lotion for head louse infestation

PubMed Central

Burgess, Ian F; Kay, Katrina; Burgess, Nazma A; Brunton, Elizabeth R

2011-01-01

Background This was a randomized, assessor-blind, controlled comparison of a soya oil- based medical device shampoo with a medicinal permethrin lotion in an alcohol vehicle for treatment of head louse infestation to generate data suitable for a regulatory submission to achieve reimbursable status for the shampoo product. Methods We treated 91 children and adults, divided between two sites, on two occasions 9 days apart. Participants washed their hair and towel-dried it before treatment. The shampoo was used twice for 30 minutes each time. The lotion was used for 30 minutes followed by rinsing. Assessments were made by dry detection combing on days 2, 9, 11, and 14 after the first treatment. According to present knowledge, this combing technique does not influence the overall head louse populations or outcome of treatment. Results The soya oil shampoo was significantly (P < 0.01) more effective than the lotion for both intention to treat (62.2% versus 34.8% successful treatment) and per-protocol (74.3% versus 36.8% success) groups. Post-treatment assessments showed the necessity for repeat treatment, but that a 9-day interval was too long because if eggs hatched after the first treatment, the lice could grow old enough to lay eggs before the second treatment. Conclusion The soya oil-based shampoo was more effective than the permethrin lotion, more cosmetically acceptable, and less irritant. PMID:22915928

Supplementing long-chain n-3 polyunsaturated fatty acids in canned wild Pacific pink salmon with Alaska salmon oil

PubMed Central

Lapis, Trina J; Oliveira, Alexandra C M; Crapo, Charles A; Himelbloom, Brian; Bechtel, Peter J; Long, Kristy A

2013-01-01

Establishing n-3 polyunsaturated fatty acid contents in canned wild Alaska pink salmon products is challenging due to ample natural variation found in lipid content of pink salmon muscle. This study investigated the effect of adding salmon oil (SO) to canned pink salmon produced from fish exhibiting two opposite degrees of skin watermarking, bright (B) and dark (D). Specific goals of the study were to evaluate the benefits of adding SO to canned pink salmon with regard to nutritional value of the product, sensory characteristics, and the oxidative and hydrolytic stability of the lipids over thermal processing. Six groups of canned pink salmon were produced with variable levels of SO, either using bright (with 0, 1, or 2% SO) or dark (with 0, 2, or 4% SO) pink salmon. Compositional analysis revealed highest (P < 0.05) lipid content in sample B2 (8.7%) and lowest (P < 0.05) lipid content in sample D0 (3.5%). Lipid content of samples B0, B1, D2, and D4 was not significantly different (P > 0.05) ranging from 5.7% to 6.8%. Consequently, addition of SO to canned pink salmon allowed for consistent lipid content between bright and dark fish. Addition of 1% or 2% SO to canned bright pink salmon was not detrimental to the sensory properties of the product. It is recommended that canned bright pink salmon be supplemented with at least 1% SO, while supplementation with 2% SO would guarantee a minimum quantity of 1.9 g of n-3 fatty acids per 100 g of product. Addition of 4% SO to canned dark pink salmon was detrimental to product texture and taste, while supplementation with 2% SO did not negatively affect sensorial properties of the product. Accordingly, canned dark pink salmon should be supplemented with 2% SO so that a minimum n-3 fatty acids content of 1.5 g per 100 g of product. PMID:24804010

WILD SALMON IN 2100: AN ALTERNATIVE FUTURES PERSPECTIVE ON SALMON RECOVERY - MAY 2006

EPA Science Inventory

The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project does not...

Dietary calcein marking of brook trout, Atlantic salmon, yellow perch, and coho salmon scales

USGS Publications Warehouse

Honeyfield, D.C.; Ostrowski, C.S.; Fletcher, J.W.; Mohler, J.W.

2006-01-01

Brook trout Salvelinus fontinalis, Atlantic salmon Salmo salar, coho salmon Oncorhynchus kisutch, and yellow perch Perca flavescens fed calcein for 5 d showed characteristic calcein scale marks 7-10 d postmarking. In fish fed 0.75 or 1.25 g of calcein per kilogram of feed, the percentage of fish that exhibited a calcein mark was 100% in brook trout, 93-98% in Atlantic salmon, 60% in yellow perch, and 0% in coho salmon. However, when coho salmon were fed 5.25 g calcein/kg feed, 100% marking was observed 7-10 d postmarking. Brook trout were successfully marked twice with distinct bands when fed calcein 5 months apart. Brook trout scale pixel luminosity increased as dietary calcein increased in experiment 2. For the second calcein mark, scale pixel luminosity from brook trout fed 1.25 g calcein/kg feed was numerically higher (P < 0.08) than scales from fish fed 0.75 g calcein/kg feed. Mean pixel luminosity of calcein-marked Atlantic salmon scales was 57.7 for fish fed 0.75 g calcein/kg feed and 55.2 for fish fed 1.25 g calcein/kg feed. Although feed acceptance presented a problem in yellow perch, these experiments provide evidence that dietary calcein is a viable tool for marking fish for stock identification. ?? Copyright by the American Fisheries Society 2006.

Molecular characterization and histochemical demonstration of salmon olfactory marker protein in the olfactory epithelium of lacustrine sockeye salmon (Oncorhynchus nerka).

PubMed

Kudo, H; Doi, Y; Ueda, H; Kaeriyama, M

2009-09-01

Despite the importance of olfactory receptor neurons (ORNs) for homing migration, the expression of olfactory marker protein (OMP) is not well understood in ORNs of Pacific salmon (genus Oncorhynchus). In this study, salmon OMP was characterized in the olfactory epithelia of lacustrine sockeye salmon (O. nerka) by molecular biological and histochemical techniques. Two cDNAs encoding salmon OMP were isolated and sequenced. These cDNAs both contained a coding region encoding 173 amino acid residues, and the molecular mass of the two proteins was calculated to be 19,581.17 and 19,387.11Da, respectively. Both amino acid sequences showed marked homology (90%). The protein and nucleotide sequencing demonstrates the existence of high-level homology between salmon OMPs and those of other teleosts. By in situ hybridization using a digoxigenin-labeled salmon OMP cRNA probe, signals for salmon OMP mRNA were observed preferentially in the perinuclear regions of the ORNs. By immunohistochemistry using a specific antibody to salmon OMP, OMP-immunoreactivities were noted in the cytosol of those neurons. The present study is the first to describe cDNA cloning of OMP in salmon olfactory epithelium, and indicate that OMP is a useful molecular marker for the detection of the ORNs in Pacific salmon.

Comparative genomics identifies candidate genes for infectious salmon anemia (ISA) resistance in Atlantic salmon (Salmo salar).

PubMed

Li, Jieying; Boroevich, Keith A; Koop, Ben F; Davidson, William S

2011-04-01

Infectious salmon anemia (ISA) has been described as the hoof and mouth disease of salmon farming. ISA is caused by a lethal and highly communicable virus, which can have a major impact on salmon aquaculture, as demonstrated by an outbreak in Chile in 2007. A quantitative trait locus (QTL) for ISA resistance has been mapped to three microsatellite markers on linkage group (LG) 8 (Chr 15) on the Atlantic salmon genetic map. We identified bacterial artificial chromosome (BAC) clones and three fingerprint contigs from the Atlantic salmon physical map that contains these markers. We made use of the extensive BAC end sequence database to extend these contigs by chromosome walking and identified additional two markers in this region. The BAC end sequences were used to search for conserved synteny between this segment of LG8 and the fish genomes that have been sequenced. An examination of the genes in the syntenic segments of the tetraodon and medaka genomes identified candidates for association with ISA resistance in Atlantic salmon based on differential expression profiles from ISA challenges or on the putative biological functions of the proteins they encode. One gene in particular, HIV-EP2/MBP-2, caught our attention as it may influence the expression of several genes that have been implicated in the response to infection by infectious salmon anemia virus (ISAV). Therefore, we suggest that HIV-EP2/MBP-2 is a very strong candidate for the gene associated with the ISAV resistance QTL in Atlantic salmon and is worthy of further study.

Arrestant Effect of Human Scalp Components on Head Louse (Phthiraptera: Pediculidae) Behavior.

PubMed

Ortega-Insaurralde, Isabel; Ceferino Toloza, Ariel; Gonzalez-Audino, Paola; Inés Picollo, María

2017-03-01

Relevant evidence has shown that parasites process host-related information using chemical, visual, tactile, or auditory cues. However, the cues that are involved in the host-parasite interaction between Pediculus humanus capitis (De Geer 1767) and humans have not been identified yet. In this work, we studied the effect of human scalp components on the behavior of adult head lice. Filter paper segments were rubbed on volunteers' scalps and then placed in the experimental arena, where adult head lice were individually tested. The movement of the insects was recorded for each arena using the software EthoVision. Average movement parameters were calculated for the treatments in the bioassays such as total distance, velocity, number of times a head louse crossed between zones of the arena, and time in each zone of the arena. We found that scalp components induced head lice to decrease average locomotor activity and to remain arrested on the treated paper. The effect of the ageing of human scalp samples in the response of head lice was not statistically significant (i.e., human scalp samples of 4, 18, 40, and 60 h of ageing did not elicit a significant change in head louse behavior). When we analyzed the effect of the sex in the response of head lice to human scalp samples, males demonstrated significant differences. Our results showed for the first time the effect of host components conditioning head lice behavior. We discuss the role of these components in the dynamic of head lice infestation. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Juvenile salmon usage of the Skeena River estuary.

PubMed

Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

2015-01-01

Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that

76 FR 65673 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

.... 101206604-1620-01] RIN 0648-BA55 Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 16 to the Salmon Fishery Management Plan AGENCY: National Marine Fisheries Service (NMFS), National... implement Amendment 16 to the Pacific Coast Salmon Fishery Management Plan for Commercial and Recreational...

History of salmon in the Great Lakes, 1850-1970

USGS Publications Warehouse

Parsons, John W.

1973-01-01

This history of the salmon in the Great Lakes describes the decline and extinction of the Atlantic salmon (Salmo salar) in Lake Ontario in the 1800's; the failure to establish, by salmon culture, permanent or sizable populations of Atlantic or Pacific salmon in any of the Great Lakes in 1867-1965; and the success of the plantings of coho (Oncorhynchus kisutch) and chinook salmon (O. tshawytsha) in the Great Lakes, in 1966-70 -- particularly in Lake Michigan. Despite plantings of 5 million fry and fingerlings from Lake Ontario stocks in 1866-84, the native Atlantic salmon in Lake Ontario became extinct in the late 1800's primarily because tributaries in which they spawned were blocked by mill dams. Plantings of 13 million chinook salmon and landlocked and anadromous forms of Atlantic salmon in Lake Ontario and the other Great Lakes in 1873-1947 failed completely. The first species to develop a self-sustaining population was the pink salmon (O. gorbuscha), which was planted in Lake Superior in 1956; however, it has not become abundant. A salmon fishery finally was established when 15 million coho salmon and 6 million chinook salmon were planted as smolt in the Great Lakes in 1966-70. In 1970, for example, 576,000 coho salmon (12% of those planted in 1969) were caught by anglers in Lake Michigan. Most weighed 5 to 10 pounds (2.3-4.5 kg). Sport fishing for salmon was fair in Lakes Superior and Huron, and poor in Lakes Erie and Ontario. By 1970, natural reproduction of coho, chinook, pink, and kokanee (O. nerka) salmon had occurred in some tributaries of one or more of the upper three Great Lakes. It is expected, however, that the sport fishery will continue to be supported almost entirely by planted fish.

Lack of evidence of infectious salmon anemia virus in pollock Pollachius virens cohabitating with infected farmed Atlantic salmon Salmo salar.

PubMed

McClure, Carol A; Hammell, K Larry; Dohoo, Ian R; Gagné, Nellie

2004-10-21

The infectious salmon anemia (ISA) virus causes lethargy, anemia, hemorrhage of the internal organs, and death in farmed Atlantic salmon Salmo salar. It has been a cause of disease in Norwegian farmed Atlantic salmon since 1984 and has since been identified in Canada, Scotland, the United States, and the Faroe Islands. Wild fish have been proposed as a viral reservoir because they are capable of close contact with farmed salmon. Laboratory studies have shown that brown trout and sea trout Salmo trutta, rainbow trout Oncorhynchus mykiss, and herring Clupea harengus tested positive for the virus weeks after intra-peritoneal injection of the ISA virus. Pollock Pollachius virens are commonly found in and around salmon cages, and their close association with the salmon makes them an important potential viral reservoir to consider. The objective of this study was to determine the presence or prevalence of ISA virus in pollock cohabitating with ISA-infected farmed Atlantic salmon. Kidney tissue from 93 pollock that were living with ISA-infected salmon in sea cages were tested with reverse transcription-polymerase chain reaction (RT-PCR) test. Results yielded the expected 193 bp product for positive controls, while no product was observed in any of the pollock samples, resulting in an ISA viral prevalence of 0%. This study strengthens the evidence that pollock are unlikely to be an ISA virus reservoir for farmed Atlantic salmon.

Juvenile Salmon Usage of the Skeena River Estuary

PubMed Central

Carr-Harris, Charmaine; Gottesfeld, Allen S.; Moore, Jonathan W.

2015-01-01

Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2–8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations

Evaluation of a chinook salmon (Oncorhynchus tshawytscha) bioenergetics model

USGS Publications Warehouse

Madenjian, Charles P.; O'Connor, Daniel V.; Chernyak, Sergei M.; Rediske, Richard R.; O'Keefe, James P.

2004-01-01

We evaluated the Wisconsin bioenergetics model for chinook salmon (Oncorhynchus tshawytscha) in both the laboratory and the field. Chinook salmon in laboratory tanks were fed alewife (Alosa pseudoharengus), the predominant food of chinook salmon in Lake Michigan. Food consumption and growth by chinook salmon during the experiment were measured. To estimate the efficiency with which chinook salmon retain polychlorinated biphenyls (PCBs) from their food in the laboratory, PCB concentrations of the alewife and of the chinook salmon at both the beginning and end of the experiment were determined. Based on our laboratory evaluation, the bioenergetics model was furnishing unbiased estimates of food consumption by chinook salmon. Additionally, from the laboratory experiment, we calculated that chinook salmon retained 75% of the PCBs contained within their food. In an earlier study, assimilation rate of PCBs to chinook salmon from their food in Lake Michigan was estimated at 53%, thereby suggesting that the model was substantially overestimating food consumption by chinook salmon in Lake Michigan. However, we concluded that field performance of the model could not be accurately assessed because PCB assimilation efficiency is dependent on feeding rate, and feeding rate of chinook salmon was likely much lower in our laboratory tanks than in Lake Michigan.

Cathepsin Gene Family Reveals Transcriptome Patterns Related to the Infective Stages of the Salmon Louse Caligus rogercresseyi

PubMed Central

Maldonado-Aguayo, Waleska; Chávez-Mardones, Jacqueline; Gonçalves, Ana Teresa; Gallardo-Escárate, Cristian

2015-01-01

Cathepsins are proteases involved in the ability of parasites to overcome and/or modulate host defenses so as to complete their own lifecycle. However, the mechanisms underlying this ability of cathepsins are still poorly understood. One excellent model for identifying and exploring the molecular functions of cathepsins is the marine ectoparasitic copepod Caligus rogercresseyi that currently affects the Chilean salmon industry. Using high-throughput transcriptome sequencing, 56 cathepsin-like sequences were found distributed in five cysteine protease groups (B, F, L, Z, and S) as well as in an aspartic protease group (D). Ontogenic transcriptome analysis evidenced that L cathepsins were the most abundant during the lifecycle, while cathepsins B and K were mostly expressed in the larval stages and adult females, thus suggesting participation in the molting processes and embryonic development, respectively. Interestingly, a variety of cathepsins from groups Z, L, D, B, K, and S were upregulated in the infective stage of copepodid, corroborating the complexity of the processes involved in the parasitic success of this copepod. Putative functional roles of cathepsins were conjectured based on the differential expressions found and on roles previously described in other phylogenetically related species. Moreover, 140 single nucleotide polymorphisms (SNP) were identified in transcripts annotated for cysteine and aspartic proteases located into untranslated regions, or the coding region. This study reports for the first time the presence of cathepsin-like genes and differential expressions throughout a copepod lifecycle. The identification of cathepsins together with functional validations represents a valuable strategy for pinpointing target molecules that could be used in the development of new delousing drugs or vaccines against C. rogercresseyi. PMID:25923525

Cathepsin Gene Family Reveals Transcriptome Patterns Related to the Infective Stages of the Salmon Louse Caligus rogercresseyi.

PubMed

Maldonado-Aguayo, Waleska; Chávez-Mardones, Jacqueline; Gonçalves, Ana Teresa; Gallardo-Escárate, Cristian

2015-01-01

Cathepsins are proteases involved in the ability of parasites to overcome and/or modulate host defenses so as to complete their own lifecycle. However, the mechanisms underlying this ability of cathepsins are still poorly understood. One excellent model for identifying and exploring the molecular functions of cathepsins is the marine ectoparasitic copepod Caligus rogercresseyi that currently affects the Chilean salmon industry. Using high-throughput transcriptome sequencing, 56 cathepsin-like sequences were found distributed in five cysteine protease groups (B, F, L, Z, and S) as well as in an aspartic protease group (D). Ontogenic transcriptome analysis evidenced that L cathepsins were the most abundant during the lifecycle, while cathepsins B and K were mostly expressed in the larval stages and adult females, thus suggesting participation in the molting processes and embryonic development, respectively. Interestingly, a variety of cathepsins from groups Z, L, D, B, K, and S were upregulated in the infective stage of copepodid, corroborating the complexity of the processes involved in the parasitic success of this copepod. Putative functional roles of cathepsins were conjectured based on the differential expressions found and on roles previously described in other phylogenetically related species. Moreover, 140 single nucleotide polymorphisms (SNP) were identified in transcripts annotated for cysteine and aspartic proteases located into untranslated regions, or the coding region. This study reports for the first time the presence of cathepsin-like genes and differential expressions throughout a copepod lifecycle. The identification of cathepsins together with functional validations represents a valuable strategy for pinpointing target molecules that could be used in the development of new delousing drugs or vaccines against C. rogercresseyi.

A survey of wild marine fish identifies a potential origin of an outbreak of viral haemorrhagic septicaemia in wrasse, Labridae, used as cleaner fish on marine Atlantic salmon, Salmo salar L., farms.

PubMed

Wallace, I S; Donald, K; Munro, L A; Murray, W; Pert, C C; Stagg, H; Hall, M; Bain, N

2015-06-01

Viral haemorrhagic septicaemia virus (VHSV) was isolated from five species of wrasse (Labridae) used as biological controls for parasitic sea lice predominantly, Lepeophtheirus salmonis (Krøyer, 1837), on marine Atlantic salmon, Salmo salar L., farms in Shetland. As part of the epidemiological investigation, 1400 wild marine fish were caught and screened in pools of 10 for VHSV using virus isolation. Eleven pools (8%) were confirmed VHSV positive from: grey gurnard, Eutrigla gurnardus L.; Atlantic herring, Clupea harengus L.; Norway pout, Trisopterus esmarkii (Nilsson); plaice, Pleuronectes platessa L.; sprat, Sprattus sprattus L. and whiting, Merlangius merlangus L. The isolation of VHSV from grey gurnard is the first documented report in this species. Nucleic acid sequencing of the partial nucleocapsid (N) and glycoprotein (G) genes was carried out for viral characterization. Sequence analysis confirmed that all wild isolates were genotype III the same as the wrasse and there was a close genetic similarity between the isolates from wild fish and wrasse on the farms. Infection from these local wild marine fish is the most likely source of VHSV isolated from wrasse on the fish farms. © 2014 Crown Copyright. Journal of Fish Diseases © 2014 John Wiley & Sons Ltd.

Salmon on the Edge: Growth and Condition of Juvenile Chum and Pink Salmon in the Northeastern Bering Sea

NASA Astrophysics Data System (ADS)

McPhee, M. V.

2016-02-01

As the Arctic and Subarctic regions warm, Pacific salmon (Oncorhynchus spp.) are expected to expand their range northward during ice-free periods in the Bering and Chukchi seas. The oscillating control hypothesis, which describes energetic differences of primary consumers between ice-associated and pelagic production phases, provides a framework for understanding how juvenile salmon might respond to changing conditions at the northern edge of their marine range. Additionally, relationships between growth/condition and temperature, salinity and bottom depth will help identify marine habitats supporting growth at the Arctic-Subarctic interface. In this study, we used survey data from NOAA and Arctic Ecosystem Integrated Survey project to 1) compare growth and condition of juvenile pink (O. gorbuscha) and chum (O. keta) salmon in the NE Bering Sea between warm and cool spring phases, and 2) describe relationships between summer environmental conditions and juvenile salmon growth and condition from 2006 - 2010. Chum and pink salmon were shorter, and chum salmon exhibited greater energy density, in years with cool springs; however, no other aspects of size and condition differed significantly between phases. Over all years, longer and more energy dense individuals of both species were caught at stations with greater bottom depths and in cooler sea-surface temperatures. We found little evidence that chlorophyll-a explained much of the variation in size or condition. We used insulin-like growth factor-1 (IGF-1) concentration as an indicator of relative growth rate for fishes sampled in 2009-2012 and that found juvenile salmon exhibited higher IGF-1 concentrations in 2010-2012 than in 2009. IGF-1 concentrations tended to increase with SST in chum salmon and with bottom depth (a proxy for distance from shore) in pink salmon, but more years of data are needed to adequately describe the relationship of IGF with environmental conditions. This study, although descriptive in

Future of Pacific salmon in the face of environmental change: Lessons from one of the world's remaining productive salmon regions

USGS Publications Warehouse

Schoen, Erik R.; Wipfli, Mark S.; Trammell, Jamie; Rinella, Daniel J.; Floyd, Angelica L.; Grunblatt, Jess; McCarthy, Molly D.; Meyer, Benjamin E.; Morton, John M.; Powell, James E.; Prakash, Anupma; Reimer, Matthew N.; Stuefer, Svetlana L.; Toniolo, Horacio; Wells, Brett M.; Witmer, Frank D. W.

2017-01-01

Pacific salmon Oncorhynchus spp. face serious challenges from climate and landscape change, particularly in the southern portion of their native range. Conversely, climate warming appears to be allowing salmon to expand northwards into the Arctic. Between these geographic extremes, in the Gulf of Alaska region, salmon are at historically high abundances but face an uncertain future due to rapid environmental change. We examined changes in climate, hydrology, land cover, salmon populations, and fisheries over the past 30–70 years in this region. We focused on the Kenai River, which supports world-famous fisheries but where Chinook Salmon O. tshawytscha populations have declined, raising concerns about their future resilience. The region is warming and experiencing drier summers and wetter autumns. The landscape is also changing, with melting glaciers, wetland loss, wildfires, and human development. This environmental transformation will likely harm some salmon populations while benefiting others. Lowland salmon streams are especially vulnerable, but retreating glaciers may allow production gains in other streams. Some fishing communities harvest a diverse portfolio of fluctuating resources, whereas others have specialized over time, potentially limiting their resilience. Maintaining diverse habitats and salmon runs may allow ecosystems and fisheries to continue to thrive amidst these changes.

Transmission ratio distortion in the human body louse, Pediculus humanus (Insecta: Phthiraptera).

PubMed

McMeniman, C J; Barker, S C

2006-01-01

We studied inheritance at three microsatellite loci in eight F, and two F2 families of the body (clothes) louse of humans, Pediculus humanus. The alleles of heterozygous female-parents were always inherited in a Mendelian fashion in these families. Alleles from heterozygous male-parents, however, were inherited in two different ways: (i) in a Mendelian fashion and (ii) in a non-Mendelian fashion, where males passed to their offspring only one of their two alleles, that is, 100% nonrandom transmission. In male body lice, where there was non-Mendelian inheritance, the paternally inherited set of alleles was eliminated. We interpret this pattern of inheritance as evidence for extreme transmission ratio distortion of paternal alleles in this species.

Comparative immunity of Salmo salar and Oncorhynchus kisutch during infestation with the sea louse Caligus rogercresseyi: An enrichment transcriptome analysis.

PubMed

Valenzuela-Muñoz, Valentina; Boltaña, Sebastian; Gallardo-Escárate, Cristian

2016-12-01

Caligus rogercresseyi, an ectoparasite affecting the Chilean salmon industry, can cause immunosuppression and physiological stress in farmed fish. Interestingly, coho salmon (Oncorhynchus kisutch) are notably resistant to infestation, whereas Atlantic salmon (Salmo salar) are phenotypically more susceptible to sea lice. However, comparative studies on immune responses to C. rogercresseyi have not been conducted. In this study, Illumina sequencing was conducted to evaluate head kidney and skin samples taken 7 and 14 days post-infestation, yielding a total of 1492 and 1522 contigs annotated to immune-related genes for Atlantic and coho salmon, respectively. Both species evidenced an upregulation of inflammatory genes. Atlantic salmon had highly upregulated TLR22 and MHCII at 14 days post-infestation, while coho salmon had highly upregulated stat5 and il1r transcripts. Fourteen transcripts related to T H 1, T H 2, TLR, and macrophage responses were corroborated via RT-qPCR. Statistical analyses indicated an upregulation of mmp13, cox2, il10, ccr3, tlr22a2, and tlr21 in Atlantic salmon and of ifnγ, cd83, T-bet, tlr13, and tlr19 in coho salmon. These results suggest strong differences between the Atlantic and coho salmon immune responses, where coho salmon, the more resistant species, presented a primary T H 1 response. Additionally, putative roles of TLRs in salmonids against sea lice were evidenced. This study is the first comparative transcriptome analysis that reveals species-specific immune responses in salmons infected with C. rogercresseyi. Copyright © 2016 Elsevier Ltd. All rights reserved.

The sex ratio distortion in the human head louse is conserved over time

PubMed Central

Perotti, M Alejandra; Catalá, Silvia S; Ormeño, Analía del V; Żelazowska, Monika; Biliński, Szczepan M; Braig, Henk R

2004-01-01

Background At the turn of the 19th century the first observations of a female-biased sex ratio in broods and populations of the head louse, Pediculus humanus capitis, had been reported. A study by Buxton in 1940 on the sex ratio of lice on prisoners in Ceylon is still today the subject of reanalyses. This sex ratio distortion had been detected in ten different countries. In the last sixty years no new data have been collected, especially on scalp infestations under economically and socially more developed conditions. Results Here we report a female bias of head lice in a survey of 480 school children in Argentina. This bias is independent of the intensity of the pediculosis, which makes local mate competition highly unlikely as the source of the aberrant sex ratio; however, other possible adaptive mechanisms cannot be discounted. These lice as well as lice from pupils in Britain were carrying several strains of the endosymbiotic bacterium Wolbachia pipientis, one of the most wide spread intracellular sex ratio distorters. Similar Wolbachia strains are also present in the pig louse, Haematopinus suis, suggesting that this endosymbiont might have a marked influence on the biology of the whole order. The presence of a related obligate nutritional bacterium in lice prevents the investigation of a causal link between sex ratio and endosymbionts. Conclusions Regardless of its origin, this sex ratio distortion in head lice that has been reported world wide, is stable over time and is a remarkable deviation from the stability of frequency-dependent selection of Fisher's sex ratio. A female bias first reported in 1898 is still present over a hundred years and a thousand generations later. PMID:15140268

Pacific salmon (Oncorhynchus spp.) runs and consumer fitness: growth and energy storage in stream-dwelling salmonids increase with salmon spawner density

USGS Publications Warehouse

Rinella, Daniel J.; Wipfli, Mark S.; Stricker, Craig A.; Heintz, Ron A.; Rinella, Matthew J.

2012-01-01

We examined how marine-derived nutrients (MDN), in the form of spawning Pacific salmon, influenced the nutritional status and δ15N of stream-dwelling fishes. We sampled juvenile coho salmon (Oncorhynchus kisutch) and Dolly Varden (Salvelinus malma) during spring and fall from 11 south-central Alaskan streams that ranged widely in spawning salmon biomass (0.1–4.7 kg·m–2). Growth rate (as indexed by RNA–DNA ratios), energy density, and δ15N enrichment in spring-sampled fishes increased with spawner biomass, indicating the persistence of spawner effects more than 6 months after salmon spawning. Point estimates suggest that spawner effects on nutrition were substantially greater for coho salmon than Dolly Varden (268% and 175% greater for growth and energy, respectively), indicating that both species benefitted physiologically, but that juvenile coho salmon accrued more benefits than Dolly Varden. Although the data were less conclusive for fall- than spring-sampled fish, they do suggest spawner effects were also generally positive during fall, soon after salmon spawned. In a follow-up analysis where growth rate and energy density were modeled as a function of δ15N enrichment, results suggested that both increased with MDN assimilation, especially in juvenile coho salmon. Our results support the importance of salmon runs to the nutritional ecology of stream-dwelling fishes.

Restitution and genetic differentiation of salmon populations in the southern Baltic genotyped with the Atlantic salmon 7K SNP array.

PubMed

Poćwierz-Kotus, Anita; Bernaś, Rafał; Kent, Matthew P; Lien, Sigbjørn; Leliűna, Egidijus; Dębowski, Piotr; Wenne, Roman

2015-05-06

Native populations of Atlantic salmon in Poland, from the southern Baltic region, became extinct in the 1980s. Attempts to restitute salmon populations in Poland have been based on a Latvian salmon population from the Daugava river. Releases of hatchery reared smolts started in 1986, but to date, only one population with confirmed natural reproduction has been observed in the Slupia river. Our aim was to investigate the genetic differentiation of salmon populations in the southern Baltic using a 7K SNP (single nucleotide polymorphism) array in order to assess the impact of salmon restitution in Poland. One hundred and forty salmon samples were collected from: the Polish Slupia river including wild salmon and individuals from two hatcheries, the Swedish Morrum river and the Lithuanian Neman river. All samples were genotyped using an Atlantic salmon 7K SNP array. A set of 3218 diagnostic SNPs was used for genetic analyses. Genetic structure analyses indicated that the individuals from the investigated populations were clustered into three groups i.e. one clade that included individuals from both hatcheries and the wild population from the Polish Slupia river, which was clearly separated from the other clades. An assignment test showed that there were no stray fish from the Morrum or Neman rivers in the sample analyzed from the Slupia river. Global FST over polymorphic loci was high (0.177). A strong genetic differentiation was observed between the Lithuanian and Swedish populations (FST = 0.28). Wild juvenile salmon specimens that were sampled from the Slupia river were the progeny of fish released from hatcheries and, most likely, were not progeny of stray fish from Sweden or Lithuania. Strong genetic differences were observed between the salmon populations from the three studied locations. Our recommendation is that future stocking activities that aim at restituting salmon populations in Poland include stocking material from the Lithuanian Neman river because of

[An outbreak of epidemic louse-borne typhus in Tokyo 1914: a study on the prevention of epidemics].

PubMed

Watanabe, Mikio

2002-12-01

In 1914, the third year of the Taisho era, a period of democracy and prosperity of Japan, Tokyo was attached by an outbreak of epidemic louse-borne typhus. The number of patients was 4,119 and number of deaths was 778 (mortality rate of 18.9%) in Tokyo and 7,309 patients had been suffering from typhus fever that year in Japan. Many possible causes of the outbreak were suspected by the Health Authority of the Home Office, but these were not confirmed. One of the most likely reasons is the poor and congested living conditions of seasonal construction workers. Laborers had moved from the northwest region of Japan where typhus fever had developed occasionally in those days. Some of the laborers probably brought pathogenic germs with lice. The main preventive method for epidemic louse-borne typhus was isolation of patients and disinfecting of the areas. Kitasato Shibasaburou proposed the improvement of residential conditions of workers to prevent the prevalence of disease, but the proposal was not accepted because of financial reasons of the government. Recurrence of the outbreak did not occur in the following years. However, a huge outbreak of typhus fever with 32,366 patients and 3,351 deaths, was documented in 1946, amidst the disordered conditions of Japan after World War II.

