Nutrient fluxes and the recent collapse of coastal California salmon populations

2011 ◽  
Vol 68 (7) ◽  
pp. 1161-1170 ◽  
Author(s):  
Jonathan W. Moore ◽  
Sean A. Hayes ◽  
Walter Duffy ◽  
Sean Gallagher ◽  
Cyril J. Michel ◽  
...  
Keyword(s):  
Life Histories ◽  
Oncorhynchus Tshawytscha ◽  
Conveyor Belt ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Import And Export ◽  
Net Export ◽  
The Relationship ◽  
Dependent Processes ◽  
Mass Balance Approach ◽  
Different Parts

Migratory salmon move nutrients both in and out of fresh waters during the different parts of their life cycle. We used a mass-balance approach to quantify recent changes in phosphorus (P) fluxes in six coastal California, USA, watersheds that have recently experienced dramatic decreases in salmon populations. As adults, semelparous Chinook ( Oncorhynchus tshawytscha ) and coho ( Oncorhynchus kisutch ) salmon imported 8.3 and 10.4 times more P from the ocean, respectively, than they exported as smolts, while iteroparous steelhead (i.e., sea-run rainbow trout, Oncorhynchus mykiss ) imported only 1.6 times more than they exported as kelts and smolts. Semelparous species whose life histories led them to import more nutrients were also the species whose populations decreased the most dramatically in California in recent years. In addition, the relationship between import and export was nonlinear, with export being proportionally more important at lower levels of import. This pattern was driven by two density-dependent processes — smolts were larger and disproportionately more abundant at lower spawner abundances. In fact, in four of our six streams we found evidence that salmon can drive net export of P at low abundance, evidence for the reversal of the “conveyor belt” of nutrients.

An examination of the PCB: lipid relationship among individual fish

1997 ◽  
Vol 54 (5) ◽  
pp. 1031-1038
Author(s):  
C A Stow ◽  
L J Jackson ◽  
J F Amrhein
Keyword(s):  
Salmo Trutta ◽  
Lake Michigan ◽  
Oncorhynchus Tshawytscha ◽  
Lake Trout ◽  
Coho Salmon ◽  
Salvelinus Namaycush ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Strong Linear Correlation ◽  
Brown Trout Salmo Trutta ◽  
The Relationship

We examined data from 1984 to 1994 for five species of Lake Michigan salmonids to explore the relationship between total PCB concentration and percent lipid. When we compared mean species lipid and PCB values, we found a strong linear correlation. When we compared values among individuals, we found modest positive PCB:lipid associations in brown trout (Salmo trutta), chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and rainbow trout (Oncorhynchus mykiss) collected during spawning, but positive associations were not apparent among nonspawning individuals. Lake trout (Salvelinus namaycush) exhibited no discernible PCB:lipid relationship. Our results are not incompatible with previous observations that contaminants are differentially partitioned into lipids within a fish, but these results do suggest that lipids are not a major factor influencing contaminant uptake.

Individual condition, standard metabolic rate, and rearing temperature influence steelhead and rainbow trout (Oncorhynchus mykiss) life histories

2014 ◽  
Vol 71 (4) ◽  
pp. 491-501 ◽  
Author(s):  
Matthew R. Sloat ◽  
Gordon H. Reeves
Keyword(s):  
Life Histories ◽  
Somatic Growth ◽  
High Standard ◽  
Standard Metabolic Rate ◽  
Temperature Treatment ◽  
Individual Growth ◽  
Whole Body ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Thermal Regimes ◽  
The Relationship

We reared juvenile Oncorhychus mykiss with low and high standard metabolic rates (SMR) under alternative thermal regimes to determine how these proximate factors influence life histories in a partially migratory salmonid fish. High SMR significantly decreased rates of freshwater maturation and increased rates of smoltification in females, but not males, after 1 year of rearing. Warmer water temperatures significantly decreased rates of freshwater maturation and increased rates of smoltification in both sexes. Variation in individual growth influenced the probability of adopting anadromy or freshwater residency as life histories, but produced paradoxical results. Individuals with the highest growth performance within their respective temperature treatments had a higher probability of freshwater maturation, but warmer temperatures decreased freshwater maturation despite significantly increasing somatic growth. Whole-body lipid content was significantly lower for fish reared in the warm temperature treatment, which may explain the decreased probability of freshwater maturation for individuals exposed to warmer temperatures. Our results indicate that changes in somatic growth induced by altered thermal regimes can influence the relationship between body size and the probability of maturation. Accordingly, somatic growth may not be a robust predictor of shifts in the prevalence of anadromy and residency in partially migratory salmonids when compared across thermal regimes.

Understanding gas bubble trauma in an era of hydropower expansion: how do fish compensate at depth?

