Eirik Fjeld - Academia.edu (original) (raw)

Papers by Eirik Fjeld

Environmental monitoring and assessment, 2016

Effects of wildfire on main water chemistry and mercury (Hg) in water and biota were studied duri... more Effects of wildfire on main water chemistry and mercury (Hg) in water and biota were studied during the first 4 post-fire years. After severe water chemical conditions during hydrological events a few months following the wildfire, the major water chemical parameters were close to pre-fire conditions 4 years after the fire. Concentrations of total Hg and methyl Hg in the surface water 4 years after the fire ranged between 1.17-2.63 ng L(-1) and 0.053-0.188 ng L(-1), respectively. Both variables were positive and strongly correlated with total organic carbon (TOC), TOC-related variables (color, UV absorbance), total phosphorous, and total iron. In addition, MeHg was positively correlated with total nitrogen and chlorophyll-a. The concurrence of increased concentrations of nutrients and chlorophyll-a in the lakes, the more enriched δ(15)N-signatures and higher Hg levels in fish 2 years after the fire, might be a result of the wildfire. However, natural factors as year-to-year variatio...

The Science of the total environment, 2016

We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) ... more We have investigated bioaccumulation and trophic transfer of both mercury (Hg) and selenium (Se) in two lakes in southern Norway to reveal a suggested mitigating effect of Se on Hg biota accumulation. The study included analysis of total Se (Se), total Hg (Hg), and methyl-mercury (MeHg) in water, littoral and pelagic invertebrates and perch (Perca fluviatilis), together with stable isotope analysis (δ(15)N and δ(13)C) in biota. Mean dissolved Se ranged from 22 to 59ngL(-1), while Hg and MeHg in lake water ranged from 1 to 3ngL(-1) and 0.01 to 0.06ngL(-1). Biota Se and Hg concentrations (dry weight) ranged from 0.41mgSekg(-1) and 0.06mgHgkg(-1) in primary littoral invertebrates and up to 2.9mg Sekg(-1) and 3.6mgHgkg(-1) in perch. Both Hg and Se biomagnified in the food web, with a trophic magnification factor (TMF) of 4.64 for Hg and 1.29 for Se. The reported positive transfer of Se in the food web, despite the low measured dissolved Se, suggest that a major proportion of the Se in t...

Ecotoxicology and Environmental Safety, Feb 29, 2004

In a laboratory experiment we documented effects of sublethal concentrations of p,p 0 -2,2-bis(p-... more In a laboratory experiment we documented effects of sublethal concentrations of p,p 0 -2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE) and butylbenzylphthalate (BBP) on feeding behavior in threespine stickleback Gasterosteus aculeatus. The fish were exposed for 31 days to either BBP (10 or 100 mg/L) or DDE (5 or 50 mg/L) or to a mixture of BBP and DDE in the corresponding concentrations. Five weeks after exposure termination, we showed that fish that had been exposed to the higher concentrations of DDE and/or BBP initiated feeding more often than control fish. The latency time to feeding (ranging from 0.25 to 5.0 min) differed between control fish and fish exposed to mixtures of DDE and BBP. This experiment shows that feeding behavior may be used as a suitable behavioral variable in the detection of effects of pollutants even long time after the termination of exposure. r

Can J Fisheries Aquat Sci, 1993

Fjeld, E., and S. Rognerud. 1993. Use of path analysis to investigate mercury accumulation in bro... more Fjeld, E., and S. Rognerud. 1993. Use of path analysis to investigate mercury accumulation in brown trout (Sairns trutta) in Norway and the influence of environmental factors. Can. 1. Fish. Aquat. Sci. 50: 1 158-1 167.

Ambio a Journal of the Human Environment, Mar 1, 2001

As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Se and Zn concentrations were determined and compared in l... more As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Se and Zn concentrations were determined and compared in lake and overbank sediments from 33 catchments without local pollution sources in southern Norway. There were no significant differences in concentrations of Be, Co, Cr, Cu, Ni, and V in overbank and pre-industrial lake sediments. In areas with shallow overburden, and significant influence from long-range atmospheric pollution, concentrations of As, Cd, Hg, Pb, Se, and Zn in overbank sediments were probably modified by vertical percolating water. In such areas, we suggest using lake sediments as a better sampling medium for mapping pre-industrial concentrations. Pre-industrial lake sediments yield natural concentrations of Hg and Se, which consist of both geogenic and natural atmospheric deposition. Important covariables like organic carbon content, Fe oxides, and fine mineral fraction were generally higher in preindustrial lake sediments as compared to overbank sediments. By adjusting for such differences overbank sediments could be used as an alternative in mapping background concentrations of trace metals in regions with few lakes.

