Shortened evaluation of surface water quality of Warnowskie Lakes (Wolin National Park)

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1 Limnological Shortened Review evaluation 8, 1-2: of surface water quality of Warnowskie lakes (Wolin National Park) 21 Shortened evaluation of surface water quality of Warnowskie Lakes (Wolin National Park) Krzysztof Grzegorczyk 1), Gorzysław Poleszczuk 2), Anna Bucior 2), Iwona Jóźwik 2) 1) Woliński Park Narodowy, ul. Niepodległości 3, Międzyzdroje, tel. (091) , 2) Uniwersytet Szczeciński, Katedra Chemii i Ochrony Środowiska Wodnego, ul. Felczaka 3C, Szczecin, tel. (091) , polesz@univ.szczecin.pl; Abstract: In spring and summer of 2005, quality of surface waters from Warnowo, Rabiąż, Czajcze and Domysłowskie Lakes has been investigated. Mentioned lakes are situated within boundaries of Wolin National Park on Wolin island territory. During analysis 19 chosen indicators of water quality have been determined: temperature, ph, COD-Mn, BOD 5, dissolved oxygen concentration, oxygenation level, content of dissolved organic matter, concentrations of NH 4+, NO 2-, NO, PO 4 and P tot., and water mineralization indices: specific electrolytic conductivity, concentrations of Ca 2+, Mg 2+, Cl - 2-, SO 4, total alkalinity and Fe tot. and Mn tot. concentrations. Collected water samples were taken from surface layer. Quality of waters was determined in accordance with valid regulations obligatory in Poland. Results of researches confirmed that examined waters had declined quality as evidenced by contents of PO 4 and P tot. (III, V class) and determination values of COD-Mn and BOD 5 (III and IV class). Obtained values show that waters were enriched in dissolved organic matter. Values of ph and oxygen regime suggest that dissimilation processes predominated over assimilation in all studied water ecosystems. Vast amount of biogenic substances (especially concentrations of mineral forms of nitrogen, but first of all amounts of PO 4 and P tot. ) suggest eutrophic and politrophic status of all lakes. Simultaneously examined waters were poorly mineralized showing relatively stabilized concentrations of examined ionic macro components of waters. Assessment of all obtained values leads to conclusion that before our researches ecosystems of Warnowskie Lake District were exposed to moderate anthropopression. Key words: surface waters, water quality, Wolin National Park, Warnowo Lake, Rabiąż Lake, Czajcze Lake, Domysłowskie Lake. Introduction Wolin National Park (WNP) situated on Wolin Island (north-west Poland) comprises not only marine ecosystems (Baltic Sea) and estuarine ecosystems (Szczecin Lagoon) but also lacustrine ecosystems, among them Warnowo, Rabiąż, Czajcze and Domysłowskie lakes, located in central part of Wolin island (Fig. 1, Tab. 1). All mentioned lakes are flowthrough lakes and belong to Warnowskie Lake District. The purpose of present paper is to carry out a shortened assessment of surface water quality of studied lakes, using official criteria applied for evaluation of surface water quality, obligatory in Poland (Rozporządzenie, 2004). Assessment was made basing on relatively small number of chosen water quality indicators, collected during examinations which had been carried in spring and summer of Table 1. Morfometric characteristics of lakes: Warnowo, Rabiąż, Czajcze and Domysłowskie (Choiński 1987). Lake Altitude (m above sea level) Surface (km 2 ) max. Depth (m) average Volume (thousand m 3 ) Max. length (m) Max. width (m) Cryptodepression (m) Warnowo Lake 1,4 0,127 2,1 1,3 160, ,7 Rabiąż Lake 1,4 0,182 2,8 1,5 280, ,4 Czajcze Lake 1,3 0,812 6,0 2,9 2316, ,7 Domysłowskie Lake 1,3 0,529 3,1 1,9 1018, ,8

2 22 Krzysztof Grzegorczyk, Gorzysław Poleszczuk, Anna Bucior, Iwona Jóźwik Fig. 1. Warnowo, Rabiąż, Czajcze and Domysłowskie lakes in Wolin National Park (WNP). 1 - lakes, 2 parts of Struga Lewińska, 3 watercourse between Wisełka and Czajcze lake (partially buried), 4 sampling stations (A-D), 5 borders of WNP, 6 direction of water flow, 7 slopes, 8 railway, 9 roads, 10 buildings. Research area Waters of Warnowo, Rabiąż, Czajcze and Domysłowskie lakes which were examined in our paper can be described as shallow, post-glacial, ribbon lakes supplied by precipitation waters (direct precipitation and surface run-off) and subsoil waters outflowing from the moraine plateau of Wolin island. Excess of those waters downflows by the watercourse of Lewińska Struga subsequently from Warnowo, Rabiąż, Czajcze and Domysłpowskie lakes, and further runs through lakes located out of Wolin National Park area, finally discharging into Kamieński Bay. Literature data (Poleszczuk 1994, 1996; Poleszczuk et al. 2005a) reveal that lakes under studies are abundant in dissolved organic matter and are classified in terms of eutrophication as eu-politrophic and poorly mineralized as far as concentration of ionic macro components of waters is regarded. According to quality assessment, carried out by PIOŚ (2002) Rabiąż lake was assigned to III class of purity, whereas Warnowo lake fulfills requirements of II class of purity. Simultaneoulsy all mentioned lakes were very susceptible for eutrophication (out of classification). Materials and methods Quality of surface waters of Warnowo, Rabiąż, Czajcze and Domysłowskie lakes was assessed using 19 indicators of water quality (18 classified in Rozporządzenie, 2004) accepted as essential for defining total status, trophic status and water mineralization level.

