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Marine chemical data


Nutrient and pollutant monitoring in the marine environment as a statutory task of the BSH

During monitoring cruises of the BSH vessels, samples of water, suspended particulate matter and sediment are taken at stations of the existing monitoring network. Part of the samples are processed and preserved on board for further analysis at the BSH’s laboratory in Hamburg-Sülldorf. The results of the analyses are used in national and international quality status reports (BLMP, OSPAR, HELCOM) and are published as information to the general public.The BSH laboratory at Hamburg-Sülldorf also specialises on determining the origin of oil spills at sea and on the coasts.

The following marine chemical data are collected and analysed at the laboratory:


Phosphate, nitrate, and silicate in sea water are essential trace substances that are needed in the formation of proteins and the shell material of diatoms. They are called nutrients because they promote growth. Too high nutrient input may cause over-fertilisation of a body of water.  

Organic pollutants

Most of the presently known chemical substances are organic compounds. About 2,000 of these substances are considered pollutants because they are either toxic or are not biodegradable or may accumulate in the food chain. The BSH routinely monitors some 100 organic substances.

Radioactive substances

Over the past years, the concentrations of most artificial radionuclides in the North Sea have decreased, while in the Baltic Sea elevated concentrations of the nuclide Cs-137 (caesium-137) are still measured today which exceed the levels before the Chernobyl reactor accident in 1986, though with a clearly decreasing tendency. Compared to the concentrations of natural radionuclides in the marine environment, the levels of artificial radionuclides are extremely low, so that hazards to flora and fauna or to human health due to the consumption of fish or other seafood are not to be expected.

Heavy metals

Metals occur naturally in the marine environment. There are numerous metals without which biological growth would not be possible. Organisms are adapted to a certain range of individual element concentrations. If this range is exceeded, negative impacts on the biotic communities within the ecosystem will occur. Human activities have led to major releases of particular elements into the environment and still continue to do so, causing natural background levels to be clearly exceeded locally.

Dissolved oxygen

Dissolved oxygen in water is a precondition for higher life forms in the ocean. The amount of dissolved oxygen in water is much smaller than in air (6.25 mg versus 300 mg per litre). While surface water is in permanent contact with the air and normally has a high oxygen content, oxygen deficiencies are not uncommon in the deepwater of the Baltic Sea.



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If you have any additional questions, please e-mail Dr. Norbert Theobald or phone +49 40 3190 - 3300


More information on the subject:
MUDAB database

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