Application of macrophytes to compare the assessment of the ecological status of the Pilica River in years 2012 - 2015

Abstract

Directive 2000/60/EC commonly called the Water Framework Directive defined as a new way of assessing the state of surface water based on two types of water bodies: natural and artificial or heavily modified water body. The assessment is made by comparing surface water status with the reference state, that is, a state close to completely natural one, based on biological, physicochemical and hydromorphological elements. The ecological state of surface water, together with the surface water chemical status is used to determine the general surface water status. The ecological state of surface water is responsible for the quality of the structure and the functioning of the aquatic ecosystem, while the chemical state is responsible for appearance in water of particularly harmful substances for the aquatic environment. The present paper compares the ecological status of the Pilica river waters in 2012 – 2015 with the use of aquatic plants as ecological quality indicators according to the requirements of the Water Framework Directive. Research was conducted in three different sections of the Pilica river, which were within the boundaries of separate but adjacent surface water body. The field research were carried out using a Polish research method called The Macrophyte Method for River Assessment (MMRA). The method is based on quantitative and qualitative evaluation of species compositions of macrophytes within a designated river section. MMRA allows the evaluation of the macrofit reaction (bioindicators of ecological quality) mainly on the degradation associated with trophic impurities. This method has been developed and successfully used to assess ecological status of rivers throughout the country. In this article, special emphasis was placed on comparative analysis of results obtained from field measurements in the years 2012 – 2015, supported by theoretical knowledge on the assessment of ecological quality of surface water. The results of the evaluation showed improvement of the ecological status of the Pilica river on two research sections: Przyłęk and Kuźnica Wąsowska, and a slight decrease on quality on the Szczekociny research section.