Excess HB-EGF, which promotes VEGF signaling, leads to hydrocephalus

Heparin binding epidermal growth factor-like growth factor (HB-EGF) is an angiogenic factor mediating radial migration of the developing forebrain, while vascular endothelial growth factor (VEGF) is known to influence rostral migratory stream in rodents. Cell migratory defects have been identified in animal models of hydrocephalus; however, the relationship between HB-EGF and hydrocephalus is unclear. We show that mice overexpressing human HB-EGF with β-galactosidase reporter exhibit an elevated VEGF, localization of β-galactosidase outside the subventricular zone (SVZ), subarachnoid hemorrhage, and ventriculomegaly. In Wistar polycystic kidney rats with hydrocephalus, alteration of migratory trajectory is detected. Furthermore, VEGF infusions into the rats result in ventriculomegaly with an increase of SVZ neuroblast in rostral migratory stream, whereas VEGF ligand inhibition prevents it. Our results support the idea that excess HB-EGF leads to a significant elevation of VEGF and ventricular dilatation. These data suggest a potential pathophysiological mechanism that elevated HB-EGF can elicit VEGF induction and hydrocephalus

Epidemiology of malaria in a village in the Rufiji River Delta, Tanzania: declining transmission over 25 years revealed by different parasitological metrics

Background: Assessments of the epidemiology of malaria over time are needed to understand changes in transmission and guide control and elimination strategies. Methods: A longitudinal population study was established in 1985 in Nyamisati village in the Rufiji River Delta, Tanzania. A physician and research team lived in the village 1984–2000. Parasite prevalence by microscopy and two PCR methods, spleen rates and haemoglobin levels were measured in repeated cross-sectional surveys between 1985 and 2010. Passive surveillance of malaria cases was maintained until end 1999. Bed nets were distributed after the surveys 1993, 1999 and 2010. Results: In 1985, overall parasite prevalence by microscopy was 70% (90% in children ages two to nine years). The prevalence decreased gradually by microscopy (38.9% 1994, 26.7% 1999) and msp2-PCR (58.7% 1994, 44.8% 1999), whereas real-time PCR prevalence remained higher throughout the 1990s (69.4% 1994, 64.8% 1999). In 2010, parasite prevalence was 17.8% by real-time PCR and 16.3% by msp2-PCR, and estimated to 4.8% by microscopy. Spleen rates in children ages two to nine years decreased earlier than parasite prevalence, from \u3e75 to 42% in the 1980s, to nil during the 1990s. The prevalence of severe and moderate anaemia decreased from 41.1 to 13.1%. No deaths at the time of acute malaria were recorded when the research team lived in the village. Conclusions:A marked decline in malaria transmission was observed over 25 years. The decrease was detected after the arrival of the research team and continued gradually both before and after distribution of bed nets. Spleen rates and microscopy identified early changes when transmission was still intense, whereas real-time PCR was a more sensitive metric when transmission was reduced. The study provides historical data on malaria within a closely monitored rural village and contributes to the understanding of changing epidemiology in sub-Saharan Africa

Diversity of resistance mechanisms in carbapenem-resistant Enterobacteriaceae at a health care system in Northern California, from 2013 to 2016

The mechanism of resistance in carbapenem-resistant Enterobacteriaceae (CRE) has therapeutic implications. We comprehensively characterized emerging mechanisms of resistance in CRE between 2013 and 2016 at a health system in Northern California. A total of 38.7% (24/62) of CRE isolates were carbapenemase gene-positive, comprising 25.0% (6/24) blaOXA-48 like, 20.8% (5/24) blaKPC, 20.8% (5/24) blaNDM, 20.8% (5/24) blaSME, 8.3% (2/24) blaIMP, and 4.2% (1/24) blaVIM. Between carbapenemases and porin loss, the resistance mechanism was identified in 95.2% (59/62) of CRE isolates. Isolates expressing blaKPC were 100% susceptible to ceftazidime–avibactam, meropenem–vaborbactam, and imipenem–relebactam; blaOXA-48 like–positive isolates were 100% susceptible to ceftazidime–avibactam; and metallo β-lactamase–positive isolates were nearly all nonsusceptible to above antibiotics. Carbapenemase gene-negative CRE were 100% (38/38), 92.1% (35/38), 89.5% (34/38), and 31.6% (12/38) susceptible to ceftazidime–avibactam, meropenem–vaborbactam, imipenem–relebactam, and ceftolozane–tazobactam, respectively. None of the CRE strains were identical by whole genome sequencing. At this health system, CRE were mediated by diverse mechanisms with predictable susceptibility to newer β-lactamase inhibitors

