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Sevinç Arcak, Koray Haktanır, Mümtaz Kibar, Orhan Dengiz Department of Soil Science, Faculty of Agriculture, University Of Ankara, Ankara ABSTRACT Manyas Lake known as bird paradise is a natural reservation and a recreation area. This region is a unique place which has A-class diploma that is awarded by European Council for wetlands for which an access requires a special permission of scientific purpose. The lake is an important reproduction habitat for Pelecanus crispus and Phalacrocorax pygmeus which are liable to extinction. The fact that the lake is rich in deep fauna and planktones, due to outstanding amount of bird's fertilizers makes it possible for diverse and intensive fish population to sustain their lives. In this study, changes resulted from human activities in water quality and boron pollution were examined. Results of the research reveal that depending on escalating pollution, water quality of the lake is deteriorating and lake water is intensively consumed for various purposes. Data obtained from the research and observations showed that boron and salt pollution as dominant phenomenon, together with increasing chemical pollution has created serious problems. In addition, both the lake and the streams which carry pollutants to the lake were found to be apt to be salty. Particularly, boron and salt levels of Sığırcı stream which affects the surrounding of National Park is so high that the contents may limit plant growth. Because of the rise at certain periods in the water level of the lake which results in overflow upon willow trees (Salix alba) and unwanted chemical factors, vegetation which is used as bird habitat has vanished. INTRODUCTION Lakes provide variable uses to human society from drinking water supply to recreational activities, or from industrial use to fishery. However, the lakes in recent years are threatened by increasing pollution as a result of human activities in lake catchment areas. Lake Manyas is one of the most important world wide natural reserves for migratory birds and wildfowl species. The northeastern part of the lake is a well known bird sanctuary, and called as Kuşcenneti National Park. The lake is one of the important reproduction area of our country for the threatened Dalmatian Pelican (Pelicanus crispus) and Pygmy Cormorant (Phalacrocorax pygmeus). Among the other bird species breeding in the area, there are 2000 pairs of Cormorants (Phalacrocorax carbo), 150 pairs of Black Crowned, Night Heron (Nycticorax nyciticorax), 100 pairs of Squacco Heron (Ardeola ralloides), 250 pairs of Grey Heron (Ardea cinera), 10 pairs of Glossy Ibis (Plegadis falcinellus), 200 pairs of Spoonbill (Platalea leucorodia) and, 150 pairs of Turtle Dove. There are some environmental problems faced with in the Lake Manyas in terms of water quantity and quality. The water level has increased uncontrolled in recent years, due to the project applied for using the water potential of the catcment. Moreover the water quality deterioration has been initiated in the lake since it is located in a region, which is very important in terms of agricultural and industrial activities in Turkey. On the other hand, the behaviour of aquatic systems should be well understood, in particular when there is a large number of different uses and pollution sources, before different water use, requirements are met. In such cases a suitable approach for an integrated use of water and land resources including potential adverse impacts of pollutant as well as nutrient inputs to the water body is needed. The production of the natural environment is possible, then by the development and implementation of management goals and strategies suitable to handle environmental is uses for the selected water body effectively. In turn, development of effective environmental management strategies usually require recognition of the existing environmental problems. Formulation and implementation of corrective policies also need considerable amount of technical support. In recent years, an environmental deterioration has been observed both in Kuş Cenneti and in the aquatic life of the Lake Manyas. The higher water levels might be the reason for these undesired results. Another important undesirable phenomena related to the lake is the increasing pollution levels especially around Kuş Cenneti. MATERIALS & METHODS General Description of the Study Area : Lake Manyas is located in the province of Balıkesir with the coordinates of 40°10' N and 28° 00' E, having an average altitude of 18 m above the mean sea level. The lake is fed with Kocacay stream coming from the south, Sığırcı stream coming from the north and rain falling on the lake area. The main outlet of the lake is Karadere. Lake Manyas is an eutrophic wetland from the standpoint of ecology and an argilotrophic (clayey) wetland from the standpoint of limnology. Since it contains colloidal clay, its water is always turbid. The depth of the deepest place of the lake is about 4 meters and the avarage depth is 1 to 2 meters (Anonymous, 1998). The dominant climate of the area is continental. The climate can be described as hot with low precipitation in summer and cold with high precipitation in winter. The annual inflows from the subcatchment sum up to 75.54 million m³. The annual precipitation to the lake surface is about 100.00 million m³. The total average annual inflow to the lake is 828.13 million m³ (Celtemen, 1998). Lake Manyas is one of the most important worldwide natural reserves for migratory birds and wildfowl species. The northeastern part of the lake, called Kuşcenneti with a total area of 64 ha, was first observed in 1938 by Prof. Curt Kosswig and declared as a National Park in 1959. Then it was awarded by "Class A Wetland Diploma" by the European Council in 1976 and the given diploma was renewed four times. In 1993, the lake was included into the list of wetlands covered by the well-known Ramsar Convention, which become effective in 21 December 1976. The aim of the convention is to prevent the decline of wetland habitats globally and maintain their ecological functions and wild life. The signatory countries agree to include wetland conservation in national planing, to promote sound utilization of wetlands, to create wardened nature reserves, and to facilitate wetland-based research (Erdem, 1995). Consequently, it becomes very important to properly manage the Lake Manyas in order to sustain its use for different purposes. Methods (Water quality of the lake) : The water quality has been monitored two times in the lake itself during the year 1998 at seventeen different locations. Those location were selected in such a way that 11 of them are located at the in-lake mixing points of the tributaries and the other one is located at the middle of the lake. The parameters measured in the samples obtained from the lake are pH, electrical