2020 ◽  
Vol 77 (3) ◽  
pp. 556-563 ◽  
Author(s):  
Naomi K. Pleizier ◽  
Charlotte Nelson ◽  
Steven J. Cooke ◽  
Colin J. Brauner
Keyword(s):  
Bubble Growth ◽  
Gas Bubble ◽  
Hydroelectric Dams ◽  
Dissolved Gas ◽  
Empirical Relationships ◽  
Lethal Effects ◽  
Exposed Fish ◽  
Total Dissolved Gas ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Relationship

Hydrostatic pressure is known to protect fish from damage by total dissolved gas (TDG) supersaturation, but empirical relationships are lacking. In this study we demonstrate the relationship between depth, TDG, and gas bubble trauma (GBT). Hydroelectric dams generate TDG supersaturation that causes bubble growth in the tissues of aquatic animals, resulting in sublethal and lethal effects. We exposed fish to 100%, 115%, 120%, and 130% TDG at 16 and 63 cm of depth and recorded time to 50% loss of equilibrium and sublethal symptoms. Our linear model of the log-transformed time to 50% LOE (R2 = 0.94) was improved by including depth. Based on our model, a depth of 47 cm compensated for the effects of 4.1% (±1.3% SE) TDG supersaturation. Our experiment reveals that once the surface threshold for GBT from TDG supersaturation is known, depth protects rainbow trout (Oncorhynchus mykiss) from GBT by 9.7% TDG supersaturation per metre depth. Our results can be used to estimate the impacts of TDG on fish downstream of dams and to develop improved guidelines for TDG.

scholarly journals How Do Consumers’ Food Values across Countries Lead to Changes in the Strategy of Food Supply-Chain Management?

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1523
Author(s):  
Jisung Jo ◽  
Eon-kyung Lee
Keyword(s):  
Supply Chain ◽  
Supply Chain Management ◽  
Random Parameter ◽  
Cold Chain ◽  
Chain Management ◽  
Consumer Values ◽  
Food Market ◽  
Import And Export ◽  
The Relationship ◽  
Food Value

Although one of the main goals of supply-chain management is to maximize consumer values, the research to date has mainly focused on the supply side. In the case of the food industry, understanding consumer needs and maximizing its utility are essential. In this study, we analyze consumers’ 12 meta-values (e.g., safety, taste, health, price, environment, etc.), then suggest the strategy of food cold-chain management satisfying consumers’ perception. We focused on consumers from three countries in Asia: Korea, China, and Japan. The survey was conducted with over 1000 consumers in those three countries, and a random parameter logit model was utilized to determine the importance of each food value that could affect consumers’ food choice. Similarities and differences were both found in share of preference of each food value across countries. While safety is one of the top three values in all three countries, naturalness and nutritional value ranked among the top three only in China. To propose the consumer-centric strategy of food cold-chain management, we investigated the relationship between each food value and each node of supply chain based on the big data analysis. It shows that consumers prefer when the entire supply chain is managed where each node is organically connected with each other instead of individual nodes being managed separately. Further, strategies for food cold-chain management should be developed differently by country, incorporating differences of consumers’ preferences on food value. These results would motivate governments and companies related to food cold chain to reconsider their marketing strategies on the import and export food market.

Elemental signatures in otoliths of hatchery rainbow trout (Oncorhynchus mykiss): distinctiveness and utility for detecting origins and movement

2009 ◽  
Vol 66 (4) ◽  
pp. 513-524 ◽  
Author(s):  
Daniel K. Gibson-Reinemer ◽  
Brett M. Johnson ◽  
Patrick J. Martinez ◽  
Dana L. Winkelman ◽  
Alan E. Koenig ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Water Chemistry ◽  
Fisheries Management ◽  
Valuable Insight ◽  
Otolith Chemistry ◽  
Considerable Potential ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Relationship ◽  
Ambient Levels

Otolith chemistry in freshwater has considerable potential to reveal patterns of origin and movement, which would benefit traditional fisheries management and provide a valuable tool to curb the spread of invasive and illicitly stocked species. We evaluated the relationship between otolith and water chemistry for five markers (Ba/Ca, Mn/Ca, Sr/Ca, Zn/Ca, and 87Sr/86Sr) in rainbow trout ( Oncorhynchus mykiss ) using the existing hatchery system in Colorado and Wyoming, USA, to provide controlled, seminatural conditions. Otolith Ba/Ca, Sr/Ca, and 87Sr/86Sr reflected ambient levels, whereas Mn/Ca and Zn/Ca did not. Using only the markers correlated with water chemistry, we classified fish to their hatchery of origin with up to 96% accuracy when element and isotope data were used together. Large changes in 87Sr/86Sr were evident in otolith transects, although subtler changes in Sr/Ca were also detectable. Our results suggest the relatively few otolith markers that reflect ambient chemistry can discriminate among locations and track movements well enough to provide valuable insight in a variety of applied contexts.

Storie di violenza in infanzia e adolescenza e prostituzione in etŕ adulta: quali legami?