Angiogenesis in human renal cell carcinoma : hypoxia, vascularity and prognosis

Background: Angiogenesis is recognised as a critical step in tumour progression. The angiogenic switch is activated by various trigger signals, such as hypoxia, low pH, and genetic mutations. Renal cell carcinoma (RCC) is often an aggressive tumour, and advanced disease has limited treatment options and bad prognosis. This study was focused on markers of angiogenesis in RCC: endoglin (CD105) and CD31 assessing microvessel density (MVD), and carbonic anhydrase (CA) IX and hypoxia-inducible factor (HIF)-2α expressed at hypoxia. Upregulation of HIF is also associated with inactivation of the von Hippel-Lindau (VHL) tumour suppressor gene, which is common in conventional/clear cell (c)RCC. Method: A tumour bank containing 308 tumours from patients operated 1982-2003 was used. The tumours were well characterised regarding tumour type, TNM stage, nuclear grade, tumour size, and patient survival. The tumours were prepared in tissue microarrays and fresh frozen in whole sections. To analyse the expression of endoglin, CD31, CA IX, and HIF-2α mRNA, immunohistochemistry and real-time PCR were used. Results: There was a higher endoglin expression in cRCC than in papillary (p)RCC and chromophobe (ch)RCC, and a higher CD31 expression in cRCC than in pRCC. MVD correlated inversely to TNM stage and nuclear grade in cRCC. There was also an inverse correlation between tumour diameter and CD31 expression in cRCCs. Patients with cRCC with high MVD had a more favourable prognosis than patients with lower MVD. Endoglin and CD31 were not independent prognostic factors. The CA IX expression was higher in cRCC than in pRCC and chRCC. Patients with cRCC expressing low CA IX had a significantly less favourable prognosis compared with those with higher expression. CA IX is an independent prognostic factor. There was a higher HIF-2α mRNA expression in cRCC than in pRCC and chRCC. In cRCC, there was a significant inverse correlation between HIF-2α mRNA expression, and TNM stage and nuclear grade. There was also an inverse correlation between HIF-2α mRNA expression and tumour size among patients with cRCC. HIF-2α was not an independent prognostic factor. Conclusion: In these studies, the factors related to hypoxia and vascularity were all inversely correlated to tumour aggressiveness in cRCC. MVD, CA IX, and HIF-2α expression were also higher in cRCC than in pRCC and chRCC. The relationship between angiogenesis, vascularity, and hypoxia is ambiguous. A line of reasoning including mutations increasing angiogenesis in advanced disease may also be applied to RCC. Measurements of individual angiogenic factors seem to provide prognostic information, and can potentially be combined in patient monitoring and treatment

General practitioners' experiences of Phosphatidylethanol in treatment of hypertension : A qualitative study

BACKGROUND: Hazardous alcohol use increases the risk of hypertension but is underdetected in primary health care patients. Use of the biomarker phosphatidylethanol (PEth), which reflects the last two to three weeks of alcohol consumption, is increasing in Swedish primary health care, but studies from that context are scarce or missing. AIM: Explore general practitioners' (GPs') experiences of using PEth to identify hazardous alcohol use in the context of managing hypertension. DESIGN & SETTING: A qualitative study of GPs (n=12) experienced in using PEth in hypertension management who were recruited at Swedish primary health care centres in 2021. METHOD: The GPs participated in five focus groups interviews. A questioning route was used. The interviews were audio recorded, transcribed verbatim, and analysed with inductive qualitative content analysis. RESULTS: The overall theme I don't hesitate anymore reflects the disappearance of GPs' fear that the PEth result might upset the patient, as this rarely occurred and that the positive effects of PEth predominated in the findings. The theme is underpinned by four sub-themes: serving as an eyeopener, improving the dialogue, using with care, and learning by doing. CONCLUSION: PEth is a useful tool that changed GPs' routines for addressing alcohol and identifying hazardous alcohol use in patients with hypertension managed in primary health care. The GPs advocated adopting PEth as a routine test in the treatment of hypertension. However, PEth needs to be used with care to maximise benefit and minimise harm

Metodikk for å fastsette miljømål for sterkt modifiserte vannforekomster. Auravassdraget som eksempel

