PCB concentrations in fish muscle
 |
||||
|
|
|
||
|
||||
Key message
sPCB concentrations show significant declining trends in the investigated biotic matrices as a result of measures taken to reduce discharges of PCB to the environment. The concentrations are still significantly higher in the Baltic Proper and in the southern Bothnian Sea compared to the Kattegatt and the Skagerrak (based on data from the Swedish Monitoring Programme).
Figure 1. Spatial variation in mean concentration (of the annual mean values 2005-2008 in ng/g lipid w.) of CB-153 in herring muscle. The highest concentration (125 ng/g) was found in the eastern part of Bothnia Sea, the lowest (15 ng/g) in the Gulf of Riga. Data obtained from ICES database
Results and assessments
Relevance of the indicator for describing developments in the environment
PCB concentration in tissues from various species show coherent trends of similar magnitudes from various regions. The investigated species are commonly used for human consumption.Policy relevance and policy references
The Helsinki Convention (HELCOM) revised 1992, especially names PCB for which special bans and restrictions on transport, trade, handling, use and disposal are imposed. The Minister Declaration from 1988, within HELCOM, calls for a reduction of stable organic substances by 50% by 1995 with 1987 as a base year. The Minister Declaration from 1996, within HELCOM, and the declaration in Esbjerg 1995, calls for measures for toxic, persistent, bioaccumulating substances to have ceased completely in the year 2020.
Assessment
The concentration of sPCB (sum of PCB’s estimated from CB-138 or peak 10 from packed column chromatography) in herring muscle from all herring sites in the Baltic show significant decreasing trends during the time period 1978/80-2007. The rates vary between 5.4 and 8.9% per year. This implies a total decrease of about 90% at Angskarsklubb and about 75% at Utlangan, of the PCB-concentration in herring muscle, since the end of the seventies.
The highest concentration of CB-153 in herring (125 ng/g) was found in the eastern parts of Bothnia Sea, the lowest (15 ng/g) in the Gulf of Riga.
The two Perch muscle time-series from northern Bothnia sea (Holmoarna) and the Baltic Proper (Kvadofjarden) show significant decreasing trends of sPCB at the rate of 8.9% and 9.4% per year (1980-2007). The time series also show a significant decrease of CB-153 from both sites at the rate of 11% and 6.8% per year.
Figure 2. Temporal trends of sPCB concentration (ug/g lipid w.) in herring muscle (1978/80-2007). The red line presented in the figure is based on a log-linear regression analyses and shows decreasing trends of 5.4-8.9% per year and the blue line is a simple 3-point running mean smoother fitted to the annual geometric mean values. The linear dotted line is the mean concentration of the analysed period.
Figure 3. Temporal trends of CB-153 concentration (ug/g lipid w.) in Perch muscle (Holmoarna 1989, 1995-2007; Kvadofjarden 1984, 1989-2007). The red line presented in the figure is based on a log-linear regression analyses and shows decreasing trends of 11% and 6.8% per year. The linear dotted line is the mean concentration of the analysed period.
References
Bignert, A., Danielsson S., Strandmark A., Nyberg E., Asplund L., Eriksson U., Wilander A. Haglund P. 2008. Comments Concerning the National Swedish Contaminant Monitoring Programme in Marine Biota. Report to the Swedish Environmental Protection Agency, 2008. 128 pp.
Data
Trend (in %) assessed from the geometric mean of concentrations of sPCB (mg/g lipid weight) in various matrices and sites during the time period 1980-2007 and the estimated mean concentration for the last year (2007). The numbers presented in brackets are the 95% confidence intervals. The age intervals for fish are also presented together with the total number of analyses and the number of years of the various time-series.
Metadata
Technical information
Data source: The National Swedish Monitoring Program of Contaminants in Biota
Sampling, sample preparation, storage in specimen bank and evaluation of results are carried out by the Department of Contaminant Research at the Swedish Museum of Natural History, Stockholm. Chemical Analysis is carried out at Institute of Applied Environmental Research at Stockholm University.
Geographical coverage: see data table and map.
Temporal coverage: see data table and figures.
Methodology and frequency of data collection, see Bignert et al, 2008
Methodology of data manipulation. For a detailed description of statistical methods use, see Bignert et al. 2008.
Quality information
The number of years required to detect an annual change of 5% with a power of 80% varied between 15 to 16 years for the herring time-series. The number of years required to detect an annual change of 5% (for CB-153) was 17 and 21 years for the two Perch time-series.
For reference purposes, please cite this indicator fact sheet as follows:
[Author’s name(s)], [Year]. [Indicator Fact Sheet title]. HELCOM Indicator Fact Sheets 2009. Online. [Date Viewed], http://www.helcom.fi/environment2/ifs/en_GB/cover/.
Last updated: 13 October 2009