Northeast Arctic cod population persistence in the Lofoten-Barents Sea system under fishing.

Population growth, and hence the population's persistence, is affected by several factors such as climate, species interaction, and harvesting pressure. Proper resource management requires an understanding of these factors. We apply techniques based upon age-structured population matrices to analyze estimated stock sizes derived from annual bottom trawl sampling in the winter feeding area of northeast Arctic cod (Gadus morhua L.) from 1981 to 2003. We run generalized additive models to explain population growth rate by different explanatory variables. Cod population growth was found to be positively related to the abundance of capelin (Mallotus villosus Miller), negatively related to the number of cannibalistic cod with a two-year lag, and marginally positively related to the winter North Atlantic Oscillation index (NAO). This model remains true independently from the population status (i.e., fished or non-fished). Capelin abundance is the main variable that to some degree can be adjusted in order to maintain the population size at a given level of cod harvesting. Our results point to the importance of managing conjointly cod and capelin stocks.     

Bioaccumulation and lack of oxidative stress response in the ragworm H. diversicolor following exposure to Ra in sediment

The main effluent from oil and gas production, produced water, from some platforms in the North Sea contains elevated concentrations of ²²⁶Ra. The aim of this study was to investigate whether ²²⁶Ra in sediment would accumulate in and affect sediment-dwelling organisms. In addition, we wanted to determine if the bioavailability would be modulated by the presence of a scale inhibitor which is used during oil and gas production. Hediste diversicolor was therefore exposed to different levels of ²²⁶Ra (30–6600 Bq kg⁻¹) in combination with scale inhibitor in the sediments in a flow through system. The levels of radioactivity in the exposures were close to levels that can be measured in proximity to oil/gas production facilities. ²²⁶Ra spiked to natural sediment partitioned into pore water and accumulated in the sediment-dwelling polychaete following a four-week exposure period. The results suggest that ²²⁶Ra did not bind strongly to sediment (low sediment:water partitioning coefficient), but it was not shown to bioaccumulate in any great extent (bioaccumulation factors of 0.019–0.022). Exposure of H. diversicolor in sediments with up to 6600 Bq kg⁻¹²²⁶Ra had no measurable effect on the total oxyradical scavenging capacity of the organisms compared to control. So although they accumulated the alpha-emitter, the treatments did not appear to cause oxidative stress in polychaete tissues.     

Amphibian recovery after a decrease in acidic precipitation

We here report the first sign of amphibian recovery after a strong decline due to acidic precipitation over many decades and peaking around 1980–90. In 2010, the pH level of ponds and small lakes in two heavily acidified areas in southwestern Scandinavia (Aust-Agder and Østfold in Norway) had risen significantly at an (arithmetic) average of 0.14 since 1988–89. Parallel with the general rise in pH, amphibians (Rana temporaria, R. arvalis, Bufo bufo, Lissotriton vulgaris, and Triturus cristatus) had become significantly more common: the frequency of amphibian localities rose from 33% to 49% (n = 115), and the average number of amphibian species per locality had risen from 0.51 to 0.88. In two other (reference) areas, one with better buffering capacity (Telemark, n = 21) and the other with much less input of acidic precipitation (Nord-Trøndelag, n = 106), there were no significant changes in pH or amphibians.     

Compound dependence of the relationship log Kow and log BCFL

Linear relatinships between log bioconcentration factor (BCF) and log K^ow for a variety of compounds have been reported many times in the literature. Analysis of the thermodynamics of the two partition processes has, however, shown that they are not analogous and that linear relationships can be expected to have different slopes for structurally unrelated compounds. In this study a set of literature lipid normalized BCF (BCF_L) values of chlorbenzenes (CBs) for rainbow trout and polycyclic aromatic hydrocarbons (PAHs) forDaphnia was put together with literature K_ow values. The slopes of the regression lines for log BCF_L versus log K_ow for the two groups of compounds proved to differ significantly in a statistical test using analysis of variance (ANOVA). The difference, which is of significance for estimates of BCFs in environmental modelling of these types of compounds, is explained by the differences in chemical structure of the two groups of compounds.     

Temperature dependent properties of environmentally important synthetic musks

Environmental fate determining physical properties including their temperature dependence for five nitro musks and for seven polycyclic musks were estimated. The properties evaluated were vapor pressure in a solid and liquid state (PS and PL), solubility in water (S), Henry's law coefficient (H = PL/S) and log octanol-water partition coefficient (log KOW). Gas chromatography for starting values of vapor pressure estimation and HPLC experiments at 5-20 degrees C for comparison of the theoretical versus experimental solubilities in water were performed. The values of temperature (T) dependence coefficients (Ai and Bi) in equations: log (Property)i = Ai - Bi/T were determined. Values of properties were compared with literature-based data, and an example of their use in environmental hazard estimation by fate modeling was given.     

Airborne exposure and biological monitoring of bar and restaurant workers before and after the introduction of a smoking ban