Finstad, A.G., Barton, D.N., Jensen, A.J., Johnsen, B.O., Järnegren, J. & Sandlund, O.T. 2007. Metodikk for å fastsette miljømål for sterkt modifiserte vannforekomster. Auravassdraget som eksempel. – NINA Rapport 292, 93 s. Bakgrunnen for dette prosjektet er et behov fra DN og NVE om å gi en naturvitenskapelig og samfunnsøkonomisk vurdering av miljømålfastsetting i sterkt modifiserte vannforekomster (SMVF). Miljømålet i SMVF er godt økologisk potensial. Dette skiller seg fra miljømålet i andre vannforekomster (god økologisk tilstand) ved at målet ikke er å etterstrebe en tilnærmet naturtilstand, men en best mulig økologisk tilstand gitt at bruken av vassdraget opprettholdes (for eksempel kraftproduksjon). Her prøves prosessen fram mot endelig klassifisering som sterkt modifisert vannforekomst og påfølgende setting av miljømål ut i praksis. Auravassdraget og Litldedals-elva er brukt som eksempelvassdrag. Vassdragene har vært gjenstand for tre store kraftutbygginger: Aura (1953), Takrenna (1962) og Grytten (1975). Identifikasjon av SMVF og identifisering av avbøtende tiltak er en flerstegs prosess hvor vannforekomsten først blir identifisert som foreløpig SMVF etter et sett med utvelgelseskriterier. Endelig bestemmelse av SMVF blir fastsatt hvis vannforekomsten ikke kan oppnå økologisk forhold som er tilnærmet lik naturtilstand (god økologisk tilstand) uten at tiltak har uforholdsmessig negative konsekvenser for utnyttelse av vannforekomsten. Miljømålet for en sterkt modifisert vannforekomst er godt økologisk potensial. Dette er i Forskrift om rammer for vannforvaltning (vannrammeforskriften) og i EUs vannrammedirektiv definert som små endringer i forhold til maksimalt økologisk potensial. Maksimalt økologisk potensial fastsettes ved å anslå økologisk tilstand etter at alle avbøtende tiltak (som ikke har uforholdmessige negative konsekvenser for bruken) er gjennomført. Veiledningsdokumenter for EUs vannrammedirektiv oppgir alternative metoder for å gå fra maksimalt til godt økologisk potensial; (i) fastsette godt økologisk potensial som ”små end-ringer” i forhold til maksimalt økologisk potensial og deretter foreslå tiltak som må til for å oppnå dette, (ii) utsiling av tiltak som ligger til grunn for maksimalt økologisk potensial. Tiltak som i sum gir svært liten økologisk effekt fjernes og de resterende danner grunnlaget for å fastsette godt økologisk potensial. Begge disse metodene er utprøvd og vurdert. Vannforekomster som har vært inkludert i denne vurderingen er Aursjømagasinet, Reinsvatnet, lakseførende del av Aura, Eikesdalsvatnet, Eira, lakseførende del av Litledalselva samt Eresfjorden og indre del av Langfjorden. Av disse faller Eikesdalsvatnet samt Eresfjorden og indre del av Langfjorden ikke inn under definisjonen av SMVF, da tiltak kan gjennomføres som fører vannforekomsten tilbake til god økologisk tilstand eller virkninger av utbygginga er små. Disse er derfor ikke vurdert nærmere med hensyn på miljømålene maksimalt og godt økologisk potensial. Erfaringer med å fastsette miljømål gjennom effekt av tiltakspakker er positive, men det er svært vanskelig å skille mellom godt økologisk potensial fastsatt med ulike metoder. Fastsatt godt økologisk potensial skiller seg også lite fra maksimalt økologisk potensial. Dette skyldes at antall mulige tiltak ofte er lavt og at vurderinger av effekter ikke kan gis uten en viss grad av usikkerhet. Bruk av to begreper for økologisk potensial gir derfor liten mening i praktisk bruk. Imidlertid bør det i utarbeidelse av generell metodikk tas hensyn til at antall tiltak ofte kan være høyere hvis formålet med inngrepet er annet enn kraftproduksjon. Kunnskapsgrunnlag for fastsetting av miljømål vil sannsynligvis også bedres i framtida. sjøørret, harr, bunnfauna, zooplankton, kraftutbygging, minstevannføring, tiltak, vannrammedirektivet, Nesset, Sunndal, Lesja, Atlantic salmon, brown trout, grayling, benthos, zooplankton, hydropower regulation, minimum flow, measures, water frame directiv

Assessment of the risk to Norwegian biodiversity and aquaculture from pink salmon (Oncorhynchus gorbuscha). Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment

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Assessment of the risk to Norwegian biodiversity and aquaculture from pink salmon (Oncorhynchus gorbuscha). Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment

The Norwegian Environment Agency and the Norwegian Food Safety Authority asked the Norwegian Scientific Committee for Food and Environment to assess the risk to Norwegian biodiversity, to the productivity of native salmonid populations, and to aquaculture, from the spread and establishment of pink salmon in Norwegian rivers, and to assess mitigation measures to prevent the spread and establishment of this alien species. Pink salmon is native to rivers around the northern Pacific Ocean. The species usually has a strict two-year life cycle, with populations spawning in even and odd years being genetically isolated. Fertilized eggs of pink salmon were transferred from Sakhalin Island to Northwest Russia in the late 1950s, and fry were released in rivers draining to the White Sea. The first abundant return to rivers in Northwest Russia, as well as to Norway and other countries in northwestern Europe, was recorded in 1960. Stocking with fish from Sakhalin was terminated in 1979. By then, no self-sustaining populations had been established. From 1985 onwards, stocking in White Sea rivers was resumed with fish from rivers in the more northerly Magadan oblast on the Russian Pacific, resulting in the establishment of reproducing populations. Stocking was continued until 1999, when the last batch of even-year fertilized eggs was imported, and the fry released in spring 2000. Thus, all pink salmon caught after 2001 in the Northeast Atlantic and the Atlantic side of the Arctic Ocean including the Barents Sea, as well as in rivers draining into these seas, are the result of reproduction in the wild. Pink salmon is now established with abundant and increasing stocks in Northwest Russia and regular occurrence in rivers in eastern Finnmark. Catches of odd-year adult pink salmon in Northwest Russia were usually below 100 tonnes before 2001 and increased to an annual average of 220.5 tonnes during the period 2001-2017. Even-year returns are smaller than odd-year returns both in Northwest Russia and in Norway. The number of pink salmon recorded in Norwegian rivers peaked in 2017, with a high number of fish in eastern Finnmark, and substantial numbers recorded in rivers all along the coast of Norway and in other European countries. In 2019, the area with abundant returns expanded in comparison with 2017, to include rivers in western Finnmark and Troms. The recorded numbers were perhaps lower in southern Norway in 2017 than in 2019 (full statistics not available when this report was finalised), but also in southern Norway there were more pink salmon in 2019 than in any year before 2017. The large numbers of pink salmon in western Finnmark and Troms in 2019 may indicate an expansion of the area in Norway with abundant odd-year pink salmon returns. In some small rivers in eastern Finnmark, between 1000 and 1500 pink salmon were fished out by local people in 2019, demonstrating the magnitude of the potential impact in terms of numbers of pink salmon. We cannot rule out that this will not happen over larger parts of Norway in the coming years. The even-year strain of pink salmon only occurs in low numbers in Russian rivers, as well as Norwegian, rivers. Adult pink salmon enter the rivers from early July, and spawning occurs in August-September. Spawning habitat requirements are like those of native salmonids: Atlantic salmon, brown trout, and Arctic charr. Spawning of pink salmon occurs earlier than the native salmonids, but observations in 2019 indicate a possible overlap with native salmonids in September in northern Norway. Pink salmon eggs hatch in late winter or spring, and the alevins remain in the gravel until most of the yolk sac has been resorbed. Emerging fry are approximately 30 mm in length. Functionally, they are smolt already at this stage, with a silvery colouration and saltwater tolerance. The fry/smolt start feeding on small invertebrates in some rivers, while the fry/smolt migrate without feeding in other rivers. They impact juveniles of native salmonids through competition for food and space and the invertebrate fauna through predation. The impact depends on the duration of their stay. This is assumed to be very short, but some observations indicate that fry/smolt that emerge from spawning redds far upstream may feed and grow to 60-70 mm before entering the sea. Pink salmon smolt may spend some time in estuaries and coastal waters before moving to the open sea. The next approximately 12 months are spent feeding in the open seas before returning to the coast to seek rivers for spawning. Homing is less precise in pink salmon than in other anadromous salmonids. All spawners die shortly after spawning. Methods This risk assessment is based on an extensive literature search, contact with scientists in North America, western Europe, Russia, Norway, the county governor in Troms and Finnmark, and local anglers’ associations, and other stakeholders in Norway. We have investigated whether ocean temperatures play an important role in the variation of pink salmon year class abundance, and whether the annual abundance of adult pink salmon is increasing with rising sea temperatures. This is an important aspect of a risk assessment in a 50-yr