Temperature and humidity effects on off-host survival of the Northern fowl mite (Acari: Macronyssidae) and the chicken body louse (Phthiraptera: Menoponidae).

PubMed

Chen, Brian L; Mullens, Bradley A

2008-04-01

Off-host survival of the northern fowl mite, Ornithonyssus sylviarum (Canestrini & Fanzago) (Acari: Macronyssidae), and the chicken body louse, Menacanthus stramineus (Nitzsch) (Phthiraptera: Menoponidae), was studied at 12 combinations of temperature (15, 21, 27, and 33 degrees C) and humidity (31, 65, and 85% RH). Mite protonymphs and louse third instars survived longer on average than the respective adult stages. Higher temperatures significantly reduced survival of adult and immature stages of both ectoparasites, whereas relative humidity had significant effects on O. sylviarum (especially protonymphs) but not M. stramineus. The LT50 values for adult northern fowl mites ranged from 1.9 (at 33 degrees C, 31%RH) to 8.3 d (at 15 degrees C, 85%RH), LT50 values for mite protonymphs ranged from 2.0 (at 33 degrees C, 31%RH) to 18.1 d (at 15 degrees C, 85%RH), LT50 values for adult lice ranged from 0.5 (at 33 degrees C, 31%RH) to 1.7 d (at 15 degrees C, 65%RH), and LT50 values for nymphal lice ranged from 1.2 (at 33 degrees C, 65%RH) to 3.3 d (at 21 degrees C, 31%RH). Maximum survival of the northern fowl mite was up to 35 d for adults and 29 d for protonymphs. Maximum survival for the chicken body louse was 3.3 d for adults and 5.8 d for nymphs. The data provide minimum guidelines for leaving poultry houses vacant long enough to allow ectoparasites to die before introduction of subsequent new flocks.

Infectious diseases of Pacific salmon

USGS Publications Warehouse

1954-01-01

A variety of bacteria has been found responsible for outbreaks of disease in salmon in sea water. The most important of these is a species of Vibrio. Tuberculosis has been found in adult chinook salmon and the evidence indicates that the disease was contracted at sea.

Comparative anatomy of the dorsal hump in mature Pacific salmon.

PubMed

Susuki, Kenta; Ban, Masatoshi; Ichimura, Masaki; Kudo, Hideaki

2017-07-01

Mature male Pacific salmon (Genus Oncorhynchus) demonstrate prominent morphological changes, such as the development of a dorsal hump. The degree of dorsal hump formation depends on the species in Pacific salmon. It is generally accepted that mature males of sockeye (O. nerka) and pink (O. gorbuscha) salmon develop most pronounced dorsal humps. The internal structure of the dorsal hump in pink salmon has been confirmed in detail. In this study, the dorsal hump morphologies were analyzed in four Pacific salmon species inhabiting Japan, masu (O. masou), sockeye, chum (O. keta), and pink salmon. The internal structure of the dorsal humps also depended on the species; sockeye and pink salmon showed conspicuous development of connective tissue and growth of bone tissues in the dorsal tissues. Masu and chum salmon exhibited less-pronounced increases in connective tissues and bone growth. Hyaluronic acid was clearly detected in dorsal hump connective tissue by histochemistry, except for in masu salmon. The lipid content in dorsal hump connective tissue was richer in masu and chum salmon than in sockeye and pink salmon. These results revealed that the patterns of dorsal hump formation differed among species, and especially sockeye and pink salmon develop pronounced dorsal humps through both increases in the amount of connective tissue and the growth of bone tissues. In contrast, masu and chum salmon develop their dorsal humps by the growth of bone tissues, rather than the development of connective tissue. © 2017 Wiley Periodicals, Inc.

Estuarine Ecology of Juvenile Salmon in Western Alaska: a Review

USGS Publications Warehouse

Zimmerman, Christian E.; Hillgruber, Nicola

2009-01-01

In the late 1990s and early 2000s, large declines in numbers of chum salmon Oncorhynchus keta and Chinook salmon O. tshawytscha returning to the Arctic-YukonKuskokwim (AYK) region (Alaska, USA) illuminated the need for an improved understanding of the variables controlling salmon abundance at all life stages. In addressing questions about salmon abundance, large gaps in our knowledge of basic salmon life history and the critical early marine life stage were revealed. In this paper, results from studies conducted on the estuarine ecology of juvenile salmon in western Alaska are summarized and compared, emphasizing timing and distribution during outmigration, environmental conditions, age and growth, feeding, and energy content of salmon smolts. In western Alaska, water temperature dramatically changes with season, ranging from 0°C after ice melt in late spring/early summer to 19°C in July. Juvenile salmon were found in AYK estuaries from early May until August or September, but to date no information is available on their residence duration or survival probability. Chum salmon were the most abundant juvenile salmon reported, ranging in percent catch from <0.1% to 4.7% and most research effort has focused on this species. Abundances of Chinook salmon, sockeye salmon O. nerka, and pink salmon O. gorbuscha varied among estuaries, while coho salmon O. kisutch juveniles were consistently rare, never amounting to more than 0.8% of the catch. Dietary composition of juvenile salmon was highly variable and a shift was commonly reported from epibenthic and neustonic prey in lower salinity water to pelagic prey in higher salinity water. Gaps in the knowledge of AYK salmon estuarine ecology are still evident. For example, data on outmigration patterns and residence timing and duration, rearing conditions and their effect on diet, growth, and survival are often completely lacking or available only for few selected years and sites. Filling gaps in knowledge concerning salmon

Identification of Different Bartonella Species in the Cattle Tail Louse (Haematopinus quadripertusus) and in Cattle Blood

PubMed Central

Gutiérrez, Ricardo; Cohen, Liron; Morick, Danny; Mumcuoglu, Kosta Y.; Harrus, Shimon

2014-01-01

Bartonella spp. are worldwide-distributed facultative intracellular bacteria that exhibit an immense genomic diversity across mammal and arthropod hosts. The occurrence of cattle-associated Bartonella species was investigated in the cattle tail louse Haematopinus quadripertusus and in dairy cattle blood from Israel. Lice were collected from cattle from two dairy farms during summer 2011, and both lice and cow blood samples were collected from additional seven farms during the successive winter. The lice were identified morphologically and molecularly using 18S rRNA sequencing. Thereafter, they were screened for Bartonella DNA by conventional and real-time PCR assays using four partial genetic loci (gltA, rpoB, ssrA, and internal transcribed spacer [ITS]). A potentially novel Bartonella variant, closely related to other ruminant bartonellae, was identified in 11 of 13 louse pools collected in summer. In the cattle blood, the prevalence of Bartonella infection was 38%, identified as B. bovis and B. henselae (24 and 12%, respectively). A third genotype, closely related to Bartonella melophagi and Bartonella chomelii (based on the ssrA gene) and to B. bovis (based on the ITS sequence) was identified in a single cow. The relatively high prevalence of these Bartonella species in cattle and the occurrence of phylogenetically diverse Bartonella variants in both cattle and their lice suggest the potential role of this animal system in the generation of Bartonella species diversity. PMID:24973066

The atlantic salmon: Genetics, conservation and management

USGS Publications Warehouse

Verspoor, Eric; Stradmeyer, Lee; Nielsen, Jennifer L.

2007-01-01

Atlantic Salmon is a cultural icon throughout its North Atlantic range; it is the focus of probably the World’s highest profile recreational fishery and is the basis for one of the World’s largest aquaculture industries. Despite this, many wild stocks of salmon are in decline and underpinning this is a dearth of information on the nature and extent of population structuring and adaptive population differentiation, and its implications for species conservation.This important new book will go a long way to rectify this situation by providing a thorough review of the genetics of Atlantic salmon. Sponsored by the European Union and the Atlantic Salmon Trust, this book comprises the work of an international team of scientists, carefully integrated and edited to provide a landmark book of vital interest to all those working with Atlantic salmon.

Diel variation in summer habitat use, feeding periodicity, and diet of subyearling Atlantic salmon in the Salmon River Basin, New York

USGS Publications Warehouse

Johnson, James H.

2013-01-01

The habitat use, diet composition, and feeding periodicity of subyearling Atlantic salmon (Salmo salar) was examined during both day and night periods during summer in tributaries of Lake Ontario. The amount of cover used was the major habitat variable that differed between day and night periods in both streams. At night subyearling Atlantic salmon were associated with significantly less cover than during the day. Principal Component Analysis showed that habitat selection of subyearling Atlantic salmon was more pronounced during the day in both streams and that salmon in Orwell Brook exhibited more diel variability in habitat use than salmon in Trout Brook. Subyearling salmon fed primarily from the benthic substrate on baetids, chironomids, and leptocerids. There was a substantial amount of diel variation in diet composition with peak feeding occurring from 0400 h to 0800 h on July 21–22, 2008.

Updraft gasification of salmon processing waste.

PubMed

Rowland, Sarah; Bower, Cynthia K; Patil, Krushna N; DeWitt, Christina A Mireles

2009-10-01

The purpose of this study was to judge the feasibility of gasification for the disposal of waste streams generated through salmon harvesting. Gasification is the process of converting carbonaceous materials into combustible "syngas" in a high temperature (above 700 degrees C), oxygen deficient environment. Syngas can be combusted to generate power, which recycles energy from waste products. At 66% to 79% moisture, raw salmon waste streams are too wet to undergo pyrolysis and combustion. Ground raw or de-oiled salmon whole fish, heads, viscera, or frames were therefore "dried" by mixing with wood pellets to a final moisture content of 20%. Ground whole salmon with moisture reduced to 12% moisture was gasified without a drying agent. Gasification tests were performed in a small-scale, fixed-bed, updraft gasifer. After an initial start-up period, the gasifier was loaded with 1.5 kg of biomass. Temperature was recorded at 6 points in the gasifier. Syngas was collected during the short steady-state period during each gasifier run and analyzed. Percentages of each type of gas in the syngas were used to calculate syngas heating value. High heating value (HHV) ranged from 1.45 to 1.98 MJ/kg. Bomb calorimetry determined maximum heating value for the salmon by-products. Comparing heating values shows the efficiency of gasification. Cold gas efficiencies of 13.6% to 26% were obtained from the various samples gasified. Though research of gasification as a means of salmon waste disposal and energy production is ongoing, it can be concluded that pre-dried salmon or relatively low moisture content mixtures of waste with wood are gasifiable.

Concentrations of trace elements in Pacific and Atlantic salmon

NASA Astrophysics Data System (ADS)

Khristoforova, N. K.; Tsygankov, V. Yu.; Boyarova, M. D.; Lukyanova, O. N.

2015-09-01

Concentrations of Hg, As, Cd, Pb, Zn, and Cu were analyzed in the two most abundant species of Pacific salmon, chum and pink salmon, caught in the Kuril Islands at the end of July, 2013. The concentrations of toxic elements (Hg, As, Pb, Cd) in males and females of these species are below the maximum permissible concentrations for seafood. It was found that farmed filleted Atlantic salmon are dominated by Zn and Cu, while muscles of wild salmon are dominated by Pb. Observed differences are obviously related to peculiar environmental geochemical conditions: anthropogenic impact for Atlantic salmon grown in coastal waters and the influence of the natural factors volcanism and upwelling for wild salmon from the Kuril waters.

Host specificity of Lepeophtheirus crassus (Wilson and Bere) (Copepoda: Caligidae) parasitic on the marlin sucker Remora osteochir (Cuvier) in the Atlantic Ocean.

PubMed

Ho, Ju-shey; Collete, Bruce B; Madinabeitia, Ione

2006-10-01

Three species of remoras--Remora brachyptera (Lowe), Remora osteochir (Cuvier), and Remora remora (Linnaeus)--were collected from 4 species of billfishes--Istiophorus platypterus (Shaw), Makaira nigricans Lacepéde, Tetrapturus albidus Poey, and Tetrapturus pfluegeri Robins and de Sylva--on board a Japanese long-liner Shoyo Maru during her cruise in 2002 across the Atlantic. However, only the marlin sucker (R. osteochir) was found to carry a parasitic copepod, Lepeophtheirus crassus (Wilson and Bere, 1936). Although 12 species of parasitic copepods have been reported from billfishes around the world ocean, none of them is L. crassus. Thus, L. crassus is considered a parasite specific to the marlin sucker.

Geomorphology and the Restoration Ecology of Salmon

NASA Astrophysics Data System (ADS)

Montgomery, D. R.

2005-05-01

Natural and anthropogenic influences on watershed processes affect the distribution and abundance of salmon across a wide range of spatial and temporal scales, from differences in species use and density between individual pools and riffles to regional patterns of threatened, endangered, and extinct runs. The specific impacts of human activities (e.g., mining, logging, and urbanization) vary among regions and watersheds, as well as between different channel reaches in the same watershed. Understanding of both disturbance history and key biophysical processes are important for diagnosing the nature and causes of differences between historical and contemporary fluvial and watershed conditions based on evaluation of both historical and spatial contexts. In order to be most effective, the contribution of geomorphologic insight to salmon recovery efforts requires both assessment protocols commensurate with providing adequate knowledge of historical and spatial context, and experienced practitioners well versed in adapting general theory to local settings. The historical record of salmon management in Europe, New England and the Pacific Northwest indicates that there is substantial need to incorporate geomorphic insights on the effects of changes in watershed processes on salmon habitat and salmon abundance into salmon recovery efforts.

Plasticity in growth of farmed and wild Atlantic salmon: is the increased growth rate of farmed salmon caused by evolutionary adaptations to the commercial diet?

PubMed

Harvey, Alison Catherine; Solberg, Monica Favnebøe; Troianou, Eva; Carvalho, Gary Robert; Taylor, Martin Ian; Creer, Simon; Dyrhovden, Lise; Matre, Ivar Helge; Glover, Kevin Alan

2016-12-01

Domestication of Atlantic salmon for commercial aquaculture has resulted in farmed salmon displaying substantially higher growth rates than wild salmon under farming conditions. In contrast, growth differences between farmed and wild salmon are much smaller when compared in the wild. The mechanisms underlying this contrast between environments remain largely unknown. It is possible that farmed salmon have adapted to the high-energy pellets developed specifically for aquaculture, contributing to inflated growth differences when fed on this diet. We studied growth and survival of 15 families of farmed, wild and F1 hybrid salmon fed three contrasting diets under hatchery conditions; a commercial salmon pellet diet, a commercial carp pellet diet, and a mixed natural diet consisting of preserved invertebrates commonly found in Norwegian rivers. For all groups, despite equal numbers of calories presented by all diets, overall growth reductions as high 68 and 83%, relative to the salmon diet was observed in the carp and natural diet treatments, respectively. Farmed salmon outgrew hybrid (intermediate) and wild salmon in all treatments. The relative growth difference between wild and farmed fish was highest in the carp diet (1: 2.1), intermediate in the salmon diet (1:1.9) and lowest in the natural diet (1:1.6). However, this trend was non-significant, and all groups displayed similar growth reaction norms and plasticity towards differing diets across the treatments. No indication of genetic-based adaptation to the form or nutritional content of commercial salmon diets was detected in the farmed salmon. Therefore, we conclude that diet alone, at least in the absence of other environmental stressors, is not the primary cause for the large contrast in growth differences between farmed and wild salmon in the hatchery and wild. Additionally, we conclude that genetically-increased appetite is likely to be the primary reason why farmed salmon display higher growth rates than

Determinants of public attitudes to genetically modified salmon.

PubMed

Amin, Latifah; Azad, Md Abul Kalam; Gausmian, Mohd Hanafy; Zulkifli, Faizah

2014-01-01

The objective of this paper is to assess the attitude of Malaysian stakeholders to genetically modified (GM) salmon and to identify the factors that influence their acceptance of GM salmon using a structural equation model. A survey was carried out on 434 representatives from various stakeholder groups in the Klang Valley region of Malaysia. Public attitude towards GM salmon was measured using self-developed questionnaires with seven-point Likert scales. The findings of this study have confirmed that public attitudes towards GM salmon is a complex issue and should be seen as a multi-faceted process. The most important direct predictors for the encouragement of GM salmon are the specific application-linked perceptions about religious acceptability of GM salmon followed by perceived risks and benefits, familiarity, and general promise of modern biotechnology. Encouragement of GM salmon also involves the interplay among other factors such as general concerns of biotechnology, threatening the natural order of things, the need for labeling, the need for patenting, confidence in regulation, and societal values. The research findings can serve as a database that will be useful for understanding the social construct of public attitude towards GM foods in a developing country.

Determinants of Public Attitudes to Genetically Modified Salmon

PubMed Central

Amin, Latifah; Azad, Md. Abul Kalam; Gausmian, Mohd Hanafy; Zulkifli, Faizah

2014-01-01

The objective of this paper is to assess the attitude of Malaysian stakeholders to genetically modified (GM) salmon and to identify the factors that influence their acceptance of GM salmon using a structural equation model. A survey was carried out on 434 representatives from various stakeholder groups in the Klang Valley region of Malaysia. Public attitude towards GM salmon was measured using self-developed questionnaires with seven-point Likert scales. The findings of this study have confirmed that public attitudes towards GM salmon is a complex issue and should be seen as a multi-faceted process. The most important direct predictors for the encouragement of GM salmon are the specific application-linked perceptions about religious acceptability of GM salmon followed by perceived risks and benefits, familiarity, and general promise of modern biotechnology. Encouragement of GM salmon also involves the interplay among other factors such as general concerns of biotechnology, threatening the natural order of things, the need for labeling, the need for patenting, confidence in regulation, and societal values. The research findings can serve as a database that will be useful for understanding the social construct of public attitude towards GM foods in a developing country. PMID:24489695

Antibody against infectious salmon anaemia virus among feral Atlantic salmon (Salmo salar)

USGS Publications Warehouse

Cipriano, R.C.

2009-01-01

Archived sera from Atlantic salmon (Salmo salar) that returned to the Penobscot River (Maine), Merrimack River (Massachusetts), and Connecticut River (in Massachusetts) from 1995 to 2002 were analysed for antibodies against infectious salmon anaemia virus (ISAV) using an enzyme-linked immunosorbent assay (ELISA). Up to 60 samples were archived per river system per year. In a given year, the number of fish sampled by ELISA for ISAV antibodies in the Penobscot River ranged from 2.9 to 11.2, and the range of salmon sampled in the Merrimack River and the Connecticut River was 31.3-100 and 20.0-67.5, respectively. Archived sera were not available for the 1995 and 2002 year classes from the Connecticut River. In all, 1141 samples were processed; 14 serum samples tested positive for antibodies to ISAV. In the Penobscot River, serum from one fish tested positive in each of the 1995 and 1999 year-class returns, and sera from two fish tested positive in the 1998 returns. In the Merrimack River, sera from four fish tested positive in each of the 1996 and 1997 returns, and sera from two fish were positive in the 2002 return. None of the archived sera from Atlantic salmon that returned to the Connecticut River tested positive. ?? 2009 United States Government, Department of the Interior.

Diet, feeding patterns, and prey selection of subyearling Atlantic salmon (Salmo salar) and subyearling chinook salmon (Oncorhynchus tshawytscha) in a tributary of Lake Ontario

USGS Publications Warehouse

Johnson, J. H.; Nash, K. J.; Chiavelli, R. A.; DiRado, J. A.; Mackey, G. E.; Knight, J. R.; Diaz, A. R.

2017-01-01

Since juvenile Atlantic salmon (Salmo salar) and Chinook salmon (Oncorhynchus tshawytscha) occupy a similar habitat in Lake Ontario tributaries, we sought to determine the degree of diet similarity between these species in order to assess the potential for interspecific competition. Atlantic salmon, an historically important but currently extirpated component of the Lake Ontario fish community, are the focus of a bi-national restoration effort. Presently this effort includes the release of hatchery produced juvenile Atlantic salmon in Lake Ontario tributaries. These same tributaries support substantial numbers of naturally reproduced juvenile Pacific salmonids including Chinook salmon. Subyearling Atlantic salmon and subyearling Chinook salmon had significantly different diets during each of the three time periods examined. Atlantic salmon fed slightly more from the benthos than from the drift and consumed mainly chirononmids (47.0%) and ephemeropterans (21.1%). The diet of subyearling Chinook salmon was more closely associated with the drift and consisted mainly of chironomids (60.2%) and terrestrial invertebrates (16.0%). Low diet similarity between subyearling Atlantic salmon and subyearling Chinook salmon likely minimizes competitive interactions for food between these species in Lake Ontario tributaries. However, the availability of small prey such as chironomids which comprise over 50% of the diet of each species, soon after emergence, could constitute a short term resource limitation. To our knowledge this is the first study of interspecific diet associations between these two important salmonid species.

Differential use of salmon by vertebrate consumers: implications for conservation

PubMed Central

Wheat, Rachel E.; Allen, Jennifer M.; Wilmers, Christopher C.

2015-01-01

Salmon and other anadromous fish are consumed by vertebrates with distinct life history strategies to capitalize on this ephemeral pulse of resource availability. Depending on the timing of salmon arrival, this resource may be in surplus to the needs of vertebrate consumers if, for instance, their populations are limited by food availability during other times of year. However, the life history of some consumers enables more efficient exploitation of these ephemeral resources. Bears can deposit fat and then hibernate to avoid winter food scarcity, and highly mobile consumers such as eagles, gulls, and other birds can migrate to access asynchronous pulses of salmon availability. We used camera traps on pink, chum, and sockeye salmon spawning grounds with various run times and stream morphologies, and on individual salmon carcasses, to discern potentially different use patterns among consumers. Wildlife use of salmon was highly heterogeneous. Ravens were the only avian consumer that fed heavily on pink salmon in small streams. Eagles and gulls did not feed on early pink salmon runs in streams, and only moderately at early sockeye runs, but were the dominant consumers at late chum salmon runs, particularly on expansive river flats. Brown bears used all salmon resources far more than other terrestrial vertebrates. Notably, black bears were not observed on salmon spawning grounds despite being the most frequently observed vertebrate on roads and trails. From a conservation and management perspective, all salmon species and stream morphologies are used extensively by bears, but salmon spawning late in the year are disproportionately important to eagles and other highly mobile species that are seasonally limited by winter food availability. PMID:26339539

Multivariate Models of Adult Pacific Salmon Returns

PubMed Central

Burke, Brian J.; Peterson, William T.; Beckman, Brian R.; Morgan, Cheryl; Daly, Elizabeth A.; Litz, Marisa

2013-01-01

Most modeling and statistical approaches encourage simplicity, yet ecological processes are often complex, as they are influenced by numerous dynamic environmental and biological factors. Pacific salmon abundance has been highly variable over the last few decades and most forecasting models have proven inadequate, primarily because of a lack of understanding of the processes affecting variability in survival. Better methods and data for predicting the abundance of returning adults are therefore required to effectively manage the species. We combined 31 distinct indicators of the marine environment collected over an 11-year period into a multivariate analysis to summarize and predict adult spring Chinook salmon returns to the Columbia River in 2012. In addition to forecasts, this tool quantifies the strength of the relationship between various ecological indicators and salmon returns, allowing interpretation of ecosystem processes. The relative importance of indicators varied, but a few trends emerged. Adult returns of spring Chinook salmon were best described using indicators of bottom-up ecological processes such as composition and abundance of zooplankton and fish prey as well as measures of individual fish, such as growth and condition. Local indicators of temperature or coastal upwelling did not contribute as much as large-scale indicators of temperature variability, matching the spatial scale over which salmon spend the majority of their ocean residence. Results suggest that effective management of Pacific salmon requires multiple types of data and that no single indicator can represent the complex early-ocean ecology of salmon. PMID:23326586

THE FUTURE OF PACIFIC NORTHWEST SALMON: ANATOMY OF A CRISIS

EPA Science Inventory

Salmon are categorized biologically into two groups: Pacific salmon or Atlantic salmon. All seven species of Pacific salmon on both sides of the North Pacific Ocean have declined substantially from historic levels, but large runs still occur in northern British Columbia, Yukon,...

The reproductive effort of Lepeophtheirus pectoralis (Copepoda: Caligidae): insights into the egg production strategy of parasitic copepods.

PubMed

Frade, D G; Santos, M J; Cavaleiro, F I

2016-01-01

The reproductive effort of Lepeophtheirus pectoralis (Müller O. F., 1776), a caligid copepod, which is commonly found infecting the European flounder, Platichthys flesus (Linnaeus, 1758), is studied in detail for the first time. Seasonal variation in body dimensions and reproductive effort are analysed. Data for 120 ovigerous females, 30 from each season of the year, were considered in the analyses. Females were larger and produced a larger number of smaller eggs in winter, than during the summer. The relationship between egg number and egg size is similar to that recorded for other copepods exploiting fish hosts. Much of the recorded variation was also similar to that reported for a copepod parasitic on an invertebrate host, which suggests the possibility of a general trend in copepod reproduction. Overall, our results provide further support for the hypothesis that there is an alternation of summer and winter generations.

Sea lice population and sex differences in P-glycoprotein expression and emamectin benzoate resistance on salmon farms in the Bay of Fundy, New Brunswick, Canada.

PubMed

Igboeli, Okechukwu O; Burka, John F; Fast, Mark D

2014-06-01

Parasitic sea lice are a major challenge for salmon aquaculture. This is especially due to the recent development of resistance to emamectin benzoate (EMB) in the parasite. We investigated: (1) whether EMB treatment success in Grand Manan, Bay of Fundy, NB, Canada can be explained through EMB bioassay and P-glycoprotein (P-gp) mRNA expression studies; (2) if other populations of sea lice not under EMB selective pressure possess similar EMB sensitivity as Grand Manan sea lice populations; and (3) the heritability of EMB resistance in Lepeophtheirus salmonis. EMB bioassay results indicated population, species, sex and temporal differences in EMB EC50 values. RT-qPCR analyses revealed population and sex differences in P-gp mRNA levels, correlating with the bioassay results. Laboratory-reared sea lice maintained their EMB sensitivity status up to the F3 generation. Caligus elongatus, collected from Grand Manan showed more than twofold lower EMB EC50 values compared with L. salmonis collected from the same site. Concurrent exposure to EMB and verapamil yielded no increase in C. elongatus sensitivity to the parasiticide. Sea lice bioassay and P-gp mRNA studies can be used to track EMB resistance and sex differences in EMB sensitivity and P-gp mRNA levels exist in the parasite. © 2013 Society of Chemical Industry.

Chinook salmon foraging patterns in a changing Lake Michigan

USGS Publications Warehouse

Jacobs, Gregory R.; Madenjian, Charles P.; Bunnell, David B.; Warner, David M.; Claramunt, Randall M.

2013-01-01

Since Pacific salmon stocking began in Lake Michigan, managers have attempted to maintain salmon abundance at high levels within what can be sustained by available prey fishes, primarily Alewife Alosa pseudoharengus. Chinook Salmon Oncorhynchus tshawytscha are the primary apex predators in pelagic Lake Michigan and patterns in their prey selection (by species and size) may strongly influence pelagic prey fish communities in any given year. In 1994–1996, there were larger Alewives, relatively more abundant alternative prey species, fewer Chinook Salmon, and fewer invasive species in Lake Michigan than in 2009–2010. The years 2009–2010 were instead characterized by smaller, leaner Alewives, fewer alternative prey species, higher abundance of Chinook Salmon, a firmly established nonnative benthic community, and reduced abundance of Diporeia, an important food of Lake Michigan prey fish. We characterized Chinook Salmon diets, prey species selectivity, and prey size selectivity between 1994–1996 and 2009–2010 time periods. In 1994–1996, Alewife as prey represented a smaller percentage of Chinook Salmon diets than in 2009–2010, when alewife comprised over 90% of Chinook Salmon diets, possibly due to declines in alternative prey fish populations. The size of Alewives eaten by Chinook Salmon also decreased between these two time periods. For the largest Chinook Salmon in 2009–2010, the average size of Alewife prey was nearly 50 mm total length shorter than in 1994–1996. We suggest that changes in the Lake Michigan food web, such as the decline in Diporeia, may have contributed to the relatively low abundance of large Alewives during the late 2000s by heightening the effect of predation from top predators like Chinook Salmon, which have retained a preference for Alewife and now forage with greater frequency on smaller Alewives.

Chimeric mitochondrial minichromosomes of the human body louse, Pediculus humanus: evidence for homologous and non-homologous recombination.

PubMed

Shao, Renfu; Barker, Stephen C

2011-02-15

The mitochondrial (mt) genome of the human body louse, Pediculus humanus, consists of 18 minichromosomes. Each minichromosome is 3 to 4 kb long and has 1 to 3 genes. There is unequivocal evidence for recombination between different mt minichromosomes in P. humanus. It is not known, however, how these minichromosomes recombine. Here, we report the discovery of eight chimeric mt minichromosomes in P. humanus. We classify these chimeric mt minichromosomes into two groups: Group I and Group II. Group I chimeric minichromosomes contain parts of two different protein-coding genes that are from different minichromosomes. The two parts of protein-coding genes in each Group I chimeric minichromosome are joined at a microhomologous nucleotide sequence; microhomologous nucleotide sequences are hallmarks of non-homologous recombination. Group II chimeric minichromosomes contain all of the genes and the non-coding regions of two different minichromosomes. The conserved sequence blocks in the non-coding regions of Group II chimeric minichromosomes resemble the "recombination repeats" in the non-coding regions of the mt genomes of higher plants. These repeats are essential to homologous recombination in higher plants. Our analyses of the nucleotide sequences of chimeric mt minichromosomes indicate both homologous and non-homologous recombination between minichromosomes in the mitochondria of the human body louse. Copyright © 2010 Elsevier B.V. All rights reserved.

SALMON 2100: THE FUTURE OF WILD PACIFIC SALMON

EPA Science Inventory

Many experts have concluded that wild salmon recovery efforts in western North America (especially California, Oregon, Washington, Idaho, and southern British Columbia), as earnest, expensive, and socially disruptive as they currently are, do not appear likely to sustain biologic...

Chronic oral DDT toxicity in juvenile coho and chinook salmon

USGS Publications Warehouse

Buhler, Donald R.; Rasmusson, Mary E.; Shanks, W.E.

1969-01-01

Technical and p,p′-DDT was incorporated into test diets and fed to juvenile chinook and coho salmon for periods as long as 95 days. Pure p,p′-DDT was slightly more toxic to young salmon than was the technical DDT mixture. Chinook salmon appeared to be 2–3 times more sensitive to a given concentration of DDT in the diet than were coho salmon. The size of the fish greatly influenced toxicity, smaller younger fish being more susceptible to a given diet than larger older fish. The dose of DDT accumulated within the median survival time ranged from 27–73 mg/kg for chinook salmon and from 56–72 mg/kg for coho salmon. The extrapolated 90-dose LD50 (Hayes, 1967) for young chinook and coho salmon were 0.0275 and 0.064 mg/kg/day, respectively. Liver size decreased on prolonged feeding with DDT, and carcass lipid content was increased. A severe surface ulceration of the nose region appeared in coho salmon fed DDT over long periods. In addition, an interesting localized degeneration of the distal convoluted tubule was observed in the kidney of coho salmon receiving DDT.

