Akersvatnet. Overvåking av vannkvalitet og toksinproduserende cyanobakterier i 2001

Årsliste 2002Formålet med overvåkningen i 2001 var å undersøke vannkvaliteten (fysisk, kjemisk og biologisk) i Akersvatnet som grunnlag for Vestfold interkommunale vannverk (VIV) til å bedømme den rådende vannkvaliteten til Akersvatnet som reserve-drikkevannskilde for Vestfold. Et annet formål var å kunne gi varsel om fare for masseutvikling av giftproduserende cyanobakterier og skadelige alger som kan medføre praktiske problemer for bruken av Akersvatnet. Rapporten presenterer resultater fra målinger og prøvetaking utført i mars og månedlig i produksjonsperioden (mai-oktober) ved hovedstasjonen i Akersvatnet. Vannkvaliteten i Akersvatnet basert på nitrogen-, fosfor- og klorofyll a-konsentrasjoner vurderes som meget dårlig (tilstandsklasse V) etter SFTs inndeling i vannkvalitetsklasser for trofigrad. Algebiomassen og planteplanktonsammensetningen viser at Akersvatnet er eutrof - hypereutrof. Cyanotoksiner av typen microcystin ble påvist i vannprøver fra juli, august og september. Nivåene var imidlertid lavere enn WHO's anbefalte maksimumsverdi for drikkevann. Hovedproblemet med Akersvatnet som reservevannskilde i 2001 var dermed de store algemengdene i juni - september, som ville kunne ført til problemer for den rensetekniske behandlingen av vannet, samt lukt- og smakpåvirkning ved bruk av vannverket i denne perioden.Vestfold interkommunale vannverk (VIV

High temperature decreases the PIC / POC ratio and increases phosphorus requirements in <i>Coccolithus pelagicus</i> (Haptophyta)

Rising ocean temperatures will likely increase stratification of the water column and reduce nutrient input into the photic zone. This will increase the likelihood of nutrient limitation in marine microalgae, leading to changes in the abundance and composition of phytoplankton communities, which in turn will affect global biogeochemical cycles. Calcifying algae, such as coccolithophores, influence the carbon cycle by fixing CO₂ into particulate organic carbon through photosynthesis (POC production) and into particulate inorganic carbon through calcification (PIC production). As calcification produces a net release of CO₂, the ratio of PIC to POC production determines whether coccolithophores act as a source (high PIC / POC) or a sink (low PIC / POC) of atmospheric CO₂. We studied the effect of phosphorus (P-) limitation and high temperature on the physiology and the PIC / POC ratio of two subspecies of Coccolithus pelagicus. This large and heavily calcified species is a major contributor to calcite export from the photic zone into deep-sea reservoirs. Phosphorus limitation did not influence exponential growth rates in either subspecies, but P-limited cells had significantly lower cellular P-content. One of the subspecies was subjected to a 5 °C temperature increase from 10 °C to 15 °C, which did not affect exponential growth rates either, but nearly doubled cellular P-content under both high and low phosphate availability. This temperature increase reduced the PIC / POC ratio by 40–60%, whereas the PIC / POC ratio did not differ between P-limited and nutrient-replete cultures when the subspecies were grown near their respective isolation temperature. Both P-limitation and elevated temperature significantly increased coccolith malformations. Our results suggest that a temperature increase may intensify P-limitation due to a higher P-requirement to maintain growth and POC production rates, possibly reducing abundances in a warmer ocean. Under such a scenario <i>C. pelagicus</i> may decrease its calcification rate relative to photosynthesis, thus favouring CO₂ sequestration over release. It seems unlikely that P-limitation by itself causes changes in the PIC / POC ratio in this species

Development of a qPCR assay to detect and quantify ichthyotoxic flagellates along the Norwegian coast, and the first Norwegian record of Fibrocapsa japonica (Raphidophyceae)

