Differences in Gene Expression Profiles of Seven Target Proteins in Third-Stage Larvae of Anisakis simplex (Sensu Stricto) by Sites of Infection in Blue Whiting (Micromesistius poutassou)

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A step towards high resolution modeling of the central Faroe shelf circulation by FarCoast800

This paper describes the FarCoast800 model setup for the Faroe shelf and the validation towards observations. We found that the circulation was in accordance with observations on the shelf and the upper 500m of the water column, away from the lateral boundaries. Furthermore, we found high correlations between the model and observations for the on-shelf water, in particular for short-term variations of temperature, demonstrating the importance of high resolution atmospheric forcing. A main challenge for this study was the lateral boundary conditions at all four open boundaries in the varying and steep bathymetry of the FarCoast800 model setup. We also investigated the origin of water reaching the different areas of the shelf. Notably our results indicated intrusion of water originating from the East Icelandic Current into the deeper areas on the eastern part of the Faroe shelf. Our long term motivation of the study was to investigate the capability of the model to drive an even higher resolution ROMS model setup for the central Faroe shelf, enabling the resolution of processes on a 100m scale or less. The study concludes that FarCoast800 can drive a high-resolution nested model area on the Faroe shelf. Here we present a Regional Ocean Model System (ROMS) model setup for the Faroe shelf with a horizontal resolution of 800m x 800m and 35 vertical layers. The model setup is forced by a high resolution atmospheric model, and forced by a 4km x 4km horizontal resolution version of the ROMS model on the lateral boundaries. We name our model setup FarCoast800. The model setup was run for the entire sample year 2013.publishedVersio

Differences in gene expression profiles of seven target proteins in third-stage larvae of anisakis simplex (Sensu stricto) by sites of infection in blue whiting (micromesistius poutassou)

The third-stage larvae of the parasitic nematode genus Anisakis tend to encapsulate in different tissues including the musculature of fish. Host tissue penetration and degradation involve both mechanic processes and the production of proteins encoded by an array of genes. Investigating larval gene profiles during the fish infection has relevance in understanding biological traits in the parasite’s adaptive ability to cope with the fish hosts’ defense responses. The present study aimed to investigate the gene expression levels of some proteins in L3 of A. simplex (s.s.) infecting different tissues of blue whiting Micromesistius poutassou, a common fish host of the parasite in the NE Atlantic. The following genes encoding for Anisakis spp. proteins were studied: Kunitz-type trypsin inhibitor (TI), hemoglobin (hb), glycoprotein (GP), trehalase (treh), zinc metallopeptidase 13 (nas 13), ubiquitin-protein ligase (hyd) and sideroflexin 2 (sfxn 2). Significant differences in gene transcripts (by quantitative real-time PCR, qPCR) were observed in larvae located in various tissues of the fish host, with respect to the control. ANOVA analysis showed that relative gene expression levels of the seven target genes in the larvae are linked to the infection site in the fish host. Genes encoding some of the target proteins seem to be involved in the host tissue migration and survival of the parasite in the hostile target tissues of the fish host