Salmon Mapper

EPA Pesticide Factsheets

Information about the web application to assist pesticide users' with an understanding of the spatial extent of certain pesticide use limitations to protect endangered or threatened salmon and steelhead in California, Oregon and Washington.

California salmon and steelhead: Beyond the crossroads

USGS Publications Warehouse

Mills, Terry J.; McEwan, Dennis R.; Jennings, Mark R.; Stouder, Deanna J.; Bisson, Peter A.; Naiman, Robert J.

1997-01-01

Virtually all California salmon (Oncorhynchus spp.) and steelhead (O. mykiss) stocks have declined to record or near-record low levels during 1980-95. Escapement of naturally spawning Klamath and Sacramento basin fall-run chinook salmon (O. tshawytscha) stocks has fallen consistently below the goals of 35,000 adults (Klamath) and 120,000 adults (Sacramento) established by the Pacific Fishery Management Council. These two stocks constitute the primary management units for ocean harvest regulations in California and southern Oregon. This decline triggered a mandatory review of ocean harvest and inland production conditions in each basin. The Sacramento winter-run chinook salmon, once numbering >100,000 adult spawners, was listed as threatened in 1990 and endangered in 1994 under the Endangered Species Act. The listing occurred as a result of a precipitous decline in abundance (to <200 adult spawners) and significant threats to this stock’s continued existence.Spring-run chinook salmon, historically an abundant component of California’s inland fish fauna with >500,000 adult spawners, has been extirpated from the San Joaquin River basin. However, remnant populations of this naturally spawning stock remain within the Klamath, Smith, and Sacramento river basins. Unfortunately, annual counts of 3,000-25,000 spawners in the Sacramento River basin during the past 25 years are largely of hatchery origin. Recent steelhead data from the same region indicate that many stocks are close to extinction, and nearly all steel-head in the Sacramento River are also of hatchery origin. Both spring-run chinook salmon and summer steelhead are considered to be species of special concern by the California Department of Fish and Game because of their limited distributions and sensitivities to degraded habitat conditions. The southern race of winter steelhead south of Point Conception is nearly extinct and remnant populations have been recently recorded in only 9 streams.Coastal cutthroat

History and effects of hatchery salmon in the Pacific

USGS Publications Warehouse

Nielsen, Jennifer L.; Gallaugher, Patricia; Wood, Laurie

2004-01-01

There has been a long history of production of hatchery salmon along the Pacific coast - from California’s first efforts in the 1870s using eggs from chinook and rainbow trout to the recent large-scale production hatcheries for pink salmon in Japan and the Russian Far East. The rationale for this production has also varied from replacement of fish lost in commercial ocean harvests to mitigation and restoration of salmon in areas where extensive habitat alteration has reduced salmonid viability and abundance. Over the years, we have become very successful in producing a certain type of product from salmon hatcheries, but until recently we seldom questioned the impacts the production and release of hatchery fish may have on freshwater and marine aquatic ecosystems and on the sustainability of sympatric wild salmon populations. This paper addresses the history of hatcheries around the Pacific Rim and considers potential negative implications of hatchery-produced salmon through discussions of biological impacts and biodiversity, ecological impacts and competitive displacement, fish and ecosystem health, and genetic impacts of hatchery fish as threats to wild populations of Pacific salmon.

Habitat Utilization by Juvenile Pink and Chum Salmon in Upper Resurrection Bay, Alaska

DTIC Science & Technology

1989-11-01

salmon Oncorhynchus kotez Chum salmon Untcorhynchua kisutch Coho salmon Orncorhynchus nerka Sockeye salmon Oncorhynchus tohawytacha Kink salmon...coho salmon, 40 Dolly Varden, 31 sculpin, 8 tomcod (Microgadus proxins), 17 starry flounder, and 10 sockeye salmon (0. nerka ) stomachs from Cliff and...AK. Godin, J. G. J. 1981. "Daily Patterns of Feeding Behavior, Daily Rations, and Diets of Juvenile Pink Salmon ( Oncorhynchus go’buscha) in Two

Habitat Suitability Index Models: Coho salmon

USGS Publications Warehouse

McMahon, Thomas E.

1983-01-01

The coho salmon (Oncorhynchus kisutch) is native to the northern Pacific Ocean, spawning and rearing in streams from Monterey Bay, California, to Point Hope, Alaska, and southward along the Asiatic coast to Japan. Its center of abundance in North America is from Oregon to Alaska (Briggs 1953; Godfrey 1965; Hart 1973; Scott and Crossman 1973). Coho salmon have been successfully introduced into the Great Lakes and reservoirs and lakes throughout the United States to provide put-and-grow sport fishing (Scott and Crossman 1973; Wigglesworth and Rawson 1974). No subspecies of coho salmon have been described (Godfrey 1965).

Addition of a selective breeding program for resistance to sea lice Lepeophtheirus salmonis (Kroyer 1838) to existing lines of Atlantic Salmon, Salmo salar L., at the USDA's National Cold Water Marine Aquaculture Center

USDA-ARS?s Scientific Manuscript database

Sea lice are likely the single most economically costly pathogen that has faced the salmon farming industry over the past 40 years. The most recent economic estimates put the annual cost of sea lice at just under $500 million USD in 2006. This is likely an underestimate of the current costs to indus...

SALMON: A WORLD AND HISTORICAL PERSPECTIVE

EPA Science Inventory

The four nations of Salmon World have existed for 10,000 years. Since the end of the last Ice Age, salmon established naturally substantial populations and prospered in four large regions of the earth: (1) the European side of the North Atlantic; (2) the North American side of...

THE FOUR NATIONS OF SALMON WORLD

EPA Science Inventory

The four nations of Salmon World have existed for 10,000 years. Since the end of the last Ice Age, salmon established naturally substantial populations and prospered in four large regions of the earth: (1) the European side of the North Atlantic; (2) the North American side of...

Salmon Supplementation Studies in Idaho Rivers, 1999-2000 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Andy; Taki, Doug; Teton, Angelo

2001-11-01

As part of the Idaho Supplementation Studies, fisheries crews from the Shoshone-Bannock Tribes have been snorkeling tributaries of the Salmon River to estimate chinook salmon (Oncorhynchus tshawytscha) parr abundance; conducting surveys of spawning adult chinook salmon to determine the number of redds constructed and collect carcass information; operating a rotary screw trap on the East Fork Salmon River and West Fork Yankee Fork Salmon River to enumerate and PIT-tag emigrating juvenile chinook salmon; and collecting and PIT-tagging juvenile chinook salmon on tributaries of the Salmon River. The Tribes work in the following six tributaries of the Salmon River: Bear Valleymore » Creek, East Fork Salmon River, Herd Creek, South Fork Salmon River, Valley Creek, and West Fork Yankee Fork Salmon River. Snorkeling was used to obtain parr population estimates for ISS streams from 1992 to 1997. However, using the relatively vigorous methods described in the ISS experimental design to estimate summer chinook parr populations, results on a project-wide basis showed extraordinarily large confidence intervals and coefficients of variation. ISS cooperators modified their sampling design over a few years to reduce the variation around parr population estimates without success. Consequently, in 1998 snorkeling to obtain parr population estimates was discontinued and only General Parr Monitoring (GPM) sites are snorkeled. The number of redds observed in SBT-ISS streams has continued to decline as determined by five year cycles. Relatively weak strongholds continue to occur in the South Fork Salmon River and Bear Valley Creek. A rotary screw trap was operated on the West Fork Yankee Fork during the spring and fall of 1999 and the spring of 2000 to monitor juvenile chinook migration. A screw trap was also operated on the East Fork of the Salmon River during the spring and fall from 1993 to 1997 and 1999 (fall only) to 2000. Significant supplementation treatments have occurred in

THE SALMON 2100 PROJECT: OPTIONS TO PROTECT, RESTORE, ANE ENHANCE SALMON ALONG THE WEST COAST OF NORTH AMERICA

EPA Science Inventory

The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and British Columbia. The Project does not support o...

50 CFR 660.412 - EFH identifications and descriptions for Pacific salmon.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Pacific salmon. 660.412 Section 660.412 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT... COAST STATES West Coast Salmon Fisheries § 660.412 EFH identifications and descriptions for Pacific salmon. Pacific salmon essential fish habitat (EFH) includes all those water bodies occupied or...

Heartworm (Acanthocheilonema spirocauda) and seal louse (Echinophthirius horridus) infections in harbour seals (Phoca vitulina) from the North and Baltic Seas

NASA Astrophysics Data System (ADS)

Lehnert, Kristina; Schwanke, Eva; Hahn, Kerstin; Wohlsein, Peter; Siebert, Ursula

2016-07-01

The seal louse (Echinophthirius [E.] horridus) and the heartworm (Acanthocheilonema [A.] spirocauda) are parasites of harbour seal (Phoca vitulina). Little is known about the role of the seal louse as a potential vector and its role for the development and transmission of heartworm larvae to their final host, the harbour seal. The life-cycle of the heartworm is still not fully understood. For the presented study, findings of 1191 stranded harbour seals collected along the North- and Baltic Sea coast between 1996 and 2013 were examined. 4.4% (n = 53) of these harbour seals were infected with adult heartworms and 3.4% (n = 40) harbour seals carried seal lice. The highest prevalence and level of infection with adult heartworms (A. spirocauda) (9.3%) and seal lice (E. horridus) (8.9%) were found on yearling harbour seals (7-18 months) compared to neonate and adult seals. Investigating seal lice (n = 35) for larval heartworm stages one larvae was encountered in an ethanol-fixated seal louse. During a health monitoring survey of live harbour seals, 109 animals were captured and examined during spring and autumn between 2008 and 2014. Blood samples were taken and microfilariae were discovered in blood smears in 41% (n = 45) of the examined harbour seals. Yearling seals (n = 21) showed higher prevalence (86%) and level of infection with microfilariae than adults. Microfilariae were identified as A. spirocauda by sequencing the species-specific COI gene in 24 blood samples. The high prevalence of microfilariae of A. spirocauda in blood samples (41%) is in contrast to the low prevalence of mature infections/adult specimens in stranded seals (4.4%) investigated. Although rare parasites of seals, the recent increase in prevalence of heartworm and seal lice in stranded seals and the relatively high occurrence of microfilaria in the free-ranging population underscore the importance of further studies investigating the immunology of infections and their transmission pathways, as

An Experimental Approach for Restoration of Salmon River Ecosystems

NASA Astrophysics Data System (ADS)

Stanford, J. A.

2005-05-01

River ecosystem theory predicts that dynamic, nonlinear physical and biological processes linking water, heat and materials (biota, sediment, plant-growth nutrients) flux and retention to fluvial landscape change in a habitat mosaic context drive salmon life histories and productivity in freshwater. Multidisciplinary studies and cross-site comparisons within a network of pristine salmon river observatories around the north Pacific Rim support these predictions. Billions of dollars have been spent on salmon-river restoration worldwide to little avail, mainly because salmon biology, rather than ecosystem process boundaries and bottlenecks, is driving restoration goals. I argue that entire river catchment restoration, in relation to these dynamic processes and bottlenecks and also coherent with the estuarine and marine implications of salmon life history parameters, is the only possibility for sustaining or restoring natural productivity and life history (genetic) diversity in salmon rivers. This can be done only in a few places owing to the continual press of human demands on river ecosystems, the morass of legal challenges to proactive salmon river restoration strategies and insufficient understanding of freshwater and marine linkages. The Elwha and Yakima Rivers in Washington, among a few others that I will name, offer real opportunities to restore entire watersheds for wild salmon. These restorations should be viewed as experimental manipulations in which outcomes may be evaluated against norms measured in the salmon river observatory network. Bias from hatcheries and harvest, among other anthropogenic interferences, must be eliminated for such experiments to be evaluated in light of contemporary river ecosystem theory. And, a much more synthetic understanding of freshwater and marine linkages must be forthcoming in concert with a much more robust general theory of river restoration.

50 CFR 679.65 - Bering Sea Chinook Salmon Bycatch Management Program Economic Data Report (Chinook salmon EDR...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 13 2014-10-01 2014-10-01 false Bering Sea Chinook Salmon Bycatch Management Program Economic Data Report (Chinook salmon EDR program). 679.65 Section 679.65 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OF THE...

Response of ecosystem metabolism to low densities of spawning Chinook salmon

USGS Publications Warehouse

Benjamin, Joseph R.; Bellmore, J. Ryan; Watson, Grace A.

2016-01-01

Marine derived nutrients delivered by large runs of returning salmon are thought to subsidize the in situ food resources that support juvenile salmon. In the Pacific Northwest, USA, salmon have declined to <10% of their historical abundance, with subsequent declines of marine derived nutrients once provided by large salmon runs. We explored whether low densities (<0.001 spawners/m2) of naturally spawning Chinook Salmon (Oncorhynchus tshawytscha) can affect ecosystem metabolism. We measured gross primary production (GPP) and ecosystem respiration (ER) continuously before, during, and after salmon spawning. We compared downstream reaches with low densities of spawning salmon to upstream reaches with fewer or no spawners in 3 mid-sized (4th-order) rivers in northern Washington. In addition, we measured chemical, physical, and biological factors that may be important in controlling rates of GPP and ER. We observed that low densities of spawning salmon can increase GPP by 46% during spawning, but values quickly return to those observed before spawning. No difference in ER was observed between up- and downstream reaches. Based on our results, salmon density, temperature, and the proximity to salmon redds were the most important factors controlling rates of GPP, whereas temperature was most important for ER. These results suggest that even at low spawning densities, salmon can stimulate basal resources that may propagate up the food web. Understanding how recipient ecosystems respond to low levels of marine derived nutrients may inform nutrient augmentation studies aimed at enhancing fish populations.

Decreased detoxification genes and genome size make the human body louse an efficient model to study xenobiotic metabolism.

PubMed

Lee, S H; Kang, J S; Min, J S; Yoon, K S; Strycharz, J P; Johnson, R; Mittapalli, O; Margam, V M; Sun, W; Li, H-M; Xie, J; Wu, J; Kirkness, E F; Berenbaum, M R; Pittendrigh, B R; Clark, J M

2010-10-01

The human body louse, Pediculus humanus humanus, has one of the smallest insect genomes, containing ∼10 775 annotated genes. Annotation of detoxification [cytochrome P450 monooxygenase (P450), glutathione-S-transferase (GST), esterase (Est) and ATP-binding cassette transporter (ABC transporter)] genes revealed that they are dramatically reduced in P. h. humanus compared to other insects except for Apis mellifera. There are 37 P450, 13 GST and 17 Est genes present in P. h. humanus, approximately half the number found in Drosophila melanogaster and Anopheles gambiae. The number of putatively functional ABC transporter genes in P. h. humanus and Ap. mellifera are the same (36) but both have fewer than An. gambiae (44) or Dr. melanogaster (65). The reduction of detoxification genes in P. h. humanus may be a result of this louse's simple life history, in which it does not encounter a wide variety of xenobiotics. Neuronal component genes are highly conserved across different insect species as expected because of their critical function. Although reduced in number, P. h. humanus still retains at least a minimum repertoire of genes known to confer metabolic or toxicokinetic resistance to xenobiotics (eg Cyp3 clade P450s, Delta GSTs, B clade Ests and B/C subfamily ABC transporters), suggestive of its high potential for resistance development. © 2010 The Authors. Insect Molecular Biology © 2010 The Royal Entomological Society.

Salmon as drivers of physical and biological disturbance in river channels

NASA Astrophysics Data System (ADS)

Albers, S. J.; Petticrew, E. L.

2012-04-01

Large migrations across landscapes and ecosystem boundaries combined with disturbances of riverine spawning habitats through nest construction indicate the huge potential that Pacific salmon (Onchorhynchus sp.) have to disturb and alter regional energy flow. Nutrients derived from ocean-reared dead and decaying salmon are released into surrounding aquatic ecosystems fertilizing the water column, recently disturbed by increased suspended sediments due to nest construction. These opposing forces of disturbance and fertilization on spawning habitat have been demonstrated to impact local geomorphic and ecological cycles within salmon streams. An often cited, yet not fully tested, hypothesis is that this pulse of nutrients provided by decaying salmon can shift freshwater habitats to higher production levels. This hypothesis, however, remains contested and uncertain. Fine sediments are increasingly being recognized as important delivery and storage vectors for marine-derived nutrients (MDNs) in spawning streams. The temporal and spatial significance of these sediment vectors on gravelbed storage of MDN have not been quantified thereby restricting our ability to estimate the impact of gravelbed storage of MDNs on the riverine habitats. The objectives of this study were to i) quantify the magnitude of sediment deposition and retention in an active spawning area and ii) determine the contribution of MDN associated with the fine sediment storage. The Horsefly River spawning channel (HFC), an artificial salmon stock enhancement stream, was used to examine the biogeomorphic impacts of salmon spawning. We organized the HFC in an upstream-downstream paired treatment approach where the upstream enclosure was kept free of salmon and the downstream enclosure was loaded with actively spawning salmon. We used the difference in suspended sediment concentration between the salmon enclosure and the control enclosure to determine the contribution of salmon nest construction to suspended

Identification and characterization of an esterase involved in malathion resistance in the head louse Pediculus humanus capitis.

PubMed

Kwon, Deok Ho; Kim, Ju Hyeon; Kim, Young Ho; Yoon, Kyong Sup; Clark, J Marshall; Lee, Si Hyeock

2014-06-01

Enhanced malathion carboxylesterase (MCE) activity was previously reported to be involved in malathion resistance in the head louse Pediculus humanus capitis (Gao et al., 2006 [8]). To identify MCE, the transcriptional profiles of all five esterases that had been annotated to be catalytically active were determined and compared between the malathion-resistant (BR-HL) and malathion-susceptible (KR-HL) strains of head lice. An esterase gene, designated HLCbE3, exhibited approximately 5.4-fold higher transcription levels, whereas remaining four esterases did not exhibit a significant increase in their transcription in BR-HL, indicating that HLCbE3 may be the putative MCE. Comparison of the entire cDNA sequences of HLCbE3 revealed no sequence differences between the BR-HL and KR-HL strains and suggested that no single nucleotide polymorphism is associated with enhanced MCE activity. Two copies of the HLCbE3 gene were observed in BR-HL, implying that the over-transcription of HLCbE3 is due to the combination of a gene duplication and up-regulated transcription. Knockdown of HLCbE3 expression by RNA interference in the BR-HL strain led to increases in malathion susceptibility, confirming the identity of HLCbE3 as a MCE responsible for malathion resistance in the head louse. Phylogenetic analysis suggested that HLCbE3 is a typical dietary esterase and belongs to a clade containing various MCEs involved in malathion resistance. Copyright © 2014 Elsevier Inc. All rights reserved.

Inclusion of Palmaria palmata (red seaweed) in Atlantic salmon diets: effects on the quality, shelf-life parameters and sensory properties of fresh and cooked salmon fillets.

PubMed

Moroney, Natasha C; Wan, Alex H L; Soler-Vila, Anna; FitzGerald, Richard D; Johnson, Mark P; Kerry, Joe P

2015-03-30

The use of Palmaria palmata (PP) as a natural ingredient in farmed Atlantic salmon diets was investigated. The effect of salmon diet supplementation with P. palmata (0, 5, 10 and 15%) or synthetic astaxanthin (positive control, PC) for 16 weeks pre-slaughter on quality indices of fresh salmon fillets was examined. The susceptibility of salmon fillets/homogenates to oxidative stress conditions was also measured. In salmon fillets stored in modified atmosphere packs (60% N2 /40% CO2 ) for up to 15 days at 4 °C, P. palmata increased surface -a* (greenness) and b* (yellowness) values in a dose-dependent manner, resulting in a final yellow/orange flesh colour. In general, the dietary addition of P. palmata had no effect on pH, lipid oxidation (fresh, cooked and fillet homogenates) and microbiological status. 'Eating quality' sensory descriptors (texture, odour and oxidation flavour) in cooked salmon fillets were not influenced by dietary P. palmata. Salmon fed 5% PP showed increased overall acceptability compared with those fed PC and 0% PP. Dietary P. palmata was ineffective at providing red coloration in salmon fillets, but pigment deposition enhanced fillets with a yellow/orange colour. Carotenoids from P. palmata may prove to be a natural pigment alternative to canthaxanthin in salmon feeds. © 2014 Society of Chemical Industry.

Comparisons of host specificity in feather louse genera (Insecta: Phthiraptera: Philopteridae) parasitizing gulls (Aves: Laridae: Larus).

PubMed

Yamagishi, Ayaka; Yao, Izumi; Johnson, Kevin P; Yoshizawa, Kazunori

2014-06-01

Data from gene sequences and morphological structures were collected for the gull feather lice, Saemundssonia lari, Quadraceps punctatus, and Q. ornatus, parasitizing Larus crassirostris and L. schistisagus. Saemundssonia lari was collected from both gull species, and no detectable morphological and genetic differences were found between lice collected from the two different hosts. In contrast, Q. punctatus was only collected from L. crassirostris, whereas Q. ornatus was only collected from L. schistisagus. The two Quadraceps species were genetically highly divergent, and body-size differences corresponding to the gull's body size (Harrison's rule) were also detected between them. Both Quadraceps species were collected from the interbarb of the remex or rectrix, and a match in body size between the louse and the interbarb space may be important in escape from host preening defenses. In contrast, Saemundssonia is a head louse, inhabiting the finer feathers of the head and neck, which the bird cannot preen. A close match to host body size may be less important for lice in the head microhabitat. The differences in the pattern of host-specificity between Saemundssonia and Quadraceps on the two focal host species of this study were probably due to their different microhabitat preferences. More broadly, comparisons of the gene sequences of S. lari and Q. punctatus to those from other gull hosts showed that genetically almost undifferentiated populations of both species were distributed on wide range of gull species. Frequent interspecific hybridization of gulls is one possible factor that may allow these lice to maintain gene flow across multiple host species.

Salmon returns and consumer fitness: growth and energy storage in stream-dwelling salmonids increases with spawning salmon abundance

USDA-ARS?s Scientific Manuscript database

We examined how biomass of marine-derived nutrients (MDN), in the form of spawning Pacific salmon, influenced the nutritional status and nitrogen stable isotope ratios (d15N) of stream-dwelling fishes. We sampled coho salmon (Oncorhynchus kisutch) parr and juvenile Dolly Varden (Salvelinus malma) d...

Salmon carcass movements in forest streams

Treesearch

Burke Strobel; Daniel R. Shivley; Brett B. Roper

2009-01-01

The movements of salmon carcasses over time were studied in two forest streams in the context of a large-scale salmon carcass supplementation program. The objectives were to assess both the level of treatment after stream flows had displaced carcasses and to evaluate whether the magnitude of carcass movements outside of a given reach could be predicted. The movements...

Atlantic salmon reovirus infection causes a CD8 T cell myocarditis in Atlantic salmon (Salmo salar L.).

PubMed

Mikalsen, Aase B; Haugland, Oyvind; Rode, Marit; Solbakk, Inge Tom; Evensen, Oystein

2012-01-01

Heart and skeletal inflammation (HSMI) of farmed Atlantic salmon (Salmo salar L.) is a disease characterized by a chronic myocarditis involving the epicardium and the compact and spongious part of the heart ventricle. Chronic myositis of the red skeletal muscle is also a typical finding of HSMI. Piscine reovirus (PRV) has been detected by real-time PCR from farmed and wild salmon with and without typical changes of HSMI and thus the causal relationship between presence of virus and the disease has not been fully determined. In this study we show that the Atlantic salmon reovirus (ASRV), identical to PRV, can be passaged in GF-1 cells and experimental challenge of naïve Atlantic salmon with cell culture passaged reovirus results in cardiac and skeletal muscle pathology typical of HSMI with onset of pathology from 6 weeks, peaking by 9 weeks post challenge. ASRV replicates in heart tissue and the peak level of virus replication coincides with peak of heart lesions. We further demonstrate mRNA transcript assessment and in situ characterization that challenged fish develop a CD8+ T cell myocarditis.

How coarse is too coarse for salmon spawning substrates?

NASA Astrophysics Data System (ADS)

Wooster, J. K.; Riebe, C. S.; Ligon, F. K.; Overstreet, B. T.

2009-12-01

Populations of Pacific salmon species have declined sharply in many rivers of the western US. Reversing these declines is a top priority and expense of many river restoration projects. To help restore salmon populations, managers often inject gravel into rivers, to supplement spawning habitat that has been depleted by gravel mining and the effects of dams—which block sediment and thus impair habitat downstream by coarsening the bed where salmon historically spawned. However, there is little quantitative understanding nor a methodology for determining when a river bed has become too coarse for salmon spawning. Hence there is little scientific basis for selecting sites that would optimize the restoration benefits of gravel injection (e.g., sites where flow velocities are suitable but bed materials are too coarse for spawning). To develop a quantitative understanding of what makes river beds too coarse for salmon spawning, we studied redds and spawning use in a series of California and Washington rivers where salmon spawning ability appears to be affected by coarse bed material. Our working hypothesis is that for a given flow condition, there is a maximum “threshold” particle size that a salmon of a given size is able to excavate and/or move as she builds her redd. A second, related hypothesis is that spawning use should decrease and eventually become impossible with increasing percent coverage by immovable particles. To test these hypotheses, we quantified the sizes and spatial distributions of immovably coarse particles in a series of salmon redds in each river during the peak of spawning. We also quantified spawning use and how it relates to percent coverage by immovable particles. Results from our studies of fall-run chinook salmon (Oncorhynchus tshawytsha) in the Feather River suggest that immovable particle size varies as a function of flow velocity over the redd, implying that faster water helps fish move bigger particles. Our Feather River study also

Response of ecosystem metabolism to low densities of spawning Chinook Salmon

Treesearch

Joseph R. Benjamin; J. Ryan Bellmore; Grace A. Watson

2016-01-01

Marine derived nutrients delivered by large runs of returning salmon are thought to subsidize the in situ food resources that support juvenile salmon. In the Pacific Northwest, USA, salmon have declined to <10% of their historical abundance, with subsequent declines of marine derived nutrients once provided by large salmon runs. We explored whether low densities...

POLICY OPTIONS TO REVERSE THE DECLINE OF WILD PACIFIC SALMON

EPA Science Inventory

The primary goal of the Salmon 2100 Project was to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in the Pacific Northwest and California. Wild salmon recovery efforts in western North Americ...

Patterns of change in climate and Pacific salmon production

Treesearch

Nathan J. Mantua

2009-01-01

For much of the 20th century a clear north-south inverse production pattern for Pacific salmon had a time dynamic that closely followed that of the Pacific Decadal Oscillation (PDO), which is the dominant pattern of North Pacific sea surface temperature variability. Total Alaska salmon production was high during warm regimes of the PDO, and total Alaska salmon...

Testing archival tag technology in coho salmon

USGS Publications Warehouse

Nielsen, Jennifer L.; Richards, Philip; Tingey, Thor; Wilson, Derek; Zimmerman, Chris

2004-01-01

Archive tags with temperature and light-geolocation sensors will be monitored for post-smolt coho salmon in Cook Inlet. Light/location relationships specific to the Gulf of Alaska developed under Project 00478 will be applied in this study of movement and migration paths for coho salmon during maturation in ocean environments in Cook Inlet. Salmon for this study will be reared in captivity (at the Alaska Department of Fish and Game hatchery at Fort Richardson) to 1+ year of age (200-250mm) and released in Cook Inlet as part of the department's Ship Creek sport-fishing hatchery release. FY 01 includes pilot studies of tag retention, behavior, and growth for coho in captivity. Ship Creek coho will be tagged mid-May. A spring release experiment in the first year will be contingent on the successful implementation and retention of these tags. Surveys for early jack recoveries will be done at the Ship Creek weir and among sport fishers. Monitoring for adult tag recoveries will be done in the coho commercial fishery in Cook Inlet and the derby sport fishery on Ship Creek. Archive tagged fish will be used to document coho salmon use of marine habitats, migration routes, contribution to the sport fishery, and hatchery/wild interactions for salmon in Cook Inlet.

77 FR 75101 - Fisheries Off West Coast States; West Coast Salmon Fisheries; Amendment 17 to the Salmon Fishery...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-19

... impacts to two coho stocks. Amendment 17 Issue 7. The description of impacts to pink salmon from the ocean fishery is updated to reflect recent analyses of exploitation rate for pink salmon, conducted since the... income in local and state economies through expenditures on harvesting, processing, and marketing of the...

First detection, isolation and molecular characterization of infectious salmon anaemia virus associated with clinical disease in farmed Atlantic salmon (Salmo salar) in Chile

PubMed Central

Godoy, Marcos G; Aedo, Alejandra; Kibenge, Molly JT; Groman, David B; Yason, Carmencita V; Grothusen, Horts; Lisperguer, Angelica; Calbucura, Marlene; Avendaño, Fernando; Imilán, Marcelo; Jarpa, Miguel; Kibenge, Frederick SB

2008-01-01

Background Infectious salmon anaemia (ISA) is a viral disease of marine-farmed Atlantic salmon (Salmo salar) caused by ISA virus (ISAV), which belongs to the genus Isavirus, family Orthomyxoviridae. The virus is considered to be carried by marine wild fish and for over 25 years has caused major disease outbreaks in marine-farmed Atlantic salmon in the Northern hemisphere. In the Southern hemisphere, ISAV was first detected in Chile in 1999 in marine-farmed Coho salmon (Oncorhynchus kisutch). In contrast to the classical presentation of ISA in Atlantic salmon, the presence of ISAV in Chile until now has only been associated with a clinical condition called Icterus Syndrome in Coho salmon and virus isolation has not always been possible. During the winter of 2007, unexplained mortalities were registered in market-size Atlantic salmon in a grow-out site located in Chiloé in Region X of Chile. We report here the diagnostic findings of the first significant clinical outbreak of ISA in marine-farmed Atlantic salmon in Chile and the first characterization of the ISAV isolated from the affected fish. Results In mid-June 2007, an Atlantic salmon marine farm site located in central Chiloé Island in Region X of Chile registered a sudden increase in mortality following recovery from an outbreak of Pisciricketsiosis, which rose to a cumulative mortality of 13.6% by harvest time. Based on the clinical signs and lesions in the affected fish, and laboratory tests performed on the fish tissues, a confirmatory diagnosis of ISA was made; the first time ISA in its classical presentation and for the first time affecting farmed Atlantic salmon in Chile. Rapid sequencing of the virus-specific RT-PCR products amplified from the fish tissues identified the virus to belong to the European genotype (Genotype I) of the highly polymorphic region (HPR) group HPR 7b, but with an 11-amino acid insert in the fusion glycoprotein, and ability to cause cytopathic effects (CPE) in CHSE-214 cell line

First detection, isolation and molecular characterization of infectious salmon anaemia virus associated with clinical disease in farmed Atlantic salmon (Salmo salar) in Chile.

