Włodzimierz Marszelewski

Lake surface temperatures [in “State of the Climate in 2015”]

Titulo del documento: State of the climate in 2015. Dentro del archivo completo se encontra el apartado correspondiente a Central America and the Caribbean.

Relationship between areal hypolimnetic oxygen depletion rate and the trophic state of five lakes in northern Poland

Relationship between areal hypolimnetic oxygen depletion rate and the trophic state of five lakes in northern Poland The oxygen content in a lake is a fundamental factor in lake ecology. In stratified lakes, deep waters are isolated from the atmosphere for several months during the summer; therefore, oxygen (substantially consumed by biological and chemical processes at this time) cannot be replaced before the autumnal mixing period. Hypolimnetic oxygen depletion has been considered an indicator of lake productivity since the early twentieth century. Many recent studies have been in opposition to this view by showing that the areal hypolimnetic oxygen depletion rate (AHOD) is poorly correlated with seston biomass and/or phosphorus concentration. The objective of this study is to show relationships between the mean values of total phosphorus (TP), total nitrogen (TN), chlorophyll a, and water transparency (Secchi disk depth, SDD) during the thermal stratification formation period and the AHOD rate. Hypolimnetic oxygen conditions in five dimictic lakes in northern Poland were examined in 2009 and 2010. Two of them were studied in the previous year. Monthly oxygen profiles taken from April to August, midsummer temperature profiles, and morphological data of the lakes were used to determine the AHOD rate. Standard water quality parameters such as concentrations of chlorophyll a, TP, and TN, as well as water transparency measured at the same time were used to calculate the trophic state indices (TSI) according to the Carlson-type formulas. On the basis of the collected data it is shown that AHOD is highly correlated with the TSI value for chlorophyll a, and poorly correlated with the TSI values for water transparency and phosphorus content. The best correlation between AHOD and TSI has been found for chlorophyll a (r2=0.702; p<0.001), as well as for overall TSI, determined by averaging separate component indices (r2=0.826; p<0.000). No correlation was found between AHOD and total nitrogen concentration. The research also confirmed previous observations, which pointed to a significant role of the hypolimnion depth in increasing oxygen deficits.

Dynamics and consequences of water level fluctuations of selected lakes in the catchment of the Ostrowo-Gopło Channel

Abstract The article discusses water level fluctuations in lakes and the associated changes in the lake surface and water resources in the years 1992-2011. On the basis of detailed field studies carried out in the hydrological year 2011, short-term and dynamic changes in the lakes’ hydrology were determined. Changes in hydrological lake types were evoked by unexpected hydro-meteorological situations, in particular high precipitation totals and sudden thaws in winter. The main symptom of the lake type change was the restoration, after nearly 10 years, of channels connecting the lakes. In addition, a strong interdependence was recorded in the difference between evaporation and precipitation, as well as the mean annual ranges of lake water levels in the years 1992-2010

Understanding Abiotic and Biotic Conditions in Post-Mining Pit Lakes for Efficient Management: A Case Study (Poland)

