scholarly journals Handling, infectious agents and physiological condition influence survival and post-release behaviour in migratory adult coho salmon after experimental displacement

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
J M Chapman ◽  
A K Teffer ◽  
A L Bass ◽  
S G Hinch ◽  
D A Patterson ◽  
...  

Abstract For Pacific salmon captured and released by fisheries, post-release behaviour and survival may be influenced by their health and condition at time of capture. We sought to characterize the interactions between infectious agent burden, fish immune and stress physiology and fisheries stressors to investigate the potential for capture-mediated pathogen-induced mortality in adult coho salmon Oncorhynchus kisutch. We used radio-telemetry paired with high-throughput qPCR of non-lethal gill biopsies for infectious agents and host biomarkers from 200 tagged fish experimentally displaced and exposed to various experimental fisheries treatments (gill net entanglement, recreational angling and recreational angling with air exposure vs. non-sampled control). We characterized relationships among post-release behaviour and survival, infectious agent presence and loads, physiological parameters and transcription profiles of stress and immune genes. All infectious agents detected were endemic and in loads consistent with previous adult Pacific salmon monitoring. Individuals exposed to fisheries treatments were less likely to reach spawning habitat compared to controls, and handling duration independent of fisheries gear had a negative effect on survival. High infectious agent burden was associated with accelerated migration initiation post-release, revealing behavioural plasticity in response to deteriorating condition in this semelparous species. Prevalence and load of infectious agents increased post-migration as well as transcription signatures reflected changes in immune and stress profiles consistent with senescence. Results from this study further our understanding of factors associated with fisheries that increase risk of post-release mortality and characterize some physiological mechanisms that underpin migratory behaviour.

2017 ◽  
Vol 9 (1) ◽  
pp. e2017035
Author(s):  
Francesco Zallio ◽  
Giulia Limberti ◽  
Marco Ladetto

Several infectious agents appear to provide a proliferative signal -- “antigen-drive” – that  could be implicated in the pathogenesis of various type of Non-Hodgkin Lymphoma (NHL). A classical model of infection-driven lymphoprolipherative disorder is Helicobacter pylori-induced gastric MALT lymphoma, where antibiotic therapy allows eradication of both the infectious agent and the clonal B-cell expansion;  following the footsteps of these example, several retrospective studies have found a correlation with other pathogens and B-cell Lymphomas, adding new important informations about pathogenesis and laying the groundwork for chemotherapy-free treatments.Although no clear association with infectious agents has yet been identified for Follicular Lymphoma (FL), a growing number of biological and clinical observations suggests that interaction with physiological and pathological microbial populations might play a role also in this subtype of lymphoma: in the last years epidemiological studies investigating the association of known risk factors and FL found a potential correlation with viral or bacterial infections; moreover recent findings about the stimulation of FL clones support the importance of microbial exposure to lymphomagenesis and disease progression.In the following review we make an attempt to find tangible evidences in favor of a role of either physiological and pathological exogenous microbial species in the pathogenesis of FL, and try to integrate the findings coming from epidemiological, biological and interventional studies to define future  novel treatment and prevention strategies for FL.


1962 ◽  
Vol 40 (7) ◽  
pp. 919-927 ◽  
Author(s):  
H. Tsuyuki ◽  
E. Roberts ◽  
R. E. A. Gadd

The muscle myogens and other components of the spring salmon (O. tshawytscha), chum salmon (O. keta), coho salmon (O. kisutch), and sockeye salmon (O. nerka), as well as the lingcod (Ophiodon elongatus), were separated by the use of diethylaminoethyl (DEAE) cellulose columns. Significant amounts of slowly dialyzable inosine and inosinic acid which may lead to spurious peaks in moving-boundary electrophoretic separations have been shown to be present in the muscle myogen preparations. The basic differences in the muscle myogen components of the Pacific salmon and the lingcod are compared.


2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.


Trudy VNIRO ◽  
2020 ◽  
Vol 179 ◽  
pp. 90-102
Author(s):  
M. N. Gorokhov ◽  
V. V. Volobuev ◽  
I. S. Golovanov

