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- Bignert, Anders, et al.
(författare)
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Comments Concerning the National Swedish Contaminant Monitoring Programme in Marine Biota, 2015
- 2015
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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, polyaromatic hydrocarbons and perfluorinated compounds. Each of these contaminants have been examined from various sites for up to six different fish species, in blue mussels, and in guillemot eggs, for varying lengths of time. The following summary examines overall trends, 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 same sites, with a few exceptions. Most of the fish species generally displayed a decreasing trend in both condition and fat content at most sites examined. Exceptions to this were increases in condition factor seen in cod liver at Fladen, perch muscle at Kvädöfjärden, and for herring at Ängskärsklubb in spring. Also, an increase in fat content was seen during the most recent ten years for herring at Ängskärsklubb in spring. There were also some sites where no log linear trends were seen.Heavy MetalsDue to a change in methods for metal analysis (not mercury) in 2004, values between 2003 and 2007 should be interpreted with care. From 2009 metals are analyzed at ACES, Stockholm University.Generally, higher mercury concentrations are found in the Bothnian Bay, but also from one station in the Northern parts of Baltic Proper, compared to other parts of the Swedish coastline. The time series show varying concentrations over the study period. The longer time series in guillemot egg and spring-caught herring from the southern Bothnian Sea and southern Baltic Proper show significant decreases of mercury. On the other hand, increasing concentrations are seen in e.g., cod muscle, but the concentrations are fairly low compared to measured concentrations in perch from fresh water and coastal sites. In most cases, the mercury concentrations are above the EQSbiota 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. The highest concentrations are seen in the southern part of the Baltic Sea. Elevated lead concentrations between 2003 and 2007 (e.g. Harufjärden) should be viewed with caution (see above regarding change in analysis methods). Lead concentrations are below the suggested target level at all stations.Cadmium concentrations show varying non-linear trends over the monitored period. It is worth 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. Cadmium concentrations in herring and perch are all below the suggested target level of 160 μg/kg wet weight.The reported nickel concentrations show no consistent decreasing trends. Some series begin with two elevated values that exert a strong leverage effect on the regression line and may give a false impression of decreasing trends. Chromium generally shows decreasing concentrations, possibly explained by a shift in analytical method. The essential trace metals, copper and zinc, show no consistent trends during the monitored period.Generally higher concentrations of arsenic and silver are found along the west coast compared to other parts of the Sweadish coast line. However for silver a few stations in the Bothnian Sea and Bothnian Bay show comparable concentrations to the west coast stations.Chlorinated CompoundsGenerally, a decreasing concentrations were observed for all compounds (DDT’s, PCB’s, HCH’s, HCB) in all species examined, with a few exceptions, such as no change in TCDD-equivalents being seen in herring muscle (except at Änskärsklubb where very high concentrations at the beginning of the sampling period were seen and also at the west coast station Fladen). The longer time-series in guillemot also show a marked decrease in TCDD-equivalents from the start in the late 1960s until about 1985 from where no change occurred for many years, however, during the most recent ten years a decrease in the concentration is seen. Concentrations of DDE and CB-118 are for some species and sites still above their respective target levels.The chlorinated compounds generally show higher concentrations in the Bothnian Sea and/or Baltic Proper when compared to the Bothnian Bay and the Swedish west coast.Brominated Flame RetardantsElevated levels of HBCDD are seen in sites from the Baltic Proper, while the investigated PBDEs show higher concentrations in the Bothnian Bay. In addition, lower concentrations of all investigated PBDEs and HBCDD are seen on the Swedish west coast compared to the east coast. Temporally, significant increases in BDE-47, -99 and -100 have been seen in guillemot eggs since the late 1960s until the early 1990s, where concentrations then began to show decreases. Also, the concentration of HBCDD in guillemot eggs shows a decrease during the most recent ten years. For fish and blue mussels, BDE-47, -99, and -153 decreased at some sites and showed no trend at other sites. The concentration of HBCDD in fish and blue mussels showed inconsistent trends. The concentration of HBCDD is below the EQSbiota of 167 μg/kg wet weight for all fish species from all areas, while the concentration of BDE-47 alone is above the EQSbiota for sumPBDE of 0.0085 ng/g wet weight.PAHsOnly blue mussels have been examined for spatial differences in PAH concentrations. Concentration of ΣPAH was found to be higher from Kvädöfjärden in the Baltic Proper compared to stations at the West coast, but individual PAHs showed varying spatial patterns. Over time, acenaphthalene was rarely found above the detection limit. Significant decreasing trends were observed for ΣPAH, chrysene, fluoranthene and pyrene at Fjällbacka; for naphthalene at Kvädöfjärden; and for pyrene at Fladen.All time series where concentrations of various PAHs were compared with the target value based on OSPAR Ecological Assessment Criteria, or EC Environmental Quality Standards were below the target value.PFASsPFHxS and PFOS show a similar spatial pattern, but PFOS concentrations were approximately 25 times higher than PFHxS levels. The distribution of PFOS is quite homogenous along the Swedish coast but with somewhat higher concentrations in the Baltic Proper. PFOS concentrations in guillemot eggs are about 100-200 times higher than in herring liver. An overall increasing concentration of PFOS in guillemot eggs has been observed throughout the whole time period, however, during the most recent ten years, a change of direction is detected. The longer herring time series from Harufjärden, Landsort, and Utlängan show increasing concentrations for PFOS and most carboxylates. For FOSA, on the other hand, decreasing concentrations are seen during the most recent ten years.Organotin compoundsThe majority of the analysed tinorganic compounds showed concentrations below LOQ. However TBT and DPhT showed concentrations above LOQ at all stations with highest reported concentrations in fish from Örefjärden in the northern part of Bothnian Sea.
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