PubMed

Godoy, Marcos G; Aedo, Alejandra; Kibenge, Molly J T; Groman, David B; Yason, Carmencita V; Grothusen, Horts; Lisperguer, Angelica; Calbucura, Marlene; Avendaño, Fernando; Imilán, Marcelo; Jarpa, Miguel; Kibenge, Frederick S B

2008-08-04

Infectious salmon anaemia (ISA) is a viral disease of marine-farmed Atlantic salmon (Salmo salar) caused by ISA virus (ISAV), which belongs to the genus Isavirus, family Orthomyxoviridae. The virus is considered to be carried by marine wild fish and for over 25 years has caused major disease outbreaks in marine-farmed Atlantic salmon in the Northern hemisphere. In the Southern hemisphere, ISAV was first detected in Chile in 1999 in marine-farmed Coho salmon (Oncorhynchus kisutch). In contrast to the classical presentation of ISA in Atlantic salmon, the presence of ISAV in Chile until now has only been associated with a clinical condition called Icterus Syndrome in Coho salmon and virus isolation has not always been possible. During the winter of 2007, unexplained mortalities were registered in market-size Atlantic salmon in a grow-out site located in Chiloé in Region X of Chile. We report here the diagnostic findings of the first significant clinical outbreak of ISA in marine-farmed Atlantic salmon in Chile and the first characterization of the ISAV isolated from the affected fish. In mid-June 2007, an Atlantic salmon marine farm site located in central Chiloé Island in Region X of Chile registered a sudden increase in mortality following recovery from an outbreak of Pisciricketsiosis, which rose to a cumulative mortality of 13.6% by harvest time. Based on the clinical signs and lesions in the affected fish, and laboratory tests performed on the fish tissues, a confirmatory diagnosis of ISA was made; the first time ISA in its classical presentation and for the first time affecting farmed Atlantic salmon in Chile. Rapid sequencing of the virus-specific RT-PCR products amplified from the fish tissues identified the virus to belong to the European genotype (Genotype I) of the highly polymorphic region (HPR) group HPR 7b, but with an 11-amino acid insert in the fusion glycoprotein, and ability to cause cytopathic effects (CPE) in CHSE-214 cell line, characteristics

Farmed Atlantic salmon: potential invader in the Pacific Northwest?

Treesearch

Jonathan Thompson; Pete Bisson

2008-01-01

Commercial farming of Atlantic salmon in marine net-pens has become a booming industry. At present, approximately 130 salmon farms exist along the Pacific coast of North America. Most of these farms are in cold marine bays within British Columbia, where farmed salmon have become the province’s most valuable agricultural export. Each year, thousands of farmed Atlantic...

Predation of Karluk River sockeye salmon by coho salmon and char

USGS Publications Warehouse

McIntyre, J.D.; Reisenbichler, R.R.; Emlen, J.M.; Wilmot, R.L.; Finn, J.E.

1988-01-01

The number of sockeye salmon, Oncorhynchus nerka, in Alaska's Karluk River (Fig. 1) declined from millions to thousands during the early part of the present century. Rounsefell (1958) discussed alternative explanations for the decline including a general loss offertility ofthe system as the number of salmon carcasses declined, competition, overfishing, subtle changes in climate, and predation; he concluded that the combined effect of predation and fishing was the most probable explanation. Later, Van Cleave and Bevan (1973) suggested that the weir constructed in the river each year to facilitate counting the fish as they entered the system was the most probable cause ofthe decline. Itprevented free movement of both adults and juveniles in the river. All of these hypotheses remain as potential explanations for the decline

150 YEARS OF SALMON RESTORATION: ASSORTED TRUTHS

EPA Science Inventory

Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline of wild Pacific salmon. Of the Earth's four regions (i.e., Asian Far East, Atlantic Europe, eastern North America, and western North America) where salmon runs originally occurred, it...

SALMON RECOVERY: LEARNING FROM SUCCESSES AND MISTAKES

EPA Science Inventory

Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline of wild Pacific salmon. Of the Earth's four regions (i.e., Asian Far East, Atlantic Europe, eastern North America, and western North America) where salmon runs occurred originally, it...

SALMON RECOVERY: LEARNING FROM SUCCESSES AND FAILURES

EPA Science Inventory

Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline of wild Pacific salmon. Of the Earth's four regions (i.e., Asian Far East, Atlantic Europe, eastern North America, and western North America) where salmon runs occurred originally, it...

Salmon redd identification using environmental DNA (eDNA)

USGS Publications Warehouse

Pilliod, David S.; Laramie, Matthew B.

2016-06-10

IntroductionThe purpose of this project was to develop a technique to use environmental DNA (eDNA) to distinguish between redds made by Chinook salmon (Oncorhynchus tshawytscha) and redds made by Coho salmon (O. kisutch) and to distinguish utilized redds from test/abandoned redds or scours that have the appearance of redds. The project had two phases:Phase 1. Develop, test, and optimize a molecular assay for detecting and identifying Coho salmon DNA and differentiating it from Chinook salmon DNA.Phase 2. Demonstrate the efficacy of the technique.Collect and preserve water samples from the interstitial spaces of 10 known redds (as identified by expert observers) of each species and 10 gravel patches that do not include a redd of either species.Collect control samples from the water column adjacent to each redd to establish background eDNA levels.Analyze the samples using the developed molecular assays for Coho salmon (phase I) and Chinook salmon (Laramie and others, 2015).Evaluate whether samples collected from Chinook and Coho redds have significantly higher levels of eDNA of the respective species than background levels (that is, from gravel, water column).Evaluate whether samples collected from the interstitial spaces of gravel patches that are not redds are similar to background eDNA levels.The Sandy River is a large tributary of the Columbia River. The Sandy River meets the Columbia River approximately 23 km upstream of Portland, Oregon. The Sandy River Basin provides overlapping spawning habitat for both Chinook and Coho salmon.Samples provided by Portland Water Bureau for analysis were collected from the Bull Run River, Sixes Creek, Still Creek, Arrah Wanna Side Channel, and Side Channel 18.

78 FR 65555 - Establishment of Class E Airspace; Salmon, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

...-0531; Airspace Docket No. 13-ANM-20] Establishment of Class E Airspace; Salmon, ID AGENCY: Federal... at the Salmon VHF Omni-Directional Radio Range/Distance Measuring Equipment (VOR/DME) navigation aid, Salmon, ID, to facilitate vectoring of Instrument Flight Rules (IFR) aircraft under control of Salt Lake...

77 FR 60631 - Fraser River Sockeye Salmon Fisheries; Inseason Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-04

...-XC222 Fraser River Sockeye Salmon Fisheries; Inseason Orders AGENCY: National Marine Fisheries Service...; inseason orders. SUMMARY: NMFS publishes Fraser River salmon inseason orders to regulate treaty and non-treaty (all citizen) commercial salmon fisheries in U.S. waters. The orders were issued by the Fraser...

75 FR 78929 - Fraser River Sockeye Salmon Fisheries; Inseason Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

...-XZ20 Fraser River Sockeye Salmon Fisheries; Inseason Orders AGENCY: National Marine Fisheries Service...; inseason orders; request for comments. SUMMARY: NMFS publishes Fraser River salmon inseason orders to regulate salmon fisheries in U.S. waters. The orders were issued by the Fraser River Panel (Panel) of the...

Neurotoxic behavioral effects of Lake Ontario salmon diets in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hertzler, D.R.

1990-03-01

Six experiments were conducted to examine possible neurotoxic effects of the exposure to contaminants in Lake Ontario salmon administered through the diets of rats. Rats were fed different concentrations of fish (8%, 15% or 30%) in one of three diet conditions: Lake Ontario salmon, Pacific Ocean salmon, or laboratory rat chow only. Following 20 days on the diets, rats were tested for five minutes per day in a modified open field for one or three days. Lake Ontario salmon diets consistently produced significantly lower activity, rearing, and nosepoke behaviors in comparison with ocean salmon or rat chow diet conditions. Amore » dose-response effect for concentration of lake salmon was obtained, and the attenuation effect occurred in males, females, adult or young animals, and postweaning females, with fish sampled over a five-year period. While only two of several potential contaminants were tested, both fish and brain analyses of mirex and PCBs relate to the behavioral effects.« less

Why aren't there more Atlantic salmon (Salmo salar)?

USGS Publications Warehouse

Parrish, D.L.; Behnke, R.J.; Gephard, S.R.; McCormick, S.D.; Reeves, G.H.

1998-01-01

Numbers of wild anadromous Atlantic salmon (Salmo salar) have declined demonstrably throughout their native range. The current status of runs on rivers historically supporting salmon indicate widespread declines and extirpations in Europe and North America primarily in southern portions of the range. Many of these declines or extirpations can be attributed to the construction of mainstem dams, pollution (including acid rain), and total dewatering of streams. Purported effects on declines during the 1960s through the 1990s include overfishing, and more recently, changing ocean conditions, and intensive aquaculture. Most factors affecting salmon numbers do not act singly, but rather in concert, which masks the relative contribution of each factor. Salmon researchers and managers should not look for a single culprit in declining numbers of salmon, but rather, seek solutions through rigorous data gathering and testing of multiple effects integrated across space and time.

Salmon's Laws.

ERIC Educational Resources Information Center

Shannon, Thomas A.

1994-01-01

Presents Paul Salmon's old-fashioned, common-sense guidelines for success in practical school administration. The maxims advise on problem ownership; the value of selective neglect; the importance of empowerment, enthusiasm, and effective communication; and the need for positive reinforcement, cultivation of support, and good relations with media,…

Single application of 4% dimeticone liquid gel versus two applications of 1% permethrin creme rinse for treatment of head louse infestation: a randomised controlled trial

PubMed Central

2013-01-01

Background A previous study indicated that a single application of 4% dimeticone liquid gel was effective in treating head louse infestation. This study was designed to confirm this in comparison with two applications of 1% permethrin. Methods We have performed a single centre parallel group, randomised, controlled, open label, community based trial, with domiciliary visits, in Cambridgeshire, UK. Treatments were allocated through sealed instructions derived from a computer generated list. We enrolled 90 children and adults with confirmed head louse infestation analysed by intention to treat (80 per-protocol after 4 drop outs and 6 non-compliant). The comparison was between 4% dimeticone liquid gel applied once for 15 minutes and 1% permethrin creme rinse applied for 10 minutes, repeated after 7 days as per manufacturer’s directions. Evaluated by elimination of louse infestation after completion of treatment application regimen. Results Intention to treat comparison of a single dimeticone liquid gel treatment with two of permethrin gave success for 30/43 (69.8%) of the dimeticone liquid gel group and 7/47 (14.9%) of the permethrin creme rinse group (OR 13.19, 95% CI 4.69 to 37.07) (p < 0.001). Per protocol results were similar with 27/35 (77.1%) success for dimeticone versus 7/45 (15.6%) for permethrin. Analyses by household gave essentially similar outcomes. Conclusions The study showed one 15 minute application of 4% dimeticone liquid gel was superior to two applications of 1% permethrin creme rinse (p < 0.001). The low efficacy of permethrin suggests it should be withdrawn. Trial registration Current Controlled Trials ISRCTN88144046. PMID:23548062

Using Grizzly Bears to Assess Harvest-Ecosystem Tradeoffs in Salmon Fisheries

PubMed Central

MacDuffee, Misty; Mangel, Marc; Paquet, Paul; Wilmers, Christopher C.

2012-01-01

Implementation of ecosystem-based fisheries management (EBFM) requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for “salmon ecosystem” function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC), Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem) equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a generalizable

Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

PubMed

Levi, Taal; Darimont, Chris T; Macduffee, Misty; Mangel, Marc; Paquet, Paul; Wilmers, Christopher C

2012-01-01

Implementation of ecosystem-based fisheries management (EBFM) requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC), Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem) equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a generalizable method

Are inland wolf-ungulate systems influenced by marine subsidies of Pacific salmon?

USGS Publications Warehouse

Adams, Layne G.; Farley, Sean D.; Stricker, Craig A.; Demma, Dominic J.; Roffler, Gretchen H.; Miller, Dennis C.; Rye, Robert O.

2010-01-01

Wolves (Canis lupus) in North America are considered obligate predators of ungulates with other food resources playing little role in wolf population dynamics or wolf–prey relations. However, spawning Pacific salmon (Oncorhyncus spp.) are common throughout wolf range in northwestern North America and may provide a marine subsidy affecting inland wolf–ungulate food webs far from the coast. We conducted stable‐isotope analyses for nitrogen and carbon to evaluate the contribution of salmon to diets of wolves in Denali National Park and Preserve, 1200 river‐km from tidewater in interior Alaska, USA. We analyzed bone collagen from 73 wolves equipped with radio collars during 1986–2002 and evaluated estimates of salmon in their diets relative to the availability of salmon and ungulates within their home ranges. We compared wolf densities and ungulate : wolf ratios among regions with differing salmon and ungulate availability to assess subsidizing effects of salmon on these wolf–ungulate systems. Wolves in the northwestern flats of the study area had access to spawning salmon but low ungulate availability and consumed more salmon (17% ± 7% [mean ± SD]) than in upland regions, where ungulates were sixfold more abundant and wolves did or did not have salmon spawning areas within their home ranges (8% ± 6% and 3% ± 3%, respectively). Wolves were only 17% less abundant on the northwestern flats compared to the remainder of the study area, even though ungulate densities were 78% lower. We estimated that biomass from fall runs of chum (O. keta) and coho (O. kisutch) salmon on the northwestern flats was comparable to the ungulate biomass there, and the contribution of salmon to wolf diets was similar to estimates reported for coastal wolves in southeast Alaska. Given the ubiquitous consumption of salmon by wolves on the northwestern flats and the abundance of salmon there, we conclude that wolf numbers in this region were enhanced by the allochthonous subsidy

Searching for a life history approach to salmon escapement management

USGS Publications Warehouse

Knudsen, E.E.; Symmes, E.W.; Margraf, F.J.

2003-01-01

A number of Pacific salmon populations have already been lost and many others throughout the range are in various states of decline. Recent research has documented that Pacific salmon carcasses serve as a key delivery vector of marine-derived nutrients into the freshwater portions of their ecosystems. This nutrient supply plays a critical biological feedback role in salmon sustainability by supporting juvenile salmon production. We first demonstrate how nutrient feedback potential to juvenile production may be unaccounted for in spawner-recruit models of populations under long-term exploitation. We then present a heuristic, life history-based, spreadsheet survival model that incorporates salmon carcass-driven nutrient feedback to the freshwater components of the salmon ecosystem. The productivity of a hypothetical coho salmon population was simulated using rates from the literature for survival from spawner to egg, egg to fry, fry to smolt, and smolt to adult. The effects of climate variation and nutrient feedback on survival were incorporated, as were density-dependent effects of the numbers of spawners and fry on freshwater survival of eggs and juveniles. The unexploited equilibrium population was subjected to 100 years of 20, 40, 60, and 80% harvest. Each harvest scenario greater than 20% brought the population to a reduced steady state, regardless of generous compensatory survival at low population sizes. Increasing harvest reduced the positive effects of nutrient contributions to population growth. Salmon researchers should further explore this modeling approach for establishing escapement goals. Given the importance of nutrient feedback, managers should strive for generous escapements that support nutrient rebuilding, as well as egg deposition, to ensure strong future salmon production.

Yolo Bypass Juvenile Salmon Utilization Study 2016—Summary of acoustically tagged juvenile salmon and study fish release, Sacramento River, California

USGS Publications Warehouse

Liedtke, Theresa L.; Hurst, William R.

2017-09-12

The Yolo Bypass is a flood control bypass in Sacramento Valley, California. Flood plain habitats may be used for juvenile salmon rearing, however, the potential value of such habitats can be difficult to evaluate because of the intermittent nature of inundation events. The Yolo Bypass Juvenile Salmon Utilization Study (YBUS) used acoustic telemetry to evaluate the movements and survival of juvenile salmon adjacent to and within the Yolo Bypass during the winter of 2016. This report presents numbers, size data, and release data (times, dates, and locations) for the 1,197 acoustically tagged juvenile salmon released for the YBUS from February 21 to March 18, 2016. Detailed descriptions of the surgical implantation of transmitters are also presented. These data are presented to support the collaborative, interagency analysis and reporting of the study findings.

The Lummi Indians and the Canadian/American Pacific Salmon Treaty.

ERIC Educational Resources Information Center

Boxberger, Daniel L.

1988-01-01

Explores the probable impact of the 1985 international Pacific Salmon Treaty on the Lummi tribe's catch of Fraser River salmon and economic well-being. Discusses the 1974 Boldt Decision, which allocated half of Washington State's salmon catch to treaty tribes, and contradictions in the federal government's conception of international treaties. (SV)

77 FR 10772 - Fresh and Chilled Atlantic Salmon From Norway

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-23

... and Chilled Atlantic Salmon From Norway Determination On the basis of the record \\1\\ developed in the... countervailing duty order and antidumping duty order on fresh and chilled Atlantic salmon from Norway would not... and Chilled Atlantic Salmon from Norway: Investigation Nos. 701-TA-302 and 731-TA-454 (Third Review...

Critical thresholds in sea lice epidemics: evidence, sensitivity and subcritical estimation

PubMed Central

Frazer, L. Neil; Morton, Alexandra; Krkošek, Martin

2012-01-01

Host density thresholds are a fundamental component of the population dynamics of pathogens, but empirical evidence and estimates are lacking. We studied host density thresholds in the dynamics of ectoparasitic sea lice (Lepeophtheirus salmonis) on salmon farms. Empirical examples include a 1994 epidemic in Atlantic Canada and a 2001 epidemic in Pacific Canada. A mathematical model suggests dynamics of lice are governed by a stable endemic equilibrium until the critical host density threshold drops owing to environmental change, or is exceeded by stocking, causing epidemics that require rapid harvest or treatment. Sensitivity analysis of the critical threshold suggests variation in dependence on biotic parameters and high sensitivity to temperature and salinity. We provide a method for estimating the critical threshold from parasite abundances at subcritical host densities and estimate the critical threshold and transmission coefficient for the two epidemics. Host density thresholds may be a fundamental component of disease dynamics in coastal seas where salmon farming occurs. PMID:22217721

Performance of salmon fishery portfolios across western North America.

PubMed

Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

2014-12-01

Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications . Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally

Performance of salmon fishery portfolios across western North America

PubMed Central

Griffiths, Jennifer R; Schindler, Daniel E; Armstrong, Jonathan B; Scheuerell, Mark D; Whited, Diane C; Clark, Robert A; Hilborn, Ray; Holt, Carrie A; Lindley, Steven T; Stanford, Jack A; Volk, Eric C

2014-01-01

Quantifying the variability in the delivery of ecosystem services across the landscape can be used to set appropriate management targets, evaluate resilience and target conservation efforts. Ecosystem functions and services may exhibit portfolio-type dynamics, whereby diversity within lower levels promotes stability at more aggregated levels. Portfolio theory provides a framework to characterize the relative performance among ecosystems and the processes that drive differences in performance. We assessed Pacific salmon Oncorhynchus spp. portfolio performance across their native latitudinal range focusing on the reliability of salmon returns as a metric with which to assess the function of salmon ecosystems and their services to humans. We used the Sharpe ratio (e.g. the size of the total salmon return to the portfolio relative to its variability (risk)) to evaluate the performance of Chinook and sockeye salmon portfolios across the west coast of North America. We evaluated the effects on portfolio performance from the variance of and covariance among salmon returns within each portfolio, and the association between portfolio performance and watershed attributes. We found a positive latitudinal trend in the risk-adjusted performance of Chinook and sockeye salmon portfolios that also correlated negatively with anthropogenic impact on watersheds (e.g. dams and land-use change). High-latitude Chinook salmon portfolios were on average 2·5 times more reliable, and their portfolio risk was mainly due to low variance in the individual assets. Sockeye salmon portfolios were also more reliable at higher latitudes, but sources of risk varied among the highest performing portfolios. Synthesis and applications. Portfolio theory provides a straightforward method for characterizing the resilience of salmon ecosystems and their services. Natural variability in portfolio performance among undeveloped watersheds provides a benchmark for restoration efforts. Locally and regionally

Arctic-Yukon-Kuskokwim Salmon Research and Restoration Plan

USGS Publications Warehouse

2006-01-01

The Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative (AYK SSI) is an innovative partnership between public and private institutions which provides a forum for non-governmental organizations and state and federal agencies to cooperatively identify and address salmon research and restoration needs. The affected region encompasses over 40% of the State of Alaska; the AYK region includes the watersheds of the Norton Sound region up to and including the village of Shishmaref, the Yukon River Watershed within Alaska, and the Kuskokwim River Watershed (including the coastal watersheds north of Cape Newenham), plus the Bering Sea marine ecosystem. The AYK SSI is a response to disastrously low salmon returns to western Alaska in the late 1990s and early 2000s, which created numerous hardships for the people and communities that depend heavily on the salmon fishery. Some stocks in the region have been in a decline for more than a decade and a half, leading to severe restrictions on commercial and subsistence fisheries. The first step for the AYK SSI has been to collaboratively develop and implement a comprehensive research plan to understand the causes of the declines and recoveries of AYK salmon.

On-site Direct Detection of Astaxanthin from Salmon Fillet Using Raman Spectroscopy.

PubMed

Hikima, Jun-Ichi; Ando, Masahiro; Hamaguchi, Hiro-O; Sakai, Masahiro; Maita, Masashi; Yazawa, Kazunaga; Takeyama, Haruko; Aoki, Takashi

2017-04-01

A new technology employing Raman spectroscopy is attracting attention as a powerful biochemical technique for the detection of beneficial and functional food nutrients, such as carotenoids and unsaturated fatty acids. This technique allows for the dynamic characterization of food nutrient substances for the rapid determination of food quality. In this study, we attempt to detect and measure astaxanthin from salmon fillets using this technology. The Raman spectra showed specific bands corresponding to the astaxanthin present in salmon and the value of astaxanthin (Raman band, 1518 cm -1 ) relative to those of protein/lipid (Raman band, 1446 cm -1 ) in the spectra increased in a dose-dependent manner. A standard curve was constructed by the standard addition method using astaxanthin as the reference standard for its quantification by Raman spectroscopy. The calculation formula was established using the Raman bands typically observed for astaxanthin (i.e., 1518 cm -1 ). In addition, we examined salmon fillets of different species (Atlantic salmon, coho salmon, and sockeye salmon) and five fillets obtained from the locations (from the head to tail) of an entire Atlantic salmon. Moreover, the sockeye salmon fillet exhibited the highest astaxanthin concentration (14.2 mg/kg), while coho salmon exhibited an intermediate concentration of 7.0 mg/kg. The Raman-based astaxanthin concentration in the five locations of Atlantic salmon was more strongly detected from the fillet closer to the tail. From the results, a rapid, convenient Raman spectroscopic method was developed for the detection of astaxanthin in salmon fillets.

21 CFR 161.170 - Canned Pacific salmon.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., the common or usual name or names of each species of fish enumerated in paragraph (a)(2)(i) of this... accordance with good manufacturing practice; and then washing. Canned Pacific salmon is prepared in one of... good manufacturing practices. (iii) “Minced salmon” consists of salmon which has been minced or ground...

Etiology of sockeye salmon 'virus' disease

USGS Publications Warehouse

Guenther, Raymond W.; Watson, S.W.; Rucker, R.R.; Ross, A.J.

1959-01-01

Violent epizootics among hatchery reared sockeye salmon fingerlings (Oncorhynchus nerka) caused by a filterable agent have occurred. In 1954, one source of this infectious, filterable agent was found to be adult sockeye viscera used in the diet for the fingerlings. The results of observations on an epizootic in 1958 indicate that the infection may be transmitted to fingerlings from a water supply to which adult sockeye salmon have access.

Salmon Supplementation Studies in Idaho Rivers, 1996-1998 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reighn, Christopher A.; Lewis, Bert; Taki, Doug

1999-06-01

Information contained in this report summarizes the work that has been done by the Shoshone-Bannock Tribes Fisheries Department under BPA Project No. 89-098-3, Contract Number 92-BI-49450. Relevant data generated by the Shoshone-Bannock Tribe will be collated with other ISS cooperator data collected from the Salmon and Clearwater rivers and tributary streams. A summary of data presented in this report and an initial project-wide level supplementation evaluation will be available in the ISS 5 year report that is currently in progress. The Shoshone-Bannock Tribal Fisheries Department is responsible for monitoring a variety of chinook salmon (Oncorhynchus tshawytscha) production parameters as partmore » of the Idaho Supplementation Studies (BPA Project No. 89-098-3, Contract Number 92-BI-49450). Parameters include parr abundance in tributaries to the upper Salmon River; adult chinook salmon spawner abundance, redd counts, and carcass collection. A rotary screw trap is operated on the East Fork Salmon River and West Fork Yankee Fork Salmon River to enumerate and PIT-tag chinook smolts. These traps are also used to monitor parr movement, and collect individuals for the State and Tribal chinook salmon captive rearing program. The SBT monitors fisheries parameters in the following six tributaries of the Salmon River: Bear Valley Creek, East Fork Salmon River, Herd Creek, South Fork Salmon River, Valley Creek, and West Fork Yankee Fork. Chinook populations in all SBT-ISS monitored streams continue to decline. The South Fork Salmon River and Bear Valley Creek have the strongest remaining populations. Snorkel survey methodology was used to obtain parr population estimates for ISS streams from 1992 to 1997. Confidence intervals for the parr population estimates were large, especially when the populations were low. In 1998, based on ISS cooperator agreement, snorkeling to obtain parr population estimates was ceased due to the large confidence intervals. A rotary screw trap

Louse- and flea-borne rickettsioses: biological and genomic analyses

PubMed Central

Gillespie, Joseph J.; Ammerman, Nicole C.; Beier-Sexton, Magda; Sobral, Bruno S.; Azad, Abdu F.

2009-01-01

In contrast to 15 or more validated and/or proposed tick-borne spotted fever group species, only three named medically important rickettsial species are associated with insects. These insect-borne rickettsiae are comprised of two highly pathogenic species, Rickettsia prowazekii (the agent of epidemic typhus) and R. typhi (the agent of murine typhus), as well as R. felis, a species with unconfirmed pathogenicity. Rickettsial association with obligate hematophagous insects such as the human body louse (R. prowazekii transmitted by Pediculus h. humanus) and several flea species (R. typhi and R. felis, as well as R. prowazekii in sylvatic form) provides rickettsiae the potential for further multiplications, longer transmission cycles and rapid spread among susceptible human populations. Both human body lice and fleas are intermittent feeders capable of multiple blood meals per generation, facilitating the efficient transmission of rickettsiae to several disparate hosts within urban/rural ecosystems. While taking into consideration the existing knowledge of rickettsial biology and genomic attributes, we have analyzed and summarized the interacting features that are unique to both the rickettsiae and their vector fleas and lice. Furthermore, factors that underlie rickettsial changing ecology, where native mammalian populations are involved in the maintenance of rickettsial cycle and transmission, are discussed. PMID:19036234

Echo characteristics of two salmon species

NASA Astrophysics Data System (ADS)

Nealson, Patrick A.; Horne, John K.; Burwen, Debby L.

2005-04-01

The Alaska Department of Fish and Game relies on split-beam hydroacoustic techniques to estimate Chinook salmon (Oncorhynchus tshawytscha) returns to the Kenai River. Chinook counts are periodically confounded by large numbers of smaller sockeye salmon (O. nerka). Echo target-strength has been used to distinguish fish length classes, but was too variable to separate Kenai River chinook and sockeye distributions. To evaluate the efficacy of alternate echo metrics, controlled acoustic measurements of tethered chinook and sockeye salmon were collected at 200 kHz. Echo returns were digitally sampled at 48 kHz. A suite of descriptive metrics were collected from a series of 1,000 echoes per fish. Measurements of echo width were least variable at the -3 dB power point. Initial results show echo elongation and ping-to-ping variability in echo envelope width were significantly greater for chinook than for sockeye salmon. Chinook were also observed to return multiple discrete peaks from a single broadcast echo. These characteristics were attributed to the physical width of chinook exceeding half of the broadcast echo pulse width at certain orientations. Echo phase variability, correlation coefficient and fractal dimension distributions did not demonstrate significant discriminatory power between the two species. [Work supported by ADF&G, ONR.

Characteristics of formed Atlantic salmon jerky.

PubMed

Oberholtzer, Ashlan S; Dougherty, Michael P; Camire, Mary Ellen

2011-08-01

Smoked salmon (Salmo salar L.) processing may generate large amounts of small pieces of trimmed flesh that has little economic value. Opportunities exist to develop new added-value foods from this by-product. Brining was compared with dry salting for the production of formed salmon jerky-style strips that were then smoked. The formulations also contained brown sugar and potato starch. Salted samples had higher salt concentrations and required less force to break using a TA-XT2 Texture Analyzer. Brined samples contained more fat and were darker, redder and more yellow than the salted samples. Processing concentrated omega-3 fatty acids compared with raw salmon, and the brined jerky had the highest omega-3 fatty acid content. A panel of 57 consumers liked the appearance and aroma of both samples equally (approximately 6.7 for appearance and 6.3 for aroma on the 9-point hedonic scale. Higher acceptability scores for taste, texture, and overall quality were given to the brined product (6.7 to 6.9 against 6.2 to 6.3). Salmon trim from smoking facilities can be utilized to produce a jerky that is a good source of omega-3 fatty acids, simultaneously adding value and reducing the waste stream. © 2011 Institute of Food Technologists®

Characterization of a Value-Added Salmon Product: Infant/Toddler Food

ERIC Educational Resources Information Center

De Santos, Felicia Ann

2009-01-01

Salmon are rich sources of omega-3 fatty acids. These are important in the human diet and especially for young children in the first two years of life. Wild Alaskan salmon was utilized in a novel way by development and investigation of basic baby food product formulations from sockeye and pink salmon. Thus, physical and sensory properties of baby…

Microbial ecology of the salmon necrobiome: evidence salmon carrion decomposition influences aquatic and terrestrial insect microbiomes.

PubMed

Pechal, Jennifer L; Benbow, M Eric

2016-05-01

Carrion decomposition is driven by complex relationships that affect necrobiome community (i.e. all organisms and their genes associated with a dead animal) interactions, such as insect species arrival time to carrion and microbial succession. Little is understood about how microbial communities interact with invertebrates at the aquatic-terrestrial habitat interface. The first objective of the study was to characterize internal microbial communities using high-throughput sequencing of 16S rRNA gene amplicons for aquatic insects (three mayfly species) in streams with salmon carcasses compared with those in streams without salmon carcasses. The second objective was to assess the epinecrotic microbial communities of decomposing salmon carcasses (Oncorhynchus keta) compared with those of terrestrial necrophagous insects (Calliphora terraenovae larvae and adults) associated with the carcasses. There was a significant difference in the internal microbiomes of mayflies collected in salmon carcass-bearing streams and in non-carcass streams, while the developmental stage of blow flies was the governing factor in structuring necrophagous insect internal microbiota. Furthermore, the necrophagous internal microbiome was influenced by the resource on which the larvae developed, and changes in the adult microbiome varied temporally. Overall, these carrion subsidy-driven networks respond to resource pulses with bottom-up effects on consumer microbial structure, as revealed by shifting communities over space and time. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

Marine-derived nutrients, bioturbation, and ecosystem metabolism: reconsidering the role of salmon in streams.

