56 research outputs found
Body condition of returning Atlantic salmon <i>Salmo salar L.</i> correlates with scale δ<sup>13</sup>C and δ<sup>15</sup>N content deposited at the last marine foraging location
No full textPatterns of feeding and growth of Atlantic salmon Salmo salar L. in the marine environment are critical to understanding how observed declines in recruitment may reflect warming or other oceanic drivers. The isotopic composition of scales can provide insight into differences in marine feeding location and possibly temperature regime. The authors used archived scale samples to measure δ13C and δ15N deposited in the scales of one sea-winter (1SW) salmon during their last season of growth at sea before they returned to five Irish rivers. δ13C values were related statistically to observed salmon body condition (Fulton’s K), and fish with higher δ13C values tended to show significantly better condition. In contrast, δ15N values were negatively related to body condition. There was no important effect on condition of length at smolt migration, and the effect of duration of marine residence varied among rivers. It is likely that δ13C values partly reflected ambient ocean temperature and recent marine feeding environment before return migration, such that the observed relationship between higher δ13C values and increased body condition may express an advantage for adult fish feeding in warmer, potentially closer, waters. If greater body condition influences fitness, then a changing temperature regime in the Northeast Atlantic may drive shifts in salmon survival and reproduction. This study provides evidence that there is spatial and trophic variation at sea between salmon from rivers of origin that are located relatively close to each other, with potential consequences for body condition and, consequently, fitness and life history; this suggests that salmon populations from geographically proximate rivers within regions may exhibit differential responses to ocean-scale climatic changes across the Northeast Atlantic
Effects of salmon lice on sea trout. A litterature review
No full textThorstad, E.B., Todd, C.D., Bjørn, P.A., Gargan, P.G., Vollset, K.W., Halttunen, E., Kålås, S., Uglem, I., Berg, M. & Finstad, B. 2014. Effects of salmon lice on sea trout. A litterature review. NINA Rapport 1044. 162 s. Salmon lice are external parasites on salmonids in the marine environment. Farmed salmonids also act as hosts for salmon lice; therefore open net cage farms can increase the production of infective larvae in coastal areas. The aim of this report is to review the existing knowledge on the effects of salmon lice on wild sea trout and focuses on reports in the peer-reviewed primary scientific literature. Fro this reason, references to so-called "grey literature" reports has been minimized. The studies reviewed here range from laboratory and field investigations of the effects of salmon lice on individual fish, to analyses of impacts on wild populations
Perspectives on ethics : profit and non-profit business leaders in Ireland
No full textAs ethical concern has reached a 30 year high among future business leaders (Drover, et al., 2012), a focus on those who lead current businesses could prove to be imperative to furthering our understanding of business ethics. The researcher studied a small sample of business leaders in Ireland, focusing on both the profit and non-profit sector in order to understand their perspectives on the subject of ethics and their own role on influencing ethical conduct within their organization. Alongside this was a comparative study between both the profit and non-profit leaders and their perspectives. Through a thematic analysis, themes were discovered based around to these topics including themes relating to reputation and transparency, the financial crisis, teaching ethics, profit versus ethics and the importance of leadership, culture and values. Regarding the profit and non-profit comparison of business leaders a key theme was discovered in relation to exposure and how it shapes ethical focus. The researcher recommended further advancement into the study of ethics, particularly focusing on leadership and profit and non-profit sector comparisons utilizing both qualitative and quantitative research. Author keywords: Ethics, perspective(s), comparison(s), Ireland, business leader(s), profit, non-profi
The river's tale a year on the Mekong
No full textBeginning in 1998, the author was able to pursue his long-held dream of traveling the three thousand miles of the Mekong River--through China, Tibet, Burma, Laos, Thailand, Cambodia, and Vietnam--and lingering where he wished
Impact of parasites on salmon recruitment in the Northeast Atlantic Ocean
No full textParasites 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.Source type: Electronic(1
Theme-based book review: Government capacity and capability
No full textGovernment capacity and capability are not only a matter of public rhetoric. Government capacity may be seen when government can “do what it wants to do” (Gargan, 1981, p. 656). Capacity has been tied to policy, resource and program management, but capacity is not exclusively a matter of management. Government capability is evidenced by institutions that “respond effectively to change . . . make decisions efficiently, effectively (i.e., rationally) and responsively, [and] . . . manage conflict” (Bowman & Kearney, 1988, p. 343). Arrangements within institutional structures help organizations to move beyond simple static capacity to kinetic movement in realization of government’s goals; in this respect, accountability, coordinating ability, staffing and resources may point to capability (Bowman & Kearney, 1988). Still,
government institutions frequently have difficulty translating capacity into realized performance (Manning & Holt, 2014). Capacity and capability have context-specific characteristics. Efforts to impose systems and capacities out of context, as mimetic isomorphism, can fail (Frumkin & Galaskiewicz, 2004; Pritchett et al., 2013). Public sector enterprises are constrained by a variety of factors, from within and outside the organization; some factors are overt, but others may be difficult to identify, borne of individual and group limitations that inform the human condition.
This themed book review looks at four recent books that on some level address government capacity and capability – what can be expected and gotten from the public administration enterprise. The books include The Three Ages of Government: From the Person, to the Group, to the World, by Jos C.N. Raadschelders; A Modern Guide to Public Policy, edited by Giliberto Capano and Michael Howlett; Transportation and the State: Governing the Public Domain, by Hans Keman and Japp J. Woldendorp; and The Death of Idealism: Development and Anti-Politics in the Peace Corps, by Meghan Elizabeth Kallman.Book ReviewJournal ArticleFinal article publishe
A novel and dedicated multidisciplinary service to manage breech presentation at term; 3 years of experience in a tertiary care maternity unit
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Evidence for sea lice-induced marine mortality of Atlantic salmon (<em>Salmo salar</em>) in western Ireland from experimental releases of ranched smolts treated with emamectin benzoate.
No full textSea trout (Salmo trutta L.) stock collapses in coastal areas of western Ireland subject to salmon aquaculture were contemporaneous with high abundances of larval sea lice (Lepeophtheirus salmonis Krøyer) on juvenile sea trout. Whereas sea trout remain in near-shore waters throughout their marine migration, Atlantic salmon (Salmo salar L.) smolts typically move quickly offshore into oceanic waters. It might therefore be predicted that salmon smolts would be less vulnerable to coastal stressors, and less likely to be negatively affected by infestations of sea lice early in their marine phase. Groups of micro-tagged, hatchery-reared Atlantic salmon smolts were fed either untreated pellets or pellets incorporating the in-feed sea louse treatment SLICE® (emamectin benzoate) prior to eight experimental releases in three marine locations over a 3-year period. In total 74,324 smolts were released and analysis of tag recaptures from returning adult salmon showed that emamectin-treated smolts experienced increased survivorship and were 1.8 times more likely to return compared to control fish. These results suggest that sea lice-induced mortality on adult Atlantic salmon returns in Ireland can be significant, and that sea lice larvae emanating from farmed salmon may influence individual survivorship and population conservation status of wild salmon in these river systems
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