Pollutants in capelin (Mallotus villosus)
Capelin have relatively low levels of environmental contaminants. Thus far, there does not appear to have been any change over time. The exception is PBDEs, which appear to have declined.
What is being monitored?
Cite these dataNational Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research (2020). HCB, dieldrin and cis-chlordane in capelin. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL: http://www.mosj.no/en/influence/pollution/pollution-capelin.html
|HCB||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||1.2||1.7||1.9||1.4||1.7||0.86||1.73||1.02||1.62||1.93|
|HCB (Low)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||1.1||1.4||0||0.94||1.6||0.86||1.73||1.02||1.62||1.5|
|HCB (High)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||1.3||2||2.4||1.8||1.8||0.86||1.73||1.02||1.62||2.6|
|Cis-chlordane||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||0.8||0.78||1.37||1.55||0.9||0.425||0.314||0.321||0.49||0.479|
|Cis-chlordane (Low)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||0.52||0.5||1.37||1.5||0.9||0.425||0.314||0.321||0.49||0.38|
|Cis-chlordane (High)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||1||1.1||1.37||1.6||0.9||0.425||0.314||0.321||0.49||0.65|
|Dieldrine||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||1.8||2.2||1.3||1.8||1.5||0.93||1.33||1.29||1.6||1.54|
|Dieldrine (Low)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||1.2||1.7||0.73||1.7||1.1||0.93||1.33||1.29||1.6||1.3|
|Dieldrine (High)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||2.3||2.7||1.9||1.8||1.9||0.93||1.33||1.29||1.6||1.8|
Cite these dataNational Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research (2020). PBDE7 in capelin. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL: http://www.mosj.no/en/influence/pollution/pollution-capelin.html
|PBDE||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||0.13||0.11||0.11||0.16||0.079||0.09||0.055||0.053||0.045||0.042||0.031||0.062|
|PBDE (Low)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||0.047||0.085||0.083||0.11||0.037||0.084||0.012||0.053||0.028||0.038||0.02||0.049|
|PBDE (High)||μg/kg||National Institute of Nutrition and Seafood Research (NIFES), Institute of Marine Research||0.18||0.15||0.12||0.22||0.11||0.097||0.083||0.053||0.059||0.048||0.04||0.078|
Cite these dataNational Institute of Nutrition and Seafood Research (NIFES) (2020). Cadmium in capelin. Environmental monitoring of Svalbard and Jan Mayen (MOSJ). URL: http://www.mosj.no/en/influence/pollution/pollution-capelin.html
|Cd||mg/kg||National Institute of Nutrition and Seafood Research (NIFES)||0.0288||0.034||0.039||0.0332||0.041||0.0289||0.0364||0.0471||0.0597||0.0218||0.016||0.0282|
|Cd (Low)||mg/kg||National Institute of Nutrition and Seafood Research (NIFES)||0.011||0.029||0.033||0.029||0.041||0.019||0.033||0.04||0.031||0.012||0.014||0.022|
|Cd (High)||mg/kg||National Institute of Nutrition and Seafood Research (NIFES)||0.038||0.039||0.049||0.041||0.041||0.038||0.041||0.054||0.11||0.033||0.018||0.038|
The sampling is mostly performed by one of the vessels from the Institute of Marine Research.
Aggregated samples of whole capelin weighing 5 kg are analysed from each position. Homogenised samples are freeze dried prior to analysis.
Freeze-dried samples are mixed with hydromatrix and an internal standard for PCDD/F, PCB and PBDE is added. The samples are extracted with hexane using Accelerated Solvent Extractor-300 (ASE) or Pressurised Liquid Extraction (PLE). The fat is broken down online with silica gel impregnated with sulphuric acid in the cells. The extract is further cleansed chromatographically on columns packed with multilayer silica, alumina and carbon, respectively, on Power Prep. 2 fractions are collected.
- Fraction 1 contains PBDE, PCBs and Mono-ortho PCBs.
- Fraction 2 contains dioxins, furans and non-ortho PCBs.