PubMed

Holtgrieve, Gordon W; Schindler, Daniel E

2011-02-01

In coastal areas of the North Pacific Ocean, annual returns of spawning salmon provide a substantial influx of nutrients and organic matter to streams and are generally believed to enhance the productivity of recipient ecosystems. Loss of this subsidy from areas with diminished salmon runs has been hypothesized to limit ecosystem productivity in juvenile salmon rearing habitats (lakes and streams), thereby reinforcing population declines. Using five to seven years of data from an Alaskan stream supporting moderate salmon densities, we show that salmon predictably increased stream water nutrient concentrations, which were on average 190% (nitrogen) and 390% (phosphorus) pre-salmon values, and that primary producers incorporated some of these nutrients into tissues. However, benthic algal biomass declined by an order of magnitude despite increased nutrients. We also measured changes in stream ecosystem metabolic properties, including gross primary productivity (GPP) and ecosystem respiration (ER), from three salmon streams by analyzing diel measurements of oxygen concentrations and stable isotopic ratios (delta O-O2) within a Bayesian statistical model of oxygen dynamics. Our results do not support a shift toward higher primary productivity with the return of salmon, as is expected from a nutrient fertilization mechanism. Rather, net ecosystem metabolism switched from approximately net autotrophic (GPP > or = ER) to a strongly net heterotrophic state (GPP < ER) in response to bioturbation of benthic habitats by salmon. Following the seasonal arrival of salmon, GPP declined to <12% of pre-salmon rates, while ER increased by over threefold. Metabolism by live salmon could not account for the observed increase in ER early in the salmon run, suggesting salmon nutrients and disturbance enhanced in situ heterotrophic respiration. Salmon also changed the physical properties of the stream, increasing air-water gas exchange by nearly 10-fold during peak spawning. We suggest

Survival of juvenile chinook salmon and coho salmon in the Roza Dam fish bypass and in downstream reaches of the Yakima River, Washington, 2016

USGS Publications Warehouse

Kock, Tobias J.; Perry, Russell W.; Hansen, Amy C.

2016-12-22

Estimates of juvenile salmon survival are important data for fishery managers in the Yakima River Basin. Radiotelemetry studies during 2012–14 showed that tagged juvenile Chinook salmon (Oncorhynchus tshawytscha) that passed through the fish bypass at Roza Dam had lower survival than fish that passed through other routes at the dam. That study also identified flow-survival relationships in the reaches between the Roza Dam tailrace and Sunnyside Dam. During 2012–14, survival also was estimated through reaches downstream of Sunnyside Dam, but generally, sample sizes were low and the estimates were imprecise. In 2016, we conducted an evaluation using acoustic cameras and acoustic telemetry to build on information collected during the previous study. The goal of the 2016 research was to identify areas where mortality occurs in the fish bypass at Roza Dam, and to estimate reach-specific survival in reaches downstream of the dam. The 2016 study included juvenile Chinook salmon and coho salmon (O. kisutch).Three acoustic cameras were used to observe fish behavior (1) near the entrances to the fish bypass, (2) at a midway point in the fish bypass (convergence vault), and (3) at the bypass outfall. In total, 504 hours of acoustic camera footage was collected at these locations. We determined that smolt-sized fish (95–170 millimeters [mm]) were present in the highest proportions at each location, but predator-sized fish (greater than 250 mm) also were present at each site. Fish presence generally peaked during nighttime hours and crepuscular periods, and was low during daytime hours. In the convergence vault, smolt-sized fish exhibited holding behavior patterns, which may explain why some fish delayed while passing through the bypass.Some of the acoustic-tagged fish were delayed in the fish bypass following release, but there was no evidence to suggest that they experienced higher mortality than fish that were released at the bypass outfall or downstream of the dam

IBSEM: An Individual-Based Atlantic Salmon Population Model

PubMed Central

Castellani, Marco; Heino, Mikko; Gilbey, John; Araki, Hitoshi; Svåsand, Terje; Glover, Kevin A.

2015-01-01

Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM) to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a ‘wild’ genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors. PMID:26383256

IBSEM: An Individual-Based Atlantic Salmon Population Model.

PubMed

Castellani, Marco; Heino, Mikko; Gilbey, John; Araki, Hitoshi; Svåsand, Terje; Glover, Kevin A

2015-01-01

Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM) to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a 'wild' genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors.

CAN WE SUSTAIN WILD SALMON THROUGH 2100? THE SALMON 2100 PROJECT

EPA Science Inventory

abstract for presentation Many experts have concluded that wild salmon recovery efforts in western North America (especially California, Oregon, Washington, Idaho, and southern British Columbia), as earnest, expensive, and socially disruptive as they currently are, do not appe...

Passage survival of juvenile steelhead, coho salmon, and Chinook salmon in Lake Scanewa and at Cowlitz Falls Dam, Cowlitz River, Washington, 2010–16

USGS Publications Warehouse

Liedtke, Theresa L.; Kock, Tobias J.; Hurst, William

2018-04-03

A multi-year evaluation was conducted during 2010–16 to evaluate passage survival of juvenile steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) in Lake Scanewa, and at Cowlitz Falls Dam in the upper Cowlitz River Basin, Washington. Reservoir passage survival was evaluated in 2010, 2011, and 2016, and included the tagging and release of 1,127 juvenile salmonids. Tagged fish were released directly into the Cowlitz and Cispus Rivers, 22.3 and 8.9 km, respectively, upstream of the reservoir, and were monitored as they moved downstream into, and through the reservoir. A single release-recapture survival model was used to analyze detection records and estimate reservoir passage survival, which was defined as successful passage from reservoir entry to arrival at Cowlitz Falls Dam. Tagged fish generally moved quickly downstream of the release sites and, on average, arrived in the dam forebay within 2 d of release. Median travel time from release to first detection at the dam ranged from 0.23 to 0.96 d for juvenile steelhead, from 0.15 to 1.11 d for juvenile coho salmon, and from 0.18 to 1.89 d for juvenile Chinook salmon. Minimum reservoir passage survival probabilities were 0.960 for steelhead, 0.855 for coho salmon and 0.900 for Chinook salmon.Dam passage survival was evaluated at the pilot-study level during 2013–16 and included the tagging and release of 2,512 juvenile salmonids. Juvenile Chinook salmon were evaluated during 2013–14, and juvenile steelhead and coho salmon were evaluated during 2015–16. A paired-release study design was used that included release sites located upstream and downstream of Cowlitz Falls Dam. The downstream release site was positioned at the downstream margin of the dam’s tailrace, which allowed dam passage survival to be measured in a manner that included mortality that occurred in the passage route and in the dam tailrace. More than one-half of the tagged Chinook salmon (52 percent

SALMON AND THE ENDANGERED SPECIES ACT: TROUBLESOME QUESTIONS

EPA Science Inventory

Throughout the Pacific Northwest and California, all wild salmon runs have declined since 1850 and some have disappeared. A sustainable future for wild salmon remains elusive. In response to requirements of the U.S. Endangered Species Act, the Canadian Species at Risk Act, and ...

Adaptive strategies and life history characteristics in a warming climate: salmon in the Arctic?

USGS Publications Warehouse

Nielsen, Jennifer L.; Ruggerone, Gregory T.; Zimmerman, Christian E.

2013-01-01

In the warming Arctic, aquatic habitats are in flux and salmon are exploring their options. Adult Pacific salmon, including sockeye (Oncorhynchus nerka), coho (O. kisutch), Chinook (O. tshawytscha), pink (O. gorbuscha) and chum (O. keta) have been captured throughout the Arctic. Pink and chum salmon are the most common species found in the Arctic today. These species are less dependent on freshwater habitats as juveniles and grow quickly in marine habitats. Putative spawning populations are rare in the North American Arctic and limited to pink salmon in drainages north of Point Hope, Alaska, chum salmon spawning rivers draining to the northwestern Beaufort Sea, and small populations of chum and pink salmon in Canada’s Mackenzie River. Pacific salmon have colonized several large river basins draining to the Kara, Laptev and East Siberian seas in the Russian Arctic. These populations probably developed from hatchery supplementation efforts in the 1960’s. Hundreds of populations of Arctic Atlantic salmon (Salmo salar) are found in Russia, Norway and Finland. Atlantic salmon have extended their range eastward as far as the Kara Sea in central Russian. A small native population of Atlantic salmon is found in Canada’s Ungava Bay. The northern tip of Quebec seems to be an Atlantic salmon migration barrier for other North American stocks. Compatibility between life history requirements and ecological conditions are prerequisite for salmon colonizing Arctic habitats. Broad-scale predictive models of climate change in the Arctic give little information about feedback processes contributing to local conditions, especially in freshwater systems. This paper reviews the recent history of salmon in the Arctic and explores various patterns of climate change that may influence range expansions and future sustainability of salmon in Arctic habitats. A summary of the research needs that will allow informed expectation of further Arctic colonization by salmon is given.

78 FR 45478 - Proposed Establishment of Class E Airspace; Salmon, ID

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-29

...-0531; Airspace Docket No. 13-ANM-20] Proposed Establishment of Class E Airspace; Salmon, ID AGENCY... action proposes to establish Class E airspace at the Salmon VHF Omni-Directional Radio Range/Distance Measuring Equipment (VOR/DME) navigation aid, Salmon, ID, to facilitate vectoring of Instrument Flight Rules...

Some Practical Considerations in the Control of Louse-borne Typhus Fever in Great Britain in the Light of Experience in Russia, Poland, Rumania and China

PubMed Central

Mackenzie, Melville D.

1941-01-01

This paper deals with some aspects of the control of louse-borne typhus fever. The epidemic form is associated with famine and overcrowding. In producing an epidemic in a hitherto endemic area malnutrition is of greater importance than over-crowding; another factor which brings this about is widespread movement of civil or military population thus bringing non-immunes into a district where typhus is endemic. Endemic typhus usually occurs in the early months of the year, whilst the epidemic form may appear at any time. Conditions under which epidemic typhus occurs favour the outbreak of other diseases so that an uncomplicated case is rarely seen. Louse-borne typhus fever lasts from twelve to sixteen days. The incubation period is usually twelve to fourteen days, though it may be from five to twenty-one days. The onset is sudden, but is often preceded by malaise and a rise of temperature. Two common initial symptoms are acute frontal or occipital headache and bronchitis. The first sign may be mental confusion or delirium. Acute delirium is usually present after the first week. PMID:19992447

Contamination of salmon fillets and processing plants with spoilage bacteria.

PubMed

Møretrø, Trond; Moen, Birgitte; Heir, Even; Hansen, Anlaug Å; Langsrud, Solveig

2016-11-21

The processing environment of salmon processing plants represents a potential major source of bacteria causing spoilage of fresh salmon. In this study, we have identified major contamination routes of important spoilage associated species within the genera Pseudomonas, Shewanella and Photobacterium in pre-rigor processing of salmon. Bacterial counts and culture-independent 16S rRNA gene analysis on salmon fillet from seven processing plants showed higher levels of Pseudomonas spp. and Shewanella spp. in industrially processed fillets compared to salmon processed under strict hygienic conditions. Higher levels of Pseudomonas spp. and Shewanella spp. were found on fillets produced early on the production day compared to later processed fillets. The levels of Photobacterium spp. were not dependent on the processing method or time of processing. In follow-up studies of two plants, bacterial isolates (n=2101) from the in-plant processing environments (sanitized equipment/machines and seawater) and from salmon collected at different sites in the production were identified by partial 16S rRNA gene sequencing. Pseudomonas spp. dominated in equipment/machines after sanitation with 72 and 91% of samples from the two plants being Pseudomonas-positive. The phylogenetic analyses, based on partial 16S rRNA gene sequencing, showed 48 unique sequence profiles of Pseudomonas of which two were dominant. Only six profiles were found on both machines and in fillets in both plants. Shewanella spp. were found on machines after sanitation in the slaughter department while Photobacterium spp. were not detected after sanitation in any parts of the plants. Shewanella spp. and Photobacterium spp. were found on salmon in the slaughter departments. Shewanella was frequently present in seawater tanks used for bleeding/short term storage. In conclusion, this study provides new knowledge on the processing environment as a source of contamination of salmon fillets with Pseudomonas spp. and

Seasonal marine growth of Bristol Bay sockeye salmon (Oncorhynchus nerka) in relation to competition with Asian pink salmon (O. gorbuscho) and the 1977 ocean regime shift

USGS Publications Warehouse

Ruggerone, Gregory T.; Farley, Ed; Nielsen, Jennifer L.; Hagen, Peter

2005-01-01

Recent research demonstrated significantly lower growth and survival of Bristol Bay sockeye salmon (Oncorhynchus nerka) during odd-numbered years of their second or third years at sea (1975, 1977, etc.), a trend that was opposite that of Asian pink salmon (O. gorbuscha) abundance. Here we evaluated seasonal growth trends of Kvichak and Egegik river sockeye salmon (Bristol Bay stocks) during even- and odd-numbered years at sea by measuring scale circuli increments within each growth zone of each major salmon age group between 1955 and 2000. First year scale growth was not significantly different between odd- and even-numbered years, but peak growth of age-2. smolts was significantly higher than age-1 smolts. Total second and third year scale growth of salmon was significantly lower during odd- than during even-numbered years. However, reduced scale growth in odd-numbered years began after peak growth in spring and continued through summer and fall even though most pink salmon had left the high seas by late July (10-18% growth reduction in odd vs. even years). The alternating odd and even year growth pattern was consistent before and after the 1977 ocean regime shift. During 1977-2000, when salmon abundance was relatively great, sockeye salmon growth was high during specific seasons compared with that during 1955-1976, that is to say, immediately after entry to Bristol Bay, after peak growth in the first year, during the middle of the second growing season, and during spring of the third season. Growth after the spring peak in the third year at sea was relatively low during 1977-2000. We hypothesize that high consumption rates of prey by pink salmon during spring through mid-July of odd-numbered years, coupled with declining zooplankton biomass during summer and potentially cyclic abundances of squid and other prey, contributed to reduced prey availability and therefore reduced growth of Bristol Bay sockeye salmon during late spring through fall of odd-numbered years.

The Influence of Salmon Recolonization on Riparian Communities in the Cedar River, Washington, USA

NASA Astrophysics Data System (ADS)

Moravek, J.; Clipp, H.; Kiffney, P.

2015-12-01

Salmon are a valuable cultural and economic resource throughout the Pacific Northwest, but increasing human activity is degrading coastal ecosystems and threatening local salmon populations. Salmon conservation efforts often focus on habitat restoration, including the re-colonization of salmon into historically obstructed areas such as the Cedar River in Washington, USA. However, to assess the implications of salmon re-colonization on a landscape scale, it is critical to consider not only the river ecosystem but also the surrounding riparian habitat. Although prior studies suggest that salmon alter riparian food web dynamics, the riparian community on the Cedar River has not yet been characterized. To investigate possible connections between salmon and the riparian habitat, we surveyed riparian spider communities along a gradient of salmon inputs (g/m2). In 10-m transects along the banks of the river, we identified spiders and spider webs, collected prey from webs, and characterized nearby aquatic macroinvertebrate communities. We found that the density of aquatic macroinvertebrates, as well as the density of spider prey, both had significant positive relationships with salmon inputs, supporting the hypothesis that salmon provide energy and nutrients for both aquatic and riparian food webs. We also found that spider diversity significantly decreased with salmon inputs, potentially due to confounding factors such as stream gradient or vegetation structure. Although additional information is needed to fully understand this relationship, the significant connection between salmon inputs and spider diversity is compelling motivation for further studies regarding the link between aquatic and riparian systems on the Cedar River. Understanding the connections between salmon and the riparian community is critical to characterizing the landscape-scale implications of sustainable salmon management in the Pacific Northwest.

Interspecific competition in tributaries: Prospectus for restoring Atlantic salmon in Lake Ontario

USGS Publications Warehouse

Johnson, James H.; Wedge, Leslie R.

1999-01-01

Historically, Lake Ontario may have supported the world's largest freshwater population of Atlantic salmon (Salmo salar). However, by the late 1800's, salmon were virtually extinct in the lake due to the damming of tributaries, overharvest, deforestation, and pollution. Of these factors, the building of dams on tributaries, which precluded access by the salmon to natal spawning streams, was probably the most detrimental. Since the extirpation of Atlantic salmon in the Lake Ontario watershed over a century ago, considerable change has occurred throughout the lake and tributary ecosystem. The changes within the ecosystem that may have the most profound effect on Atlantic salmon restoration include the presence of exotic species, including other salmonines, and reduced habitat quality, especially in tributaries. These changes must be taken into account when considering Atlantic salmon restoration.

Energy economy of salmon aquaculture in the Baltic sea

NASA Astrophysics Data System (ADS)

Folke, Carl

1988-07-01

Resource utilization in Atlantic salmon aquaculture in the Baltic Sea was investigated by means of an energy analysis. A comparison was made between cage farming and sea ranching enterprises each with yearly yields of 40 t of Atlantic salmon. A variety of sea ranching options were evaluated, including (a) conventional ranching, (b) ranching employing a delayed release to the sea of young smolts, (c) harvesting salmon both by offshore fishing fleets and as they return to coastal areas, and (d) when offshore fishing is banned, harvesting salmon only as they return to coastal areas where released. Inputs both from natural ecosystems (i.e., fish consumed by ranched salmon while in the sea and raw materials used for producing dry food pellets) and from the economy (i.e., fossil fuels and energy embodied in economic goods and services) were quantified in tonnes for food energy and as direct plus indirect energy cost (embodied energy). The fixed solar energy (estimated as primary production) and the direct and indirect auxiliary energy requirements per unit of fish output were expressed in similar units. Similar quantities of living resources in tonnes per unit of salmon biomass output are required whether the salmon are feeding in the sea or are caged farmed. Cage farming is about 10 times more dependent on auxiliary energies than sea ranching. Sea ranching applying delayed release of smolts is 35 45% more efficient in the use of auxiliary energies than conventional sea ranching and cage farming. Restriction of offshore fishing would make sea ranching 3 to 6.5 times more efficient than cage farming. The fixed solar energy input to Atlantic salmon aquaculture is 4 to 63 times larger than the inputs of auxiliary energy. Thus, cage farming and sea ranching are both heavily dependent on the productivity of natural ecosystems. It is concluded that sustainable development of the aquaculture industry must be founded on ecologically integrated technologies which utilize the free

Diet composition and feeding periodicity of wild and hatchery subyearling Chinook salmon in Lake Ontario

USGS Publications Warehouse

Johnson, J. H.

2008-01-01

Diel feeding periodicity, daily ration, and diet composition of wild and hatchery subyearling Chinook salmon Oncorhynchus tshawytscha were examined in Lake Ontario and the Salmon River, New York. The diet of wild riverine salmon was composed mainly of aquatic invertebrates (63.4%), mostly ephemeropterans (25.8%), chiromomids (15.8%), and trichopterans (8.3%). The diet of riverine Chinook was more closely associated with the composition of drift samples rather than bottom samples, suggesting mid-water feeding. In Lake Ontario terrestrial invertebrates were more important in the diet of hatchery Chinook (49.0%) than wild salmon (30.5%) and diet overlap between hatchery and wild salmon was low (0.46%). The diet of both hatchery and wild Chinook salmon was more closely associated with the composition of mid-water invertebrate samples rather than benthic core samples, indicating mid-water and surface feeding. Hatchery Chinook salmon consumed significantly less food (P < 0.05) than wild Chinook salmon in the lake and in the river, and wild salmon from Lake Ontario consumed more food than wild salmon in the Salmon River. Peak feeding of wild Chinook salmon occurred between 1200-1600 hours in Lake Ontario and between 1600-2000 hours in the Salmon River; there was no discernable feeding peak for the hatchery Chinook in Lake Ontario. Hatchery Chinook salmon also had the least diverse diet over the 24-hour sample period. These results suggest that at 7 days post-stocking hatchery Chinook salmon had not yet fully adapted to their new environment.

Effects of dam removal on Tule Fall Chinook salmon spawning habitat in the White Salmon River, Washington

USGS Publications Warehouse

Hatten, James R.; Batt, Thomas R.; Skalicky, Joseph J.; Engle, Rod; Barton, Gary J.; Fosness, Ryan L.; Warren, Joe

2016-01-01

Condit Dam is one of the largest hydroelectric dams ever removed in the USA. Breached in a single explosive event in October 2011, hundreds-of-thousands of cubic metres of sediment washed down the White Salmon River onto spawning grounds of a threatened species, Columbia River tule fall Chinook salmon Oncorhynchus tshawytscha. We investigated over a 3-year period (2010–2012) how dam breaching affected channel morphology, river hydraulics, sediment composition and tule fall Chinook salmon (hereafter ‘tule salmon’) spawning habitat in the lower 1.7 km of the White Salmon River (project area). As expected, dam breaching dramatically affected channel morphology and spawning habitat due to a large load of sediment released from Northwestern Lake. Forty-two per cent of the project area that was previously covered in water was converted into islands or new shoreline, while a large pool near the mouth filled with sediments and a delta formed at the mouth. A two-dimensional hydrodynamic model revealed that pool area decreased 68.7% in the project area, while glides and riffles increased 659% and 530%, respectively. A spatially explicit habitat model found the mean probability of spawning habitat increased 46.2% after dam breaching due to an increase in glides and riffles. Shifting channels and bank instability continue to negatively affect some spawning habitat as sediments continue to wash downstream from former Northwestern Lake, but 300 m of new spawning habitat (river kilometre 0.6 to 0.9) that formed immediately post-breach has persisted into 2015. Less than 10% of tule salmon have spawned upstream of the former dam site to date, but the run sizes appear healthy and stable. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

The Influence of Salmon Recolonization on Riparian Communities in the Cedar River, Washington, USA

NASA Astrophysics Data System (ADS)

Moravek, J.; Clipp, H.; Kiffney, P.

2016-02-01

Salmon are a valuable resource throughout the Pacific Northwest, but increasing human activity is degrading coastal ecosystems and threatening local salmon populations. Salmon conservation efforts often focus on habitat restoration, including the re-colonization of salmon into historically obstructed areas such as the Cedar River in Washington, USA. However, to assess the long term implications of salmon re-colonization on a landscape scale, it is critical to consider not only the river ecosystem but also the surrounding riparian habitat. Although prior studies suggest that salmon alter riparian food web dynamics, the riparian community on the Cedar River has not yet been characterized. To investigate possible connections between salmon and the riparian habitat after 12 years of re-colonization, we surveyed riparian spider communities along a gradient of salmon inputs (g/m2). In 10-m transects along the banks of the river, we identified spiders and spider webs, collected prey from webs, and characterized nearby aquatic macroinvertebrate communities. We found that the density of aquatic macroinvertebrates, as well as the density of spider prey, both had significant positive relationships with salmon inputs, supporting the hypothesis that salmon provide energy and nutrients for both aquatic and riparian food webs. We also found that spider diversity significantly decreased with salmon inputs, potentially due to confounding factors such as stream gradient or vegetation structure. Although additional information is needed to fully understand this relationship, the significant connection between salmon inputs and spider diversity is compelling motivation for further studies regarding the link between aquatic and riparian systems on the Cedar River. Understanding the connections between salmon and the riparian community is critical to characterizing the long term, landscape-scale implications of sustainable salmon management in the Pacific Northwest.

Experimental model to evaluate the human body louse as a vector of plague.

PubMed

Houhamdi, Linda; Lepidi, Hubert; Drancourt, Michel; Raoult, Didier

2006-12-01

Yersinia pestis has been found in human body lice during plague outbreaks. To evaluate the role that the human body louse plays as a vector of plague, we allowed lice to feed on rabbits made bacteremic by intravenous inoculation of 10(9) colony-forming units of 3 strains of Y. pestis. High mortality rates were observed in all lice 2 and 3 days after infection. The lice remained infected with the strains for their life span and excreted viable organisms in their feces from day 1, although they were unable to lay eggs. The lice infected with 2 virulent strains of Y. pestis transmitted the organisms during feeding to uninfected rabbits, which became septicemic and died of plague (with 1 exception) 1 day later. Infections were transmitted to naive lice that were fed on these rabbits, showing that lice can be vectors of Y. pestis in an experimental model.

Dietary and spatial overlap between sympatric ursids relative to salmon use

USGS Publications Warehouse

Fortin, Jennifer K.; Farley, Sean D.; Rode, Karyn D.; Robbins, Charles T.

2007-01-01

We hypothesized that there would be minimal dietary overlap between sympatric brown bears (Ursus arctos) and American black bears (U. americanus) relative tosalmon (Oncorhynchus spp.) utilization when alternative foods (e.g., fruits) are abundant. To maximize the chance that we would reject this hypothesis, we examined the diets of brown and black bears known to have visited salmon streams. Species, sex, and individual identification of bears visiting salmon streams were determined by DNA analysis of hair and feces collected in 2002-2004 along those streams. Diets were estimated from fecal residues and stable isotope analyses of hair. Assimilated diets of brown bears were 66.0% (SD = 16.7%) salmon, 13.9% (SD = 7.5%) terrestrial animal matter, and 20.1% (SD = 17.2%) plant matter. Assimilated diets of black bears were 8.0% (SD = 5.4%)salmon, 8.4% (SD = 9.7%) terrestrial animal matter, and 83.6% (SD = 7.7%) plant matter. Male and female brown bears did not differ in either the proportion of dietary salmon, terrestrial animal matter, or plant matter. The relative amounts of fruit residues in the feces of brown bears (87.0%, SD = 15.2%) and black bears (91.8%, SD = 7.2%) did not differ. Both sexes of brown bears visited salmon streams and consumed significant amounts of salmon, but only male American black bears visited streams and then consumed minimal amounts of salmon. Thus, brown bears were largely carnivorous and black bears were largely herbivorous and frugivorous. This reduced dietary overlap relative to salmon and fruit use is understandable in light of the concentrated, defendable nature of salmon in small streams, the widely dispersed, non-defendable nature of abundant fruits, the dominance of brown over black bears, the higher energy requirement of the larger brown bear, and, therefore, the differing ability of the species to efficiently exploit different food resources.

Diel behavior of rearing fall Chinook salmon

USGS Publications Warehouse

Tiffan, Kenneth F.; Kock, Tobias J.; Skalicky, Joseph J.

2010-01-01

In fisheries science, habitat use is often inferred when fish are sampled or observed in a particular location. Physical habitat is typically measured where fish are found, and thus deemed important to habitat use. Although less common, a more informative approach is to measure or observe fish behavior within given habitats to more thoroughly assess their use of those locations. While this approach better reflects how fish use habitat, fish behavior can be difficult to quantify, particularly at night. For example, Tiffan and others (2002, 2006) were able to quantify habitat availability and characteristics that were important for rearing juvenile fall Chinook Salmon (Oncorhynchus tshawytscha) in the Hanford Reach of the Columbia River. The authors, however, could only speculate as to how juvenile salmon use habitat and respond to changes in water level fluctuations. Conversely, in this study we provide data on the diel activities of rearing juvenile wild fall Chinook Salmon which provides a better understanding of how fish “use” these rearing habitats. Diel behavior patterns are important because fish in the Hanford Reach are often stranded on shorelines when the water level rapidly recedes because of hydroelectric power generation at upriver dams (Nugent and others 2002; Anglin and others 2006). We hypothesize that juvenile salmon are at greater risk of stranding at night because they are less active and occupy habitat differently than during the day. We used underwater videography to collect behavioral information during the day and night to determine if juvenile fall Chinook Salmon are more susceptible to stranding when water level fluctuations occur at night.

Salmon River Habitat Enhancement. 1990 Annual Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowe, Mike

1991-12-01

The annual report contains three individual subproject sections detailing tribal fisheries work completed during the summer and fall of 1990. Subproject I contains summaries of evaluation/monitoring efforts associated with the Bear Valley Creek, Idaho enhancement project. Subproject II contains an evaluation of the Yankee Fork of the Salmon River habitat enhancement project. Subproject III concerns the East Fork of the Salmon River, Idaho.

Salmon as a food-poisoning vehicle--two successive Salmonella outbreaks.

PubMed Central

Cartwright, K. A.; Evans, B. G.

1988-01-01

Gastroenteritis due to Salmonella montevideo occurred amongst guests attending two social functions held within 24 h, food for both having been provided by the same catering firm. Salmon was the most likely vehicle of infection in each case, although cross-contamination of other foods occurred. There were no deaths; four patients were admitted to hospital, one of whom underwent appendicectomy. A review of salmon-associated food-poisoning outbreaks suggests that fresh salmon is an infrequent cause of food poisoning in the United Kingdom. The two outbreaks described here resulted from a failure of simple kitchen hygiene measures at a time of high ambient temperatures. Some current cooking instructions for salmon are inadequate. PMID:3181309

Early human use of anadromous salmon in North America at 11,500 y ago.

PubMed

Halffman, Carrin M; Potter, Ben A; McKinney, Holly J; Finney, Bruce P; Rodrigues, Antonia T; Yang, Dongya Y; Kemp, Brian M

2015-10-06

Salmon represented a critical resource for prehistoric foragers along the North Pacific Rim, and continue to be economically and culturally important; however, the origins of salmon exploitation remain unresolved. Here we report 11,500-y-old salmon associated with a cooking hearth and human burials from the Upward Sun River Site, near the modern extreme edge of salmon habitat in central Alaska. This represents the earliest known human use of salmon in North America. Ancient DNA analyses establish the species as Oncorhynchus keta (chum salmon), and stable isotope analyses indicate anadromy, suggesting that salmon runs were established by at least the terminal Pleistocene. The early use of this resource has important implications for Paleoindian land use, economy, and expansions into northwest North America.

Early human use of anadromous salmon in North America at 11,500 y ago

PubMed Central

Halffman, Carrin M.; Potter, Ben A.; McKinney, Holly J.; Finney, Bruce P.; Rodrigues, Antonia T.; Yang, Dongya Y.; Kemp, Brian M.

2015-01-01

Salmon represented a critical resource for prehistoric foragers along the North Pacific Rim, and continue to be economically and culturally important; however, the origins of salmon exploitation remain unresolved. Here we report 11,500-y-old salmon associated with a cooking hearth and human burials from the Upward Sun River Site, near the modern extreme edge of salmon habitat in central Alaska. This represents the earliest known human use of salmon in North America. Ancient DNA analyses establish the species as Oncorhynchus keta (chum salmon), and stable isotope analyses indicate anadromy, suggesting that salmon runs were established by at least the terminal Pleistocene. The early use of this resource has important implications for Paleoindian land use, economy, and expansions into northwest North America. PMID:26392548

POLICY CONUNDRUM: RESTORING WILD SALMON TO THE PACIFIC NORTHWEST

EPA Science Inventory

Restoring wild salmon runs to the Pacific Northwest is technically challenging, politically nasty, and socially divisive. Past restoration efforts have been largely unsuccessful. Society's failure to reverse the continuing decline of wild salmon has the characteristics of a pol...

The influence of fall-spawning coho salmon (Oncorhynchus kisutch) on growth and production of juvenile coho salmon rearing in beaver ponds on the Copper River Delta, Alaska.

Treesearch

Dirk W. Lang; Gordon H. Reeves; James D. Hall; Mark S. Wipfli

2006-01-01

This study examined the influence of fall-spawning coho salmon (Oncorhynchrcs kisutch) on the density, growth rate, body condition, and survival to outmigration of juvenile coho salmon on the Copper River Delta, Alaska, USA. During the fall of 1999 and 2000, fish rearing in beaver ponds that received spawning salmon were compared with fish from...

Environmental variability and chum salmon production at the northwestern Pacific Ocean

NASA Astrophysics Data System (ADS)

Kim, Suam; Kang, Sukyung; Kim, Ju Kyoung; Bang, Minkyoung

2017-12-01

Chum salmon, Oncorhynchus keta, are distributed widely in the North Pacific Ocean, and about 76% of chum salmon were caught from Russian, Japanese, and Korean waters of the northwestern Pacific Ocean during the last 20 years. Although it has been speculated that the recent increase in salmon production was aided by not only the enhancement program that targeted chum salmon but also by favorable ocean conditions since the early 1990s, the ecological processes for determining the yield of salmon have not been clearly delineated. To investigate the relationship between yield and the controlling factors for ocean survival of chum salmon, a time-series of climate indices, seawater temperature, and prey availability in the northwestern Pacific including Korean waters were analyzed using some statistical tools. The results of cross-correlation function (CCF) analysis and cumulative sum (CuSum) of anomalies indicated that there were significant environmental changes in the North Pacific during the last century, and each regional stock of chum salmon responded to the Pacific Decadal Oscillation (PDO) differently: for Russian stock, the correlations between PDO index and catch were significantly negative with a time-lag of 0 and 1 years; for Japanese stock, significantly positive with a timelag of 0-2 years; and for Korean stock, positive but no significant correlation. The results of statistical analyses with Korean chum salmon also revealed that a coastal seawater temperature over 14°C and the return rate of spawning adults to the natal river produced a significant negative correlation.

