Principal component analysis (PCA) is a favorite tool in environmetrics for data compression and information extraction. It has shown a great efficiency in various applications both in chemistry and biology.

The content and character of accumulation of heavy metals (Pb, Cd, Zn, Mn and Co) which are the most dangerous and well studied pollutants of superficial waters, in three kinds of fish of different trophic levels were investigated. There are pseudobenthophage (roach), both predators — a perch and a pike (in a food of the perch, along with fish, the important place belongs to bottom dwellers; the pike diet consists exclusively of fish).

Metals in fish are not evenly distributed. It is associated with biochemical features of organs and tissues, specificity of physiological functions, non-identical behavior of different forms of metals, and etc. It was revealed that the analyzed organs and tissues accumulate various metals in different degrees.

Fig. 1. Principal component analysis. Distribution of samples in liver of fish.

Liver, as an organ where occurs detoxication of xenobiotics, represents an interest (Fig. 1). Pb, Cd, Mn and Co are more accumulated in the liver. Application of PCA has allowed to distinguish different kinds of fish of different trophic levels on the content of heavy metals in the liver (Fig. 1). At the first it depends on differences in their ecology, mainly in the feeding nature.

Fig. 2. Principal component analysis. Distribution of samples in muscles of fish depending on gender.

Muscles also serve as indicators of pollutions, but in lesser extent than the liver. Muscle, like the liver, can be attributed to the deposition agencies because it constitutes a large percentage of body weight. The PCA revealed sex differences in deposition of metals in the muscles of all investigated fish whereas in a liver the similar was not observed (Fig. 2).

Work is executed at Russian Federal Property Fund support (the grant № 08-05-98029-r_Sib_a)