PBDE is analysed on GC/MS NCI and quantified with the help of an internal standard and a 5-point calibration curve. PCB7 is analysed with a GC/MS EI and quantified with the help of an internal standard and a monopoint calibration curve through origo. PCB7 is the sum of PCB 28, 52, 101, 118, 138, 153 and 180. Sum 7 PBDE is the sum of PBDE 28, 47, 99, 100, 153, 154 and 186. See, for example, Frantzen et al. (2010).
For PFAS: A mass-marked internal standard and methanol are added to a weighed amount of the sample and extraction is performed in an ultrasound bath. Following centrifuging, the supernatant is decanted into a syringe and filtered through a 0.45μm nylon filter before water is added, followed by cleansing on ASPEC. The extract from ASPEC is further cleansed by filtering through a 3K ultrafilter. The samples are ultimately analysed with an LC-MS/MS and quantified with the help of an internal standard. The method is validated, but not accredited.
A single method that determines many pesticides is used. Freeze-dried samples are mixed with hydromatrix and an internal standard is added and the samples are packed in ASE cells. The samples are extracted with hexane at 75ºC and a pressure of 1500 psi. The extract is vapourised to about 0.5ml on tubovap and then divided into two equal parts.
One of two methods is used for further cleansing and ultimate determination, depending upon whether the compound tolerates acid or not:
- Acid treatment, determines ultimately with a GCMS in EI
- Automatised SPE cleansing on ASPEC (3 columns: ChemElut, QuEChERS and C18), and then ultimate determination with a GCMS in NCI.
For both methods, the solvent is changed to isooctane and a recovery standard is added before analysis with a GC/MS. A calibration curve is developed with each series of samples and this is used for quantification.
- Analyses of aggregated samples give no information on the variation between fish caught at each position and limit the opportunity for statistical processing.
- Any time series must be interpreted bearing in mind that the fish that have been sampled are collected in different parts of the Barents Sea from year to year. Differences between years can therefore not necessarily be interpreted as time series for changes in levels.
- A lower Limit of Quantification (LOQ) and a measurement uncertainty for individual parameters in the analysis methods are given in the table below. When there are several congeners in the group, the LOQ and measurement uncertainty applies to individual parameters.
- For the pesticides (DDT, chlordanes, dieldrin, HCH, HCB and toxaphene), the method has been under development in the period the monitoring has been taking place, and the lower Limit of Quantification has changed considerably from year to year. The limits given here are those used today (as of September 2010).
|Parameter||LOQ||Measurement uncertainty %||Accredited?|
|PCB (28, 52, 101, 118, 138, 153, 180)||0.10 µg/kg||40||Yes|
|PBDE (28, 47, 99, 100, 153, 154, 186)||0.010 µg/kg||30–60||Yes|
|DDT and metabolites||0.9 µg/kg ww||40||No|
|Chlordanes (cis-, trans-, oxy-) and nonachlor (cis-, trans-)||0.15–0.9 µg/kg ww||40||No|
|Dieldrin||0.15 µg/kg ww||40||No|
|HCH (α, β)||0.3 µg/kg ww||40||No|
|γ-HCH||1.2 µg/kg ww||40||–|
|HCB||0.3 µg/kg ww||40||No|
|Toxaphenes (26, 40-41, 42, 50, 62)||0.6 µg/kg ww||40||No|
|Toxaphene 32||1.5 µg/kg ww||40||No|
|PFOS, PFOA, PFUnA||1.0–1.5 µg/kg||25||No|
The laboratory at the Institute of Marine Research is accredited in accordance with ISO 17025 (see the table above). All the methods are tested annually in proficiency tests.
Reference level and action level
Reference values for the unaffected state of substances not found in the natural environment, like persistent organic pollutants, will be zero (really the detection limit). Since these are in practice widespread, it will be natural to compare the levels in capelin with those measured in other comparable species.
Should capelin be used directly for human consumption, it will be relevant to compare with the maximum levels applying to products intended for human consumption in the EU and Norway (EU 2006 and FOR 2002-09-27 no. 1028, see the reference list). There are three persistent organic pollutants on this list, sum of dioxins, sum of dioxins and dioxin-like PCBs and sum of six non-dioxin-like PCBs.
