Due to the extremely high affinity of selenium (Se) mercury (Hg), Se sequesters Hg and reduces its biological availability in organisms. However converse is also true. Se, causing inhibit formation dependent enzymes while supplemental supports their continued synthesis. Hence, whether or not toxic effects accompany exposure depends upon tissue Se:Hg molar ratio organism. The main objective present study was investigate how levels affected metallothionein (MT) induction free-ranging brown...

Abstract Mercury (Hg) is a toxic element that enters the biosphere from natural and anthropogenic sources, emitted gaseous Hg Arctic lower latitudes by long‐range transport. In aquatic systems, anoxic conditions favor bacterial transformation of inorganic to methylmercury (MeHg), which has greater potential for bioaccumulation than most form Hg. The main objective present study was quantify biomagnification MeHg in marine pelagic food web, comprising species zooplankton, fish, seabirds,...

Seasonal dynamics can vastly influence the natural depletion of oil spilled into ocean and Arctic regions are characterized by large seasonal changes, especially in temperature daylight. To determine influences variation on processes like dissolution, photooxidation biodegradation, we deployed thin films three oils seawater during summer winter Svalbard, Norway. The extent varied with season type oil, however, considerable n-alkanes polycyclic aromatic compounds were observed both winter....

AbstractThe objectives of this study were to (1) determine the acute toxicity selected shoreline washing agents (SWA) and dispersants, (2) assess interspecies differences in sensitivity products. Eight (Hela saneringsvæske, Bios, Bioversal, Absorrep K212, Corexit 9580) chemical dispersants (Corexit 9500, Dasic NS, Gamlen OD4000) tested on five marine species, algae Skeletonema costatum, planktonic copepod species Acartia tonsa (temperate species), Calanus finmarchicus (boreal species)...

During accidental crude oil spills and permitted discharges of produced water into the marine environment, a large fraction naturally occurring components will be contained in micron-sized droplets. Toxicity is assumed to associated with dissolved components, however potential contribution droplets toxicity currently not well known. In present work we wanted evaluate effects on normal development Atlantic cod (Gadus morhua) through exposing embryos for 96 h un-filtered (dispersions...

Conflicting reports on the contribution of chemical dispersants crude oil dispersion toxicity have been published. This can partly be ascribed to influence physical properties in different experimental conditions. In present study potential reproductive effects dispersed marine copepod Calanus finmarchicus (Gunnerus) was isolated by keeping concentrations and droplet size distributions comparable between parallel chemically (CD, dispersant:oil ratio 1:25) mechanically (MD, no dispersant)...

Abstract The rates of ingestion oil microdroplets and fouling were investigated in the zooplankton filter‐feeder Calanus finmarchicus (Gunnerus, 1770) at 3 concentrations dispersions ranging from 0.25 mg/L to 5.6 mg/L. To compare responses mechanically chemically dispersed oil, copepods exposed comparable micron‐sized droplets made with without use a chemical dispersant (similar droplet size range concentrations) together constant supply microalgae for period 4 d. filtration as well...

The risk of accidental oil spills in the Arctic is on rise due to increased shipping and exploration activities, making it essential calibrate parameters for assessment conditions. toxicokinetics crude components were assessed by exposing one lipid-poor (CIII) lipid-rich (CV) stage copepod Calanus hyperboreus WSF (water-soluble fraction). Water concentrations total body residues (BR), as well lipid volume fractions, measured at regular intervals during exposure recovery. Bioconcentration...

Although pharmaceuticals are increasingly detected in abiotic matrices the Arctic, accumulation of drugs resident biota and trophic transfer have not been yet examined. This study investigated behaviour several rocky-bottom, macrobenthic food web coastal zone Isfjorden (western Spitsbergen) using stable isotope analyses (SIA) coupled with liquid chromatography-mass spectrometry (LC-MS/MS). Across 16 macroalgal invertebrate species highest average concentration was measured for ciprofloxacin...

Copepods of the genus Calanus have potential for accumulating lipophilic oil components due to their high lipid content and found filter ingest droplets during exposure. As female copepods produce eggs at expense storage, there is a concern transfer contaminants offspring. To assess maternal components, ovigerous (Calanus finmarchicus) were exposed filtered unfiltered dispersions 4 days, collected maintained in clean seawater hatching gene expression examined hatched nauplii. Oil droplet...

In this investigation, acute toxicity data were used from two previously reported studies where cold-water copepods exposed to mechanically dispersed (MD) and chemically (CD) oil. one of these studies, concentration-dependent mortality was observed, whereas no apparent relationship between exposure concentration found in the other. The only marked difference is that first experiment displayed a lower lipid sac volume (on average) than second one. study additional biometric on content...

Abstract Fluxes of carbon dioxide (CO 2 ) and methane (CH 4 from hydroelectric water supply reservoirs are receiving increasing attention around the world with a number research groups having undertaken measurements these emissions across range lakes located in different climates landscapes. The use floating chambers (aka flux chambers) is most common technique for direct measurement fluxes. However, relative performance systems, especially chamber designs, not well documented. We report...

The impact of oil microdroplets on the partitioning polycyclic aromatic hydrocarbons (PAHs) between water and marine zooplankton was evaluated. experimental approach allowed direct comparison crude dispersions (containing both micro-oil droplets water-soluble fraction; WSF) with corresponding WSF (without droplets). Dispersion concentration type have an PAH composition WSFs therefore affect dispersion bioavailability. Higher T-PAH body residues were observed in copepods treated compared to...

Although increasing, there is still limited knowledge of the presence 'contaminants emerging concern' in Arctic marine biota, particularly lower trophic species. In present study, we have applied a novel pipeline to investigate contaminants variety benthic and pelagic low-trophic organisms: amphipods, copepods, arrow worms krill. Samples collected Kongsfjorden Svalbard 2018 were subject extraction two-dimensional gas chromatography coupled high-resolution mass spectrometry (GC×GC-HRMS)....

Efficiently assessing and managing the risks of pollution in marine environment requires mechanistic models for toxic effects. The General Unified Threshold model Survival (GUTS) provides a framework deriving toxicokinetic-toxicodynamic (TKTD) end point survival. Two recurring questions application GUTS concern most appropriate death mechanism, whether total body residue is proper dose metric We address these with case study dimethylnaphthalene copepod Calanus finmarchicus. A detailed...

After marine oil spills, natural processes like photooxidation and biodegradation can remove the from environment. However, these are strongly influenced by environmental conditions. To achieve a greater understanding of how seasonal variations in temperature, light exposure bacterial community affect depletion environment, we performed two field experiments during spring autumn. Field systems equipped with thin film Statfjord, Grane or ULSFO were deployed northern Norway. Depletion total...

Inorganic mercury (Hg) is highly toxic to organisms including crustaceans and displays multiple modes of action (MoA). The main aim this investigation was assess the acute sublethal toxicity mediated by chloride (HgCl2) in marine copepod Calanus finmarchicus. A combination short-term static studies determine a transcriptional characterize MoA HgCl2 were conducted with an in-house continuous culture C. Transcriptional changes determined custom 6.6 k finmarchicus Agilent oligonucleotide...