| 1. |
- Bignert, Anders, et al.
(författare)
-
Consequences of using pooled versus individual samples for designing environmental monitoring sampling strategies
- 2014
-
Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 94, s. 177-182
-
Tidskriftsartikel (refereegranskat)abstract
- Choosing an appropriate sampling strategy for chemical analysis within environmental monitoring includes the important decision of whether to sample and store individual or pooled samples. This choice impacts on future analyses from Environmental Specimen Bank samples. A number of advantages exist to support using either individual or pooled samples for temporal trend studies. However, it is important to know the total and analytical variance to be able to design the best sampling strategy. Statistical power in temporal or spatial studies is determined by the random/unexplained sample variation. The relationship between chemical analytical error and other sources of variation, as well as the cost for collection, preparation of samples and chemical analysis, will determine the number of individuals in each pool, and the number of pools that should be analysed to achieve high cost efficiency and good statistical power. Various scenarios of different numbers of individual samples, different numbers of pooled samples containing various numbers of individual specimens, the relationships between chemical analytical error and other sources of sample variance, have been compared by simulating random sampling from computer generated populations using realistic measures of variation from ongoing monitoring activities. These results offer guidance in the design of a cost-efficient, statistically sound sampling strategy.
|
|
| 2. |
|
|
| 3. |
- Bignert, Anders, et al.
(författare)
-
Övervakning av metaller och organiska miljögifter i marin biota, 2011
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The environmental toxicants examined in this report can be classified into five groups –heavy metals, chlorinated compounds, brominated flame retardants, polyaromatichydrocarbons and perfluorinated compounds. Each of these contaminants has beenexamined from various sites for up to six different fish species, in blue mussels, and inguillemot eggs, for varying lengths of time. The following summary examines overalltrends, spatial and temporal, for the five groups.Condition and Fat ContentCondition and fat content in different species tended to follow the same pattern at the samesites, with a few exceptions. Most of the fish species generally displayed a decreasing trendin both condition and fat content at most sites examined. Exceptions to this were increasesin fat content seen in herring (the last ten years) and cod at Fladen; an increase in conditionfor herring at Ängskärsklubb in spring; and in perch, a decrease in fat content atKvädöfjärden but no trend in condition for the same site.Heavy MetalsDue to a change in methods for metal analysis (not Hg) in 2004, values between 2003 and2007 should be interpreted with care. From 2009 metals are analyzed at ITM, Stockholmuniversity.The longer time series in guillemot egg and spring-caught herring from the southernBothnian Sea and southern Baltic Proper show significant decreases of mercury. Theherring site in the southern Bothnain Sea indicates a local Hg-source. The rest of the timeseries show varying concentrations over the study period, and even increasing trends in e.g.cod muscle and blue mussels, but the concentrations are fairly low compared to measuredconcentrations in perch from fresh water and coastal sites. However, in most cases, theseconcentrations are above the newly suggested EU-target level of 20 ng/g wet weight.Lead is generally decreasing over the study period (in time series of sufficient length),supposedly due to the elimination of lead in gasoline. Elevated lead concentrations between2003 and 2007 (e.g. Harufjärden) should be viewed with caution (see above regardingchange in analysis methods).Cadmium concentrations show varying non-linear trends over the monitored period. It isworth noting that despite several measures taken to reduce discharges of cadmium,generally the most recent concentrations are similar to concentrations measured 30 yearsago in the longer time series.The reported nickel concentrations show no consistent decreasing trends. Some series beginwith two elevated values that exert a strong leverage effect on the regression line and maygive a false impression of decreasing trends. Chromium generally shows decreasing trends,possibly explained by a shift in analytical method. The essential trace metals, copper andzinc, show no consistent trends during the monitored period.
|
|
| 4. |
- Boalt, Elin, et al.