Snake River Sockeye Salmon Habitat and Limnological Research : 2008 Annual Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Andre E.; Griswold, Robert G.; Taki, Doug

2009-07-31

In March 1990, the Shoshone-Bannock Tribes petitioned the National Marine Fisheries Service (NMFS) to list Snake River sockeye salmon (Oncorhynchus nerka) as endangered. Snake River sockeye salmon were officially listed as endangered in November 1991 under the Endangered Species Act (56 FR 58619). In 1991, the Snake River Sockeye Salmon Habitat and Limnological Research Project was implemented. This project is part of an interagency effort to prevent the extinction of the Redfish Lake stock of Snake River sockeye salmon. The Shoshone-Bannock Tribal goal for this project is two tiered: the immediate goal is to increase the population of Snake Rivermore » sockeye salmon while preserving the unique genetic characteristics of the evolutionarily significant unit (ESU). The Tribes long term goal is to maintain a viable population that warrants delisting and provides Tribal harvest opportunities. The Bonneville Power Administration (BPA) provides funding for this interagency Recovery effort. Collaborators in the recovery effort include the National Oceanic and Atmospheric Administration (NOAA), the Idaho Department of Fish and Game (IDFG), the University of Idaho (UI), and the Shoshone-Bannock Tribes (SBT). This report summarizes activities conducted by Shoshone-Bannock Tribal Fisheries Department personnel during the 2008 calendar year. Project tasks include: (1) monitor limnological parameters of the Sawtooth Valley lakes to assess lake productivity; (2) conduct lake fertilization in Pettit and Alturas lakes; (3) reduce the number of mature kokanee salmon spawning in Alturas Lake Creek; (4) monitor, enumerate, and evaluate sockeye salmon smolt migration from Pettit and Alturas lakes; (5) monitor spawning kokanee salmon escapement and estimate fry recruitment in Fishhook and Alturas Lake creeks; (6) conduct sockeye and kokanee salmon population surveys; (7) evaluate potential competition and predation between stocked juvenile sockeye salmon and a variety of fish

Overview of environmental and hydrogeologic conditions at King Salmon, Alaska

USGS Publications Warehouse

Waythomas, C.F.

1994-01-01

The Federal Aviation Administration is conducting preliminary environmental assessments at most of its present or former facilities in Alaska. Information about environmental conditions at King Salmon, Alaska are presented in this report. This report gives an overview of the geology, hydro- logy, and climate of the King Salmon area and describes general geohydrologic conditions. A thick alluvial aquifer underlies King Salmon and both ground water and surface water are plentiful in the area.

Characterisation of a monoclonal antibody detecting Atlantic salmon endothelial and red blood cells, and its association with the infectious salmon anaemia virus cell receptor.

PubMed

Aamelfot, Maria; Weli, Simon C; Dale, Ole B; Koppang, Erling O; Falk, Knut

2013-05-01

Endothelial cells (ECs) line the luminal surfaces of the cardiovascular system and play an important role in cardiovascular functions such as regulation of haemostasis and vasomotor tone. A number of fish and mammalian viruses target these cells in the course of their infection. Infectious salmon anaemia virus (ISAV) attacks ECs and red blood cells (RBCs) of farmed Atlantic salmon (Salmo salar L.), producing the severe disease of infectious salmon anaemia (ISA). The investigation of ISA has up to now been hampered by the lack of a functional marker for ECs in Atlantic salmon in situ. In this study, we report the characterisation and use of a novel monoclonal antibody (MAb) detecting Atlantic salmon ECs (e.g. vessel endothelium, endocardial cells and scavenger ECs) and RBCs. The antibody can be used with immunohistochemistry, IFAT and on Western blots. It appears that the epitope recognised by the antibody is associated with the ISAV cellular receptor. Besides being a tool to identify ECs in situ, it could be useful in further studies of the pathogenicity of ISA. Finally, the detection of an epitope shared by ECs and RBCs agrees with recent findings that these cells share a common origin, thus the MAb can potentially be used to study the ontogeny of these cells in Atlantic salmon. © 2013 Anatomical Society.

Salmon 2100: Some recovery strategies that just might work

EPA Science Inventory

The primary goal of the Salmon 2100 Project is to identify practical options that have a high probability of maintaining biologically significant, sustainable populations of wild salmon in California, Oregon, Washington, Idaho, and southern British Columbia. The Project does not ...

POLICY CONUNDRUM: RESTORING WILD SALMON TO THE PACIFIC NORTHWEST

EPA Science Inventory

Across the Pacific Northwest region of North America, many runs of wild (in contrast to hatchery-bred) salmon have declined and some have been extirpated. Restoring wild salmon runs to the Pacific Northwest is technically challenging, politically nasty, socially divisive, and ...

Net trophic transfer efficiency of PCBs to Lake Michigan coho salmon from their prey

USGS Publications Warehouse

Madenjian, Charles P.; Elliott, Robert F.; Schmidt, Larry J.; DeSorcie, Timothy J.; Hesselberg, Robert J.; Quintal, Richard T.; Begnoche, Linda J.; Bouchard, Patrick M.; Holey, Mark E.

1998-01-01

Most of the polychlorinated biphenyl (PCB) body burden accumulated by coho salmon (Oncorhynchus kisutch) from the Laurentian Great Lakes is from their food. We used diet information, PCB determinations in both coho salmon and their prey, and bioenergetics modeling to estimate the efficiency with which Lake Michigan coho salmon retain PCBs from their food. Our estimate was the most reliable estimate to date because (a) the coho salmon and prey fish sampled during our study were sampled in spring, summer, and fall from various locations throughout the lake, (b) detailed measurements were made on the PCB concentrations of both coho salmon and prey fish over wide ranges in fish size, and (c) coho salmon diet was analyzed in detail from April through November over a wide range of salmon size from numerous locations throughout the lake. We estimated that coho salmon from Lake Michigan retain 50% of the PCBs that are contained within their food.

Coronary arteriosclerosis in Atlantic salmon. No regression of lesions after spawning.

PubMed

Saunders, R L; Farrell, A P

1988-01-01

The incidence and severity of coronary arteriosclerosis were studied in 209 wild and cultured Atlantic salmon (Salmo salar L.) during various stages of recovery of bodily condition after spawning. All recently spawned fish had lesions of moderate to extreme severity. The incidence of lesions for each fish was high (73% to 94% of all arterial cross-sections examined). The incidence and severity of lesions did not decrease during 5 months in a group of wild salmon reconditioned in the laboratory. Wild salmon that were examined in the spring angling fishery in the Miramichi River, New Brunswick, about 5 months after spawning had a high incidence (89%) of severe lesions, not significantly different from recently spawned salmon from the same and another river. A population of cultured salmon sampled at intervals from a sea cage during 9 months after spawning showed no evidence of lesion regression, but rather a continued increase in both incidence and severity during recovery of bodily condition and growth. Thus, in contrast with previous studies with steelhead trout and Atlantic salmon where the possibility of lesion regression has been suggested, our observations on a large number of Atlantic salmon from various sources gave no evidence of lesion regression. Coronary arteriosclerosis in Salmo salar appears to be a progressive condition, which continues during recovery of bodily condition and growth after spawning.

Spawning sockeye salmon fossils in Pleistocene lake beds of Skokomish Valley, Washington

NASA Astrophysics Data System (ADS)

Smith, Gerald R.; Montgomery, David R.; Peterson, N. Phil; Crowley, Bruce

2007-09-01

An assemblage of fossil sockeye salmon was discovered in Pleistocene lake sediments along the South Fork Skokomish River, Olympic Peninsula, Washington. The fossils were abundant near the head of a former glacial lake at 115 m elevation. Large adult salmon are concentrated in a sequence of death assemblages that include individuals with enlarged breeding teeth and worn caudal fins indicating migration, nest digging, and spawning prior to death. The specimens were 4 yr old and 45-70 cm in total length, similar in size to modern sockeye salmon, not landlocked kokanee. The fossils possess most of the characteristics of sockeye salmon, Oncorhynchus nerka, but with several minor traits suggestive of pink salmon, O. gorbuscha. This suggests the degree of divergence of these species at about 1 million yr ago, when geological evidence indicates the salmon were deposited at the head of a proglacial lake impounded by the Salmon Springs advance of the Puget lobe ice sheet. Surficial geology and topography record a complicated history of glacial damming and river diversion that implies incision of the modern gorge of the South Fork Skokomish River after deposition of the fossil-bearing sediments.

Behavior patterns and fates of adult steelhead, Chinook salmon, and coho salmon released into the upper Cowlitz River Basin, 2005–09 and 2012, Washington

USGS Publications Warehouse

Kock, Tobias J.; Ekstrom, Brian K.; Liedtke, Theresa L.; Serl, John D.; Kohn, Mike

2016-08-26

A multiyear radiotelemetry evaluation was conducted to monitor adult steelhead (Oncorhynchus mykiss), Chinook salmon (O. tshawytscha), and coho salmon (O. kisutch) behavior and movement patterns in the upper Cowlitz River Basin. Volitional passage to this area was eliminated by dam construction in the mid-1960s, and a reintroduction program began in the mid-1990s. Fish are transported around the dams using a trap-and-haul program, and adult release sites are located in Lake Scanewa, the uppermost reservoir in the system, and in the Cowlitz and Cispus Rivers. Our goal was to estimate the proportion of tagged fish that fell back downstream of Cowlitz Falls Dam before the spawning period and to determine the proportion that were present in the Cowlitz and Cispus Rivers during the spawning period. Fallback is important because Cowlitz Falls Dam does not have upstream fish passage, so fish that pass the dam are unable to move back upstream and spawn. A total of 2,051 steelhead and salmon were tagged for the study, which was conducted during 2005–09 and 2012, and 173 (8.4 percent) of these regurgitated their transmitter prior to, or shortly after release. Once these fish were removed from the dataset, the final number of fish that was monitored totaled 1,878 fish, including 647 steelhead, 770 Chinook salmon, and 461 coho salmon.Hatchery-origin (HOR) and natural-origin (NOR) steelhead, Chinook salmon, and coho salmon behaved differently following release into Lake Scanewa. Detection records showed that the percentage of HOR fish that moved upstream and entered the Cowlitz River or Cispus River after release was relatively low (steelhead = 38 percent; Chinook salmon = 67 percent; coho salmon = 41 percent) compared to NOR fish (steelhead = 84 percent; Chinook salmon = 82 percent; coho salmon = 76 percent). The elapsed time from release to river entry was significantly lower for NOR fish than for HOR fish for all three species. Tagged fish entered the Cowlitz River in

Olfactory gene expression in migrating adult sockeye salmon Oncorhynchus nerka.

PubMed

Bett, N N; Hinch, S G; Kaukinen, K H; Li, S; Miller, K M

2018-04-16

Expression of 12 olfactory genes was analysed in adult sockeye salmon Oncorhynchus nerka nearing spawning grounds and O. nerka that had strayed from their natal migration route. Variation was found in six of these genes, all of which were olfc olfactory receptors and had lower expression levels in salmon nearing spawning grounds. The results may reflect decreased sensitivity to natal water olfactory cues as these fish are no longer seeking the correct migratory route. The expression of olfactory genes during the olfactory-mediated spawning migration of Pacific salmon Oncorhynchus spp. is largely unexplored and these findings demonstrate a link between migratory behaviours and olfactory plasticity that provides a basis for future molecular research on salmon homing. © 2018 The Fisheries Society of the British Isles.

76 FR 70062 - Fraser River Sockeye and Pink Salmon Fisheries; Inseason Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-10

...-XA803 Fraser River Sockeye and Pink Salmon Fisheries; Inseason Orders AGENCY: National Marine Fisheries...; inseason orders. SUMMARY: NMFS publishes Fraser River salmon inseason orders to regulate treaty and non-treaty (all citizen) commercial salmon fisheries in U.S. waters. The orders were issued by the Fraser...

78 FR 69002 - Fraser River Sockeye and Pink Salmon Fisheries; Inseason Orders

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-18

...-XC965 Fraser River Sockeye and Pink Salmon Fisheries; Inseason Orders AGENCY: National Marine Fisheries...; inseason orders. SUMMARY: NMFS publishes Fraser River salmon inseason orders to regulate treaty and non-treaty (all citizen) commercial salmon fisheries in U.S. waters. The orders were issued by the Fraser...

ESTIMATING THE SIZE OF HISTORICAL COASTAL OREGON SALMON RUNS

EPA Science Inventory

Increasing the abundance of salmon in Oregon's rivers and streams is a high priority public policy objective. Salmon runs have been reduced from pre-development conditions (typically defined as prior to the 1850s), but it is unclear by how much. Considerable public and private ...

PACIFIC NORTHWEST SALMON: IN SEARCH OF A SUSTAINABLE FUTURE

EPA Science Inventory

Throughout the Pacific Northwest, all wild salmon runs have declined since 1850 and some have disappeared. A sustainable future for wild salmon remains elusive. Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline. Each year, hundreds...

An Assessment of Potential Mining Impacts on Salmon ...

EPA Pesticide Factsheets

The Bristol Bay watershed in southwestern Alaska supports the largest sockeye salmon fishery in the world, is home to 25 federally recognized tribal governments, and contains large mineral resources. The potential for large-scale mining activities in the watershed has raised concerns about the impact of mining on the sustainability of Bristol Bay’s world-class commercial, recreational and subsistence fisheries and the future of Alaska Native tribes in the watershed who have maintained a salmon-based culture and subsistence-based way of life for at least 4,000 years. The purpose of this assessment is to provide a characterization of the biological and mineral resources of the Bristol Bay watershed, increase understanding of the potential impacts of large-scale mining on the region’s fish resources, and inform future government decisions related to protecting and maintaining the chemical, physical, and biological integrity of the watershed. It will also serve as a technical resource for the public, tribes, and governments who must consider how best to address the challenges of mining and ecological protection in the Bristol Bay watershed. The purpose of this assessment is to understand how future large-scale mining may affect water quality and the Bristol Bay salmon fisheries, which includes the largest wild sockeye salmon fishery in the world. Bristol Bay, Alaska, is home to a salmon fishery that is of significant economic and subsistence value to the peopl

Development of a Conceptual Chum Salmon Emergence Model for Ives Island

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murray, Christopher J.; Geist, David R.; Arntzen, Evan V.

2011-02-09

The objective of the study described herein was to develop a conceptual model of chum salmon emergence that was based on empirical water temperature of the riverbed and river in specific locations where chum salmon spawn in the Ives Island area. The conceptual model was developed using water temperature data that have been collected in the past and are currently being collected in the Ives Island area. The model will be useful to system operators who need to estimate the complete distribution of chum salmon emergence (first emergence through final emergence) in order to balance chum salmon redd protection andmore » power system operation.« less

The Peacock versus the louse (pediculus humanus corporis): one soldier's contribution to combating trench fever in the First World War.

PubMed

Peacock, A; Pearson, W

2010-09-01

Trench fever became a major worry for the Allied High Command during the First World War because of its debilitating effects on troop performance. The causes of the fever were not previously known, but entomological research identified the body louse (pediculus humanus corporis) as the carrier, and the Royal Army Medical Corps developed effective methods of control through disinfestation. These were markedly influenced by the researches of a young entomologist, Alexander David Peacock, which were conducted under campaign conditions. Peacock subsequently occupied a Chair of Zoology at St. Andrews University for 30 years.

Salmon Gill Poxvirus, the Deepest Representative of the Chordopoxvirinae

PubMed Central

Yutin, Natalya; Tengs, Torstein; Senkevich, Tania; Koonin, Eugene; Rønning, Hans Petter; Alarcon, Marta; Ylving, Sonja; Lie, Kai-Inge; Saure, Britt; Tran, Linh; Dale, Ole Bendik

2015-01-01

ABSTRACT Poxviruses are large DNA viruses of vertebrates and insects causing disease in many animal species, including reptiles, birds, and mammals. Although poxvirus-like particles were detected in diseased farmed koi carp, ayu, and Atlantic salmon, their genetic relationships to poxviruses were not established. Here, we provide the first genome sequence of a fish poxvirus, which was isolated from farmed Atlantic salmon. In the present study, we used quantitative PCR and immunohistochemistry to determine aspects of salmon gill poxvirus disease, which are described here. The gill was the main target organ where immature and mature poxvirus particles were detected. The particles were detected in detaching, apoptotic respiratory epithelial cells preceding clinical disease in the form of lethargy, respiratory distress, and mortality. In moribund salmon, blocking of gas exchange would likely be caused by the adherence of respiratory lamellae and epithelial proliferation obstructing respiratory surfaces. The virus was not found in healthy salmon or in control fish with gill disease without apoptotic cells, although transmission remains to be demonstrated. PCR of archival tissue confirmed virus infection in 14 cases with gill apoptosis in Norway starting from 1995. Phylogenomic analyses showed that the fish poxvirus is the deepest available branch of chordopoxviruses. The virus genome encompasses most key chordopoxvirus genes that are required for genome replication and expression, although the gene order is substantially different from that in other chordopoxviruses. Nevertheless, many highly conserved chordopoxvirus genes involved in viral membrane biogenesis or virus-host interactions are missing. Instead, the salmon poxvirus carries numerous genes encoding unknown proteins, many of which have low sequence complexity and contain simple repeats suggestive of intrinsic disorder or distinct protein structures. IMPORTANCE Aquaculture is an increasingly important global

Salmon and steelhead in the White Salmon River after the removal of Condit Dam–Planning efforts and recolonization results

USGS Publications Warehouse

Allen, Brady; Engle, Rod O; Zendt, Joseph S; Shrier, Frank C; Wilson, Jeremy T; Connolly, Patrick J.

2016-01-01

Condit Dam, at river kilometer 5.3 on the White Salmon River, Washington, was breached in 2011 and completely removed in 2012. This action opened habitat to migratory fish for the first time in 100 years. The White Salmon Working Group was formed to create plans for fish salvage in preparation for fish recolonization and to prescribe the actions necessary to restore anadromous salmonid populations in the White Salmon River after Condit Dam removal. Studies conducted by work group members and others served to inform management decisions. Management options for individual species were considered, including natural recolonization, introduction of a neighboring stock, hatchery supplementation, and monitoring natural recolonization for some time period to assess the need for hatchery supplementation. Monitoring to date indicates that multiple species and stocks of anadromous salmonids are finding and spawning in the now accessible and recovering habitat.

Development and characterization of two cell lines from gills of Atlantic salmon

USGS Publications Warehouse

Gjessing, Mona C.; Aamelfot, Maria; Batts, William N.; Benestad, Sylvie L.; Dale, Ole B.; Thoen, Even; Weli, Simon C.; Winton, James R.

2018-01-01

Gill disease in Atlantic salmon, Salmo salar L., causes big losses in the salmon farming industry. Until now, tools to cultivate microorganisms causing gill disease and models to study the gill responses have been lacking. Here we describe the establishment and characterization of two cell lines from the gills of Atlantic salmon. Atlantic salmon gill cell ASG-10 consisted of cells staining for cytokeratin and e-cadherin and with desmosomes as seen by transmission electron microscopy suggesting the cells to be of epithelial origin. These structures were not seen in ASG-13. The cell lines have been maintained for almost 30 passages and both cell lines are fully susceptible to infection by infectious hematopoietic necrosis virus (IHNV), viral hemorrhagic septicemia virus (VHSV), infectious pancreatic necrosis virus (IPNV), Atlantic salmon reovirus TS (TSRV) and Pacific salmon paramyxovirus (PSPV). While infectious salmon anemia virus (ISAV) did not cause visible CPE, immunofluorescent staining revealed a sub-fraction of cells in both the ASG-10 and ASG-13 lines may be permissive to infection. ASG-10 is able to proliferate and migrate to close scratches in the monolayer within seven days in vitro contrary to ASG-13, which does not appear to do have the same proliferative and migratory ability. These cell lines will be useful in studies of gill diseases in Atlantic salmon and may represent an important contribution for alternatives to experimental animals and studies of epithelial–mesenchymal cell biology.

Evaluation of Salmon Spawning Below Bonneville Dam, 2005-2006 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arntzen, Evan; Mueller, Robert; Murray, Christopher

2007-03-01

Since FY 2000, scientists at Pacific Northwest National Laboratory (PNNL) have conducted research to assess the extent of spawning by chum salmon (Oncorhynchus keta) and fall Chinook salmon (O. tshawytscha) in the lower mainstem Columbia River. Their work supports a larger project funded by the Bonneville Power Administration (BPA) aimed at characterizing the physical habitat used by mainstem fall Chinook and chum salmon populations. Multiple collaborators in addition to PNNL are involved in the BPA project--counterparts include the Washington Department of Fish and Wildlife (WDFW), U.S. Fish and Wildlife Service (USFWS), Pacific States Marine Fisheries Commission (PSMFC), U.S. Geological Surveymore » (USGS), and Oregon Department of Fish and Wildlife (ODFW). Data resulting from the individual tasks each agency conducts are providing a sound scientific basis for developing strategies to operate the Federal Columbia River Power System (FCRPS) in ways that will effectively protect and enhance the chum and tule fall Chinook salmon populations--both listed as threatened under the Endangered Species Act (ESA). Fall Chinook salmon, thought to originate from Bonneville Hatchery, were first noted to be spawning downstream of Bonneville Dam by WDFW biologists in 1993. Known spawning areas include gravel beds on the Washington side of the river near Hamilton Creek and near Ives Island. Limited surveys of spawning ground were conducted in the area around Ives and Pierce islands from 1994 through 1997. Based on those surveys, it is believed that fall Chinook salmon are spawning successfully in this area. The size of this population from 1994 to 1996 was estimated at 1800 to 5200 fish. Chum salmon also have been documented spawning downstream of Bonneville Dam. Chum salmon were listed as threatened under the ESA in March 1999. At present there is a need to determine the number of fall Chinook and chum salmon spawning downstream of Bonneville Dam, the characteristics of their

A remarkable new genus and a new species of chewing louse (Phthiraptera, Ischnocera, Philopteridae) from Brazil

PubMed Central

Valim, Michel P.; Cicchino, Armando C.

2015-01-01

Abstract A new genus of chewing louse as Bobdalgleishia, and its type species Bobdalgleishia stephanophallus sp. n. (Phthiraptera) belonging to the Brueelia-complex (Ischnocera: Philopteridae) are described. Adults of the new species are fully described, illustrated and compared morphologically with the type species of Motmotnirmus Mey & Barker, 2014, which is its closest relative. The type host of Bobdalgleishia stephanophallus is a subspecies of the great jacamar Jacamerops aureus ridgwayi Todd, 1943, an endemic Amazonian bird distributed in northern Brazil, and the type locality is the State of Pará. Bobdalgleishia is a remarkable genus with unique morphological and chaetotaxic characters which readily separate it from other members of the Brueelia-complex, in particular by having the first two marginal temporal and ocular setae very long. PMID:26798280

Post-release behavior and movement patterns of Chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) after capture using alternative commercial fish gear, lower Columbia River, Washington and Oregon, 2013

USGS Publications Warehouse

Liedtke, Theresa L.; Kock, Tobias J.; Evans, Scott D.; Hansen, Gabriel S.; Rondorf, Dennis W.

2014-01-01

In 2011 and 2012, WDFW conducted post-release mortality studies of steelhead (Oncorhynchus mykiss), Chinook salmon (Oncorhynchus tshawytscha), and coho salmon (Oncorhynchus kisutch) that were captured using beach or purse seines. These studies were comprised of two groups of fish tagged with passive integrated transponder tags (PIT tags): (1) treatment fish that were captured by one of the gear types 9–25 river kilometers (rkm) downstream of Bonneville Dam (rkm 234); and (2) control fish that were captured at the Adult Fish Facility near the Washington shore fish ladder at Bonneville Dam, and then transported and released 8 rkm downstream of the Bonneville Dam. Fish were confirmed to have survived if they moved upstream and were detected on PIT-tag antennas at or upstream of Bonneville Dam, were recovered at hatcheries or at the dam, or were captured by commercial or sport fishers. Post-release survival estimates were higher for steelhead (89–98 percent) than for Chinook salmon and coho salmon (50–90 percent; Washington Department of Fish and Wildlife, unpub. data, 2014). However, some Chinook salmon and coho salmon return to hatcheries, or spawn in the mainstem Columbia River and in tributaries downstream of Bonneville Dam. The proportion of Chinook salmon and coho salmon in the treatment group that were destined for areas downstream of Bonneville Dam likely was higher than in the control group because the control fish were collected as they were attempting to pass the dam. If this assertion was true, mortality would have been overestimated in these studies, so WDFW developed a study plan to determine the post-release movements and intended location of Chinook salmon and coho salmon collected with beach and purse seines in the lower Columbia River.

Reduced trace element concentrations in fast-growing juvenile Atlantic salmon in natural streams.

PubMed

Ward, Darren M; Nislow, Keith H; Chen, Celia Y; Folt, Carol L

2010-05-01

To assess the effect of rapid individual growth on trace element concentrations in fish, we measured concentrations of seven trace elements (As, Cd, Cs, Hg, Pb, Se, Zn) in stream-dwelling Atlantic salmon (Salmo salar) from 15 sites encompassing a 10-fold range in salmon growth. All salmon were hatched under uniform conditions, released into streams, and sampled approximately 120 days later for trace element analysis. For most elements, element concentrations in salmon tracked those in their prey. Fast-growing salmon had lower concentrations of all elements than slow growers, after accounting for prey concentrations. This pattern held for essential and nonessential elements, as well as elements that accumulate from food and those that can accumulate from water. At the sites with the fastest salmon growth, trace element concentrations in salmon were 37% (Cs) to 86% (Pb) lower than at sites where growth was suppressed. Given that concentrations were generally below levels harmful to salmon and that the pattern was consistent across all elements, we suggest that dilution of elements in larger biomass led to lower concentrations in fast-growing fish. Streams that foster rapid, efficient fish growth may produce fish with lower concentrations of elements potentially toxic for human and wildlife consumers.

Preserving Salmon Byproducts through Smoke-Processing Prior to Ensilage

USDA-ARS?s Scientific Manuscript database

Salmon is an important fishery in Alaska and accounts for about 9% of the annual catch. Processing these fish results in valuable byproducts that contain oils with high concentrations of long-chain n-3 polyunsaturated fatty acids (PUFA). Previous research demonstrated that when discarded salmon head...

Evidence for a carrier state of infectious hematopoietic necrosis virus in chinook salmon Oncorhynchus tshawytscha.

PubMed

St Hilaire, S; Ribble, C; Traxler, G; Davies, T; Kent, M L

2001-10-08

In British Columbia, Canada, infectious hematopoietic necrosis virus (IHNV) is prevalent in wild sockeye salmon Oncorhynchus nerka and has caused disease in seawater net-pen reared Atlantic salmon Salmo salar. In this study, chinook salmon Oncorhynchus tshawytscha experimentally exposed to an isolate of IHNV found in British Columbia became carriers of the virus. When Atlantic salmon were cohabited with these virus-exposed chinook salmon, IHNV was isolated from the Atlantic salmon. Identification of chinook salmon populations that have been exposed to IHNV may be difficult, as virus isolation was successful only in fish that were concurrently infected with either Renibacterium salmoninarum or Piscirickettisia salmonis. Also, IHNV-specific antibodies were detected in only 2 of the 70 fish experimentally exposed to the virus. Two samples collected from chinook salmon exposed to IHNV while at a salt water net-pen site had a seroprevalence of 19 and 22%; however, the inconsistencies between our laboratory and field data suggest that further research is required before we can rely on serological analysis for identifying potential carrier populations. Because of the difficulty in determining the exposure status of populations of chinook salmon, especially if there is no concurrent disease, it may be prudent not to cohabit Atlantic salmon with chinook salmon on a farm if there is any possibility that the latter have been exposed to the virus.

Tissue astaxanthin and canthaxanthin distribution in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar).

PubMed

Page, G I; Davies, S J

2006-01-01

A comparative investigation of tissue carotenoid distribution between rainbow trout, Oncorhynchus mykiss, and Atlantic salmon, Salmo salar, was undertaken to identify the relative efficiency of utilization of astaxanthin and canthaxanthin. Higher apparent digestibility coefficients (ADCs) (96% in trout vs. 28-31% in salmon; P<0.05), and pigment retention efficiencies (11.5-12.5% in trout vs. 5.5% in salmon; P<0.05), for both astaxanthin and canthaxanthin, were observed for rainbow trout. Astaxanthin deposition was higher than canthaxanthin in rainbow trout, while the reverse was true for Atlantic salmon, suggesting species-specificity in carotenoid utilization. The white muscle (95% in trout vs. 93% in salmon) and kidneys (0.5% in trout vs. 0.2% in salmon) represented higher proportions of the total body carotenoid pool in rainbow trout than in Atlantic salmon (P<0.05), whereas the liver was a more important storage organ in Atlantic salmon (2-6% in salmon vs. 0.2% in trout; P<0.05). The liver and kidney appeared to be important sites of carotenoid catabolism based on the relative proportion of the peak chromatogram of the fed carotenoid in both species, with the pyloric caecae and hind gut being more important in Atlantic salmon than in the rainbow trout. Liver catabolism is suspected to be a critical determinant in carotenoid clearance, with higher catabolism expected in Atlantic salmon than in rainbow trout.

Piscine myocarditis virus (PMCV) in wild Atlantic salmon Salmo salar.

PubMed

Garseth, Ase Helen; Biering, Eirik; Tengs, Torstein

2012-12-27

Cardiomyopathy syndrome (CMS) is a severe cardiac disease of sea-farmed Atlantic salmon Salmo salar L., but CMS-like lesions have also been found in wild Atlantic salmon. In 2010 a double-stranded RNA virus of the Totiviridae family, provisionally named piscine myocarditis virus (PMCV), was described as the causative agent of CMS. In the present paper we report the first detection of PMCV in wild Atlantic salmon. The study is based on screening of 797 wild Atlantic salmon by real-time RT-PCR. The samples were collected from 35 different rivers along the coast of Norway, and all individuals included in the study were classified as wild, based on visual appearance and scale reading. Two samples tested positive during PCR analysis, and the results were confirmed by sequencing.

On signals of phase transitions in salmon population dynamics

PubMed Central

Krkošek, Martin; Drake, John M.

2014-01-01

Critical slowing down (CSD) reflects the decline in resilience of equilibria near a bifurcation and may reveal early warning signals (EWS) of ecological phase transitions. We studied CSD in the recruitment dynamics of 120 stocks of three Pacific salmon (Oncorhynchus spp.) species in relation to critical transitions in fishery models. Pink salmon (Oncorhynchus gorbuscha) exhibited increased variability and autocorrelation in populations that had a growth parameter, r, close to zero, consistent with EWS of extinction. However, models and data for sockeye salmon (Oncorhynchus nerka) indicate that portfolio effects from heterogeneity in age-at-maturity may obscure EWS. Chum salmon (Oncorhynchus keta) show intermediate results. The data do not reveal EWS of Ricker-type bifurcations that cause oscillations and chaos at high r. These results not only provide empirical support for CSD in some ecological systems, but also indicate that portfolio effects of age structure may conceal EWS of some critical transitions. PMID:24759855

1992 Columbia River Salmon Flow Measures Options Analysis/EIS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-01-01

This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FSWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and onemore » private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described.« less

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Northwest). Coho Salmon.