The aims were to assess the impact of a total smoking ban on the level of airborne contaminants and the urinary cotinine levels in the employees in bars and restaurants. In a follow up design, 13 bars and restaurants were visited before and after the implementation of a smoking ban. Ninety-three employees in the establishments were initially included into the study. The arithmetic mean concentration of nicotine and total dust declined from 28.3 microg m(-3) (range, 0.4-88.0) and 262 microg m(-3) (range, 52-662), respectively, to 0.6 microg m(-3) (range, not detected-3.7) and 77 microg m(-3) (range, not detected-261) after the smoking ban. The Pearson correlation coefficient between airborne nicotine and total dust was 0.86 (p < 0.001; n = 48). The post-shift geometric mean urinary cotinine concentration declined from 9.5 microg g(-1) creatinine (cr) (95% CI 6.5-13.7) to 1.4 microg g(-1) cr (95% CI 0.8-2.5) after the ban (p < 0.001) in 25 non-snuffing non-smokers. A reduction from 1444 microg g(-1) cr (95% CI 957-2180) to 688 microg g(-1) cr (95% CI 324-1458) was found (p < 0.05) in 29 non-snuffing smokers. The urinary cotinine levels increased from 11.7 microg g(-1) cr (95% CI 7.0-19.6) post-shift to 21.9 microg g(-1) cr (95% CI 13.3-36.3) (p < 0.01) in the next morning in 24 non-snuffing non-smokers before the smoking ban. A substantial reduction of airborne nicotine and total dust was observed after the introduction of a smoking ban in bars and restaurants. The urinary cotinine levels were reduced in non-smokers. The decline found in smokers may suggest a reduction in the amount of smoking after intervention. In non-smokers cotinine concentrations were higher based on urine sampled the morning after a shift than based on urine sampled immediately post-shift.     

PCBs,PCNs, PCDD/Fs,PAHs and Cl-PAHs in air and water particulate samples--patterns and variations

Methodology for the determination of biologically active polychlorinated biphenyls (PCBs), non-ortho PCBs, polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) was used to investigate concentrations and patterns of certain chlorinated PAH (Cl-PAH) in source related samples using synthetic reference mixtures. Thus, in addition to the above mentioned compounds, mono-heptachlorosubstituted fluorenes, phenanthrenes/anthracenes and pyrenes/fluoranthenes (Cl-PAHs) were measured in vapour and particulate air samples from urban road tunnels, samples of settling particulate matter (SPM), and in bottom sediment samples from two point source locations (pulp and paper, and Mg-plant/Fe-Mn-smelter/chlor-alkali) and in the Baltic Sea. Concentrations in air samples followed: PAHs>PCBs>PCNs>non-ortho PCBs or Cl-PAHs>PCDD/Fs. SPM samples collected at increasing distance to the urban area of Stockholm showed: PAHs>PCBs>PCNs>PCDD/Fs>non-ortho PCBs or Cl-PAHs. For all compound groups there was a tenfold (Cl-PAHs fivefold) concentration decrease in SPM samples from highest levels in the urban water area to lowest levels at a distance of 26 km from city centre. PCB profiles of SPM showed similarities with combined profiles of Aroclor 1242 and 1254. PCN profiles of SPM showed similarities with combined profiles of Halowax 1099 and 1014. A correlation with concentration of all tested Cl-PAH and their corresponding parent PAH was found only for Cl-fluorene.     

Swimming and feeding in Periphylla periphylla (Scyphozoa, Coronatae)

Some western Norwegian fjords host extraordinarily abundant and persistent populations of the mesopelagic, coronate scyphomedusa, Periphylla periphylla. In these environments, from late autumn to spring, the medusae undertake regular diel vertical migrations into surface waters. From unique observations obtained with a remotely operated vehicle (ROV), including observations made without artificial light, we observed that 90% of the medusae swam with their tentacles in aboral position. Stomach content analyses of surface-collected specimens revealed that the medusae ate mainly calanoid copepods, but ostracods and large euphausiids were also prominent components of their diets. The clearance rate potential of P. periphylla, assessed from in situ observations and stomach contents, was comparable to that of similar-sized, epipelagic gelatinous species. Our findings suggest that P. periphylla behave as active predators in surface waters.     

Organophosphates in aircraft cabin and cockpit air--method development and measurements of contaminants

Methods for measurements and the potential for occupational exposure to organophosphates (OPs) originating from turbine and hydraulic oils among flying personnel in the aviation industry are described. Different sampling methods were applied, including active within-day methods for OPs and VOCs, newly developed passive long-term sample methods (deposition of OPs to wipe surface areas and to activated charcoal cloths), and measurements of OPs in high-efficiency particulate air (HEPA) recirculation filters (n = 6). In total, 95 and 72 within-day OP and VOC samples, respectively, have been collected during 47 flights in six different models of turbine jet engine, propeller and helicopter aircrafts (n = 40). In general, the OP air levels from the within-day samples were low. The most relevant OP in this regard originating from turbine and engine oils, tricresyl phosphate (TCP), was detected in only 4% of the samples (min-max 相似文献   

Testing common sediment-porewater distribution models for their ability to predict dissolved concentrations of POPs in The Grenlandsfjords, Norway

This study compares in situ observed porewater concentration of persistent organic pollutants (POPs) with predictions by common solid-water phase distribution models. Bottom sediments were sampled in The Grenlandsfjords, Norway, and the interstitial porewater was isolated from the solids by centrifugation and filtration. Both phases were analysed for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F), polycyclic aromatic hydrocarbons (PAH), and organic carbon. Based on the sediments' solid phase content of POPs, organic carbon, and soot carbon, we used the organic matter partitioning (OMP), and also the soot and organic matter partitioning (SOMP) model to estimate the porewater concentration. The OMP model gave better agreement to observations than the SOMP model for both PCDD/Fs and PAHs. The observed concentration of the PCDD/Fs in the sediments' porewater was much higher than in the deep water of the fjord. The logarithm of the organic matter-water partitioning coefficent (log K(OC)) in the porewater had positive linear regression on the logarithm of the octanol-water partitioning coefficient (log K(OW)). The slope of the regression model was indistinguishable from 1, except for the PAHs as a group which had a slope less than 1. This contrasts to previous studies undertaken in The Grenlandsfjords water column, where the slopes were higher than 1 for PCDD/Fs, and the K(OC) were much higher than the K(OW). One explanation may be that the influence of POPs adsorption to soots decrease because competitive sorption by other compounds in the sediment are higher than in the water column. This indicates that the sorption isotherms for these POPs need better understanding in order to be applicable in both the water column and the porewater.