Canadian Journal of Fisheries and Aquatic Sciences, 1998

Cu, Hg, Ni, Pb, Se, and Zn concentrations in surface and preindustrial freshwater sediments from ... more Cu, Hg, Ni, Pb, Se, and Zn concentrations in surface and preindustrial freshwater sediments from 66 lakes in the Norwegian and Russian Arctic were used for studying modern atmospheric deposition of these elements. Statistical analysis showed that, after adjusting for the effects of scavenging factors in sediments (organic matter, Al, and Fe), there were, in general, significantly higher concentrations of Hg and Pb in surface sediments than preindustrial sediments. The differences decreased with increasing latitude and increasing longitude to the east, and in the lakes from arctic islands of Svalbard and along the the arctic coastline of Russia, only Hg concentrations were elevated in surface sediments. We attribute this pattern to modern anthropogenic atmospheric deposition. There were no such differences or regional gradients for the other trace metals. A multivariate analysis of the sediment data showed that Hg and Se were associated with organic matter, whereas Cu, Ni, and Zn were associated with inorganic matter (Al, Fe). There was a shift in Pb association from inorganic matter in the reference sediment to organic matter in the surface sediment, which we interpret as an historic change in importance of sources (from bedrock-derived to atmospheric deposition).

Aquaculture, Jun 15, 1987

in the noble crayfish (Astacus astacus). Aquaculture, 64: 77-82. Egg development time in Astacus ... more in the noble crayfish (Astacus astacus). Aquaculture, 64: 77-82. Egg development time in Astacus astacus was strongly influenced by temperature. Five batches of eggs were subjected to different temperature regimes after approximately 600 degree days and, by increasing the temperature, the total number of degree days to hatching was reduced from 1900 to 1300. There were no systematic differences in hatching success or juvenile survival due to different temperature treatments. Females molted and rematured ( 50-100% ) 4-8 weeks after hatching.

Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology, 1999

The fungicide propiconazole (1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4... more The fungicide propiconazole (1-(2-(2,4-dichlorophenyl)-4-propyl-1,3-dioxolan-2-ylmethyl)-1H-1,2,4-triazole) induced the hepatic cytochrome P4501A (CYP1A) activity towards ethoxyresorufin-O-deethylase (EROD), the content of CYP1A protein as quantified by enzyme-linked immunosorbent assay (ELISA) and the glutathione S-transferase (GST) activity towards the three commonly used substrates CDNB(1-chloro-2,4-dinitrobenzene), cumene hydroperoxide (CU) and ethachrynic acid (EA) in brown trout (Salmo trutta) depending on dose and body weight. An exponential dose -response relationship existed between propiconazole exposure and CYP1A activity. A 2. order polynomial regression of the propiconazole concentration (square root transformed) on the data for CDNB, EU and CU revealed a bell-shaped pattern of the GST induction. Reverse-phase HPLC of the GSH-affinity chromatography purified GST isozymes in trout exposed to respectively 8.3, 23, 93, 313 and 606 mg l − 1 propiconazole in the water indicated that the propiconazole treatment may lead to changes in the composition of the subunits compared to the controls. Thus, propiconazole exposure through the water changed the properties of the brown trout hepatic CYP1A and GST, and these changes may be used as a bioindicator on the molecular level of exposure and effect of propiconazole in controlled experiments. The use in monitoring of propiconazole exposure under natural field conditions is possible, however needs further investigation.