There are two main areas of pacific salmon fishing in the Magadan region: Shelikhova Gulf and Tauiskaya Bay. The main fishing species is pink salmon in the region. Its share of total salmon catch by odd-year returns reaches 85 %. Data on the dynamics of escapement to the spawning grounds of pink salmon of the Shelikhova Gulf and Tauiskaya Bay are presented. The displacement of the level of spawning returns of pink salmon into the Shelihova Gulf with the simultaneous reduction of its returns to the Tauiskaya Bay is shown. Data on the dynamics of the fishing indicators of pink salmon for the two main fishing areas are provided. The Tauiskaya Bay as the main pink salmon fishery area loses its importance is shown. Graphical data on the escapement of producers pink salmon to the spawning grounds are presented and the optimal values of spawning escapements are estimated. Chum salmon is the second largest and most fishing species. Information on the dynamics of the number of returns, catch and escapement to the spawning grounds of chum salmon is given. The indicators of escapement to the spawning areas and their compliance with the optimal passes of salmon producers are analyzed. The issues of the dynamics of returns number, catch and the escapement to the spawning grounds of coho salmon producers are considered. The level of the escapement to the spawning areas is shown and the ratio of actual to optimal values of passes is estimated. The role of coho salmon as an object of industrial fishing and amateur fishing is shown. The extent of fishing press on individual groups of salmon populations is discussed. It is concluded that it is necessary to remove the main salmon fishery from the Tauiskaya Bay to the Shelikhova Gulf.


2019 ◽  
Author(s):  
Quentin Rougemont ◽  
Jean-Sébastien Moore ◽  
Thibault Leroy ◽  
Eric Normandeau ◽  
Eric B. Rondeau ◽  
...  

AbstractA thorough reconstruction of historical processes is essential for a comprehensive understanding the mechanisms shaping patterns of genetic diversity. Indeed, past and current conditions influencing effective population size have important evolutionary implications for the efficacy of selection, increased accumulation of deleterious mutations, and loss of adaptive potential. Here, we gather extensive genome-wide data that represent the extant diversity of the Coho salmon (Oncorhynchus kisutch) to address two objectives. We demonstrate that a single glacial refugium is the source of most of the present-day genetic diversity, with detectable inputs from a putative secondary micro-refugium. We found statistical support for a scenario whereby ancestral populations located south of the ice sheets expanded in postglacial time, swamping out most of the diversity from other putative micro-refugia. Demographic inferences revealed that genetic diversity was also affected by linked selection in large parts of the genome. Moreover, we demonstrate that the recent demographic history of this species generated regional differences in the load of deleterious mutations among populations, a finding that mirrors recent results from human populations and provides increased support for models of expansion load. We propose that insights from these historical inferences should be better integrated in conservation planning of wild organisms, which currently focuses largely on neutral genetic diversity and local adaptation, with the role of potentially maladaptive variation being generally ignored.


2011 ◽  
Vol 68 (6) ◽  
pp. 1122-1130 ◽  
Author(s):  
James R. Irvine ◽  
Masa-aki Fukuwaka

Abstract Irvine, J. R., and Fukuwaka, M. 2011. Pacific salmon abundance trends and climate change. – ICES Journal of Marine Science, 68: 1122–1130. Understanding reasons for historical patterns in salmon abundance could help anticipate future climate-related changes. Recent salmon abundance in the northern North Pacific Ocean, as indexed by commercial catches, has been among the highest on record, with no indication of decline; the 2009 catch was the highest to date. Although the North Pacific Ocean continues to produce large quantities of Pacific salmon, temporal abundance patterns vary among species and areas. Currently, pink and chum salmon are very abundant overall and Chinook and coho salmon are less abundant than they were previously, whereas sockeye salmon abundance varies among areas. Analyses confirm climate-related shifts in abundance, associated with reported ecosystem regime shifts in approximately 1947, 1977, and 1989. We found little evidence to support a major shift after 1989. From 1990, generally favourable climate-related marine conditions in the western North Pacific Ocean, as well as expanding hatchery operations and improving hatchery technologies, are increasing abundances of chum and pink salmon. In the eastern North Pacific Ocean, climate-related changes are apparently playing a role in increasing chum and pink salmon abundances and declining numbers of coho and Chinook salmon.


1977 ◽  
Vol 55 (10) ◽  
pp. 1756-1758 ◽  
Author(s):  
Bryan Ludwig ◽  
David A. Higgs ◽  
Ulf H. M. Fagerlund ◽  
Jack R. McBride

As part of an ongoing survey to identify hormones capable of stimulating growth in Pacific salmon, groups of underyearling coho salmon were injected with bovine (Ultralente) insulin (0.32, 1.0, 3.2, or 10 IU/kg body weight) into the peritoneal cavity either once or twice weekly for 70 days.All doses of insulin, when injected twice weekly, increased the values for specific growth rates and decreased those for food–gain ratios relative to solvent-injected controls, but the differences were not statistically significant. All doses of insulin caused a marked increase in the granulation of the pancreatic B cells. Plasma glucose concentrations in starved coho injected with 10 IU insulin/kg body weight were significantly lower than in solvent-injected controls 4 h after injection.It is concluded that proper evaluation of the effectiveness of insulin as a growth promoter for salmon requires further studies preferably using insulin preparations specific to teleosts.


