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Validation of a Liquid–Liquid Extraction Method to Study the Temporal Production of D-Series Resolvins by Head Kidney Cells from Atlantic Salmon (Salmon salar) Exposed to Docosahexaenoic Acid
Get PDFA simple and rapid method for the extraction of D-series resolvins (RvD1, RvD2, RvD3, RvD4, RvD5) released into Leibovitz’s L-15 complete medium by head kidney cells from Atlantic salmon and the further determination of liquid chromatography triple quadrupole mass spectrometry is proposed. A three-level factorial design was proposed to select the optimal concentrations of internal standards that were used in the evaluation of the performance parameters, such as linear range (0.1–50 ng mL−1), limits of detection and quantification (0.05 and 0.1 ng mL−1, respectively), and recovery values ranging from 96.9 to 99.8%. The optimized method was used to determine the stimulated production of resolvins by head kidney cells exposed to docosahexaenoic acid, and the results indicated that it is possible that the production was controlled by circadian responses.publishedVersio
Is there a generational shift in preferences for forest carbon sequestration vs. preservation of agricultural landscapes?
Get PDFAfforestation is considered an important measure for climate change mitigation. As land area that can be used for tree planting serves multiple purposes, it is vital to strike the right balance between climate and other objectives. We conducted a national survey in Norway to infer potential land use conflicts that may arise from executing a large-scale afforestation program. Citizens were presented three land use alternatives to replace formerly grazed agriculture land. We used manipulated landscape photos to illustrate policy impacts to the respondents and employed a combination of multiple correspondence analysis and a latent class regression model to reveal preference heterogeneity. Respondents cluster into three latent classes according to their value orientation, where approximately 20%, 40% and 40% citizens perceive forest carbon sequestration, agriculture, and recreation, respectively, as the most important land use functions to retain. Birth cohort is a strong predictor of the class membership: there is a stark generational difference between the baby boomers (born before 1960) and the generations born after 1980, with the baby boomers overwhelmingly supporting the continuation of agricultural landscapes. However, every ten-year reduction in respondent age increases the odds of a respondent belonging to the recreation- or forestation-preferring class (relative to the agriculture class) by factors of 1.9 and 1.4, respectively. Natural forests were perceived more favorably than mono-culture spruce plantation even among the respondents classified as the most climate concerned.publishedVersio
Population structure discovered in juveniles of Greenland halibut (Reinhardtius hippoglossoides Walbaum, 1792)
Get PDFUnderstanding the genetic differentiation among populations of most marine fish requires investigating the differences among spawning grounds. However, this can be challenging as spawning grounds for some species are not well known, or spawning fish are difficult to collect. An alternative is to collect juvenile fish in nursery habitats closely associated with potential spawning grounds. Greenland halibut is a deep-dwelling, commercially important species with at least two identified major offshore spawning grounds in the North Atlantic and weak genetic differentiation across the Atlantic. In this study, we sampled juveniles from three sites representing the Davis Strait spawning area in the northwest Atlantic and one site in the northeast Atlantic representing the primary spawning area along the western slope of the Barents Sea. We applied genotype by sequencing and discovered 90 genetic markers that could be used to assess genetic differentiation among the four sites. The northeast and northwest Atlantic showed major genetic differentiation, supporting the existence of the two primary spawning clusters. Additionally, we found genetic differentiation between the three northwest Atlantic samples implying the existence of more than one spawning area in the northwest.publishedVersio
Building leaders for the UN Ocean Science Decade: a guide to supporting early career women researchers within academic marine research institutions