The Science of the total environment, 2014

Environmental drivers of total mercury (TotHg) concentrations, methylmercury (MeHg) concentration... more Environmental drivers of total mercury (TotHg) concentrations, methylmercury (MeHg) concentrations, and MeHg fractions (a proxy for methylation potential, expressed as %MeHg) were assessed in a synoptic study of 51 lakes in southeast (Boreal) and northeast (Subarctic) Norway. Concentrations of TotHg and MeHg ranged between 0.5-6.6 ng/L and <0.02-0.70 ng/L, respectively. The lakes span wide ranges of explanatory environmental variables, including water chemistry, catchment characteristics, climate conditions, and atmospheric deposition of Hg, sulphur and nitrogen (N). Dissolved organic matter (DOM), measured as total organic carbon (TOC), was the variable most strongly correlated with TotHg (r(2)=0.76) and MeHg (r(2)=0.64) concentrations. Lakes in the Subarctic region had significantly lower TotHg and MeHg concentrations, and %MeHg than lakes in the Boreal region (p<0.01), implying a lower aquatic food web exposure of aqueous Hg species in Subarctic Norway than in the Boreal la...

Environment international, Jan 27, 2015

Eight organic UV filters and stabilizers were quantitatively determined in wastewater sludge and ... more Eight organic UV filters and stabilizers were quantitatively determined in wastewater sludge and effluent, landfill leachate, sediments, and marine and freshwater biota. Crab, prawn and cod from Oslofjord, and perch, whitefish and burbot from Lake Mjøsa were selected in order to evaluate the potential for trophic accumulation. All of the cod livers analysed were contaminated with at least 1 UV filter, and a maximum concentration of almost 12μg/g wet weight for octocrylene (OC) was measured in one individual. 80% of the cod livers contained OC, and approximately 50% of cod liver and prawn samples contained benzophenone (BP3). Lower concentrations and detection frequencies were observed in freshwater species and the data of most interest is the 4 individual whitefish that contained both BP3 and ethylhexylmethoxycinnamate (EHMC) with maximum concentrations of almost 200ng/g wet weight. The data shows a difference in the loads of UV filters entering receiving water dependent on the exte...

Environmental toxicology and chemistry / SETAC, 2014

The authors examined the seasonal and year-to-year variations of mercury (Hg) concentrations in p... more The authors examined the seasonal and year-to-year variations of mercury (Hg) concentrations in populations of perch (Perca fluviatilis) from 2 boreal freshwater lakes in southeast Norway. Fish Hg concentrations were determined seasonally (spring, summer, and autumn) over 3 yr (2010, 2011, and 2012) to test the hypothesis that there are substantial changes in fish Hg concentrations during the year (seasonal variation) as well as annually. Concentrations were significantly (p < 0.0001) different in the 2 study lakes, with mean seasonal concentrations varying from 0.24 mg/kg to 0.36 mg/kg and from 0.29 mg/kg to 0.37 mg/kg, respectively. The Hg concentrations of both perch populations showed significant year-to-year (p < 0.0001) and seasonal variation (p < 0.01). The changing fish Hg concentrations were 25% and 28% (2010-2011) and 17% and 0% (2011-2012) in the 2 lakes over the 3 yr, respectively. The results demonstrate how the significant year-to-year increase is, among other...

TheScientificWorldJournal, Jan 16, 2002

Short-chain polychlorinated alkanes (sPCAs) have been measured in freshwater fish samples from di... more Short-chain polychlorinated alkanes (sPCAs) have been measured in freshwater fish samples from different lakes all over Norway and from the Norwegian Arctic. The analyses were performed with high-resolution GC coupled to high-resolution MS in electron capture negative ion mode. The species investigated were trout, Arctic char, and burbot (Lota lota). Muscle tissue in the lake trout and Arctic char, and liver in burbot, were selected for analyses because of their high lipid content. SigmasPCA concentration ranged from 108 to 3700 ng/g fat. The highest value was found in the south of Norway near an industrial area.

Journal of Limnology, 2014

Seasonal variations of mercury (Hg) concentration in muscle tissue of northern pike -Esox lucius ... more Seasonal variations of mercury (Hg) concentration in muscle tissue of northern pike -Esox lucius L, European whitefish -Coregonus lavaretus L and European perch -Perca fluviatilis L have been investigated in Lake Heddalsvatn, southern Norway. Our data confirmed seasonal differences in the Hg concentrations in fish, but the causes for that may vary depending on fish species. Length (pike and perch) and age (perch and whitefish) were the strongest explanatory factors for the Hg fluctuations. Fish caught in December (pike and whitefish) had the highest Hg concentrations, while the concentrations in May were higher than in September for all 3 species, statistically significant for perch (P<0.0001) and close to significant for pike (P=0.07).