3 Shortened evaluation of surface water quality of Warnowskie lakes (Wolin National Park) 23 Water samples were collected to plastic or glass bottles (in accordance with PN/C ) from the depth of 0,5 m below the water level in places of measurements (Fig. 1) in two arbitrary chosen dates, in spring and summer of In place of water sampling, temperature, ph, electrical conductivity and total alkalinity were determined. Collected water samples were stabilized and fixed in compliance with Polish Norms (PN/C ). Other indices of water quality were determined in laboratory within 24 hours: COD-Mn, BOD 5, concentrations of dissolved oxygen, NH 4+, NO 2-, NO, PO 4 diss. and P tot. contents of ionic macro components of waters calcium, magnesium, chlorides, sulphates (VI), and also concentrations of Fe tot. and Mn tot. Additionally, water oxygenation was measured. All analysis were conducted according to regulations contained in compendium of Hermanowicz (1999). Results and discussion Results of measurements of selected indicators of water quality of Warnowo, Rabiąż, Czajcze and Domysłowskie lakes with categorization of obtained values, classified in accordance with criteria included in Rozporządzenie (2004) were presented in Tab. 2. In period of measurements (spring and summer of 2005) waters of all lakes revealed moderate ph level - near neutral (I quality class). Oxygene regime varied in consequtive lakes and was changing due to seasonal changes during the year, especially in springtime (April) waters were highly deoxygenated (especially waters of Domysłowskie lake were deoxygenated in 50%) while in summer (July) oxygenation was high (approximately 100%) in Rabiąż lake or insufficient (70-80%) in other water bodies. Such a considerable oxygen deficit in waters of shallow polymictic lakes, apart from freezing time (Letki, 1984), as well as insufficient oxygenation of water in summer time, with relatively low ph values, proves the prevailence of dissimilation over assimilation processes. Waters of investigated lakes contained significant quantity of organic matter, what can be confirmed by results of determination of COD-Mn and BOD 5 (values always corresponded to III IV class of water purity).examined waters always contained relatively small amount of NO 3 - and NO 2-, both in spring and in summer. Concentrations of NH 4 + were decreased in summer (I-II class of water quality) whereas high content of NH 4 + was observed in spring only in the case of Warnowo and Domysłowskie lakes (III class of water quality). Concentrations of PO 4 diss. i P were formed tot. very specifically, especially in Warnowo (PO and 4 diss. P tot corresponded to III and V class of water quality, adequately) and in Czajcze lake (III class of water quality according to P tot. ). In summer time values of indices characterizing amount of dissolved phosphorous compounds were relatively low. Concentration of PO 4 assigned waters of Rabiąż Lake to II class, diss. while waters of Domysłowskie Lake to III class of water quality. Concentration of P tot. was adequate to II class only in waters of Warnowo Lake. Assessment of water quality according to number of P tot. in period of spring circulation (Lampert and Sommer 2001, p. 352), revealed that waters of Warnowo and Czajcze lakes have high trophic status. Comparatively low amount of total phosphorous in summer time in comparison to spring time was typical for eutrophic lakes (Lampert and Sommer 2001, p. 342). Increase of PO 4 in Rabiąż and Domysłowskie lakes diss. in summer in comparison to spring, most probably resulted from supplying both lakes by waters abundant in phosphorous compounds, which had been dowflowing with Struga Lewińska watercourse from Warnowo and Czajcze lakes, adequately. Changes in number of phosphorous compounds along the downflow of Struga Lewińska waters from Warnowo to Domysłowskie Lakes suggest that most abundant in phosporous compounds were Warnowo Lake and in lesser degree Czajcze Lake. Mentioned lakes were probably exposed to stronger anthropopression due to discharge of municipal sewages into ground and into subsoil waters and also due to surface and subsoil runoff of precipitation waters from the farms fertilized with natural manures and artificial phosphorus fertilizers. In case of Warnowo pollutions and nutrient supply come from buildings of Warnowo village and surrounding fields. Increased concentration of phosphorous compounds in ecosystem of Czajcze Lake is related to inflow of waters from Wisełka Lake, enriched in phosphorous compounds, what can be confirmed by the fact thar Wisełka lake is located close to well-known health resort of Wisełka a major source of nutrient enrichment. Watercourse connecting Wisełka and Czajcze Lakes had been, in the matter of facts, partially buried since the half of 90- thies of the last century albeit waters of Wisełka Lake still percolate to Czajcze Lake. Substantial pollution of surface and subsoil waters of Wolin National Park ecosystems by phosphorous compounds was ascertained earlier (Poleszczuk et al.