A tidally driven fjord-like strait close to an amphidromic region

The strait studied in this paper, “Sundalagið Norður”, is the northern part of a narrow body of seawater separating the two largest islands in the Faroe Islands (Faroes). It has shallow sills in both ends and considerably deeper waters in between. South of the southern end of the strait there is an amphidromic region for the semidiurnal tides so that the tidal range is much lower south of the strait than north of it. The resulting tidal forcing generates periodically varying inflow of seawater across the northern sill, but only a part of that manages to cross the narrow and shallow southern sill. Combined with a large input of freshwater, this gives the strait a fjord-like character. To investigate how this fjord-like character affects the circulation within the strait and its exchanges with outside waters, a pilot project was initiated to simulate the dynamics of the strait with a high-resolution ocean model for a month. The model simulations show clearly the dominance of tidal forcing over freshwater (estuarine) and wind on timescales up to a day. On longer timescales, the simulations indicate systematic variations in the net flows (averaged over a diurnal tidal period) through both the upper and deeper layers. These long-period variations of net flow in the model simulations are forced by sea level differences between both ends of the strait generated by the dominant fortnightly and monthly tidal constituents (Mf, MSf, Mm, MSm). Harmonic analysis of sea level records from two tide gauges located off each end of the strait demonstrates that this behaviour is not a model artefact and it has pronounced effects on the strait. Not only does it induce long-period (mainly fortnightly) variations in the net flow through the strait, but it also generates variations in the estuarine characteristics. According to the model simulations, periods with net southward flow, typically lasting a week, have a strait-like character with net southward flow almost everywhere. Periods with net northward flow, in contrast, have a more fjord-like character with stronger salinity stratification and a southward counter-flow in the deep layer. This also induces a large difference in renewal rate of the deep water between the two periods, which is important to consider for human utilization of the strait, especially the local aquaculture plant. The combination of topographic, freshwater, and tidal characteristics creating these long-period variations is rather unusual, and it is not known whether similar systems exist elsewhere, but the long-period variations tend to be masked by the stronger semidiurnal and diurnal variations and may easily be overlooked.publishedVersio

Mellem Laks, Lus og Putin. Om erhvervsøkonomisk succes, storpolitik og bæredygtighed

På trods af at være et lille perifert øsamfund i Nordatlanten med en ganske lille befolkning, så har Færøerne formået at udvikle en industriel sektor, der opretholder høje standarder og er internationalt konkurrencedygtig. Udviklingen af den færøske lakseindustri til en af verdens absolut førende eksemplificerer, hvordan småstater kan udnytte lokale ressourcer og viden til stor lokal værdiskabelse, og hvordan små ø-jurisdiktioner kan manøvrere storpolitisk for at positionere sig gunstigt på det globale marked. Artiklen belyser, hvordan den færøske lakseindustri er forankret i en meget lokal kontekst, og diskuterer udviklingen af den færøske lakseindustri i et storpolitisk og bæredygtighedsperspektiv

Differential gene expression during early development in recently evolved and sympatric Arctic charr morphs

Phenotypic differences between closely related taxa or populations can arise through genetic variation or be environmentally induced, leading to altered transcription of genes during development. Comparative developmental studies of closely related species or variable populations within species can help to elucidate the molecular mechanisms related to evolutionary divergence and speciation. Studies of Arctic charr (Salvelinus alpinus) and related salmonids have revealed considerable phenotypic variation among populations and in Arctic charr many cases of extensive variation within lakes (resource polymorphism) have been recorded. One example is the four Arctic charr morphs in the ∼10,000 year old Lake Thingvallavatn, which differ in numerous morphological and life history traits. We set out to investigate the molecular and developmental roots of this polymorphism by studying gene expression in embryos of three of the morphs reared in a common garden set-up. We performed RNA-sequencing, de-novo transcriptome assembly and compared gene expression among morphs during an important timeframe in early development, i.e., preceding the formation of key trophic structures. Expectedly, developmental time was the predominant explanatory variable. As the data were affected by some form of RNA-degradation even though all samples passed quality control testing, an estimate of 3′-bias was the second most common explanatory variable. Importantly, morph, both as an independent variable and as interaction with developmental time, affected the expression of numerous transcripts. Transcripts with morph effect, separated the three morphs at the expression level, with the two benthic morphs being more similar. However, Gene Ontology analyses did not reveal clear functional enrichment of transcripts between groups. Verification via qPCR confirmed differential expression of several genes between the morphs, including regulatory genes such as AT-Rich Interaction Domain 4A (arid4a) and translin (tsn). The data are consistent with a scenario where genetic divergence has contributed to differential expression of multiple genes and systems during early development of these sympatric Arctic charr morphs.he project was funded by The Icelandic Center for Research (grant number: 100204011) to Sigurður S. Snorrason, Arnar Pálsson, Zophonías O. Jónsson and Bjarni K. Kristjánsson. The University of Iceland Doctoral Fund to Jóhannes Guðbrandsson and University of Iceland research fund to Arnar Pálsson, Sigurður S. Snorrason and Zophonías O. Jónsson. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer Reviewe