This study was aimed at determining whether the origin, morphometry, and hydrology of post-mining lakes affect their hydrochemical and hydrobiological parameters (i.e. water quality). The investigated post-mining lakes were very young compared to glacial lakes and represent early stages of ecosystem succession. Despite their different ages and morphometries, they are all mesotrophic and have good water quality. They have not been supplied with phosphorus and nitrogen, which can cause excessive development of pelagic phytoplankton; as a result, they share low chlorophyll a (Chl a) content, low phytoplankton biomass, and relatively high water transparency. Low abundance and species richness of zooplankton indicate low trophic levels in all of the lakes. Chl a in Lakes Przykona and Bogdałów were within the range typical of mesotrophic lakes, while Lake Janiszew had very low Chl a, typical of an oligotrophic water body. The low N:P ratios (4–6), especially in summer, indicates nitrogen limitation of primary production. There is a risk that such a proportion of the major biogenic elements could lead to harmful cyanobacterial blooms. The lake basins were formed using quaternary deposits (sand, clay) at their bottoms; as a result, the lakes had a slightly alkaline pH (>8), which favors the development of aquatic organisms. Optimum depth helps establish lake stratification and ensures ecological stability. This applies to post-mining lakes as well; an optimum depth should be determined to ensure the development of thermal stratification, which affects lake processes.ZusammenfassungDiese Studie sollte ermitteln, ob der Ursprung, die Morphologie und Hydrologie von Bergbauseen Auswirkungen auf hydrochemische und hydrobiologische Parameter (z.B. Wasserqualität) haben. Im Vergleich zu glazialen Seen sind die Bergbauseen sehr jung und haben frühe Stadien der Ökosystemfolge. Trotz unterschiedlicher Alter und Morphologie sind sie alle mesotroph und haben gute Wasserqualität. Phosphor und Stickstoff wurden nicht zugeführt, welche exzessive Vermehrung von pelagischem Phytoplankton bewirken können; daraus resultiert ein niedriger Chlorophyll a-Gehalt (Chl a), eine geringe Phytoplanktonbiomasse und eine relativ hohe Transparenz des Wassers. Eine geringe Menge und Artenarmut von Zooplankton indizieren in allen Seen geringe Nährstoffgehalte. Chl a in den Przykona und Bogdałów Seen war in der gewöhnlichen Bandbreite mesotropher Seen, während der Janiszewsee sehr wenig Chl a enthielt, typisch für ein oligotrophes Gewässer. Niedrige N:P Verhältnisse (4–6), besonders im Sommer, zeigen an, daß die primäre Produktion N-limitiert ist. Dieses Verhältnis der wichtigsten biogenen Elemente bedeutet ein Risiko der Entstehung schädlicher Blüten von Cyanobakterien. Die Böden der Seebecken wurden aus quartärem Material (Sand, Ton) hergestellt; deshalb haben die Seen leicht alkalischen pH (>8), was die Entwicklung aquatischer Organismen fördert. Eine optimale Tiefe fördert eine Stratifikation der Wasserkörper und garantiert ökologische Stabilität. Das gilt auch für Bergbauseen; die optimale Tiefe sollte erkundet werden, um die Entwicklung einer thermalen Stratifikation zu sichern, welche limnische Prozesse steuert.ResumenEste estudio fue realizado para determinar si el origen, morfometría e hidrología de los lagos postminería afectan sus parámetros hidroquímicos e hidrobiológicos (i.e. calidad del agua). Los lagos postminería investigados fueron muy recientes comparados con lagos glaciales y representan estados tempranos del desarrollo sucesivo dentro del ecosistema. Independientemente de sus diferentes edades y morfometrías, ambos tipos de lagos son mesotróficos y tienen una buena calidad de agua. En general, no poseen fósforo y nitrógeno que podría causar un excesivo desarrollo de fitoplancton pelágico; debido a eso, comparten bajo contenido de clorofila a (Chl a), baja biomasa de fitoplancton y relativamente alta transparencia del agua. La baja abundancia y riqueza de especies de zooplancton indican bajos niveles tróficos en todos los lagos. La Chl a en los lagos Przykona y Bogdałów estuvieron dentro del rango típico de los lagos mesotróficos mientras que el lago Janiszew tenía muy baja cantidad de Chl a, típico de un cuerpo de agua oligotrófico. La baja relación N:P (4-6), especialmente en verano, indica limitación de nitrógeno para la producción primaria. Hay cierto riesgo de que tal proporción de los principales elementos biogénicos pudieran generar floraciones de cianobacterias nocivas. Las cuencas del lago fueron formadas con depósitos cuaternarios (arena, arcilla) en el fondo; como un resultado de ello, los lagos tenían un pH ligeramente alcalino (> 8), lo que favorece el desarrollo de organismos acuáticos. La profundidad óptima ayuda el establecimiento de la estratificación del lago y asegura la estabilidad ecológica. Esto aplica también a lagos formados luego de la actividad minera; una profundidad óptima debería ser determinada para asegurar el desarrollo de la estratificación termal que afecta los procesos en el lago.摘要

