Eutrophication as a Priority Issue of Water Quality in Small Retention Reservoirs

Abstract

The study aimed at comparing changes in the trophic status of waters in two small retention reservoirs "Otapy-Kiersnówek" and "Jasionówka", located in the Podlasie region, which have a similar way of management and the similarity of catchments, using the TSI trophy indicators. The obtained results show that total phosphorus is the limiting factor in both reservoirs. Analyzing the average annual value of TSI in the tested waters, it was found that both reservoirs can be classified as hypertrophic. Trophic state of the tested waters is strictly dependent on the processes taking place in their vicinity. The reservoirs revealed a clear effect of a surface runoff on water quality. Factors that favor the poor quality of water in both reservoirs are unfavorable morphometric conditions of reservoirs due to their small depth, which allows continuous mixing and strong heating of water in spring and summer. Additional causes can include an open space around the reservoirs and the lack of high vegetation that would shield the edges against the wind, which facilitates often mixing of waters to the bottom and resuspension of bottom sediments, which in turn increases the concentration of phosphorus in water.

Ecological risks of dammed reservoir waters using the example of the Turawa Reservoir in southern Poland

“…Sampling sites in reservoir feed waters are designated on the rivers: Mała Panew (1-14 and 16-18), Libawa (19)(20)(21)(22)(23) and Myślina (15). Ion concentrations are presented as an average value from three repetitions.…”

“…The problem of eutrophication affects all surface water types, from small watercourses to lakes and arti cial reservoirs, rivers and marine waters 18 . Some of the more vulnerable types exposed to eutrophication are shallow reservoirs fed by rivers whose catchments are located in agricultural areas 19 or exposed to other sources of nutrients, and it is in this context that the ecological and chemical status of the Turawa Reservoir retention waters was investigated. For more than three decades, an excessive bloom of cyanobacteria (Cyanophyta) has been observed in the reservoir, indicating its overfertilisation and progressive eutrophication process.…”

Assessment of the trophic state of the Soła River dam cascade, Polish Carpathians: a comparison of the methodology

“…It is therefore necessary to monitor the parameters of the reservoir water 2 , 3 . Identifying the trophic state of a reservoir is a very practical measure that is used for the comprehensive assessment of water quality in a reservoir 4 , 5 . Trophy reflects the abilities of the entire geosystem of the reservoir for biological production 6 , which includes food abundance, often called fertility.…”

Characteristics of Spatial Distribution of Phosphorus and Nitrogen in the Bottom Sediments of the Water Reservoir Poraj

“…The increase in the fertility of reservoirs is part of a natural process, which is sometimes referred to as "water aging" and is a manifestation of the natural evolution of all water reservoirs. Sometimes, however, it happens that the accelerated eutrophication of many reservoirs is the result of broader human activity [Siemieniuk et al 2016].…”