Get PDFDiverse and inclusive marine research is paramount to addressing ocean sustainability challenges in the 21st century, as envisioned by the UN Decade of Ocean Science for Sustainable Development. Despite increasing efforts to diversify ocean science, women continue to face barriers at various stages of their career, which inhibits their progression to leadership within academic institutions. In this perspective, we draw on the collective experiences of thirty-four global women leaders, bolstered by a narrative review, to identify practical strategies and actions that will help empower early career women researchers to become the leaders of tomorrow. We propose five strategies: (i) create a more inclusive culture, (ii) ensure early and equitable career development opportunities for women ECRs, (iii) ensure equitable access to funding for women ECRs, (iv) offer mentoring opportunities and, (v) create flexible, family-friendly environments. Transformational, meaningful, and lasting change will only be achieved through commitment and collaborative action across various scales and by multiple stakeholders.publishedVersio
Assessing the viability of estimating baleen whale abundance from tourist vessels
Get PDFMany populations of southern hemisphere baleen whales are recovering and are again becoming dominant consumers in the Southern Ocean. Key to understanding the present and future role of baleen whales in Southern Ocean ecosystems is determining their abundance on foraging grounds. Distance sampling is the standard method for estimating baleen whale abundance but requires specific logistic requirements which are rarely achieved in the remote Southern Ocean. We explore the potential use of tourist vessel-based sampling as a cost-effective solution for conducting distance sampling surveys for baleen whales in the Southern Ocean. We used a dataset of tourist vessel locations from the southwest Atlantic sector of the Southern Ocean and published knowledge from Southern Ocean sighting surveys to determine the number of tourist vessel voyages required for robust abundance estimates. Second, we simulated the abundance and distributions of four baleen whale species for the study area and sampled them with both standardized line transect surveys and non-standardized tourist vessel-based surveys, then compared modeled abundance and distributions from each survey to the original simulation. For the southwest Atlantic, we show that 12-22 tourist vessel voyages are likely required to estimate abundance for humpback and fin whales, with relative estimates for blue, sei, Antarctic minke, and southern right whales. Second, we show tourist vessel-based surveys outperformed standardized line transect surveys at reproducing simulated baleen whale abundances and distribution. These analyses suggest tourist vessel-based surveys are a viable method for estimating baleen whale abundance in remote regions. For the southwest Atlantic, the relatively cost-effective nature of tourist vessel-based survey and regularity of tourist vessel voyages could allow for annual and intra-annual estimates of abundance, a fundamental improvement on current methods, which may capture spatiotemporal trends in baleen whale movements on forging grounds. Comparative modeling of sampling methods provided insights into the behavior of general additive model-based abundance modeling, contributing to the development of detailed guidelines of best practices for these approaches. Through successful engagement with tourist company partners, this method has the potential to characterize abundance across a variety of marine species and spaces globally, and deliver high-quality scientific outcomes relevant to management organizations.publishedVersio
Program for fremmedstoffer i fôrmidler av fisk - Rapport for prøver innsamlet i 2022
Get PDFMattilsynet er oppdragsgiver for dette overvåkningsprogrammet, som har som formål å undersøke innholdet av fremmedstoffer i fôrmidler av fisk, og som gjennomføres ved Havforskningsinstituttet. Overvåkingsprogrammet supplerer «Program for overvåking av fiskefôr» med data på uønskede stoffer i fôrmidler av fisk som er produsert i Norge og tatt ut på produksjonsvirksomhetene. I 2022 ble 20 prøver analysert: 9 prøver av fiskeolje og 11 prøver av fiskemel. Fremmedstoffene som det ble analysert for i 2022 var dioksiner og furaner (PCDD/F), dioksinlignende PCB (dl-PCB), PCB6 (ndl-PCB), polybromerte diphenyleter (PBDE), perfluorerte forbindelser (PFAS) og klorerte pesticider (dieldrin/aldrin, DDT, toksafen, klordan, endosulfan, sum heptaklor, sum HCH og HCB). Fiskemel ble i tillegg analysert for metaller (kvikksølv, bly, kadmium og arsen), syntetiske antioksidanter (ethoxyquin, ethoxyquin dimer, BHA og BHT), prosesserte animalske proteiner (PAP), vitamin E og Salmonella. Resultatene