Relation Between Air Temperature and Inland Surface Water Temperature During Climate Change (1961–2014): Case Study of the Polish Lowland

The chapter describes the relations between changes in mean annual and mean monthly (1961–2014) air and water temperatures in rivers and lakes, as well as their spatial variability in the Polish Lowland. The determination of the directions and rate of changes in air and water temperatures involved the application of linear regression. Its significance was verified by means of F test at a level of 0.05. The rate of increase in air temperature in the western part of the Polish Lowland was determined to average 0.32 ℃·10 years−1 and decrease towards its eastern part to 0.22 ℃·10 years−1. In the case of rivers, the mean increase in water temperature varied from 0.26 ℃·10 years−1 in the western part to 0.20 ℃·10 years−1 in the eastern part, and for lake waters, from 0.30 to 0.15 ℃·10 years−1. Increase in water temperature in particular months throughout the analysed period was much more variable. Its highest increase occurred in May and ranged in lakes from 3.1 to 3.9 ℃, and in rivers from 1.9 to 2.6 ℃. The lowest increases in water temperature (usually from 0.1 to 1.0 ℃) were observed in autumn and winter months, whereas water temperature in some lakes showed a negative tendency in winter months. In the case of Lake Hancza, in November it decreased during the analysed period by 1.3 ℃. During longer periods such as a year or half-year, an evident increase was found to occur in air and inland water temperature. During shorter month-long periods, the increase is not always so evident, and sometimes even a decrease in temperature is observed.

Differentiation of the concentration of heavy metals and persistent organic pollutants in lake sediments depending on the catchment management (Lake Gopło case study)

This paper presents the results of the study on the concentration of heavy metals and persistent organic pollutants (POPs), including PAHs and PCBs, in the bottom sediments of Lake Goplo. This lake is significantly elongated (about 25 km); its longitudinal profile is diversified, and there are deeps and thresholds impeding the flow of water. The shoreline is varied, which is characteristic of tunnel valley lakes. The catchment has a typical agricultural character with a point arrangement of industrial centres. The analysis of the diversity of the concentration of heavy metals and POPs was based on 37 samples from two representative cores: one collected in the northern part of the lake, the catchment of which shows an industrial character, and the second one in the southern part where the catchment is agricultural in character. In the sediments, the content of the following heavy metals was analysed: Cu, Pb, Cd, Zn, Ni, Cr, Hg and As, as well as PAHs and PCBs. The sediment age was determined by the 210Pb dating method. In order to assess the contamination level of the bottom sediments with heavy metals, the contamination factor (CF) and degree of contamination (DC) were calculated. Moreover, the impact of the changes in the catchment’s land use over the past 100 years was determined. The results showed that the sediments from the industrial part of the lake significantly exceed the geochemical background for both the heavy metals from the group identified as industrial pollution and from the group of agricultural pollutants. The southern core shows only a slight increase in the amount of pollution from the agricultural group, lack of industrial pollution and a low degree of contamination. A slight increase in persistent organic pollutants is also recorded, without any apparent effect on the state of the deposited sediment. The 210PB dating enabled the main stages of human impact to be determined: the pre-industrial revolution, from the beginning of industrialisation to the 1950s, intensive human impact from the 1960s to the 1980s, and a gradual decrease in the human impact starting from the 1990s. In addition, attention was paid to the changing sedimentation rate.

Dammed lakes – Present state of knowledge and research requirements

Abstract The paper presents the current state of knowledge on dammed lakes in Poland and identifies the crucial research necessities in this area. The analysis of documents concerning dammed lakes and information obtained from institutions responsible for water management in Poland were the basis for a preliminary qualitative and quantitative assessment of dammed lakes located in north-west Poland. This allowed the identification of the necessary directions to be taken in the study of dammed lakes. In many cases, the indicated directions are innovative and have high potential for application.