2009 ◽  
pp. 93-112
Author(s):  
Emanuela Confalonieri ◽  
Cristina Giuliani ◽  
Alessandra Bongiana ◽  
Paola Pavesi
Keyword(s):  
Childhood Maltreatment ◽  
Life Histories ◽  
Descriptive Analysis ◽  
Sexual Exploitation ◽  
Sexual Revictimization ◽  
East Europe ◽  
The Social ◽  
Forced Prostitution ◽  
The One ◽  
The Relationship

- The present study, related to the one published some years ago (Confalonieri et al., 2004), is an investigation on forced prostitution and the related violence's types in immigrant women involved in streetwalking prostitution. Using the social records available by the Ufficio Stranieri (Comune di Milano), the purpose is to identify the presence of 1) childhood maltreatments or violence before the entry in sex exploitation market and 2) subsequent adult sexual revictimization from partners, pimps and clients. Data were analysed using phenomenological descriptive analysis. The relationship between childhood maltreatment and abuse and subsequent involvement in sex work is discussed comparing data and life histories of immigrant prostitutes coming from Nigeria and East Europe. The role played by social and contexual variables in sexual exploitation story are also considered.Key words: immigration, violence, prostitution, infancy, adulthood.Parole chiave: immigrazione, violenza, prostituzione, infanzia, etŕ adulta.

Inter-tissue differences in mitochondrial enzyme activity, RNA and DNA in rainbow trout (Oncorhynchus mykiss)

1998 ◽  
Vol 201 (24) ◽  
pp. 3377-3384 ◽  
Author(s):  
S. C. Leary ◽  
B. J. Battersby ◽  
C. D. Moyes
Keyword(s):  
Enzyme Activity ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Citrate Synthase ◽  
Mitochondrial Protein ◽  
Molecular Organization ◽  
Mitochondrial Rna ◽  
Mitochondrial Enzyme ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
The Relationship

We examined whether the relationships between mitochondrial enzyme activity, mitochondrial DNA (mtDNA) and mitochondrial RNA (mtRNA) were conserved in rainbow trout (Oncorhynchus mykiss) tissues that differ widely in their metabolic and molecular organization. The activity of citrate synthase (CS), expressed either per gram of tissue or per milligram of total DNA, indicated that these tissues (blood, brain, kidney, liver,cardiac, red and white muscles) varied more than 100-fold in mitochondrial content. Several-fold differences in the levels of CS mRNA per milligram of DNA and CS activity per CS mRNA were also observed, suggesting that fundamental differences exist in the regulation of CS levels across tissues. Although tissues varied 14-fold in RNA g-1, poly(A+) RNA (mRNA)was approximately 2 % of total RNA in all tissues. DNA g-1 also varied 14-fold across tissues, but RNA:DNA ratios varied only 2.5-fold. The relationship between two mitochondrial mRNA species (COX I, ATPase VI) and one mitochondrial rRNA (16S) species was constant across tissues. The ratio of mtRNA to mtDNA was also preserved across most tissues; red and white muscle had 10- to 20-fold lower levels of mtDNA g-1 but 7- to 10-fold higher mtRNA:mtDNA ratios, respectively. Collectively, these data suggest that the relationship between mitochondrial parameters is highly conserved across most tissues, but that skeletal muscles differ in a number of important aspects of respiratory gene expression ('respiratory genes'include genes located on mtDNA and genes located in the nucleus that encode mitochondrial protein) and mtDNA transcriptional regulation.

Estimating the influence of temperature on the survival of chinook salmon smolts (Oncorhynchus tshawytscha) migrating through the Sacramento – San Joaquin River Delta of California

1995 ◽  
Vol 52 (4) ◽  
pp. 855-863 ◽  
Author(s):  
Peter Fritz Baker ◽  
Franklin K. Ligon ◽  
Terence P. Speed
Keyword(s):  
Water Temperature ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Logistic Function ◽  
Laboratory Findings ◽  
Natural Systems ◽  
San Joaquin River ◽  
Influence Of Temperature On ◽  
The Relationship ◽  
Good Agreement

Data from the U.S. Fish and Wildlife Service are used to investigate the relationship between water temperature and survival of hatchery-raised fall-run chinook salmon (Oncorhynchus tshawytscha) smolts migrating through the Sacramento – San Joaquin Delta of California. A formal statistical model is presented for the release of smolts marked with coded-wire tags (CWTs) in the lower Sacramento River and the subsequent recovery of marked smolts in midwater trawls in the Delta. This model treats survival as a logistic function of water temperature, and the release and recovery of different CWT groups as independent mark–recapture experiments. Iteratively reweighted least squares is used to fit the model to the data, and simulation is used to establish confidence intervals for the fitted parameters. A 95% confidence interval for the upper incipient lethal temperature, inferred from the trawl data by this method, is 23.01 ± 1.08 °C This is in good agreement with published experimental results obtained under controlled conditions (24.3 ± 0.1 and 25.1 ± 0.1 °C for chinook salmon acclimatized to 10 and 20 °C, respectively): this agreement has implications for the applicability of laboratory findings to natural systems.

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