Scarce abundance : a critical analysis of Iceland’s renewable energy sector in times of growth’s cultural hegemony

Renewable energy is increasingly gaining currency as a sustainable substitute for fossil fuels. Iceland has been framed as one of the world’s renewable energy success cases and the country’s renewable energy production has multiplied in recent decades. This thesis approaches Iceland’s renewable energy sector from a critical perspective. It investigates the dominant discourse around the expansion of the energy sector in Iceland and its social and environmental consequences. The investigation was carried out by applying Hajer’s argumentative discourse analysis. Empirical material was qualitatively collected through conducting 17 semi-structured interviews and analysing publicly available text-documents, radio and TV broadcasts. Quantitative data were gathered through a questionnaire and by reviewing official statistics. The material was analysed in light of Gramsci’s concept of cultural hegemony. Additional concepts were employed to critically highlight flaws in the dominant discourse. These concepts are: Ecological modernisation, carbon fetishism and depoliticization. The results show that a) the dominant discourse promotes an expansion of the energy sector at the expense of Icelandic nature, b) it does so – among other things – by contrasting capitalism's notion of scarcity with the notion of abundance attributed to Iceland's natural resources, c) the dominant discourse is heavily influenced by ecological modernisation (EM) and uncritically adopts its rationale and also its shortcomings, and d) the dominant discourse preserves its hegemonic status despite its inherent contradictions and negative side-effects by attempting to conceal conflicts over resource utilisation and by marginalising critical views. Despite the full adoption of EM as guiding principle for the expansion of the energy sector Iceland has not experienced the fulfilment of the promises that come with EM. In other words, a reconciliation of environment and economy has not taken place as is demonstrated by Iceland's growing CO2 emissions and environmental degradation while companies in the energy sector experience ongoing financial difficulties. This thesis concluded that environmental politics cannot be reduced to argumentative struggles, as Hajer suggests. Alternative discourses can only gain ground if the cultural hegemony of the dominant discourse is met with resistance on all levels of social life; in thoughts, norms and beliefs

The impact of damming on riverine fluxes to the ocean: A case study from Eastern Iceland

Anthropogenic water management has extensively altered the world's river systems through impoundments and channel diversions to meet the human's need for water, energy and transportation. To illuminate the effect of such activities on the environment, this study describes the impact of the installation of the Kárahnjúkar Dam in Eastern Iceland on the transport of riverine dissolved- and particulate material to the ocean by the Jökulsá á Dal and the Lagarfljót rivers. This dam, completed in 2007, collects water into the 2.2 km3 Hálslón reservoir and diverts water from the glacial Jökulsá á Dal river into the partially glaciated Lagarfljót lagoon via a headrace tunnel. The impact of the damming was evaluated by sampling water from both the Jökulsá á Dal and the Lagarfljót rivers over a 15 year period spanning from 1998 to 2013. The annual flux of most dissolved elements increased substantially due to the damming. The fluxes of dissolved Zn, Al, Co, Ti and Fe increased most by damming; these fluxes increased by 46–391%. These differences can be attributed to changed saturation states of common secondary minerals in the Jökulsá á Dal due to reduced discharge, increased residence time and dissolution of suspended material, and, to a lesser degree, reduced photosynthesis due to less transparency in the Lagarfljót lagoon. The removal of particulate material and thus decreasing adsorption potential in the Jökulsá á Dal is the likely reason for the Fe flux increase. In contrast, approximately 85% of the original riverine transported mass of particulate material is trapped by the dam; that which passes tends to be relatively fine grained, increasing the average specific surface area of that which continues to flow towards the ocean. Consequently, the particulate geometric surface area flux is decreased by only 50% due to the damming. The blooming of silica diatoms during the spring consumes dissolved silica from the coastal waters until it becomes depleted; making the riverine spring dissolved silica flux an important source of this nutrient. Despite extensive riverine flux changes due to the Kárahnjúkar dam construction, the total spring dissolved silica flux increased, and thus so too the potential for a silica diatom spring bloom in the coastal waters. This is likely because the spring flux is dominated by snow melting downstream of the dam