perspective. We have used a semi-quantitative risk assessment. The overall risk is the product of the magnitude of the consequences of the event and the likelihood that the event will occur, as judged by the project group experts. The level of confidence in the risk assessment is described, and uncertainties and data gaps identified. Results The dynamics and environmental impact of introduced pink salmon in Norwegian rivers, coastal waters, and the ocean, depend on their abundance. In all habitats and for all life stages, high abundance may have serious repercussions, whereas low numbers may be of little consequence. An increasing abundance of reproducing pink salmon will likely present hazards to biodiversity and river ecosystems. Establishment of reproducing pink salmon over larger areas in Norway will probably increase the regularity of abundant returns to Norwegian waters. The invertebrate fauna will be negatively affected where large numbers of pink salmon juveniles use it as a food source. This is more likely in long than in short rivers. The river pearl mussel, Margaritifera margaritifera, may be particularly vulnerable, as it has a larval stage in juvenile Atlantic salmon or brown trout, but cannot use pink salmon as a host. Pathogens that may be affected by the increased occurrence of pink salmon in Norway include viruses, bacteria, and parasites (eukaryotic organisms). Very little is known about the susceptibility of pink salmon to viral pathogens. Among 11 viral pathogens assessed, only three or four are known to infect pink salmon. The project group assesses that the potential impact for aquaculture is moderate if infectious haematopoietic necrosis virus is spread by pink salmon in the marine ecosystems. Salmonid alphavirus (SAV)-infected pink salmon, potentially infected through contact with Atlantic salmon aquaculture, moving from south to north could introduce a risk of spread of this virus and the resulting pancreas disease. The project group assesses that the overall potential impact of SAV for aquaculture in the marine ecosystems is low with medium to low confidence. The project group assesses that the potential impacts for aquaculture if Renibacterium salmoninarum and Piscirickettsia salmonis are spread by pink salmon in the marine ecosystems are moderate with low confidence. The potential negative impact on biodiversity in the marine ecosystems and productivity of native salmonid species is assessed as low to minimal for all viral and bacterial pathogens considered, apart from for Renibacterium salmoninarum and viral haemorrhagic septicaemia virus for which the risks were assessed as moderate. Parasites can potentially represent a major hazard to both wild and farmed salmonids, and we have considered three groups of parasites; (1) those that may impact the health and welfare of native salmonids (in the wild and in aquaculture), (2) zoonotic parasites, and (3) aquatic organisms that have a parasitic stage in their life cycle, but are of relevance and interest in Norwegian ecosystems. The abundance and spread of some of these parasites may be affected by the incursion of pink salmon. Hybridization between pink salmon (genus Oncorhynchus) and native salmonids (genera Salmo and Salvelinus) has not been documented in the wild. In the laboratory, intergeneric hybridizations between these species have produced only sterile offspring. Interactions with native salmonids may occur in two ways: through competition for food or through competition for space in the river before spawning and on the spawning grounds. If feeding in the river, pink salmon fry ingest the same prey as native salmonid fry. Thus, competition for food and space may occur if there are high densities of pink salmon for a substantial period. High densities of pink salmon fry may also influence the ability of native salmonid fry to establish territories. On the other hand, emerging pink salmon fry may serve as food for older life stages of native salmonids. Competition for spawning grounds may be restricted due to pink salmon spawning earlier in the autumn. However, there may be temporal overlap between Arctic charr and pink salmon spawning in northern Norway, and a possible overlap in both time and space with early-spawning brown trout. High numbers of pink salmon spawners may have a crowding effect on native salmonids before the actual spawning time. Agonistic behaviour, like chasing of up-migrating Atlantic salmon and brown trout by pink salmon, is known to occur. The effect of this aggressive behaviour on the spawning success of native salmonids is not known. Pink salmon spawners transport organic matter and nutrients from the sea to the rivers. Water quality will be influenced by pink salmon carcasses in rivers after spawning. Decomposition of dead spawners will release organic matter and nutrients (phosphorous and nitrogen) into the water. In nutrient-poor rivers, this will enhance production of algae and zoobenthos, and likely benefit juvenile native salmonids. The impact will likely be negative in more nutrient-rich rivers. Any effect from nutrient input on water quality is likely governed by the number of dead fish, river morphology, and the current nutrient status of the river. Dead and decomposing spawners benefit scavengers of all types and may therefore also affect terrestrial food webs and biodiversity. In the coastal and marine systems, juvenile and adult