(författare)
-
Cadmium, lead, and mercury concentrations in whole-fish, liver, and muscle of herring (Clupea harengus) and perch (Perca fluviatilis)
- 2012
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Monitoring of metal concentrations in fish is commonly conducted using samples of fish liver or muscle. This becomes problematic when these values are used for environmental status evaluations regarding chemical pollution, as many of the thresholds evaluating environmental status are designed to evaluate concentrations in whole-fish.In this study, concentrations of cadmium, lead, and mercury in herring and perch are compared between liver, muscle, and whole-fish. The aim is to create conversion factors that can be used to convert metal concentrations between tissues and organs.Mercury and cadmium were detected in all analyzed organs and tissues, whereas lead concentrations were below the level of quantification for most muscle and liver samples. In general, there was a strong relationship between liver and muscle concentrations and concentrations in whole-fish, indicating that creation of conversion factors between tissues and organs is suitable.The resulting conversion factor between whole-fish and liver concentrations for cadmium was 0.1 and 0.16 for herring and perch, respectively. The conversion factor between whole-fish and liver concentrations for mercury was 0.52 and 1.66 for herring and perch, respectively, while for whole-fish and muscle concentrations for mercury, the conversion factor was 0.86 and 0.74 for herring and perch. As there was no significant relationship between liver and whole-fish concentrations for lead, a conversion is not appropriate. Conversion factors levels differed significantly between herring and perch, indicating that species-specific conversion factors are necessary.
|
|
| 5. |
- Faxneld, Suzanne, et al.
(författare)
-
Temporal Trends and Geographical Differences of Perfluoroalkyl Acids in Baltic Sea Herring and White-Tailed Sea Eagle Eggs in Sweden
- 2016
-
Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 50:23, s. 13070-13079
-
Tidskriftsartikel (refereegranskat)abstract
- Temporal and spatial trends of perfluoroalkyl acids (PFAAs) were investigated in Baltic Sea herring liver (Clupea harengus) from three sites, and white-tailed sea eagle (WTSE) eggs (Haliaeetus albicilla) from two freshwater and two marine areas in Sweden. Trends of most quantifiable PFAAs increased over the monitored period (1980-2014 in herring, 1960s/1980s-2010 in WTSE). No significant decreasing trends were observed for the most recent ten years for any substances, except perfluorooctane sulfonamide (FOSA). Concentrations of perfluorooctanesulfonic acids (PFOS) in herring showed a distinct decreasing spatial trend moving from the more southern site toward the more northern site, indicating main input of PFOS into the southern Baltic Sea. For WTSE, PFOS concentration was higher in the marine compared to the freshwater environment, explained by the cumulative historic contamination of the Baltic Sea. Similarly, concentrations in WTSE were lower in the northern part of the Baltic Sea compared to further south. Concentrations of PFUnDA, representing long-chain perfluoroalkyl carboxylic acids (PFCAs), showed a more homogeneous spatial distribution compared to PFOS for both herring and WTSE, indicating that atmospheric inputs (via precursors) of the long-chain PFCAs are important contributors in the study areas.
|
|
| 6. |
- Miller, Aroha, et al.
(författare)
-
Comparing temporal trends of organochlorines in guil-lemot eggs and Baltic herring : Advantages and disadvantages for se-lecting sentinel species for environmental monitoring
- 2014
-
Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136 .- 1879-0291. ; 100, s. 38-47
-
Tidskriftsartikel (refereegranskat)abstract
- Within Europe, the Marine Strategy Framework Directive (MSFD) is aimed at addressing the chemical status and quality of the marine environment. One of the main goals is to achieve Good Environmental Status (GES) in the marine environment. Environmental monitoring of biota e.g., Baltic herring and guillemot eggs, is conducted annually in Sweden to follow temporal changes in environmental contaminants. To determine the suitability of guillemot eggs as a sentinel species for investigating GES, we compared temporal trends of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in these two species from single sampling sites within Sweden.Lipid content from guillemot eggs was consistently high and stable (yearly mean for >40 years, ∼12%) compared to that of herring (yearly mean for >20 years, ∼3%). A significant decreasing trend of ΣPCDD/F in TEQ WHO1998 was observed in guillemot eggs, but no trend was seen in herring. CB118 significantly decreased in both species, but in the last 10 years this decrease was not significant in herring. A number of advantages, such as high lipid content in the egg and a low coefficient of variation make guillemot suitable as a sentinel species. The advantages and disadvantages of using either guillemot eggs or Baltic herring are compared.
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Miller, Aroha, et al.