viste at konsentrasjonene av alle organiske miljøgifter i fiskemel og fiskeolje var lave. Ingen av fiskemelene eller fiskeoljene hadde konsentrasjoner av PCDD/PCDF («sum dioksiner»), PCDD/PCDF + dl-PCB («sum dioksiner og dioksinlignende PCB» eller PCB6 over de øvre grenseverdiene. Resultatene for 2022 viste lave nivå av metaller i fiskemel, og ingen overskridelser av grenseverdiene for arsen, kvikksølv, kadmium eller bly. Det ble ikke påvist salmonella, PAP, ethoxyquin eller ethoxyquin dimer i noen av prøvene analysert i 2022. Generelt var nivåene av uønskede stoffer i fôrmidler av fisk analysert i 2022 sammenlignbare med resultatene fra tidligere års undersøkelser.Program for fremmedstoffer i fôrmidler av fisk - Rapport for prøver innsamlet i 2022publishedVersio
Remote acoustic sizing of tethered fish using broadband acoustics
Get PDFRemote fish sizing is desirable in fisheries (e.g., pre-catch) and research (e.g., platforms without biological sampling capacity) applications. In those contexts, the high spatial resolution of pulse compressed broadband echoes combined with narrow beamwidth transducers makes it feasible to resolve the scattering from different parts of the fish body and hence can be used to measure the body size. A motorized apparatus was used to suspend individual fish in the acoustic beam of two laterally oriented transducers (45–90 kHz, 160–260 kHz, 12.2 m range) with precise control of rotation angle. Broadband scattering was measured from tethered Atlantic mackerel (Scomber scombrus), saithe (Pollachius virens), and pollack (Pollachius pollachius) ranging in standard length from 239 to 491 mm as a function of orientation angle to validate sizing based on the acoustic resolution of fish body parts. Under these controlled conditions, fish size was underestimated by 11–19 mm, varying with broadband pulse characteristics, orientation angle, species, and fish size. The best remote acoustic sizing results were obtained using 160–260 kHz pulses with a slow rise and fall of pulse amplitude (aka, taper).publishedVersio
Rømt og vill fisk i Etneelva 2022 - Resultat frå den nasjonale forskingsplattforma i Etne
Get PDFI 2022 vart fiskefella i Etneelva sett i drift 19. april og registreringa pågjekk til 12. november. Det var noko redusert fangseffektivitet i løpet av sesongen pga høg vassføring. I tilsaman 12 driftsdøgn (6% av driftstida) var fangsten i fella redusert pga mykje vatn. Tilsvarande reduksjon i fangsteffektivitet hadde vi også i 2021 (9%), 2020 (5%) og 2019 (5%). Fyrste villaks blei registrert i veke 17 og fyrste rømling i veke 24. I alt vart 4063 fiskar handtert på fella i 2022, mot 3746 i 2021, 5093 i 2020 og 2693 i 2019. Av dei registrerte fiskane var 2042 villaks,1916 sjøaure, 51 forskingsfisk, 1 pukkellaks og 53 rømte laks. I 2022 hadde 50% av villaksen vandra opp pr. veke 28, fire veker tidlegare enn rømlingane. Som tidlegare år dominerte storlaksen tidleg i oppvandringa medan terten dominerte i slutten av oppvandringsforløpet. For rømlingane registrert på fella varierte storleiken frå 0,85 kg til 9,2 kg, med ei overvekt av individ på 3,0 til 4,0 kg. Skjellkontrollen stadfesta oppdrettsbakgrunn til alle dei registrerte oppdrettslaksane. Av dei 53 registrerte rømlingane på fella, var 47% kjønnsmodne og 49% umodne. Gjennom uttaksfisket om hausten nedstraums fella i sone 1 og 2, vart det fanga 33 oppdrettslaksar. Av dei vart 3 (9%) klassifisert som modne, 25 (76%) vart klassifisert som umodne og 5 (15%) vart ikkje modningsbestemt. Frå sportsfisket blei det rapportert inn 17 oppdrettslaksar nedstraums fella, og ein regnbogeaure oppstraums. Av dei 17 rapporterte rømlingane nedstraums, vart seks verifisert ved skjellkontroll. For dei 11 andre vart det ikkje teke skjellprøve. Det vart heller ikkje teke skjellprøve frå regnbogeauren fanga oppstraums fella, men det vart lagt ved eit foto ved rapporteringa som stadfesta at dette var ein rømling. I dei resterande skjellprøvane frå sportsfisket nedstraums fella, blei det ikkje oppdaga fleire rømlingar. I skjellmaterialet av villaks teke i fiskefella er det heller ikkje funne fleire rømlingar. Basert på registreringane i fiskefella og rapporteringar av sportsfisket i Elveguiden, er andel rømt fisk i 2022 redusert frå 2,5 % til <0,1 %. Rundt 10 personar var i større eller mindre grad engasjert på fella og Havforskingsinstituttet sitt budsjett for drifta var ca 4 mill kroner med tillegg på 0,5 mill kroner frå OURO.Rømt og vill fisk i Etneelva 2022 - Resultat frå den nasjonale forskingsplattforma i EtnepublishedVersio
A genetic cline shapes population structure of the round sardinella along its West African distribution