2020 ◽  
Author(s):  
Pascale Gibeau ◽  
Michael J. Bradford ◽  
Wendy J. Palen

AbstractOver 1 billion USD are devoted annually to rehabilitating freshwater habitats to improve survival for the recovery of endangered salmon populations. Mitigation often requires the creation of new habitat (e.g. habitat compensation) to offset population losses from human activities, however compensation schemes are rarely evaluated. Anadromous Pacific salmon are ecologically, culturally, and economically important in the US and Canada, and face numerous threats from climate change, over-harvesting, and degradation of freshwater habitats. Here we used a matrix population model of coho salmon (Oncorhynchus kisutch) to determine the amount of habitat compensation needed to offset mortality (2-20% per year) caused by a range of development activities. We simulated chronic mortality to three different life stages (egg, parr, smolt/adult), individually and in combination, to mimic impacts from development, and evaluated if the number of smolts produced from constructed side-channels demographically offset losses. We show that under ideal conditions, the typical size of a constructed side-channel in the Pacific Northwest (PNW) (3405 m2) is sufficient to compensate for only relatively low levels of chronic mortality to either the parr or smolt/adult stages (2-7% per year), but populations do not recover if mortality is >10% per year. When we assumed lower productivity (e.g.; 25th percentile), or imposed mortality at multiple life stages, we found that constructed channels would need to be larger (0.2-4.5 times) than if we assumed mean productivity or as compared to the typical size built in the PNW, respectively, to maintain population sizes.. We conclude that habitat compensation has the potential to mitigate chronic mortality to early life stages, but that current practices are likely not sufficient when we incorporate more realistic assumptions about productivity of constructed side-channels and cumulative effects of anthropogenic disturbances on multiple life stages.


<em>Abstract</em>—The North Fork Toutle River drains the northwest face of Mount St. Helens to the Cowlitz River, a major tributary of the Columbia River in southwestern Washington. In response to the 1980 eruption of Mount St. Helens, the U.S. Army Corps of Engineers constructed a sediment retention structure (SRS) in the North Fork Toutle River watershed to reduce the transport of fine sediment to the lower Cowlitz and Columbia River systems. The SRS was built without fish passage facilities and currently presents a significant barrier to migrating adult salmonids. To facilitate passage of coho salmon <em>Oncorhynchus kisutch </em>and steelhead <em>O. mykiss </em>to the upper watershed, a fish collection facility (FCF) was constructed 1.5 km downstream of the SRS, where fish are currently captured and transported to tributaries upstream of the SRS. We used radio telemetry to evaluate the movement of adult coho salmon and steelhead in the North Fork Toutle River in 2005 and 2006. A total of 40 coho and 42 steelhead were released from four different release sites in varied proportions. Release sites included the FCF, the SRS, and Alder Creek and Hoffstadt Creek, both North Fork Toutle River tributaries upstream of the SRS. Results from this research effort suggest that (1) unlike adult coho, adult steelhead are able to ascend the SRS spillway; (2) upstream adult coho and steelhead passage through the sediment plain is possible but may be flow-dependent; (3) adult coho and steelhead released in Alder Creek and Hoffstadt Creek tend to remain within their respective release tributary; and (4) postspawn steelhead emigration is limited. Future research is required to adequately address factors that influence movement of adult coho and steelhead in the upper North Fork Toutle River. The information resulting from this collaborative effort is enabling natural resource managers to determine whether the SRS spillway is a barrier to anadromous fish, to refine existing trap and haul operations, or, if appropriate, to consider modifying the spillway to enable volitional passage by upstream-migrating fish.


<em>Abstract</em>.-Pacific salmon <em>Oncorhynchus </em>spp. catches are at historic high levels. It is significant that one of the world's major fisheries for a group of species that dominates the surface waters of the subarctic Pacific is actually very healthy. Natural trends in climate are now recognized to cause large fluctuations in Pacific salmon production, as shown in historical records of catch and recent changes probably have been affected by greenhouse gas induced climate changes. Pink salmon <em>O. gorbuscha </em>and chum salmon <em>O. keta </em>production and catch has increased in the past 30 years and may continue in a similar trend for for the next few decades. Coho salmon <em>O. kisutch </em>and Chinook salmon <em>O. tshawytscha </em>catches have been declining for several decades, particularly at the southern end of their range, and they may continue to decline. In the 1970s, hatcheries were considered to be a method of adding to the wild production of coho and Chinook salmon because the ocean capacity to produce these species was assumed to be underutilized. Large-scale changes in Pacific salmon abundances are linked to changes in large-scale atmospheric processes. These large-scale atmospheric processes are also linked to planetary energy transfers, and there is a decadal scale pattern to these relationships. Pacific salmon production in general is higher in decades of intense Aleutian lows than in periods of weak Aleutian lows. Key to understanding the impact of climate change on Pacific salmon is understanding how the Aleutian low will change. Chinook and coho salmon are minor species in the total commercial catch, but important socially and economically in North America. A wise use of hatcheries may be needed to maintain abundances of these species in future decades.


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