4 24 Krzysztof Grzegorczyk, Gorzysław Poleszczuk, Anna Bucior, Iwona Jóźwik Table 2. Results of researches on quality of surface waters from Warnowo, Rabiąż, Czajcze and Domysłowskie lakes (spring and summer of 2005) and classification of obtained values in accordance with Rozporzdzenie (2004). Lp. No Water quality indices (units) Warnowo Lake Rabiąż Lake Czajcze Lake Domysłowskie Lake I. General parameters I.1 Temperature of water ( C) 3,0 (I) 20,0 (I) 1) 3,0 (I) 20,0 (I) 2,0 (I) 19,0 (I) 2,0 (I) 19,0 (I) I.2 ph (ph units) 7,66 (I) 7,85 (I) 7,64 (I) 7,79 (I) 7,71 (I) 7,70 (I) 7,69 (I) 7,81 (I) I.3 COD-Mn (mg O 2.dm -3 ) 7,5 (III) 9,7 (III) 8,0(III) 8,6 (III) 6,9(III) 8,6 (III) 10,5 (III) 10,8 (III) I.4 BOD 5 (mgo 2.dm -3 ) 2,7 (II) 6,3 (IV) 3,5 (III) 5,0 (III) 2,3 (II) 4,8 (III) 4,7 (III) 4,7 (III) I.5 O 2 diss. (mg O 2.dm -3 ) 8,2 (I) 6,6 (I) 8,0(I) 9,0 (I) 8,2 (I) 7,4 (I) 7,0 (I) 6,6 (I) I.6 1) Oxygenation (%) 60,8 71,8 59,3 97,9 59,2 79,0 50,5 70,4 II. Content of biogenics substances. II.2 NO - 2 (mg N.dm -3 ) 0,013 (I) 0,016 (I) 0,002 (I) 0,030 (I) 0,002 (I) 0,015 (I) 0,031 (II) 0,031 (II) + II.3 NH 4 (mg N.dm -3 ) 1,92 (III) 0,09 (I) 0,97 (II) 0,07 (I) 0,86 (II) 0,04 (I) 2,16 (III) 0,13 (I) II.4 PO 4 diss. (mg PO 4.dm-3 ) 1,18 (V) 0,05 (I) 0,10(I) 0,34 (II) 0,18 (I) 0,16 (I) 0,22 (II) 0,46 (III) II.5 P tot. (mg P.dm -3 ) 0,44 (III) 0,24 (II) 0,33 (II) 0,12 (I) 0,44 (III) 0,18 (I) 0,09 (I) 0,17 (I) III. Mineralization indices III.1 Specyfic electrical conductivity (μs.cm -1 ) 300 (I) 280 (I) 340 (I) 310 (I) 310 (I) 280 (I) 290 (I) 300 (I) III.2 Ca 2+ (mg Ca.dm -3 ) 48 (I) 54 (II) 56 (II) 58 (II) 58 (II) 58 (II) 50 (I) 50 (I) III.3 Mg 2+ (mg Mg.dm -3 ) 12 (I) 6 (I) 9 (I) 6 (I) 10 (I) <5 (I) 11 (I) 5 (I) III.4 Cl - (mg Cl.dm -3 ) 18 (I) 19 (I) 19 (I) 21 (I) 18 (I) 18 (I) 18 (I) 8 (I) III.5 2- SO 4 (mg SO 4.dm -3 ) 26 (I) 111 (II) 40 (I) 84 (I) 32 (I) 58 (I) 35 (I) 111 (II) III.6 Total alkalinity (mg CaCO 3.dm -3 ) 143 (II) 185 (II) 155 (II) 160 (II) 125 (II) 165 (II) 148 (II) 160 (II) III.7 Fe tot. (mg Fe.dm -3 ) 0,03 (I) 0,09 (I) 0,11 (II) 0,15 (II) 0,04 (I) 0,13 (II) 0,01 (I) 0,30 (II) III.8 Mn tot. (mg Mn.dm -3 ) 0,06 (II) 0,02 (I) 0,09 (II) 0,03 (I) 0,03 (I) 0,03 (I) 0,06 (II) <0,01 (I) Explanations: 1) not classificated in Rozporządzenie (2004).