DTIC Science & Technology

1986-04-01

method in fingerlinqs prey on sockeye salmon Puqet Sound to predict coho salmon fry ( Oncorhynchus nerka ); 30% of catches from stream discharqe data, coho...numbers of males distinguish it from chinook salmon and females in a soawninq run are sim- ( Oncorhynchus tshawytscha), which have ilar males may...behind sockeye salmon (qnco- qoal is te umber of spawners rhynchus nerka ), pink salmon (. necesar) to majinta1n the run of a -orhuscha), and chum salmon

SALMON-TRINITY ALPS WILDERNESS, CALIFORNIA.

USGS Publications Warehouse

Hotz, Preston E.; Thurber, Horace K.

1984-01-01

The Salmon-Trinity Alps Wilderness in the Klamath Mountains province occupies an area of about 648 sq mi in parts of Trinity, Siskiyou, and Humboldt Counties, northwestern California. As a result of field studies it was determined that the Salmon-Trinity Alps Wilderness has an area with substantiated potential for gold resources in known lode deposits. Small amounts of quicksilver have been produced from one mine but there is little promise for the discovery of additional mercury resources. Geochemical sampling showed that anomalously high amounts of several other metals occur in a few places, but there is little promise for the discovery of energy or mineral resources other than mercury and gold.

Histopathology of fish. II. The salmon-poisoning fluk

USGS Publications Warehouse

1956-01-01

THE SALMON-POISONING FLUKE is misnamed as far as the fish culturist is concerned, for the disease affects dogs, not fish. There is considerable evidence, however, that fish may also suffer from the complex chain of events leading from snail to dying dog. Histological studies indicate that young salmon and trout may be severely damaged by the encysted stage of the fluke.

Interactions between brown bears and chum salmon at McNeil River, Alaska

USGS Publications Warehouse

Peirce, Joshua M.; Otis, Edward O.; Wipfli, Mark S.; Follmann, Erich H.

2013-01-01

Predation on returning runs of adult salmon (Oncorhynchus spp.) can have a large influence on their spawning success. At McNeil River State Game Sanctuary (MRSGS), Alaska, brown bears (Ursus arctos) congregate in high numbers annually along the lower McNeil River to prey upon returning adult chum salmon (O. keta). Low chum salmon escapements into McNeil River since the late 1990s have been proposed as a potential factor contributing to concurrent declines in bear numbers. The objective of this study was to determine the extent of bear predation on chum salmon in McNeil River, especially on pre-spawning fish, and use those data to adjust the escapement goal for the river. In 2005 and 2006, 105 chum salmon were radiotagged at the river mouth and tracked to determine cause and location of death. Below the falls, predators consumed 99% of tagged fish, killing 59% of them before they spawned. Subsequently, the escapement goal was nearly doubled to account for this pre-spawning mortality and to ensure enough salmon to sustain both predators and prey. This approach to integrated fish and wildlife management at MRSGS can serve as a model for other systems where current salmon escapement goals may not account for pre-spawning mortality.

Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research : Annual Report 1992.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spaulding, Scott

1993-05-01

This report outlines long-term planning and monitoring activities that occurred in 1991 and 1992 in the Stanley Basin Lakes of the upper Salmon River, Idaho for the purpose of sockeye salmon nerka) recovery. Limnological monitoring and experimental sampling protocol, designed to establish a limnological baseline and to evaluate sockeye salmon production capability of the lakes, are presented. Also presented are recommended passage improvements for current fish passage barriers/impediments on migratory routes to the lakes. We initiated O. nerka population evaluations for Redfish and Alturas lakes; this included population estimates of emerging kokanee fry entering each lake in the spring andmore » adult kokanee spawning surveys in tributary streams during the fall. Gill net evaluations of Alturas, Pettit, and Stanley lakes were done in September, 1992 to assess the relative abundance of fish species among the Stanley Basin lakes. Fish population data will be used to predict sockeye salmon production potential within a lake, as well as a baseline to monitor long-term fish community changes as a result of sockeye salmon recovery activities. Also included is a paper that reviews sockeye salmon enhancement activities in British Columbia and Alaska and recommends strategies for the release of age-0 sockeye salmon that will be produced from the current captive broodstock.« less

50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California Coasts Coho Salmon (Oncorhynchus kisutch). 226.210... Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California Coasts Coho Salmon...

50 CFR 226.210 - Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Central California Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California Coasts Coho Salmon (Oncorhynchus kisutch). 226.210... Coast Coho Salmon (Oncorhynchus kisutch), Southern Oregon/Northern California Coasts Coho Salmon...

Aniakchak sockeye salmon investigations

USGS Publications Warehouse

Hamon, Troy R.; Pavey, Scott A.; Miller, Joe L.; Nielsen, Jennifer L.

2005-01-01

Aniakchak National Monument and Preserve provides unusual and dramatic landscapes shaped by numerous volcanic eruptions, a massive flood, enormous landslides, and ongoing geological change. The focal point of the monument is Aniakchak Caldera, a restless volcano that embodies the instability of the Alaska Peninsula. This geological instability creates a dynamic and challenging environment for the biological occupants of Aniakchak and unparalleled opportunities for scientists to measure the adaptability of organisms and ecosystems to change. The sockeye salmon (Oncorhynchus nerka) is one member of the Aniakchak ecosystem that has managed to adapt to geologic upheaval and is now thriving in the park. Aside from just surviving in the harsh environment, these salmon are also noteworthy for providing essential marinederived nutrients to plants and animals and as a source of food for historic and present day people in the region.

40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart are...

40 CFR 408.170 - Applicability; description of the Alaskan mechanized salmon processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Alaskan mechanized salmon processing subcategory. 408.170 Section 408.170 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Mechanized Salmon Processing Subcategory § 408.170 Applicability; description of the Alaskan mechanized salmon processing subcategory. The provisions of this subpart are...

Involvement of hormones in olfactory imprinting and homing in chum salmon.

PubMed

Ueda, Hiroshi; Nakamura, Shingo; Nakamura, Taro; Inada, Kaoru; Okubo, Takashi; Furukawa, Naohiro; Murakami, Reiichi; Tsuchida, Shigeo; Zohar, Yonathan; Konno, Kotaro; Watanabe, Masahiko

2016-02-16

The olfactory hypothesis for salmon imprinting and homing to their natal stream is well known, but the endocrine hormonal control mechanisms of olfactory memory formation in juveniles and retrieval in adults remain unclear. In brains of hatchery-reared underyearling juvenile chum salmon (Oncorhynchus keta), thyrotropin-releasing hormone gene expression increased immediately after release from a hatchery into the natal stream, and the expression of the essential NR1 subunit of the N-methyl-D-aspartate receptor increased during downstream migration. Gene expression of salmon gonadotropin-releasing hormone (sGnRH) and NR1 increased in the adult chum salmon brain during homing from the Bering Sea to the natal hatchery. Thyroid hormone treatment in juveniles enhanced NR1 gene activation, and GnRHa treatment in adults improved stream odour discrimination. Olfactory memory formation during juvenile downstream migration and retrieval during adult homing migration of chum salmon might be controlled by endocrine hormones and could be clarified using NR1 as a molecular marker.

Norwegian Salmon Goes to Market: The Case of the Austevoll Seafood Cluster

ERIC Educational Resources Information Center

Phyne, John; Hovgaard, Gestur; Hansen, Gard

2006-01-01

This paper examines the impact of the globalisation of the farmed salmon commodity chain upon farmed salmon production in the western Norwegian municipality of Austevoll. On the basis of field research conducted in 2002 and 2003, we conclude that salmon farming in Austevoll has responded to the challenges of "buyer-driven" food chains by…

Intestinal morphology of the wild Atlantic salmon (Salmo salar).

PubMed

Løkka, Guro; Austbø, Lars; Falk, Knut; Bjerkås, Inge; Koppang, Erling Olaf

2013-08-01

The worldwide-industrialized production of Atlantic salmon (Salmo salar) has increased dramatically during the last decades, followed by diseases related to the on-going domestication process as a growing concern. Even though the gastrointestinal tract seems to be a target for different disorders in farmed fish, a description of the normal intestinal status in healthy, wild salmon is warranted. Here, we provide such information in addition to suggesting a referable anatomical standardization for the intestine. In this study, two groups of wild Atlantic salmon were investigated, consisting of post smolts on feed caught in the sea and of sexually mature, starved individuals sampled from a river. The two groups represent different stages in the anadromous salmon life cycle, which also are part of the production cycle of farmed salmon. Selected regions of gastrointestinal tract were subjected to morphological investigations including immunohistochemical, scanning electron microscopic, and morphometric analyses. A morphology-based nomenclature was established, defining the cardiac part of the stomach and five different regions of the Atlantic salmon intestine, including pyloric caeca, first segment of the mid-intestine with pyloric caeca, first segment of the mid-intestine posterior to pyloric caeca, second segment of the mid-intestine and posterior intestinal segment. In each of the above described regions, for both groups of fish, morphometrical measurements and regional histological investigations were performed with regards to magnitude and direction of mucosal folding as well as the composition of the intestinal wall. Additionally, immunohistochemistry showing cells positive for cytokeratins, α-actin and proliferating cell nuclear antigen, in addition to alkaline phosphatase reactivity in the segments is presented. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

Spring Chinook Salmon Production for Confederated Tribes of the Umatilla Indian Reservation, Little White Salmon National Fish Hatchery, Annual Report 2006.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doulas, Speros

2007-01-01

This annual report covers the period from January 1, 2006 through December 31, 2006. Work completed supports the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) effort to restore a locally-adapted stock of spring Chinook to the Umatilla River Basin. During the year, staff at the Little White Salmon/Willard National Fish Hatchery Complex have completed the rearing of 218,764 Brood Year 2004 spring Chinook salmon for release into the Umatilla River during spring 2006 and initiated production of approximately 220,000 Brood Year 2005 spring Chinook for transfer and release into the Umatilla River during spring 2007. All work under thismore » contract is performed at the Little White Salmon and Willard National Fish Hatcheries (NFH), Cook, WA.« less

Predation on stocked Atlantic salmon (Salmo salar) fry

USGS Publications Warehouse

Henderson, J.N.; Letcher, B.H.

2003-01-01

We studied predator-prey interactions between juvenile Atlantic salmon (Salmo salar) and trout in three Massachusetts, U.S.A., streams and in artificial streams. We sampled stomach contents of age-1+ and older salmon and trout (Salvelinus fontinalis, Salmo trutta) following salmon fry stocking in the spring of 1997 and 1998. Between 4.3 and 48.6% of the stocked fry were consumed within the first 2 days after stocking, and total fry mortality from predation varied from 4.3 to 60.7%. No significant differences were found between stomach weights of predators (without fry weight) that consumed fry and those that did not. Artificial stream experiments testing effects of habitat complexity and predator species on predator consumption rates revealed that consumption rates were not different between brook (S. fontinalis) and brown (S. trutta) trout (p = 0.59). Predation rate tended to decrease as the percentage of riffle habitat increased but the decrease was not significant (p = 0.22). Our results indicate that predation on stocked Atlantic salmon fry can be substantial (up to 60%), appears to be short lived (2 days), and is not related in a simple way to abiotic and biotic factors.

Linkages between Alaskan sockeye salmon abundance, growth at sea, and climate, 1955-2002

USGS Publications Warehouse

Ruggerone, G.T.; Nielsen, J.L.; Bumgarner, J.

2007-01-01

We tested the hypothesis that increased growth of salmon during early marine life contributed to greater survival and abundance of salmon following the 1976/1977 climate regime shift and that this, in turn, led to density-dependent reductions in growth during late marine stages. Annual measurements of Bristol Bay (Bering Sea) and Chignik (Gulf of Alaska) sockeye salmon scale growth from 1955 to 2002 were used as indices of body growth. During the first and second years at sea, growth of both stocks tended to be higher after the 1976-1977 climate shift, whereas growth during the third year and homeward migration was often below average. Multiple regression models indicated that return per spawner of Bristol Bay sockeye salmon and adult abundance of western and central Alaska sockeye salmon were positively correlated with growth during the first 2 years at sea and negatively correlated with growth during later life stages. After accounting for competition between Bristol Bay sockeye and Asian pink salmon, age-specific adult length of Bristol Bay salmon increased after the 1976-1977 regime shift, then decreased after the 1989 climate shift. Late marine growth and age-specific adult length of Bristol Bay salmon was exceptionally low after 1989, possibly reducing their reproductive potential. These findings support the hypothesis that greater marine growth during the first 2 years at sea contributed to greater salmon survival and abundance, which in turn led to density-dependent growth during later life stages when size-related mortality was likely lower. Our findings provide new evidence supporting the importance of bottom-up control in marine ecosystems and highlight the complex dynamics of species interactions that continually change as salmon grow and mature in the ocean. ?? 2007 Elsevier Ltd. All rights reserved.

Temporal patterns in adult salmon migration timing across southeast Alaska

USGS Publications Warehouse

Kovach, Ryan P.; Ellison, Stephen; Pyare, Sanjay; Tallmon, David

2015-01-01

Pacific salmon migration timing can drive population productivity, ecosystem dynamics, and human harvest. Nevertheless, little is known about long-term variation in salmon migration timing for multiple species across broad regions. We used long-term data for five Pacific salmon species throughout rapidly warming southeast Alaska to describe long-term changes in salmon migration timing, interannual phenological synchrony, relationships between climatic variation and migratory timing, and to test whether long-term changes in migration timing are related to glaciation in headwater streams. Temporal changes in the median date of salmon migration timing varied widely across species. Most sockeye populations are migrating later over time (11 of 14), but pink, chum, and especially coho populations are migrating earlier than they did historically (16 of 19 combined). Temporal trends in duration and interannual variation in migration timing were highly variable across species and populations. The greatest temporal shifts in the median date of migration timing were correlated with decreases in the duration of migration timing, suggestive of a loss of phenotypic variation due to natural selection. Pairwise interannual correlations in migration timing varied widely but were generally positive, providing evidence for weak region-wide phenological synchrony. This synchrony is likely a function of climatic variation, as interannual variation in migration timing was related to climatic phenomenon operating at large- (Pacific decadal oscillation), moderate- (sea surface temperature), and local-scales (precipitation). Surprisingly, the presence or the absence of glaciers within a watershed was unrelated to long-term shifts in phenology. Overall, there was extensive heterogeneity in long-term patterns of migration timing throughout this climatically and geographically complex region, highlighting that future climatic change will likely have widely divergent impacts on salmon

Thiamine and fatty acid content of Lake Michigan Chinook salmon

USGS Publications Warehouse

Honeyfield, D.C.; Peters, A.K.; Jones, M.L.

2008-01-01

Nutritional status of Lake Michigan Chinook salmon (Oncorhynchus tshawytscha) is inadequately documented. An investigation was conducted to determine muscle and liver thiamine content and whole body fatty acid composition in small, medium and large Chinook salmon. Muscle and liver thiamine concentrations were highest in small salmon, and tended to decrease with increasing fish size. Muscle thiamine was higher in fall than spring in large salmon. The high percentage of Chinook salmon (24-32% in fall and 58-71% in spring) with muscle thiamine concentration below 500 pmol/g, which has been associated with loss of equilibrium and death in other Great Lake salmonines, suggest that Chinook appear to rely less on thiamine than other Great Lakes species for which such low concentrations would be associated with thiamine deficiency (Brown et al. 2005b). A positive correlation was observed between liver total thiamine and percent liver lipids (r = 0.53, P < 0.0001, n = 119). In medium and large salmon, liver lipids were observed to be low in fish with less than 4,000 pmol/g liver total thiamine. In individuals with greater than 4,000 pmol/g liver thiamine, liver lipid increased with thiamine concentration. Individual fatty acids declined between fall and spring. Essential omega-3 fatty acids appear to be conserved as lipid content declined. Arachidonic acid (C20:4n6), an essential omega-6 fatty acid was not different between fall and spring, although the sum of omega-6 (Sw6) fatty acids declined over winter. Elevated concentrations of saturated fatty acids (sum) were observed in whole body tissue lipid. In summary, thiamine, a dietary essential vitamin, and individual fatty acids were found to vary in Lake Michigan Chinook salmon by fish size and season of the year.

Light-mediated predation by northern squawfish on juvenile Chinook salmon

USGS Publications Warehouse

Petersen, James H.; Gadomski, Dena M.

1994-01-01

Northern squawfish Ptychocheilus oregonensis cause significant mortality of juvenile salmon in the lower Columbia River Basin (U.S.A.). The effects of light intensity on this predator-prey interaction were examined with laboratory experiments and modelling studies. In laboratory experiments, the rate of capture of subyearling chinook salmon Oncorhynchus tshawytscha by northern squawfish was inversely related to light intensity. In a large raceway, about five times more salmon were captured during 4 h periods of relative darkness (0–03 Ix) than during periods with high light intensity (160 Ix). The rate of predation could be manipulated by increasing or decreasing light intensity.A simulation model was developed for visual predators that encounter, attack, and capture juvenile salmon, whose schooling behaviour was light-sensitive. The model was fitted to laboratory results using a Monte Carlo filtering procedure. Model-predicted predation rate was especially sensitive to the visual range of predators at low light intensity and to predator search speed at high light. Modelling results also suggested that predation by northern squawfish on juvenile salmon may be highest across a narrow window of fight intensity.

Optimum cooking conditions for shrimp and Atlantic salmon.

PubMed

Brookmire, Lauren; Mallikarjunan, P; Jahncke, M; Grisso, R

2013-02-01

The quality and safety of a cooked food product depends on many variables, including the cooking method and time-temperature combinations employed. The overall heating profile of the food can be useful in predicting the quality changes and microbial inactivation occurring during cooking. Mathematical modeling can be used to attain the complex heating profile of a food product during cooking. Studies were performed to monitor the product heating profile during the baking and boiling of shrimp and the baking and pan-frying of salmon. Product color, texture, moisture content, mass loss, and pressed juice were evaluated during the cooking processes as the products reached the internal temperature recommended by the FDA. Studies were also performed on the inactivation of Salmonella cocktails in shrimp and salmon. To effectively predict inactivation during cooking, the Bigelow, Fermi distribution, and Weibull distribution models were applied to the Salmonella thermal inactivation data. Minimum cooking temperatures necessary to destroy Salmonella in shrimp and salmon were determined. The heating profiles of the 2 products were modeled using the finite difference method. Temperature data directly from the modeled heating profiles were then used in the kinetic modeling of quality change and Salmonella inactivation during cooking. The optimum cooking times for a 3-log reduction of Salmonella and maintaining 95% of quality attributes are 100, 233, 159, 378, 1132, and 399 s for boiling extra jumbo shrimp, baking extra jumbo shrimp, boiling colossal shrimp, baking colossal shrimp, baking Atlantic salmon, and pan frying Atlantic Salmon, respectively. © 2013 Institute of Food Technologists®

Evidence of Olfactory Imprinting at an Early Life Stage in Pink Salmon (Oncorhynchus gorbuscha)

PubMed Central

Bett, Nolan N.; Hinch, Scott G.; Dittman, Andrew H.; Yun, Sang-Seon

2016-01-01

Pacific salmon (Oncorhynchus spp.) navigate towards spawning grounds using olfactory cues they imprinted on as juveniles. The timing at which imprinting occurs has been studied extensively, and there is strong evidence that salmon imprint on their natal water during the parr-smolt transformation (PST). Researchers have noted, however, that the life histories of some species of Pacific salmon could necessitate imprinting prior to the PST. Juvenile pink salmon (O. gorbuscha) spend less time in fresh water than any other species of Pacific salmon, and presumably must imprint on their natal water at a very young age. The time at which imprinting occurs in this species, however, has not been experimentally tested. We exposed juvenile pink salmon as alevins to phenethyl alcohol (PEA) or control water, reared these fish to adulthood, and then tested their behavioural responses to PEA to determine whether the fish successfully imprinted. We found that pink salmon exposed to PEA as alevins were attracted to the chemical as adults, suggesting that imprinting can occur during this stage. Our finding provides some of the first evidence to support the long-standing belief that imprinting can occur in pink salmon prior to the PST. PMID:27827382

Evidence of Olfactory Imprinting at an Early Life Stage in Pink Salmon (Oncorhynchus gorbuscha).

PubMed

Bett, Nolan N; Hinch, Scott G; Dittman, Andrew H; Yun, Sang-Seon

2016-11-09

Pacific salmon (Oncorhynchus spp.) navigate towards spawning grounds using olfactory cues they imprinted on as juveniles. The timing at which imprinting occurs has been studied extensively, and there is strong evidence that salmon imprint on their natal water during the parr-smolt transformation (PST). Researchers have noted, however, that the life histories of some species of Pacific salmon could necessitate imprinting prior to the PST. Juvenile pink salmon (O. gorbuscha) spend less time in fresh water than any other species of Pacific salmon, and presumably must imprint on their natal water at a very young age. The time at which imprinting occurs in this species, however, has not been experimentally tested. We exposed juvenile pink salmon as alevins to phenethyl alcohol (PEA) or control water, reared these fish to adulthood, and then tested their behavioural responses to PEA to determine whether the fish successfully imprinted. We found that pink salmon exposed to PEA as alevins were attracted to the chemical as adults, suggesting that imprinting can occur during this stage. Our finding provides some of the first evidence to support the long-standing belief that imprinting can occur in pink salmon prior to the PST.

Mucous lysozyme levels in hatchery coho salmon (Oncorhynchus kisutch) and spring chinook salmon (O. tshawytscha) early in the parr-smolt transformation

USGS Publications Warehouse

Schrock, R.M.; Smith, S.D.; Maule, A.G.; Doulos, S.K.; Rockowski, J.J.

2001-01-01

Mucous lysozyme concentrations were determined in juvenile coho salmon (Oncorhynchus kisutch) and spring chinook salmon (O. tshawytscha) to establish reference levels during the time associated with the parr-smolt transformation. The first reported naris and vent mucous lysozyme levels are provided for spring chinook salmon and coho salmon. Naris mucous lysozyme levels ranged between 300 and 700 ??g ml-1, vent mucous lysozyme from 100 to 300 ??g ml-1, and skin mucous lysozyme levels were below 130 ??g ml-1. Lysozyme levels in the two species showed the same relationship with the highest levels in naris mucous, and the lowest in skin mucous. A seasonal decrease occurred in both species with a significant decrease in naris mucous lysozyme between February and March. Gill ATPase levels used to monitor smolt development during the same period did not reach ranges reported for smolts for either species during emigration. Identification of seasonal levels of lysozyme activity in mucous provides an alternative determination of developmental status prior to release of fish from the hatchery when salmonids are still undergoing the parr-smolt transformation. ?? 2001 Elsevier Science B.V.

Growth of enterotoxigenic Bacillus cereus on salmon (Oncorhynchus nerka).

PubMed

Labbé, Ronald; Rahmati, Talat

2012-06-01

We previously demonstrated the widespread presence of enterotoxigenic Bacillus cereus in marine foods. In view of the widespread consumption of raw fish, we sought to determine the ability of this organism to grow on the surface of wild Alaskan salmon at abusive temperatures (12, 16, and 20°C), using an isolate able to produce elevated levels of hemolysin BL enterotoxin and nonhemolytic enterotoxin. An incubation temperature of 37°C for colony formation was found to be selective for B. cereus grown on salmon held for up to 24 h at each temperature. A fivefold increase in log CFU per gram was observed after 26 and 22 h at 16 and 20°C, respectively, while a >4-log CFU/g increase occurred on salmon held at 12°C for 48 h. Generation times of 169.7, 53.5, and 45.6 min were observed at 12, 16, and 20°C. Nonhemolytic enterotoxin was detected when levels of B. cereus were in excess of 10(8) CFU/g. Nisin, at concentrations of 1 and 15 m g/g of salmon, reduced levels of B. cereus 2.5- and 25-fold, respectively. Our results indicate that fresh salmon can serve as an excellent substrate for enterotoxigenic B. cereus and that this organism can reach levels associated with foodborne illness following moderate temperature abuse.

Quantifying Temperature Effects on Fall Chinook Salmon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jager, Yetta

2011-11-01

The motivation for this study was to recommend relationships for use in a model of San Joaquin fall Chinook salmon. This report reviews literature pertaining to relationships between water temperature and fall Chinook salmon. The report is organized into three sections that deal with temperature effects on development and timing of freshwater life stages, temperature effects on incubation survival for eggs and alevin, and temperature effects on juvenile survival. Recommendations are made for modeling temperature influences for all three life stages.

Differential incorporation of natural spawners vs. artificially planted salmon carcasses in a stream food web: Evidence from delta 15N of juvenile coho salmon

EPA Science Inventory

Placement of salmon carcasses is a common restoration technique in Oregon and Washington streams, with the goal of improving food resources and productivity of juvenile salmon. To explore the effectiveness of this restoration technique, we measured the δ15N of juvenile coho salmo...

Doubling sockeye salmon production in the Fraser River—Is this sustainable development?

NASA Astrophysics Data System (ADS)

Henderson, Michael A.; Healey, Michael C.

1993-11-01

We evaluate a proposal to double sockeye salmon production from the Fraser River and conclude that significant changes will be required to current management processes, particularly the way available catch is allocated, if the plan is to be consistent with five major principles embodied in the concept of sustainable development. Doubling sockeye salmon production will not, in itself, increase economic equity either regionally or globally. Developing nations may actually be hindered in their attempts to institute other, nonsalmon fisheries in the North Pacific Ocean as a result of the possible interception of salmon. Further, other users of the Fraser River basin will have to forgo opportunities so that salmon habitat can be conserved. If doubling sockeye salmon production is to meet the goal of doing more with less, it will be necessary to develop more efficient technologies to harvest the fish. If increasing salmon production is to reflect the integration of environmental and economic decision making at the highest level, then a serious attempt must be made to incorporate environmental assets into national economic accounting. Finally, to promote biodiversity and cultural self-sufficiency within the Fraser River basin, it will be important to safeguard the small, less-productive salmon stocks as well as the large ones and to allocate a substantial portion of the increased production to the Native Indian community.

Novel air-based system transfers large salmon during harvest

USDA-ARS?s Scientific Manuscript database

In April of 2015, near the end of our last harvest of 4-6 kg Atlantic salmon, we evaluated an exciting new fish transport technology from Whooshh Innovations (Bellevue, WA) that uses air to move live Atlantic salmon from our growout tank to a finishing/purging tank. The Whooshh system uses a combina...

Epizootics of wild fish induced by farm fish.

PubMed

Krkosek, Martin; Lewis, Mark A; Morton, Alexandra; Frazer, L Neil; Volpe, John P

2006-10-17

The continuing decline of ocean fisheries and rise of global fish consumption has driven aquaculture growth by 10% annually over the last decade. The association of fish farms with disease emergence in sympatric wild fish stocks remains one of the most controversial and unresolved threats aquaculture poses to coastal ecosystems and fisheries. We report a comprehensive analysis of the spread and impact of farm-origin parasites on the survival of wild fish populations. We mathematically coupled extensive data sets of native parasitic sea lice (Lepeophtheirus salmonis) transmission and pathogenicity on migratory wild juvenile pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon. Farm-origin lice induced 9-95% mortality in several sympatric wild juvenile pink and chum salmon populations. The epizootics arise through a mechanism that is new to our understanding of emerging infectious diseases: fish farms undermine a functional role of host migration in protecting juvenile hosts from parasites associated with adult hosts. Although the migratory life cycles of Pacific salmon naturally separate adults from juveniles, fish farms provide L. salmonis novel access to juvenile hosts, in this case raising infection rates for at least the first approximately 2.5 months of the salmon's marine life (approximately 80 km of the migration route). Spatial segregation between juveniles and adults is common among temperate marine fishes, and as aquaculture continues its rapid growth, this disease mechanism may challenge the sustainability of coastal ecosystems and economies.

A Modeled Comparison of Direct and Food Web-Mediated Impacts of Common Pesticides on Pacific Salmon

PubMed Central

Macneale, Kate H.; Spromberg, Julann A.; Baldwin, David H.; Scholz, Nathaniel L.

2014-01-01

In the western United States, pesticides used in agricultural and urban areas are often detected in streams and rivers that support threatened and endangered Pacific salmon. Although concentrations are rarely high enough to cause direct salmon mortality, they can reach levels sufficient to impair juvenile feeding behavior and limit macroinvertebrate prey abundance. This raises the possibility of direct adverse effects on juvenile salmon health in tandem with indirect effects on salmon growth as a consequence of reduced prey abundance. We modeled the growth of ocean-type Chinook salmon (Oncorhynchus tshawytscha) at the individual and population scales, investigating insecticides that differ in how long they impair salmon feeding behavior and in how toxic they are to salmon compared to macroinvertebrates. The relative importance of these direct vs. indirect effects depends both on how quickly salmon can recover and on the relative toxicity of an insecticide to salmon and their prey. Model simulations indicate that when exposed to a long-acting organophosphate insecticide that is highly toxic to salmon and invertebrates (e.g., chlorpyrifos), the long-lasting effect on salmon feeding behavior drives the reduction in salmon population growth with reductions in prey abundance having little additional impact. When exposed to short-acting carbamate insecticides at concentrations that salmon recover from quickly but are lethal to invertebrates (e.g., carbaryl), the impacts on salmon populations are due primarily to reductions in their prey. For pesticides like carbaryl, prey sensitivity and how quickly the prey community can recover are particularly important in determining the magnitude of impact on their predators. In considering both indirect and direct effects, we develop a better understanding of potential impacts of a chemical stressor on an endangered species and identify data gaps (e.g., prey recovery rates) that contribute uncertainty to these assessments. PMID

An injectable acoustic transmitter for juvenile salmon

DOE PAGES

Deng, Zhiqun; Carlson, Thomas J.; Li, Huidong; ...

2015-01-29

Salmon recovery, and the potential detrimental effects of dams on fish, has been attracting national attention in due to great environmental and economic implications. Acoustic Telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter offers improved performance and 30% weight reduction. Because the new transmitter costs significantly less to use, substantially reduces adverse effects of implantation,more » and provides additional biological benefits for tagged fish, it will become the enabling technology for studying migration behavior and survival of species and sizes of fish that have never been studied before. This will lead to critical information for salmon recovery and the development of fish-friendly hydroelectric systems.« less

An injectable acoustic transmitter for juvenile salmon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Zhiqun; Carlson, Thomas J.; Li, Huidong

Salmon recovery, and the potential detrimental effects of dams on fish, has been attracting national attention in due to great environmental and economic implications. Acoustic Telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter offers improved performance and 30% weight reduction. Because the new transmitter costs significantly less to use, substantially reduces adverse effects of implantation,more » and provides additional biological benefits for tagged fish, it will become the enabling technology for studying migration behavior and survival of species and sizes of fish that have never been studied before. This will lead to critical information for salmon recovery and the development of fish-friendly hydroelectric systems.« less

An injectable acoustic transmitter for juvenile salmon

PubMed Central

Deng, Z. D.; Carlson, T. J.; Li, H.; Xiao, J.; Myjak, M. J.; Lu, J.; Martinez, J. J.; Woodley, C. M.; Weiland, M. A.; Eppard, M. B.

