Pollutants in capelin (Mallotus villosus)

Capelin on white background.
Photo: Institute of Marine Research

Capelin is an important species in the ecosystem of the Barents Sea and pollutants in capelin would rapidly be transferred upwards in the food chain. Capelin contain low levels of pollutants. There has been little change over time, with the exception of PBDE, which has declined.

What is being monitored?

POPs in capelin

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The levels of HCB, dieldrin and chlordane in 2013-2018 were generally lower than the maximum levels applying to animal feedin EC and Norway. Partly because of changed analytical methods, it is not possible to assess whether there has been any real change in the level of pesticides in capelin over time. HCB levels are well below the environmental quality standard (EQS) for HCB, which is 10 μg/kg wet weight.

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The data set shows levels of PBDE7 measured in capelin in the Barents Sea. PBDE levels in capelin are well above the environmental quality standard for PBDE6, which is 0.0085 μg/kg wet weight.

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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 2019, the mean cadmium concentration was around the mean for the entire period.

Status and trend

Capelin from the Barents Sea generally have low levels of environmental contaminants. Cadmium levels have been relatively stable since 2007, with concentrations well below the limit for fish feed (2 mg/kg feed product with 12 per cent water). In 2019, the mean cadmium concentration was around the mean for the whole period.

Levels of dioxins and dioxin-like PCBs, such as PCB6 and brominated flame retardant (PBDE), were low during 2019, as in previous years.

There do not appear to have been any changes in the levels of dioxins and PCBs since monitoring began in 2007, while the level of PBDE has been lower since 2010. Nevertheless, PBDE levels in capelin are well above the environmental quality standard for PBDE6, which is 0.0085 μg/kg wet weight.

In 2017 and 2019, the levels of the brominated flame retardants HBCD and TBBP-A were also measured in capelin. Levels of α-HBCD were approximately equal to the level of total PBDE7, while TBBP-A was below the measurable level.
Levels of HCB, dieldrin, toxaphene, chlordane and α-HCH in 2013-2018 were generally lower than the limits set for the sale of feed. The exception was one sample in 2013 that had a toxaphene level of 7.2 µg/kg wet weight, while the limit converted to wet weight is 5.7 µg/kg. However, these limits only apply to capelin used as a raw material for the feed industry, without being first processed into fish meal and fish oil.

Levels of HCB were also well below the environmental quality standard of 10 μg/kg wet weight set for this substance. Other chlorinated pesticides for which there are environmental quality standards are endosulfan, heptachlor and heptachlor epoxide, as well as total DDT. Levels of heptachlor and heptachlor oxide are above the environmental quality standard, while the other substances are well below it.

Partly because different methods of analysis have been used, for some pesticides it is not possible to assess whether there have been any real changes in pesticide concentrations in capelin over time. For cis-Chlordane, the levels in capelin from 2014 onwards have been lower than previously.

Levels of all measured PFAS compounds were below the respective detection limits. This means that all samples are well within the environmental quality standard set for PFOA of 91.3 μg/kg wet weight.

During the period 2013-2019, PAH compounds in capelin were also analysed. Only a few of the substances showed measurable, but low, levels.

Causal factors

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.

The quantities of pollutants in capelin affect the level of pollutants in species which feed on the species, such as herring, cod, marine mammals and sea birds, as well as species higher up the food chain.

Consequences

Capelin contain relatively low levels of environmental contaminants. There is no evidence of any increases in the pollutants which were analysed.

Levels of PBDE, heptachlor and heptachlor epoxide are consistently above the environmental quality standards for these substances. These are man-made substances which should not have been present in the environment at all. Environmental quality standards are set at a low level in order to protect the most vulnerable species at the top of the food chain, such as seabirds and marine mammals.

EU legislation:

  • 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

Norwegian legislation:

About the monitoring

The indicator describes the level of pollutants in capelin and how this level changes over time.

Concentrations of pollutants in capelin from the Barents Sea were first analysed in 2000, and has been monitored by the Institute of Marine Research (HI) every year since 2007 (before 2018; National Institute of Nutrition and Seafood Research, NIFES).
The sampling is primarily carried out on the Institute of Marine Research's winter expedition in January/February. In general, testing is performed at three different positions, often in different areas from year to 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