Measures

Water and lipid

Many analytical methods for determining substance concentrations require dried samples. The respective results are based on dry weight. Dry weight-based concentrations are standard for instance for metals and organotin compounds. Nevertheless, comparability with published wet weight-based data may require the calculation of substance concentrations based on wet weight: for instance as comparison if effect concentrations on a cellular level are known for a specific compound. To accomplish this, the water content of the samples is determined as difference between fresh weight and dry weight by an appropriate drying method. Moreover, the water contents may give information about the physiological state of the organisms.

Non-polar organic compounds are often persistent and tend to bioaccumulate. Due to their fat solubility (lipophilicity) they are concentrated mainly in the lipid fraction of organisms. Depending on their lipid contents, residue levels may differ considerably between individuals, species and size groups. Variations in these data often can be reduced when normalising chemical concentrations by lipid content. Furthermore, lipid normalisation facilitates the comparison between species and sites.

Substances

  • Lipid content
    Parameter to normalise concentrations of lipophilic substances
  • Water content
    Parameter to calculate wet weight from dry weight and vice versa

Specimen

  • Common mussel species as invasive animal in rivers and lakes with high information level for water pollution
  • Bioindicator in rivers and lakes
  • Common brown alga of the coastal areas of the North and Baltic Sea
  • One of the most important edible mussel species common in the North and Baltic Sea
  • As the only viviparous fish in German nearshore waters, it is a bioindicator in nearshore coastal marine ecosystems.
  • Inshore, the herring gull mainly feeds from the sea: upon fish, mussels, and crabs.
  • A major primary producer in semi-natural and anthropogenic affected ecosystems.
  • A major primary producer in semi-natural and anthropogenic affected ecosystems.
  • A deciduous tree typical of ecosystems close to dense conurbations and an indicator for the characterisation of the immission situation during the vegetation period.
  • As the most dominant deciduous tree species in Central Europe, it plays a significant role in most nearly natural and also anthropogenically influenced forest ecosystems up to an altitude of 1100 m.
  • The roe deer is the most common of the larger herbivores (first order-consumer) to be found in the wild in Europe.
  • A pigeon species home in nearly every city.
  • As an organism living at ground level, it is a major driver of the decomposition of organic material (e.g. plant litter).
  • As an organism living at ground level, it is a major driver of the decomposition of organic material (e.g. plant litter).
  • Soil is livelihood and biosphere for humans, animals, plants and soil organisms. All the substances brought in are transported, transformed and/or accumulated in the soil.

Sampling area

Sampling period

1985 - 2019