2015-01-01

Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems. PMID:25630763

An injectable acoustic transmitter for juvenile salmon

NASA Astrophysics Data System (ADS)

Deng, Z. D.; Carlson, T. J.; Li, H.; Xiao, J.; Myjak, M. J.; Lu, J.; Martinez, J. J.; Woodley, C. M.; Weiland, M. A.; Eppard, M. B.

2015-01-01

Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems.

Dispersal of Udonella australis (Monogenea: Udonellidae) between caligid copepods Caligus rogercresseyi and Lepeophtheirus mugiloidis on Chilean rock cod.

PubMed

Marin, Sandra L; Carvajal, Juan; George-Nascimento, Mario

2007-04-01

Udonella australis is a platyhelminth that lives on the surface of the ectoparasite copepods Caligus rogercresseyi and Lepeophtheirus mugiloidis, which coexist on the Chilean rock cod Eleginops maclovinus. The absence of a planktonic oncomiracidium stage in the life cycle of udonellids may limit their dispersal ability. However, the high prevalence and intensity of U. australis on C. rogercresseyi suggest they have developed dispersal strategies to compensate for the lack of a free-living larval stage. The goals of this study were to determine the main dispersal mechanisms of U. australis in 1 copepod species and to compare the dispersal ability of U. australis between 2 different copepod species. Chilean rock cods were infected with female (without udonellids) and male (with and without udonellids) C. rogercresseyi. Other fishes were also infected with this copepod (with U. australis) and with L. mugiloidis (without U. australis). The dispersal of udonellids among copepods occurs through both intraspecific and interspecific processes. The main dispersal mechanism appears to be copepod mating; contact between same-sex individuals is less important. Intraspecific dispersal seems to be more dependent on the number of udonellids per fish than on copepod abundance, as observed for interspecific dispersal.

Diphyllobothrium nihonkaiense Tapeworm Larvae in Salmon from North America

PubMed Central

Oros, Mikuláš; Ferguson, Jayde; Scholz, Tomáš

2017-01-01

Diphyllobothriosis is reemerging because of global importation and increased popularity of eating raw fish. We detected Diphyllobothrium nihonkaiense plerocercoids in the musculature of wild pink salmon (Oncorhynchus gorbuscha) from Alaska, USA. Therefore, salmon from the American and Asian Pacific coasts and elsewhere pose potential dangers for persons who eat these fish raw. PMID:28098540

Louse-borne relapsing fever (Borrelia recurrentis) diagnosed in 15 refugees from northeast Africa: epidemiology and preventive control measures, Bavaria, Germany, July to October 2015.

PubMed

Hoch, Martin; Wieser, Andreas; Löscher, Thomas; Margos, Gabriele; Pürner, Friedrich; Zühl, Jürgen; Seilmaier, Michael; Balzer, Lukas; Guggemos, Wolfgang; Rack-Hoch, Anita; von Both, Ulrich; Hauptvogel, Katja; Schönberger, Katharina; Hautmann, Wolfgang; Sing, Andreas; Fingerle, Volker

2015-01-01

We report 15 imported louse-borne relapsing fever (LBRF) cases in refugees in Bavaria, Germany. One patient died. Epidemiological findings confirmed that all were young males from the Horn of Africa (12 from Somalia), who had similar migration routes converging in Sudan continuing through Libya and Italy. The majority likely acquired their infection during migration. Healthcare workers should be aware of LBRF in refugees passing through north Africa to ensure correct treatment and preventive measures.

Controlling Listeria monocytogenes in Cold Smoked Salmon with the Antimicrobial Peptide Salmine.

PubMed

Cheng, Christopher; Arritt, Fletcher; Stevenson, Clinton

2015-06-01

Listeria monocytogenes (LM) is a major safety concern for smoked salmon producers, as it can survive both the brining and smoking process in cold smoked salmon production. Salmine is a cationic antimicrobial peptide derived from the milt of salmon that has been shown to inhibit the growth of LM in vitro. Commercialization of this peptide would add value to a waste product produced when raising salmon. The purpose of this study was to determine the anti-listeria activity of salmine in smoked salmon by measuring the viable counts of LM over time. Cold smoked salmon was treated with a salmine solution or coated with agar or k-carrageenan films incorporating salmine to maintain a high surface concentration of the antimicrobial. Samples were then inoculated with approximately 1.0 × 10(3) cells of LM. The viable counts were then enumerated throughout 4 wk at 4 °C storage. It was found that 5 mg/g salmine delayed the growth of LM on smoked salmon. These samples had significantly (P < 0.05) lower LM counts than on the untreated samples on days 13 and 22. Edible films did not significantly (P > 0.05) improve the antimicrobial efficacy of salmine. The peptide combined with biopolymers also had lower antimicrobial activity in vitro when compared to salmine alone. These results suggest there is potential for salmine to be used as a natural hurdle to inhibit growth of LM due to post process contamination; however, future investigations for extending this effect throughout the shelf life of smoked salmon products are warranted. © 2015 Institute of Food Technologists®

Migratory salmonid redd habitat characteristics in the Salmon River, New York

USGS Publications Warehouse

Johnson, James H.; Nack, Christopher C.; McKenna, James E.

2010-01-01

Non-native migratory salmonids ascend tributaries to spawn in all the Great Lakes. In Lake Ontario, these species include Chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), steelhead (O. mykiss), and brown trout (Salmo trutta). Although successful natural reproduction has been documented for many of these species, little research has been conducted on their spawning habitat. We examined the spawning habitat of these four species in the Salmon River, New York. Differences in fish size among the species were significantly correlated with spawning site selection. In the Salmon River, the larger species spawned in deeper areas with larger size substrate and made the largest redds. Discriminant function analysis correctly classified redds by species 64–100% of the time. The size of substrate materials below Lighthouse Hill Dam is within the preferred ranges for spawning for these four species indicating that river armoring has not negatively impacted salmonid production. Intra-specific and inter-specific competition for spawning sites may influence redd site selection for smaller salmonids and could be an impediment for Atlantic salmon (S. salar) restoration.

Efficacy and toxicity of iodine disinfection of Atlantic salmon eggs

USGS Publications Warehouse

Chalupnicki, M.A.; Ketola, H.G.; Starliper, C.E.; Gallagher, D.

2011-01-01

Recent interest in the restoration of Atlantic salmon Salmo salar in the Great Lakes has given rise to new culture techniques and management programs designed to reduce pathogen transmission while stabilizing and enhancing wild populations. We examined the toxicity of iodine to Atlantic salmon eggs and its effectiveness as a disinfectant against bacteria on egg surfaces. We spawned and fertilized eight gravid Atlantic salmon from Cayuga Lake, New York, and exposed their eggs to 10 concentrations of iodine (5, 10, 50, 75, 100, 500, 750, 1,000, 5,000, and 7,500 mg/L) for 30 min during water hardening. An additional subsample of unfertilized eggs was also exposed to some of the same concentrations of iodine (5, 10, 50, 75, and 100 mg/L) to determine the efficiency of disinfection. Viable eggs were only obtained from four females. Survival of eggs to the eyed stage and hatch tended to be reduced at iodine concentrations of 50 and 75 mg/L and was significantly reduced at concentrations of 100 mg/L iodine or more. We calculated the concentrations of iodine that killed 50% of the Atlantic salmon eggs at eye-up and hatch to be 175 and 85 mg/L, respectively. Aeromonas veronii, A. schubertii, A. hydrophila, A. caviae, Plesiomonas shiggeloides, and Citrobacter spp. were the predominant bacteria present on the surface of green eggs and were significantly reduced by an iodine immersion. The use of iodine as a disinfectant on Atlantic salmon eggs was effective at low concentrations (50–75 mg/L), for which toxicity to Atlantic salmon was minimal.

Comparing life history characteristics of Lake Michigan’s naturalized and stocked Chinook Salmon

USGS Publications Warehouse

Kerns, Janice A; Rogers, Mark W.; Bunnell, David B.; Claramunt, Randall M.; Collingsworth, Paris D.

2016-01-01

Lake Michigan supports popular fisheries for Chinook Salmon Oncorhynchus tshawytscha that have been sustained by stocking since the late 1960s. Natural recruitment of Chinook Salmon in Lake Michigan has increased in the past few decades and currently contributes more than 50% of Chinook Salmon recruits. We hypothesized that selective forces differ for naturalized populations born in the wild and hatchery populations, resulting in divergent life history characteristics with implications for Chinook Salmon population production and the Lake Michigan fishery. First, we conducted a historical analysis to determine if life history characteristics changed through time as the Chinook Salmon population became increasingly naturalized. Next, we conducted a 2-year field study of naturalized and hatchery stocked Chinook Salmon spawning populations to quantify differences in fecundity, egg size, timing of spawning, and size at maturity. In general, our results did not indicate significant life history divergence between naturalized and hatchery-stocked Chinook Salmon populations in Lake Michigan. Although historical changes in adult sex ratio were correlated with the proportion of naturalized individuals, changes in weight at maturity were better explained by density-dependent factors. The field study revealed no divergence in fecundity, timing of spawning, or size at maturity, and only small differences in egg size (hatchery > naturalized). For the near future, our results suggest that the limited life history differences observed between Chinook Salmon of naturalized and hatchery origin will not lead to large differences in characteristics important to the dynamics of the population or fishery.

Scour of chinook salmon redds on suction dredge tailings

Treesearch

Bret C. Harvey; Thomas E. Lisle

1999-01-01

Abstract - We measured scour of the redds of chinook salmon Oncorhynchus tshawytscha on dredge tailings and natural substrates in three tributaries of the Klamath River, California. We measured maximum scour with scour chains and net scour by surveying before and after high winter flows. Scour of chinook salmon redds located on dredge tailings exceeded scour of redds...

Temporal signal processing of dolphin biosonar echoes from salmon prey.

PubMed

Au, Whitlow W L; Ou, Hui Helen

2014-08-01

Killer whales project short broadband biosonar clicks. The broadband nature of the clicks provides good temporal resolution of echo highlights and allows for the discriminations of salmon prey. The echoes contain many highlights as the signals reflect off different surfaces and parts of the fish body and swim bladder. The temporal characteristics of echoes from salmon are highly aspect dependent and six temporal parameters were used in a support vector machine to discriminate between species. Results suggest that killer whales can classify salmon based on their echoes and provide some insight as to which features might enable the classification.

Humpback whales feed on hatchery-released juvenile salmon

PubMed Central

Straley, Janice M.; McPhee, Megan V.; Atkinson, Shannon; Reifenstuhl, Steve

2017-01-01

Humpback whales are remarkable for the behavioural plasticity of their feeding tactics and the diversity of their diets. Within the last decade at hatchery release sites in Southeast Alaska, humpback whales have begun exploiting juvenile salmon, a previously undocumented prey. The anthropogenic source of these salmon and their important contribution to local fisheries makes the emergence of humpback whale predation a concern for the Southeast Alaska economy. Here, we describe the frequency of observing humpback whales, examine the role of temporal and spatial variables affecting the probability of sighting humpback whales and describe prey capture behaviours at five hatchery release sites. We coordinated twice-daily 15 min observations during the spring release seasons 2010–2015. Using logistic regression, we determined that the probability of occurrence of humpback whales increased after releases began and decreased after releases concluded. The probability of whale occurrence varied among release sites but did not increase significantly over the 6 year study period. Whales were reported to be feeding on juvenile chum, Chinook and coho salmon, with photographic and video records of whales feeding on coho salmon. The ability to adapt to new prey sources may be key to sustaining their population in a changing ocean. PMID:28791145

Humpback whales feed on hatchery-released juvenile salmon.

PubMed

Chenoweth, Ellen M; Straley, Janice M; McPhee, Megan V; Atkinson, Shannon; Reifenstuhl, Steve

2017-07-01

Humpback whales are remarkable for the behavioural plasticity of their feeding tactics and the diversity of their diets. Within the last decade at hatchery release sites in Southeast Alaska, humpback whales have begun exploiting juvenile salmon, a previously undocumented prey. The anthropogenic source of these salmon and their important contribution to local fisheries makes the emergence of humpback whale predation a concern for the Southeast Alaska economy. Here, we describe the frequency of observing humpback whales, examine the role of temporal and spatial variables affecting the probability of sighting humpback whales and describe prey capture behaviours at five hatchery release sites. We coordinated twice-daily 15 min observations during the spring release seasons 2010-2015. Using logistic regression, we determined that the probability of occurrence of humpback whales increased after releases began and decreased after releases concluded. The probability of whale occurrence varied among release sites but did not increase significantly over the 6 year study period. Whales were reported to be feeding on juvenile chum, Chinook and coho salmon, with photographic and video records of whales feeding on coho salmon. The ability to adapt to new prey sources may be key to sustaining their population in a changing ocean.

Evolutionary history of Pacific salmon in dynamic environments

PubMed Central

Waples, Robin S; Pess, George R; Beechie, Tim

2008-01-01

Contemporary evolution of Pacific salmon (Oncorhynchus spp.) is best viewed in the context of the evolutionary history of the species and the dynamic ecosystems they inhabit. Speciation was complete by the late Miocene, leaving c. six million years for intraspecific diversification. Following the most recent glacial maximum, large areas became available for recolonization. Current intraspecific diversity is thus the product of recent evolution overlaid onto divergent historical lineages forged during recurrent episodes of Pleistocene glaciation. In northwestern North America, dominant habitat features have been relatively stable for the past 5000 years, but salmon ecosystems remain dynamic because of disturbance regimes (volcanic eruptions, landslides, wildfires, floods, variations in marine and freshwater productivity) that occur on a variety of temporal and spatial scales. These disturbances both create selective pressures for adaptive responses by salmon and inhibit long-term divergence by periodically extirpating local populations and creating episodic dispersal events that erode emerging differences. Recent anthropogenic changes are replicated pervasively across the landscape and interrupt processes that allow natural habitat recovery. If anthropogenic changes can be shaped to produce disturbance regimes that more closely mimic (in both space and time) those under which the species evolved, Pacific salmon should be well-equipped to deal with future challenges, just as they have throughout their evolutionary history. PMID:25567626

Sexual difference in PCB concentrations of coho salmon (Oncorhynchus kisutch)

USGS Publications Warehouse

Madenjian, Charles P.; Schrank, Candy S.; Begnoche, Linda J.; Elliott, Robert F.; Quintal, Richard T.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 35 female coho salmon (Oncorhynchus kisutch) and 60 male coho salmon caught in Lake Michigan (Michigan and Wisconsin, United States) during the fall of 1994 and 1995. In addition, we determined PCB concentrations in the skin-on fillets of 26 female and 19 male Lake Michigan coho salmon caught during the fall of 2004 and 2006. All coho salmon were age-2 fish. These fish were caught prior to spawning, and therefore release of eggs could not account for sexual differences in PCB concentrations because female coho salmon spawn only once during their lifetime. To investigate whether gross growth efficiency (GGE) differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, males were 19% higher in PCB concentration than females, based on the 1994–1995 dataset. Similarly, males averaged a 20% higher PCB concentration in their skin-on fillets compared with females. According to the bioenergetics modeling results, GGE of adult females was less than 1% higher than adult male GGE. Thus, bioenergetics modeling could not explain the 20% higher PCB concentration exhibited by the males. Nonetheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations.

Climate and ecosystem linkages explain widespread declines in North American Atlantic salmon populations.

PubMed

Mills, Katherine E; Pershing, Andrew J; Sheehan, Timothy F; Mountain, David

2013-10-01

North American Atlantic salmon (Salmo salar) populations experienced substantial declines in the early 1990s, and many populations have persisted at low abundances in recent years. Abundance and productivity declined in a coherent manner across major regions of North America, and this coherence points toward a potential shift in marine survivorship, rather than local, river-specific factors. The major declines in Atlantic salmon populations occurred against a backdrop of physical and biological shifts in Northwest Atlantic ecosystems. Analyses of changes in climate, physical, and lower trophic level biological factors provide substantial evidence that climate conditions directly and indirectly influence the abundance and productivity of North American Atlantic salmon populations. A major decline in salmon abundance after 1990 was preceded by a series of changes across multiple levels of the ecosystem, and a subsequent population change in 1997, primarily related to salmon productivity, followed an unusually low NAO event. Pairwise correlations further demonstrate that climate and physical conditions are associated with changes in plankton communities and prey availability, which are ultimately linked to Atlantic salmon populations. Results suggest that poor trophic conditions, likely due to climate-driven environmental factors, and warmer ocean temperatures throughout their marine habitat area are constraining the productivity and recovery of North American Atlantic salmon populations. © 2013 John Wiley & Sons Ltd.

Evaluation of Salmon Spawning Below Bonneville Dam Annual Report October 2006 - September 2007.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arntzen, Evan V.; Mueller, Robert P.; Murray, Katherine J.

2008-08-08

From 1999 through 2007, the Fish and Wildlife Program of the Bonneville Power Administration funded a project to determine the number of fall Chinook and chum salmon spawning downstream of Bonneville Dam, the characteristics of their spawning areas, and the flows necessary to ensure their long-term survival. Data were collected to ensure that established flow guidelines are appropriate and provide adequate protection for the species of concern. The projects objectives are consistent with the high priority placed by the Northwest Power and Conservation Council Independent Scientific Advisory Board and the salmon managers on determining the importance of mainstem habitats tomore » the production of salmon in the Columbia River Basin. Because of the influence of mainstem habitat on salmon production, there is a continued need to better understand the physical habitat variables used by mainstem fall Chinook and chum salmon populations and the effects of hydropower project operations on spawning and incubation. During FY 2007, Pacific Northwest National Laboratory focused on (1) locating and mapping deep-water fall Chinook salmon and chum salmon spawning areas, (2) investigating the interaction between groundwater and surface water near fall Chinook and chum salmon spawning areas, and (3) providing in-season hyporheic temperature and water surface elevation data to assist state agencies with emergence timing and redd dewatering estimates. This report documents the studies and tasks performed by PNNL during FY 2007. Chapter 1 provides a description of the searches conducted for deepwater redds-adjacent to Pierce and Ives islands for fall Chinook salmon and near the Interstate 205 bridge for chum salmon. The chapter also provides data on redd location, information about habitat associations, and estimates of total spawning populations. Chapter 2 documents the collection of data on riverbed and river temperatures and water surface elevations, from the onset of spawning

Multiscale thermal refugia and stream habitat associations of chinook salmon in northwestern Oregon

USGS Publications Warehouse

Torgersen, Christian E.; Price, David M.; Li, Hiram W.; McIntosh, B.A.

1999-01-01

We quantified distribution and behavior of adult spring chinook salmon (Oncorhynchus tshawytscha) related to patterns of stream temperature and physical habitat at channel-unit, reach-, and section-level spatial scales in a wilderness stream and a disturbed stream in the John Day River basin in northeastern Oregon. We investigated the effectiveness of thermal remote sensing for analyzing spatial patterns of stream temperature and assessed habitat selection by spring chinook salmon, evaluating whether thermal refugia might be responsible for the persistence of these stocks in rivers where water temperatures frequently exceed their upper tolerance levels (25A?C) during spawning migration. By presenting stream temperature and the ecology of chinook salmon in a historical context, we could evaluate how changes in riverine habitat and thermal spatial structure, which can be caused by land-use practices, may influence distributional patterns of chinook salmon. Thermal remote sensing provided spatially continuous maps of stream temperature for reaches used by chinook salmon in the upper subbasins of the Middle Fork and North Fork John Day River. Electivity analysis and logistic regression were used to test for associations between the longitudinal distribution of salmon and cool-water areas and stream habitat characteristics. Chinook salmon were distributed nonuniformly in reaches throughout each stream. Salmon distribution and cool water temperature patterns were most strongly related at reach-level spatial scales in the warm stream, the Middle Fork (maximum likelihood ratio: P 0.30). Pools were preferred by adult chinook salmon in both subbasins (Bonferroni confidence interval: P a?? 0.05); however, riffles were used proportionately more frequently in the North Fork than in the Middle Fork. Our observations of thermal refugia and their use by chinook salmon at multiple spatial scales reveal that, although heterogeneity in the longitudinal stream temperature profile may

Within-farm spread of infectious salmon anemia virus (ISAV) in Atlantic salmon Salmo salar farms in Chile.

PubMed

Mardones, F O; Jansen, P A; Valdes-Donoso, P; Jarpa, M; Lyngstad, T M; Jimenez, D; Carpenter, T E; Perez, A M

2013-09-24

Spread of infectious salmon anemia virus (ISAV) at the cage level was quantified using a subset of data from 23 Atlantic salmon Salmo salar farms located in southern Chile. Data collected from official surveillance activities were systematically organized to obtain detailed information on infectious salmon anemia (ISA) outbreaks. Descriptive statistics for outbreak duration, proportion of infected fish, and time to secondary infection were calculated to quantify the magnitude of ISAV incursions. Linear and multiple failure time (MFT) regression models were used to determine factors associated with the cage-level reproduction number (Rc) and hazard rate (HR) for recurrent events, respectively. In addition, the Knox test was used to assess if cage-to-cage transmissions were clustered in space and time. Findings suggest that within farms, ISA outbreaks, on average, lasted 30 wk (median = 26 wk, 95% CI = 24 to 37 wk) and affected 57.3% (95% CI = 47.7 to 67.0%) of susceptible cages. The median time to secondarily diagnosed cages was 23 d. Occurrence of clinical ISAV outbreaks was significantly associated with increased Rc, whereas increased HR was significantly associated with clinical outbreaks and with a large number of fish. Spatio-temporal analysis failed to identify clustering of cage cases, suggesting that within-farm ISAV spread is independent of the spatial location of the cages. Results presented here will help to better understand ISAV transmission, to improve the design of surveillance programs in Chile and other regions in which salmon are intensively farmed, and to examine the economic impact of ISAV and related management strategies on various cost and demand shifting factors.

77 FR 12800 - Fresh and Chilled Atlantic Salmon From Norway: Revocation of Antidumping and Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-02

... Atlantic Salmon From Norway: Revocation of Antidumping and Countervailing Duty Orders AGENCY: Import...'') and countervailing duty (``CVD'') orders on fresh and chilled Atlantic salmon (``salmon'') from Norway... orders on salmon from Norway, pursuant to sections 751(c) and 752 of the Tariff Act of 1930, as amended...

PACIFIC NORTHWEST SALMON: THE MOST LIKELY FUTURE AND SOME ALTERNATIVES

EPA Science Inventory

Throughout the Pacific Northwest, all wild salmon runs have declined since 1850 and some have disappeared. A sustainable future for wild salmon remains elusive. Billions of dollars have been spent in a so-far failed attempt to reverse the long-term decline. Each year, hundreds of...

Stabilizing Smoked Salmon (Oncorhynchus gorbuscha) Tissue after Extraction of Oil

USDA-ARS?s Scientific Manuscript database

Alaska salmon oils are rich in n-3 polyunsaturated fatty acids and are prized by the food and pharmaceutical industries. However, the tissue that remains after oil extraction does not have an established market. Discarded salmon tissues were preserved using a combination of smoke-processing and acid...

PACIFIC SALMON FISHERIES OF THE WORLD: STATUS, PROSPECTS, AND CHALLENGES

EPA Science Inventory

All seven species of Pacific salmon on both sides of the North Pacific have declined significantly from historic levels, but not as dramatically as have Atlantic salmon. Hatchery production has been used to maintain some runs in the southern region of the range (e.g., Japan, Kor...

Lucy Maynard Salmon (1853-1927): Pioneering Views on Teaching History.

ERIC Educational Resources Information Center

Nelson, Murry R.

1996-01-01

Profiles the career and contributions of educator and historian Lucy Maynard Salmon. Salmon's work on uniform standards for college admission became the basis of the College Entrance Examination. She developed a curriculum for elementary school history instruction that incorporated classical literature, folk tales, and biographies. (MJP)

Application of Diversity Indices to Quantify Early Life-History Diversity for Chinook Salmon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Gary E.; Sather, Nichole K.; Skalski, John R.

2014-03-01

We developed an index of early life history diversity (ELHD) for Pacific salmon (Oncorhynchus spp.) Early life history diversity is the variation in morphological and behavioral traits expressed within and among populations by individual juvenile salmon during their downstream migration. A standard quantitative method does not exist for this prominent concept in salmon biology.

40 CFR 408.190 - Applicability; description of the West Coast mechanized salmon processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Coast mechanized salmon processing subcategory. 408.190 Section 408.190 Protection of Environment... PROCESSING POINT SOURCE CATEGORY West Coast Mechanized Salmon Processing Subcategory § 408.190 Applicability; description of the West Coast mechanized salmon processing subcategory. The provisions of this subpart are...

76 FR 36896 - Salmon-Challis National Forest, ID; Forestwide Invasive Plant Treatment Environmental Impact...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-23

... DEPARTMENT OF AGRICULTURE Forest Service Salmon-Challis National Forest, ID; Forestwide Invasive... to the biological diversity and ecological integrity within and outside the Salmon-Challis National... loss of recreational opportunities. Within the 3,108,904 acres of the of the Salmon-Challis National...

40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart are...

40 CFR 408.190 - Applicability; description of the West Coast mechanized salmon processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Coast mechanized salmon processing subcategory. 408.190 Section 408.190 Protection of Environment... PROCESSING POINT SOURCE CATEGORY West Coast Mechanized Salmon Processing Subcategory § 408.190 Applicability; description of the West Coast mechanized salmon processing subcategory. The provisions of this subpart are...

40 CFR 408.160 - Applicability; description of the Alaskan hand-butchered salmon processing subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Alaskan hand-butchered salmon processing subcategory. 408.160 Section 408.160 Protection of Environment... PROCESSING POINT SOURCE CATEGORY Alaskan Hand-Butchered Salmon Processing Subcategory § 408.160 Applicability; description of the Alaskan hand-butchered salmon processing subcategory. The provisions of this subpart are...

Using image analysis to predict the weight of Alaskan salmon of different species.

PubMed

Balaban, Murat O; Unal Sengör, Gülgün F; Gil Soriano, Mario; Guillén Ruiz, Elena

2010-04-01

After harvesting, salmon is sorted by species, size, and quality. This is generally manually done by operators. Automation would bring repeatability, objectivity, and record-keeping capabilities to these tasks. Machine vision (MV) and image analysis have been used in sorting many agricultural products. Four salmon species were tested: pink (Oncorhynchus gorbuscha), red (Oncorhynchus nerka), silver (Oncorhynchus kisutch), and chum (Oncorhynchus keta). A total of 60 whole fish from each species were first weighed, then placed in a light box to take their picture. Weight compared with view area as well as length and width correlations were developed. In addition the effect of "hump" development (see text) of pink salmon on this correlation was investigated. It was possible to predict the weight of a salmon by view area, regardless of species, and regardless of the development of a hump for pinks. Within pink salmon there was a small but insignificant difference between predictive equations for the weight of "regular" fish and "humpy" fish. Machine vision can accurately predict the weight of whole salmon for sorting.

Research on Captive Broodstock Programs for Pacific Salmon, 2001-2002 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berejikian, Barry; Tezak, E.; Endicott, Rick

The efficacy of captive broodstock programs depends on high in-culture survival and the fitness of cultured salmon after release, either as adults or juveniles. Continuing captive broodstock research designed to improve technology is being conducted to cover all major life history stages of Pacific salmon. The following summarizes some of the work performed and results from the FY 2001 performance period: (1) The incidence of male maturation of age-1 chinook salmon was significantly reduced by reducing growth in the first year of rearing. (2) Experimentally manipulated growth rates of captively-reared coho salmon had significant effects on female maturation rate, eggmore » size, and fecundity, and the effects were stage-specific (i.e., pre-smolt vs. post-smolt). (3) A combination of Renogen and MT239 vaccination of yearling chinook salmon given an acute R. salmoninarum challenge had a significantly longer survival time than the mock-vaccinated group. The survival time was marginally higher than was seen in acutely challenged fish vaccinated with either Renogen or MT239 alone and suggests that a combination vaccine of Renogen and MT239 may be useful as both a prophylactic and therapeutic agent against BKD. (4) Full-sib (inbred) groups of chinook salmon have thus far exhibited lower ocean survival than half-sib and non-related groups. Effects of inbreeding on fluctuating asymmetry did not follow expected patterns. (5) Sockeye salmon were exposed to specific odorants at either the alevin/emergent fry stage or the smolt stage to determine the relative importance of odorant exposure during key developmental periods and the importance of exposure duration. (6) Experimental studies to determine the effects of exercise conditioning on steelhead reproductive behavior and the effects of male body size on chinook salmon fertilization success during natural spawning were completed.« less

Genetic variation in chinook, Oncorhynchus tshawytscha, and coho, O. Kisutchsalmon from the north coast of Washington

USGS Publications Warehouse

Reisenbichler, R.R.; Phelps, S.R.

1987-01-01

We used starch-gel electrophoresis to genetically characterize the populations of chinook salmon, Oncorhynchus tshawytscha, and coho salmon, O. kisutch, in the major drainages of the north coast of Washington (the Quillayute, Uoh, Queets, and Quinault Rivers). Of 55 loci examined for electrophoretically detectable variation. 6 were polymorphic (frequency of the common allele was less than 0.95) in chinook salmon and 3 in coho salmon. Statistical tests of interdrainage and intradrainage variation for coho salmon were tenuous because most of the fish examined were from a single year class so that we could not account for variation among year classes. Nevertheless, these tests suggested that distinct stocks ofcoho salmon exist within drainages. and that variation was not significantly greater among drainages than within drainages. Interdrainage variation for wild chinook salmon was not significant. The data suggested that summer chinook salmon were electrophoretically different from fall chinook salmon, and the hatchery populations of chinook salmon were distinct from wild fish. A hatchery population developed primarily from north coast fish was electrophoretically more similar to wild chinook salmon than were the others.

Classroom-Community Salmon Enhancement Project.

ERIC Educational Resources Information Center

Hubbard-Gray, Sarah

1988-01-01

Describes a program in the Bellevue (Washington) public schools in which elementary and middle school teachers and students raise coho and Chinook salmon in the classroom and later release them into a nearby stream. (TW)

Comparison of allergenic properties of salmon (Oncorhynchus nerka) between landlocked and anadromous species.

PubMed

Kondo, Yasuto; Ahn, Jeakun; Komatsubara, Ryo; Terada, Akihiko; Yasuda, Toshitaka; Tsuge, Ikuya; Urisu, Atsuo

2009-06-01

Salmon is one of the most widely consumed seafoods in Japan and many other countries around the world. Due to the confirmed cases of salmon-induced allergy, the food sanitation law in Japan stipulates salmon as one of the specific food items for which labeling is recommended when used as an ingredient of processed foods. However, trout, the landlocked form of anadromous salmon, is not subject to the allergen-labeling requirements, even though both populations belong to a single species. Since no supporting data have been demonstrated to make a clear distinction between these two populations in terms of allergenicity, we comparatively examined their allergenic properties using sera from patients allergic to fish. Extracts of Oncorhynchus nerka from different habitats were obtained: kokanee (landlocked) and red salmon (anadromous). Control extracts were derived from four other species. This study focused on the (1) IgE-binding capacity of the fish extracts in patients' sera (n = 50), (2) ELISA inhibition test (n = 6), and (3) inhibition immunoblot test (n = 8) between the kokanee and red salmon. The extracts from kokanee and red salmon showed the highest correlation with each other in terms of the IgE-binding capacity, and showed complete (100%) reciprocal cross-inhibition in the ELISA inhibition test. On immunoblotting, there was no marked difference in the staining pattern between the two extracts, and each IgE-binding band gradually disappeared when the patients' sera were preincubated with the counterpart antigen in a dose-dependent manner. These results suggest that kokanee has similar allergenic properties to red salmon.