Blooms of ichthyotoxic microalgae pose a great challenge to the aquaculture industry world-wide, and there is a need for fast and specific methods for their detection and quantification in monitoring programs. In this study, quantitative real-time PCR (qPCR) assays for the detection and enumeration of three ichthyotoxic flagellates: the dinoflagellate Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup and the two raphidophytes Heterosigma akashiwo (Hada) Hada ex Hara & Chihara and Fibrocapsa japonica Toriumi & Takano were developed. Further, a previously published qPCR assay for the dinoflagellate Karlodinium veneficum (Ballantine) Larsen was used. Monthly samples collected for three years (Aug 2009–Jun 2012) in outer Oslofjorden, Norway were analysed, and the results compared with light microscopy cell counts. The results indicate a higher sensitivity and a lower detection limit (down to 1 cell L−1) for both qPCR assays. Qualitative and semi-quantitative results were further compared with those obtained by environmental 454 high throughput sequencing (HTS, metabarcoding) and scanning electron microscopy (SEM) examination from the same samplings. All four species were detected by qPCR and HTS and/or SEM in outer Oslofjorden (Aug 2009–Jun 2012); Karlodinium veneficum was present year-round, whereas Karenia mikimotoi, Heterosigma akashiwo and Fibrocapsa japonica appeared mainly during the autumn in all three years. This is the first observation of Fibrocapsa japonica in Norwegian coastal waters. This species has previously been recorded off the Swedish west coast and German Bight, which may suggest a northward dispersal

Non-tuberculous mycobacteria isolated from slaughter pigs in Mubende district, Uganda

<p>Abstract</p> <p>Background</p> <p>The importance of infections caused by non-tuberculous mycobacteria (NTM) in animals and humans has gained considerable recognition during the past few years. In the developed world, where pig production is extensively practiced, studies on mycobacterial infections and related control strategies have received increasing attention. The infections are reported to be caused by a wide spectrum of NTM. Unfortunately, these infections have been less recognized in sub-Saharan Africa owing to lack of awareness and systematic studies. In this study we aimed at isolating and identifying species of mycobacteria involved in causing infections in slaughter pigs in Mubende district of Uganda. Furthermore we wanted to identify factors associated with infection prevalence in the study area.</p> <p>Methods</p> <p>A total of 363 lymph nodes were collected and cultured for the presence of mycobacteria. Isolates were identified by 16S rDNA gene sequencing. A questionnaire survey was administered to identify production related factors associated with infection prevalence. Data were assembled and analysed using descriptive statistics and mixed effects logistic regression analysis.</p> <p>Results</p> <p>Mycobacteria were detected in 39 % (143/363) of the examined lymph nodes, 63 % (59/93) of lymph nodes with gross lesions typical of mycobacteriosis and 31% (84/270) of lymph nodes with no visible lesions. Nineteen per cent of the isolated mycobacteria were identified as <it>Mycobacterium (M) avium</it>, of these 78% and 22% were <it>M. avium</it> sub sp. <it>Hominissuis</it> and <it>avium</it> respectively. Other mycobacterial species included <it>M. senuense</it> (16%)<it>, M. terrae</it> (7%) and <it>M. asiaticum</it> (6%). This study found free range systems (OR = 3.0; P = 0.034) and use of water from valley dams (OR = 2.0; P = 0.049) as factors associated with high prevalence of mycobacteria in slaughter pigs.</p> <p>Conclusions</p> <p>This study demonstrated a high prevalence of NTM infections among slaughter pigs in Mubende district of Uganda. <it>M. avium</it> was the most prevalent of all NTM isolated and identified. Free range system of pig management and valley dam water were the most significant factors associated with NTM prevalence in Mubende district. These findings could be of a major public health concern given that it is in a predominantly pork consuming population with 18% HIV/AIDS prevalence. Therefore, stringent post-mortem inspection at the slaughter houses is of paramount importance to reduce human exposure.</p

Intracellular Infection of Diverse Diatoms by an Evolutionary Distinct Relative of the Fungi

