Application of Macrophytes to the Assessment and Classification of Ecological Status above and below the Barrage with Hydroelectric Buildings

Abstract

The key goal of the Water Framework Directive is to achieve a good ecological status in water bodies. The ecological status is mainly determined by the biological elements, which are a very good indicator of the changes taking place in water environments. Thus, this article focuses on the analysis of different methods of assessment of the ecological status of water bodies based on macrophytes used in selected countries in the European Union (the Macrophyte Index for Rivers (MMOR)—Poland; the Mean Trophic Rank (MTR)—Ireland; the Trophic Index of Macrophytes (TIM)—Bavaria, Germany; the Bulgarian Reference Index of Macrophytes (RI-BG)—Bulgaria). Three research sections have been selected for research on the river Ślęza: The reference section, the section above the barrage and the section below the barrage. The analysis carried out revealed considerable similarity between the results obtained by all these methods—the differences were at most by one class of ecological status (and the analysis of sums of Wilcoxon’s ranks revealed that there were no differences between the results obtained using different methods, i.e., p = 0.860). With respect to surface waters, investigation of biological elements is important because it allows one to retrace the past and foresee the future based on the past and present trends in the changes occurring in the species diversity and structure of not only macrophytes, but also other groups of organisms. Further action is required that would determine the scope of influence of barrages with hydroelectric buildings on the environment (in the case of the investigated barrage this influence is negative).

Challenges in the Development of Hydropower in Selected European Countries

“…Comprehensive planning and the impact assessment of the activities, including the development of compensatory measures and a monitoring system [61], are necessary. This is in line with the principle of sustainable development, considering natural, social, and economic interests [62].…”

The Macrophyte Index for Rivers (MIR) as an Advantageous Approach to Running Water Assessment in Local Geographical Conditions

“…The analyses carried out with the use of a uniform formula revealed that the detected differences in biomonitoring result not only from the different equations used, but also from the set of species and their ascribed indicator values. The significant differentiation of sets of indicator species considered by various macrophyte systems on lowland rivers has already been demonstrated in the literature [50]. The weaker response of the foreign methods compared with the MIR persisted even when the assessment was based on a uniform equation.…”

Determination of Changes in the Quality of Surface Water in the River—Reservoir System

“…According to Iticescu et al [27], the highest WQI index was in summer 2015 (WQI above 80), and the lowest in winter 2014 (WQI below 50). Tomczyk et al [19] emphasized that, in the assessment of water quality in a river-reservoir system, the physico-chemical properties are important in assessing the degree of water pollution.…”

“…According to Malik and Hashmi [6], surface water is used for various purposes, such as drinking water supply and irrigating farmland; hence, water quality is also closely related to public health. Therefore, monitoring of water quality parameters should be carried out at various points in a river network to prevent river pollution and apply remedial policies [1,19]. The monitoring of water quality is also important in modelling water resources [20] and the distribution of pollutants, source location, and health hazards, in addition to protecting water resources and controlling water pollution [21].…”