No full textSmall pelagic fishes play an important role in human-food security and marine food webs relationships. Among them, the round sardinella Sardinella aurita is an extremely valuable fish resource in West Africa. A suite of twelve microsatellite loci was developed ad hoc for this species using ddRADseq technology, and genotyped on some 1,300 individuals collected in the coastal area spanning from Morocco to Angola. The significant differentiation detected between the northernmost samples (from Morocco to Guinea) and the southernmost ones (from Liberia to Angola) was due to one single locus, which was strong and consistently flagged as a candidate outlier to positive selection, thus suggesting that local adaptation might be one of the drivers of the observed pattern. Furthermore, the signal due to this locus resided uniquely in the frequency of allele SauMS002_131, which displayed a remarkable latitudinal cline with the centre situated in the coastal waters off Sierra Leone. This allele frequency, starting around 47-63% in Morocco-Guinea and dropping to 0% in Gabon and southwards, accounts for the aforementioned North-South declining trend, and can be used as a meaningful tool to assist the outline of the population structure for this species in the West coast of Africa for management purposes.The information deposited here consists of two excel files:
1. Sardinella aurita_Microsatellites.xlsx. A set of twelve microsatellites was isolated for Sardinella aurita through the analysis of ddRADsequencing fragments. Markers were developed ad hoc using individuals from Morocco, Gabon and Angola. The file contains two spreadsheets.
a. Optimized microsatellites: Refers to the twelve microsatellites genotyped in the current study. Detailed information about forward and reverse primers, annealing temperature, MgCl2 concentration and arrangement in multiplex reactions is provided.
b. Sequences for microsatellites: Consists of 49 sequences containing motif repeats that would allow the eventual isolation of some extra markers.
2. Sardinella aurita_Genotypes.xlsx: Genotypic data obtained from the mentioned twelve microsatellite loci, which were genotyped on 1294 individuals sampled along the NW coast of Africa, from Morocco to Angola. Individuals were collected by trawl onboard the R.V. “Dr. Fridtjof Nansen”.
a. Geographic & genetic information: Contains: ID, sampling year, survey code, sampling station with geographic coordinates, name of the sample, country it belongs to, and genotypic information at 12 microsatellites per individual.
b. GenAlEx_Format: File ready for exportation into different formats
Is there a limit to the potential effects of shortening lastridge ropes on the size selectivity of diamond mesh codends?
Get PDFShortening codend lastridge ropes can be an effective fishing gear modification to improve the size selection properties in diamond mesh codends. Lastridge ropes attached to codend selvedges withstand the longitudinal forces created by the catch building up and therefore, prevent the codend meshes from closing. However, the extent to which the lastridge ropes should be shortened to maximize the effect of this measure is unclear. Besides opening codend meshes, shortening lastridge ropes can also lead to net folding, which can potentially have negative consequences for size selectivity. In the present study, we tested the size selective properties of a 129 mm diamond mesh codend in three different configurations: 0 %, 15 % and 30 % shortened lastridge ropes. Selectivity data were collected for cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and redfish (Sebastes spp.) in the Barents Sea gadoid bottom trawl fishery. Shortening the lastridge ropes by 15 % had a significant effect on the release efficiency of haddock between 35 and 50 cm, whereas to obtain a similar result for cod, the lastridge ropes had to be shortened by 30 %. However, the use of shortened lastridge ropes significantly increased the retention of fish below 35 cm for both species, especially when the lastridge ropes were shortened from 15 % to 30 %. The effect on redfish size selectivity was in general limited. Exploitation pattern indicators showed that there was no added benefit from shortening them further from 15 % to 30 % for any of the three species. This study concludes that, while shortening lastridge ropes can contribute to improved size selection of diamond mesh codends, reducing them beyond 15 % is not recommended because it can substantially increase the retention of undersized fish, probably due to net folding.publishedVersio