This is the final version. Available on open access from Elsevier via the DOI in this recordData and Code Availability: All data and code are available with DOI’s given in the methods section. Specifically, physical and chemical parameters of the water column obtained using CTD ocean water sampling are available at http://biomarks.eu/ctd007 (and replicated here at figshare DOI: 10.6084/m9.figshare.9821936). The phylogenetic tree file, masked and unmasked SSU rDNA alignments are available at Zenodo repository: DOI 10.5281/zenodo.2788876. All sequence data used were derived from the NCBI ‘GenBank’ database and accession numbers are provided in Figure. 1B. The R code used to test statistical association in the FISH data are available at Zenodo repository: DOI 10.5281/zenodo.2788876.The Fungi are a diverse kingdom, dominating terrestrial environments and driving important ecologies. Although fungi, and the related Opisthosporidia, interact with photosynthetic organisms on land and in freshwater as parasites, symbionts, and/or saprotrophic degraders, such interactions in the marine environment are poorly understood. One newly identified uncultured marine lineage has been named novel chytrid-like-clade-1 (NCLC1) or basal-clone-group-I. We use ribosomal RNA (rRNA) encoding gene phylogenies to demonstrate that NCLC1 is a distinct branch within the Opisthosporidia (Holomycota). Opisthosporidia are a diverse and largely uncultured group that form a sister branch to the Fungi or, alternatively, the deepest branch within the Fungi, depending on how the boundary to this kingdom is inferred. Using culture-free lineage-specific rRNA-targeted fluorescent in situ hybridization (FISH) microscopy, we demonstrate that NCLC1 cells form intracellular infection of key diatom species, establishing that intracellular colonization of a eukaryotic host is a consistent lifestyle across the Opisthosporidia. NCLC1 infection-associated loss and/or envelopment of the diatom nuclei infers a necrotrophic-pathogenic interaction. Diatoms are one of the most diverse and ecologically important phytoplankton groups, acting as dominant primary producers and driving carbon fixation and storage in many aquatic environments. Our results provide insight into the diversity of microbial eukaryotes that interact with diatoms. We suggest that such interactions can play a key role in diatom associated ecosystem functions, such as the marine carbon pump through necrotrophic-parasitism, facilitating the export of diatoms to the sediment.Agence Nationale de la Recherche (ANR)Genome CanadaDonald Hill Family FellowshipRoyal SocietyBiodivERsAGordon and Betty Moore Foundatio

Comparison of anadromous and landlocked Atlantic salmon genomes reveals signatures of parallel and relaxed selection across the Northern Hemisphere

Most Atlantic salmon (Salmo salarL.) populations follow an anadromous life cycle, spending early life in freshwater, migrating to the sea for feeding, and returning to rivers to spawn. At the end of the last ice age similar to 10,000 years ago, several populations of Atlantic salmon became landlocked. Comparing their genomes to their anadromous counterparts can help identify genetic variation related to either freshwater residency or anadromy. The objective of this study was to identify consistently divergent loci between anadromous and landlocked Atlantic salmon strains throughout their geographical distribution, with the long-term aim of identifying traits relevant for salmon aquaculture, including fresh and seawater growth, omega-3 metabolism, smoltification, and disease resistance. We used a Pool-seq approach (n = 10-40 individuals per population) to sequence the genomes of twelve anadromous and six landlocked Atlantic salmon populations covering a large part of the Northern Hemisphere and conducted a genomewide association study to identify genomic regions having been under different selection pressure in landlocked and anadromous strains. A total of 28 genomic regions were identified and includedcadm1on Chr 13 andppargc1aon Chr 18. Seven of the regions additionally displayed consistently reduced heterozygosity in fish obtained from landlocked populations, including the genes gpr132, cdca4, and sertad2 on Chr 15. We also found 16 regions, includingigf1on Chr 17, which consistently display reduced heterozygosity in the anadromous populations compared to the freshwater populations, indicating relaxed selection on traits associated with anadromy in landlocked salmon. In conclusion, we have identified 37 regions which may harbor genetic variation relevant for improving fish welfare and quality in the salmon farming industry and for understanding life-history traits in fish.Peer reviewe

Endurance exercise training volume is not associated with progression of coronary artery calcification

Background Recent cross‐sectional studies have suggested a dose‐dependent relationship between lifelong exposure to physical activity and the burden of calcified coronary artery disease (CAD). No longitudinal studies have addressed this concern. Hypothesis Exercise volume is associated with progression of coronary artery calcium (CAC), defined as ≥10 units increase in CAC score. Methods Sixty‐one recreational athletes who were assessed by coronary computed tomography angiography (CCTA) as part of the NEEDED 2013/14 study were re‐assessed 4‐5 years later, in 2018. Results Subjects were 45.9 ± 9.6 years old at inclusion, and 46 (74%) were male. Between 2013 and 2018, the participants reported median 5 (range: 0‐20, 25th‐75th percentile: 4‐6) hours of high‐intensity exercise per week. None of the included subjects smoked during follow‐up. At inclusion, 21 (33%) participants had coronary artery calcifications. On follow‐up CCTA in 2018, 15 (25%) subjects had progressive coronary calcification (≥10 Agatston units increase in CAC). These subjects were older (53 ± 9 vs 44 ± 9 years old, P = .002) and had higher levels of low‐density lipoprotein at baseline (3.5 (2.9‐4.3) vs 2.9 (2.3‐3.5) mmol/L, P = .031) as compared to subjects with stable condition. No relationship was found between hours of endurance training per week and progression of coronary artery calcification. In multiple regression analysis, age and baseline CAC were the only significant predictors of progressive CAC. Conclusion No relationship between exercise training volume and the progression of coronary artery calcification was found in this longitudinal study of middle‐aged recreational athletes.publishedVersio

