Sigurd Rognerud - Academia.edu (original) (raw)

Papers by Sigurd Rognerud

Environmental Chemistry, 2012

Environmental context. Mercury, in its methylated form, is a neurotoxin that biomagnifies in mari... more Environmental context. Mercury, in its methylated form, is a neurotoxin that biomagnifies in marine and terrestrial foodwebs leading to elevated levels in fish and fish-eating mammals worldwide, including at numerous Arctic locations. Elevated mercury concentrations in Arctic country foods present a significant exposure risk to Arctic people. We present a detailed review of the fate of mercury in Arctic terrestrial and marine ecosystems, taking into account the extreme seasonality of Arctic ecosystems and the unique processes associated with sea ice and Arctic hydrology.

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...

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...

Fauna norvegica, 2013

Sandlund OT, Haugerud E, Rognerud S and Borgstrøm R. 2013. Arctic charr (Salvelinus alpinus) sque... more Sandlund OT, Haugerud E, Rognerud S and Borgstrøm R. 2013. Arctic charr (Salvelinus alpinus) squeezed in a complex fish community dominated by perch (Perca fluviatilis). Fauna norvegica 33: 1-11.

Developments in Paleoenvironmental Research, 2007

Water, Air, & Soil …, 2002

High concentration of Hg, less volatile PCB congeners and p, p'-DDE in Arctic charr from an ... more High concentration of Hg, less volatile PCB congeners and p, p'-DDE in Arctic charr from an arctic lake was mainly causedby biomagnification in the food chain where cannibalism was thedriving force. We suggest that low sediment fluxes of Hg, low net production of methyl ...

Journal of Environmental Science and Health, Part B, 2010

Hydrobiologia, 2010

Stable coexistence of Arctic charr and whitefish does occur in a number of native lake fish commu... more Stable coexistence of Arctic charr and whitefish does occur in a number of native lake fish communities in Scandinavia. Even so, whitefish introductions into Arctic charr lakes have resulted in serious decline and possibly local extinction of Arctic charr. In this article, we analyze the habitat use and diet of the two species in five Norwegian lakes differing in basin shape and environmental conditions. In two of the lakes, both species are native, and appear to live in a relatively stable coexistence. Here, whitefish mainly occupy the littoral and upper pelagic zone, while Arctic charr live in the deeper habitats. Diets are generally quite different in terms of the zooplankton species eaten. In the three other lakes, either whitefish or both species have been introduced. In the shallowest lake, habitat segregation is similar to that seen in the pristine lakes, although Arctic charr appears to be on the brink of extinction. In the remaining two lakes, however, Arctic charr dominates, and occurs in higher numbers than whitefish in all the habitats. Our observations indicate that coexistence of the two species in oligotrophic and relatively pristine lakes requires an extensive profundal zone to serve as a refugium for Arctic charr. If the littoral zone is rendered inaccessible or unprofitable for whitefish due to dominance of a third competitor or predator, or as a result of lake regulation, then Arctic charr may be the dominant species.

NINA Rapport 388: 63 …, 2008

NINAs publikasjoner NINA Rapport Dette er en ny, elektronisk serie fra 2005 som erstatter de tidl... more NINAs publikasjoner NINA Rapport Dette er en ny, elektronisk serie fra 2005 som erstatter de tidligere seriene NINA Fagrapport, NINA Oppdragsmelding og NINA Project Report. Normalt er dette NINAs rapportering til oppdragsgiver etter gjennomført forsknings-, overvåkings-eller utredningsarbeid. I tillegg vil serien favne mye av instituttets øvrige rapportering, for eksempel fra seminarer og konferanser, resultater av eget forsknings-og utredningsarbeid og litteraturstudier. NINA Rapport kan også utgis på annet språk når det er hensiktsmessig.

Environmental Monitoring and Assessment, 2013

The Stockholm Convention, which aspires to manage persistent organic pollutants (POPs) at the int... more The Stockholm Convention, which aspires to manage persistent organic pollutants (POPs) at the international level, was recently ratified in Bosnia and Herzegovina (BiH). Despite this fact, there is in general a paucity of data regarding the levels of POPs in the environment in BiH. In the present study, screening for POPs was conducted in one of the country's major rivers, the Bosna. A two-pronged approach was applied using passive samplers to detect the freely dissolved and bioavailable concentrations in the water phase and sediment analysis to provide an integrated measure of historical contamination. At several places along the river, the concentrations of polycyclic aromatic hydrocarbons (PAH) were high and exhibited potential for both chronic and acute effects to biota. River water also showed elevated concentrations of PAH, up to 480 ng L −1 near the city of Doboj, and diagnostic ratios suggested combustion sources for the contamination present in both types of sample. The levels of the other contaminants measured-polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers-were generally low in the water phase. However, PCBs and some OCPs were present in river sediments at levels which breach the international criteria and thus suggest potential for ecological damage. Additionally, the levels of heptachlor breached these criteria in many of the sites investigated. This study presents the first screening data for some of these Stockholm Convention relevant compounds in BiH and reveals both low concentrations of some chemical groups, but significant point sources and historic contamination for others.

Environmental Geology, 2000

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, 1994

and Eiliv Steinnes hlniversity s f Trondheinl, A VH, Department sf Chemistry, Fjeld, E., S. Rogne... more and Eiliv Steinnes hlniversity s f Trondheinl, A VH, Department sf Chemistry, Fjeld, E., S. Rognerud, and E. . Influence of environmental factors on heavy metal concentration in lake sediments in southern Norway indicated by path analysis. Can. j. Fish. Aquat. Sci. 51: 1708 -1 720.

Canadian Journal of Fisheries and Aquatic Sciences, 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.

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).

AMBIO: A Journal of the Human Environment, 2001