pink salmon will constitute a new and additional prey for many predators. Pink salmon in the seas may feed on similar prey as native salmonids, and high densities of pink salmon may negatively affect native salmonids as well as the marine ecosystem, as seen in the North Pacific Ocean. Hazards for the aquaculture industry are mainly associated with spreading of disease-causing pathogens. This is directly related to the number of pink salmon in the waters around aquaculture installations. The higher the number of pink salmon, the higher is the probability of individuals carrying pathogens that may be transferred to aquaculture fish. If pink salmon come to dominate the number of salmonids in rivers, this will negatively affect both the economic value of salmon angling, and the value in terms of an important ecosystem service, as catches may be dominated by 1.5 kg fish (that are not fit for human consumption, except early in the season) compared with the larger Atlantic salmon. Under present climatic conditions, pink salmon may spawn and produce offspring in all rivers along the Norwegian coast. Regular occurrence of the odd-year strain has so far only been seen in rivers in eastern Finnmark, where we believe self-sustaining populations have been established. The change from 2017 to 2019 may indicate that the area with rivers receiving high numbers is expanding westwards and southwards into Troms. Establishment of self-sustaining populations depend, in general, on a suffiently high survival of offspring after hatching and when they leave the rivers, and during the marine phase. Abundant returns of pink salmon are correlated with ocean surface temperatures in the North Atlantic Ocean and Barents Sea. Using sea-surface temperature data from 1900 to 2019, we find that the number of pink salmon returning can be relatively well predicted (adjusted R2 > 0.5 for a positive relationship) by sea-surface temperature in the area south of Svalbard and of the cohort size two years previously for all three data sets considered. Hence, the increasing sea surface temperatures and reduced ice cover over the last 20 years may benefit pink salmon in the ocean and be one reason for the increasing number of pink salmon in Northwest Russian and Norwegian waters. However, the average surface temperature of the Arctic Ocean seems to be increasing so rapidly at present that the ecosystem is probably in flux. The effects of this rapid change are unpredictable; however, it is likely that a climate warming over the next 50 years will facilitate the establishment of circumpolar pink salmon populations in Arctic rivers. Whether a warmer climate will benefit pink salmon in all Norwegian rivers remains unclear, as it is considered a cold-water species. However, pink salmon seem to be able to adapt to new conditions over a few generations. Conclusions It has already been demonstrated that pink salmon can occur in large numbers and high densities in Norwegian rivers. The impact of pink salmon on biodiversity and ecosystems in Norwegian waters depends on their numbers. This is valid for all aspects of the river systems. A low number of pink salmon are likely of little consequence, whereas abundant spawning pink salmon in a river may have substantial impact on native salmonids, as well as on water quality and biodiversity. Thousands of spawners will possibly produce millions of offspring that may impact small invertebrates and crustaceans negatively and compete with native salmonids for food and space after hatching. The impact in the sea also depends on the abundance of pink salmon, as they may compete with native salmonids and other species for food as well as have other impacts on the food-web of marine ecosystem. The likelihood of spreading of disease to native wild fish, as well as to aquaculture fish, is also directly correlated with the number of pink salmon. However, only a few fish may have a serious impact if heavily infested with a pathogen to which native wild fish or aquaculture fish are susceptible, and conditions favour transmission. The current increasing trend in sea-surface temperatures and reduced ice cover seem to benefit the survival of pink salmon in the sea, and the projected climate change may enhance this. The impact of a warmer climate on the river stages of pink salmon is less clear. The effects of further climate change may introduce unexpected interactions with pathogens and with other species, as the accelerating change since about 2010 has been moving the Arctic Ocean into previously unobserved temperature regimes. Feasible measures to reduce the impact of pink salmon in rivers include targeted fishing adapted to local conditions. Experience from 2017 and 2019 shows that such efforts are effective and can decrease or even eliminate the threat of pink salmon to native salmonids and biodiversity in individual rivers, at least in smaller rivers. In order to reduce the number of pink salmon and the recurring returns of pink salmon spawners to Norwegian coastal waters and rivers in general, however, concerted action on a regional, national and international level is required.publishedVersio

Assessment of the risk to Norwegian biodiversity and aquaculture from pink salmon (Oncorhynchus gorbuscha). Scientific Opinion of the Panel on Alien Organisms and Trade in Endangered Species of the Norwegian Scientific Committee for Food and Environment

publishedVersio