Deep analysis of trophic state assessment methods has led to conclusion, that currently there is no universal methodology and existing methods are characterized by significant shortcomings. The approach proposed by the authors is different from generally used. Authors start from the assumption, that trophic state can be reflected by the state of biotic balance, which can be described by the values of Index of Trophic State. Researches were carried out in order to assess the trophic state of running waters and to estimate the limiting role of biogenic substances for eutrophication process development on the base of author's concept founded on above mentioned index.
 Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for community action in the field of water policy (in Polish: Dyrektywa 2000/60/WE Parlamentu Europejskiego i Rady z dnia 23 października 2000 r. ustanawiająca ramy wspólnotowego działania w dziedzinie polityki wodnej). http://eur-lex.europa.eu.
 Council Directive 91/676/EEC of 12 December 1991 concerning the protection of waters against pollution caused by nitrates from agricultural sources (in Polish: Dyrektywa Rady z dnia 12 grudnia 1991 r. dotycząca ochrona wód przed zanieczyszczeniami powodowanymi przez azotany pochodzenia rolniczego 91/676/EWG). http://eur-lex.europa.eu.
 Council Directive 91/271/EEC of 21 May 1991 concerning urban waste-water treatment (in Polish: Dyrektywa Rady z dnia 21 maja 1991 r. dotycząca oczyszczania ścieków komunalnych 91/271/EWG). http://eur-lex.europa.eu.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.