(författare)
-
Temporal trends in dioxins (polychlorinated dibenzo-p-dioxin and dibenzofurans) and dioxin-like polychlorinated biphenyls in Baltic herring (Clupea harengus)
- 2013
-
Ingår i: Marine Pollution Bulletin. - : Elsevier BV. - 0025-326X .- 1879-3363. ; 73:1, s. 220-230
-
Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyl (dl-PCBs) concentrations in Baltic herring (Clupea harengus) have been relatively stable since the mid to late 1990s. It is unclear why concentrations in Baltic herring are not following the observed decreases in other environmental matrices. Here, changes in long-term temporal trends in Baltic herring were examined. A number of biological variables were examined alongside the temporal trends to investigate whether fish biology e.g., growth (length, weight, age), lipid content, reproductive phase or fishing date may provide an explanation for the temporal trends observed. Significant (p < 0.05) decreasing trends were observed for PCDD/F toxic equivalents (TEQ(PCDD/F)) at three of the four sites (lipid weight (lw) and wet weight (ww), Swedish west coast lw only); however, other TEQ values e.g., TEQ(PCDD), TEQ(PCDF), TEQ(dl-PCB), TEQ(PCDD/F+dl-PCB) were inconsistent, decreasing at some sites but not others. In the most recent 10 years of data, fewer significant decreases were seen overall. Over the examined time period, significant decreases (Bothnian Bay, p < 0.01, southern Baltic Proper, p < 0.02) and increases (Swedish west coast, p < 0.02) in lipid content, growth dilution or lack thereof, and significant changes in age were observed. However herring were not randomly selected which biases this result. Continual efforts to decrease PCDD/F and dl-PCB emissions and to locate/reduce hotspots are necessary, while bearing in mind that herring biology may be impeding faster decreases of these chemicals.
|
|
| 10. |
|
|
| 11. |
|
|
| 12. |
- Nyberg, Elisabeth, et al.
(författare)
-
Spatio-temporal trends of PCBs in the Swedish freshwater environment 1981-2012
- 2014
-
Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 43, s. 45-57
-
Tidskriftsartikel (refereegranskat)abstract
- Polychlorinated biphenyls (PCBs) have been monitored in perch (Perca fluviatilis), pike (Esox lucius), and Arctic char (Salvelinus alpinus) in reference lakes since the late 1960s. Temporal trends and spatial patterns are currently monitored in nine and 32 lakes, respectively. Overall, PCB concentrations are decreasing. However, this is not consistent for all congeners across all lakes and species. Perch has comparatively low PCB concentrations relative to suggested target levels, but individual congener concentrations in some lakes are concerningly high. No temporal trend is seen for CB-118 and CB-153 in perch, but significant decreasing trends exist for Arctic char and pike, for which monitoring started earlier than for perch. The lower/higher chlorinated congener ratio decreased over time in most lakes, indicating fewer new emissions. CB-118 and CB-153 concentrations in perch show spatial gradients across Sweden, with higher concentrations found near urban/industrial areas.
|
|
| 13. |
- Nyberg, Elisabeth, et al.
(författare)
-
Temporal and spatial trends of PCBs, DDTs, HCHs, and HCB in Swedish marine biota 1969-2012
- 2015
-
Ingår i: Ambio. - Stockholm : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 44, s. 484-497
-
Tidskriftsartikel (refereegranskat)abstract
- In the 1960s, the Baltic Sea was severely polluted by organic contaminants such as PCBs, HCHs, HCB, and DDTs. Elevated concentrations caused severe adverse effects in Baltic biota. Since then, these substances have been monitored temporally and spatially in Baltic biota, primarily in herring (Clupea harengus) and in guillemot (Uria aalge) egg, but also in cod (Gadus morhua), perch (Perca fluviatilis), eelpout (Zoarces viviparous), and blue mussel (Mytilus edulis). These chemicals were banned in Sweden in the late 1970s/early 1980s. Since the start of monitoring, overall significant decreases of about 70-90 % have been observed. However, concentrations are still higher in the Baltic Sea than in, for example, the North Sea. CB-118 and DDE exceed the suggested target concentrations (24 lg kg(-1) lipid weight and 5 lg kg(-1) wet weight, respectively) at certain sites in some of the monitored species, showing that concentrations may still be too high to protect the most sensitive organisms.
|
|
| 14. |
|
|