DNA damage and health effects in juvenile haddock exposed to sediment or produced water associated PAHs

Tilstandsundersøkelsene i Nordsjøen har det siste tiår vist gentoksiske effekter (DNA-addukter) i fisk samlet inn i områder med offshore olje- og gassvirksomhet. Kilden og identiteten til de gentoksiske forbindelsene har til nå ikke blitt identifisert. Målsetningen for prosjektet har vært å studere dannelsen av DNA-skade i hyse som utsettes for ulike petrogene eller pyrogene polyaromatiske hydrokarboner (PAH). Målet har vært å identifisere kildene til forurensningen som medfører DNA-addukter observert i hyse fanget rundt oljefeltene i Nordsjøen. Dannelsen av DNA-skade over tid i hyse under kronisk eksponering for PAH og andre oljehydrokarboner fra følgende kilder er blitt studert: Ekstrakter av produsert vann (Statfjord A); destillasjonsfraksjoner av råolje fra Gullfaks (representere oljebasert borevæske); pyrogene PAH. Denne rapporten presenterer resultatene av studiene på DNA addukter i hyse og et utvalg av andre biologiske effektparametre.The Condition Monitoring in the North Sea the last ten years have documented genotoxic effects (DNA adduct) in fish collected in areas with extensive offshore oil and gas activity. However, the source and identity of genotoxic compound has not been identified. The objective of this project has been to study the formation of DNA damage in haddock exposed to petrogenic or pyrogenic polyaromatic hydrocarbons (PAHs) from different sources: Extracts of produced water (Statfjord A); distillation fractions of crude oil from Gullfaks (representing oil based drilling mud); pyrogenic PAH This report presents all the results from the study on DNA adducts and a selection of other biological effect parameters

Loss of stra8 Increases Germ Cell Apoptosis but Is Still Compatible With Sperm Production in Atlantic Salmon (Salmo salar)

Entering meiosis strictly depends on stimulated by retinoic acid 8 (Stra8) gene function in mammals. This gene is missing in a number of fish species, including medaka and zebrafish, but is present in the majority of fishes, including Atlantic salmon. Here, we have examined the effects of removing stra8 on male fertility in Atlantic salmon. As in mammals, stra8 expression was restricted to germ cells in the testis, transcript levels increased during the start of puberty, and decreased when blocking the production of retinoic acid. We targeted the salmon stra8 gene with two gRNAs one of these were highly effective and produced numerous mutations in stra8, which led to a loss of wild-type (WT) stra8 expression in F0 salmon testis. In maturing stra8 crispants, the spermatogenetic tubuli were partially disorganized and displayed a sevenfold increase in germ cell apoptosis, in particular among type B spermatogonia and spermatocytes. The production of spermatogenic cysts, on the other hand, increased in maturing stra8 crispants. Gene expression analysis revealed unchanged (lin28a, ret) or reduced levels (egr1, dusp4) of transcripts associated with undifferentiated spermatogonia. Decreased expression was recorded for some genes expressed in differentiating spermatogonia including dmrt1 and ccnd2 or in spermatocytes, such as ccna1. Different from Stra8-deficient mammals, a large number of germ cells completed spermatogenesis, sperm was produced and fertilization rates were similar in WT and crispant males. While loss of stra8 increased germ cell apoptosis during salmon spermatogenesis, crispants compensated this cell loss by an elevated production of spermatogenic cysts, and were able to produce functional sperm. It appears that also in a fish species with a stra8 gene in the genome, the critical relevance this gene has attained for mammalian spermatogenesis is not yet given, although detrimental effects of the loss of stra8 were clearly visible during maturation.publishedVersio

Field testing for toxic algae with a microarray: initial results from the MIDTAL project

One of the key tasks in the project MIDTAL (MIcroarrays for the Detection of Toxic ALgae) is to demonstrate the applicability of microarrays to monitor harmful algae across a broad range of ecological niches and toxic species responsible for harmful algal events. Water samples are collected from a series of sites used in national phytoplankton and biotoxin monitoring programmes across Europe. The samples are filtered; the rRNA is extracted, labelled with a fluorescent dye and applied to a microarray chip. The signal intensity from >120 probes previously spotted on the chip is measured and analysed. Preliminary results comparing microarray signal intensities with actual field counts are presented