5 Shortened evaluation of surface water quality of Warnowskie lakes (Wolin National Park) , Poleszczuk et al. 2005b ). Especially near chalk lakes in south-west part of moraine plateau of Wolin island significant contamination of surface and subsoil waters adequate to V class of water quality had been discovered. It is a result of waste waters and sewages discharged directly into ground and underground waters in the vicinity of Lubin, Wapnica and Trzciągowo. As far as abundance of waters in mineral substances is concerned, studied ecosystems reveal comparatively stabilized values of concentrations of examined ionic macro components of waters (I-II class of water quality). Results presented above, although not comprehensive yet, explicitly and unmistakably prove - adequately to interpretation of water quality assessment published in Rozporządzenie (2004) that ecosystems of lakes under researches were subjected to moderate anthropopression. Conclusions 1) In measurement period - in spring and summer of surface waters of Warnowo, Rabiąż, Czajcze and Domysłowskie lakes had declined quality, mainly due to COD-Mn and BOD 5 values (III, IV class of water quality) and concentrations of PO and 4 diss. P tot. (III, V class of water quality). 2) Values of ph, content of dissolved oxygen and values of water oxygenation suggest that in ecosystems of examined reservoirs dissimilation predominated over assimilation processes. 3) Considering concentrations of biogenic substances, especially content of phosphorous compounds, examined ecosystems should be classified as water ecosystems of increased trophic status. 4) Waters of Warnowo, Rabiąż, Czajcze and Domysłowskie lakes, in period of researches (spring and summer of 2005), contained concentrations of ionic macro components typical for poorly mineralized inland lakes. 5) Values of parameters characterizing amounts of dissolved organic matter revealed moderate effect of anthropogenic factors on studied lakes, assessed in accordance with official and standard criteria applied for water quality classification. references Choiński A Katalog jezior polskich, Cz. I. Pojezierze Pomorskie, Wyd. Naukowe UAM w Poznaniu, Poznań, 215 ss. Hermanowicz W., Dojlido J., Dożańska W., Koziorowski B., Zerbe J Fizycznochemiczne badanie wody i ścieków, Wyd. Arkady, Warszawa, 556 ss. Lampert W., Sommer U Ekologia wód śródlądowych, Wyd. Nauk. PWN, Warszawa, 415 ss. Letki P Warunki hydrochemiczne jezior Wolińskiego Parku Narodowego w okresie jesienno-wiosennym, Praca magisterska, AR w Szczecinie, Szczecin, 37 ss. PIOŚ Raport o stanie środowiska w województwie zachodniopomorskim w roku 2001, Bibl. Monitoringu Środowiska, Szczecin, s Poleszczuk G Ekosystemy wodne Wolińskiego Parku Narodowego, Klify, 1: Poleszczuk G Jeziora Wolińskiego Parku Narodowego status troficzny, tendencje zmian i możliwość przeciwdziałania degradacji, Mater. Konf. Uniw. Szczecińskiego, 19: Poleszczuk G., Jakubiak E., Grzegorczyk K., Water flowing down from Trzciągowska Valley to Wicko Małe Lake chemical investigation (buffer protection zone and reservoir of Wolin National Park), Baltic Coast. Zone, 8: Poleszczuk G., Bucior A., Nowicka E., Grzegorczyk K. 2005a. O jakości wód powierzchniowych jezior Czajczego i Domysłowskiego w Wolińskiem Parku Narodowym w różnych porach roku, Rocznik Ochr. Środ. (Koszalin), 7: Poleszczuk G., Bucior A., Grzegorczyk K., Suzin B., 2005b. Water of spring in Trzciągowska Valley (buffer protection zone and areas of Wolin National Park) results of chemical investigations, Chem. Eng. Ecol., 12 (11): Polskie Normy (Polish Norms): PN/C Woda i ścieki. Ogólne zasady pobierania próbek do badań fizycznych, chemicznych i biologicznych. Technika pobierania próbek; PN/C Woda i ścieki. Ogólne zasady pobierania próbek do badań fizycznych, chemicznych i biologicznych. Utrwalanie i przechowywanie próbek. Rozporządzenie Ministra Środowiska z dn roku w sprawie klasyfikacji dla prezentowania stanu wód powierzchniowych i podziemnych, sposobu prowa dzenia monitoringu oraz sposobu interpretacji wyników i prezentacji stanu tych wód, Dz.U. 2004, Nr 32, poz. 284.

6 26 Krzysztof Grzegorczyk, Gorzysław Poleszczuk, Anna Bucior, Iwona Jóźwik