The maximum levels set for food and feedstuffs for fish, however, cannot be applied directly to the levels in the fish. This is because the fish undergoes an industrial process en route to fish meal and fish oil, and thence to feed, which can change the content of contaminants from the raw material. It is only when the Norwegian Food Safety Authority takes samples from ingredients like fish meal and fish oil or the finished feed product that the maximum levels are applicable and measures can be taken if the concentrations are too high.
Status and trend
The cadmium level has been relatively stable since 2007, with concentrations well below the maximum level for animal feed (2 mg/kg feed product with 12 per cent water). In 2017 the average concentration of cadmium was the lowest that has been measured since monitoring started in 2007. All samples of capelin had low levels of both mercury and lead. Mercury levels were below the EQS of 0.02 mg/kg wet weight.
The levels of dioxins and dioxin-like PCBs, sum PCB6 and brominated flame retardant (PBDE) were low in 2018, as in previous years. The level of PBDE appears to have decreased since 2010, even though being above the EQS. The PCB7 level was below the EQS for the first time in 2017-2018, and future monitoring will show whether this is a decreasing trend.
The levels of HCB, dieldrin, toxaphene, chlordane and α-HCH in 2015-2018 were lower than the maximum levels for animal feed. However these limits only apply to capelin used as a raw material for fish feed, without being first processed into fish meal and fish oil. Partly because of changed analysis methods, it is not possible to determine whether there has been any real change in the level of pesticides in capelin over time.
Capelin may have consumed contaminants which have originated locally or been transported to the Barents Sea via atmospheric and ocean currents. Some environmental contaminants may occur naturally rather than being caused by pollution. This applies for example to cadmium.
The levels of contaminants in capelin are affected by the levels in what the capelin eat, which are medium sized zooplankton. Capelin are thus at a relatively low level in the food chain. Together with a short lifespan, this contributes to the level of contaminants in general being relatively low in capelin.
Levels of PBDEs appear to have been declining since 2010 through to 2018. One possible explanation might be the ban implemented within the EU since 2004, and consequently reduced use of these compounds.
Capelin contain relatively low levels of environmental contaminants, and no compounds have been shown to have levels exceeding the maximum levels for the safety of food and feed. The levels of contaminants in capelin is generally not a concern whether being used for human consumption or in fish feed. Nevertheless, these compounds will be transferred to organisms feeding on capelin, e.g., cod, marine mammals and seabirds, as well as species even higher in the food web. Environmental Quality Standards (EQS) have been set to protect the more vulnerable parts of the ecosystems. Of all the compounds that have been measured, only PBDEs currently show levels above the EQS, levels which have been set particularly low for PBDEs.
- EC (2002). Directive 2002/32/EC of the European Parliament and of the Council on undesirable substances in animal feed. Official Journal of the European Union.
- EC (2006). Commission regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union 364: 5–24.
- EC (2008). Directive 2008/105/EC of the European Parliament and of the Council of 16 December 2008 on environmental quality standards in the field of water policy, amending and subsequently repealing Council Directives 82/176/EEC, 83/513/EEC, 84/156/EEC, 84/491/EEC, 86/280/EEC and amending Directive 2000/60/EC of the European Parliament and of the Council. EU. Official Journal of the European Union 348: 1–27
- FOR 2002-09-27 nr. 1028. Forskrift om visse forurensende stoffer i næringsmidler.
- FOR 2002-07-07 nr. 1290. Forskrift om fôrvarer.
- FOR 2006-12-15 nr. 1446. Forskrift om rammer for vannforvaltningen.
About the monitoring
The indicator describes the levels of environmental contaminants in capelin and how these levels change with time.
Environmental contaminants in capelin have been monitored by the Norwegian Institute of Marine Research (before 2018: National Institute of Nutrition and Seafood Research, NIFES), since 2007. Sampling is mainly carried out at the IMR winter cruise in January/February. Normally samples are collected at three different locations, and often in different areas each year.
Places and areas
Data are collected to give a representative presentation of the situation for capelin in the Barents Sea, hence samples are taken at different positions every time. Each year, samples of capelin are taken at three locations in the Barents Sea.
Relations to other monitoring
- Monitoring programme
- International environmental agreements
- Voluntary international cooperation
- Related monitoring