conductivity, hardness, chloride (Cl), sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), carbonate (CO3), bicarbonate (HCO3) and boron (B) (Rump and Krist, 1992). After water samples were put into jars, for calcium and magnesium analysis, nitric acid (HNO3) was added to the water samples to lower acidity below pH 2, thereby prevent the possibility of Fe and Mg being bound. Samples brought to the laboratory were analyzed within 24 hours. Water parameters were analyzed as indicated by standard methods (APHA, 1992). The parameters measured by the field instruments were temperature, depth, dissolved, oxygen, pH, electrical conductivity, secchi depth. In order to understand whether the data taken from two different levels at the same station, are significantly different from each other or not. RESULTS & DISCUSSION According to the data of May 1998 and October 1998 pertaining to the lake and the streams, pH values and seasonal changes in pH are not such as to hamper biota. However, from the standpoint of limit values, lake water is of class III by Water Quality Criteria For Inland Water Based on Water Pollution Regulation. Electrical conductivity values of the water samples vary in the lake and the streams. Spring and autumn measurements give similar results (Table 1 and Table 2). Lake water is medium salty. However, water samples of Sığırcı and Dutlu streams were found excess salty in the same seasons. Due to its direct relation with the National Park Area and unwanted characteristics of its water in relation to both terrestrial vegetation and water organisms, Sığırcı stream together with other factors might create hampering impact. The limit values of the dissolved oxygen of the lake water in May correspond to class I, but in October limit values remain between class I and II (Table 1 and Table 2). Although water quality of class IV was determined in Sığırcı stream which carries heavy load of pollutants in spring, because of rich surface phytoplankton population, abundance of oxygen occurs in October. According to the permanganate values of the lake water which is the indicator of the chemical oxygen demand of water, measurements of various sites in the lake reveal that lake water is of class I by Water Pollution Regulation, whereas, waters of Sığırcı stream is of class IV. This suggests that Sığırcı stream which has most influence on Manyas (Bird) Lake, transfers considerable amount of organic pollutants to the region. Boron levels of the surface and deep water samples are below the certain concentration that might be phytotoxic However, in October 1998, in the marshy area close to the National Park high level of boron was determined. It is likely that flows of high boron-loaded Sığırcı stream through delta opening reaches the marshy area. Therefore, National Park area which is under the influence of Sığırcı stream has been very often in contact with the high concentration of boron (Table 1 and Table 2). Examination of water samples, from the view point of the change in chloride shows that lake water of class I determined in May 1998 by Water Pollution Regulation, was transformed to class III in October 1998. Various streams incorporating into the lake have chloride concentration up to 1686 mgl-1 that excess the level of 400 mgl-1 fourfold, being the parameter of class IV. Whereas, chloride concentration below 70 mgl-1 can be suitable for plants. Data obtained show that both the lake and the streams carrying pollutants to the lake are apt to be salty. Particularly, in Sığırcı stream concentration are high enough that might confine plant growth. Keeping in mind that even salt-resistant plant may subject to slight or medium damage at the concentration of 280 mgl-1 and up (Rump and Krist, 1992), it can be well understood how an important risk there is in the region. Boron values of the soils samples taken from Simavlı meadow soil are 1.77 ppm, from the vicinity of Ergili Regulators are 1.44 ppm which reflect high and medium boron levels in the soils respectively (Table 3).  For instance boron level between 0.7-1.5 ppm is not secure for some plants. Therefore Simavlı meadow soils are considered toxic for most plants. Soil samples of Kocaçay, Hamamlı and Dutlu streams involve boron problem. The fact that extremely high level of boron is determined within the National Park, particularly in the vicinity of Sığırcı stream where the vegetation is severely deteriorated and the areas close to Park Quay indicate a great risk for the vegetation. Examination of the bottom mud samples reveal medium level of salt and high level of boron concentration in Sığırcı stream which consistent with the water quality of the stream, if the existent situation lasts this problem will become aggravated. On the other hand, boron pollution of October 1998 is far beyond acceptable limits (Table 4 and 5). Boron concentration increases from the centre of the lake towards shore bringing about high concentration of boron (in the immediate vicinity of Pelican nests and National Park Quay and its surrounding). This indicates a potential threat towards the lake by way of Sığırcı stream.   Apart from the extreme rising and subsiding in the lake level, in recent years particularly following the year 1993, an abrupt permanent rising has attracted attention. This may be because of the fact that by bringing the south right shore line embankments nearer to the lake shore, they were reconstructed at the altitude of 15 meter. It seems that the main problem has a close relationship with the keeping water movements of a natural ecosystem under control. The environmental problems faced with in the Lake Manyas are both qualitative and quantitative. The natural life has been affected adversely in recent years, due to the conditions caused by various man-made activities around the lake. The periodical fluctuation of water to support natural needs of waterfowl could not be achieved, and the higher water level most probably caused damages on plantation. In recent years, an environmental deterioration has been observed both in Kuş cenneti and in the aquatic life of the Lake Manyas. The higher water levels might be the reason for these undesired results. Another important undesirable phenomena related to the lake is the increasing pollution levels especially around Kuşcenneti. The feeding stream of Kuşcenneti, namely the Sıgırcı stream, are being polluted by uncontrolled domestic and industrial wastewater discharges. The towns and the increasing industrial activities around Sıgırcı stream have been adversely impacting the water quality of the stream for several years. The organic and inorganic pollutants have been carried by water and they accumulated in the sediments of Kuşcenneti. In addition due to intensive agricultural activities fertilizer and pesticide utilization in highly fertile farmlands have affected the water quality in the some part (Table 6).  The water quality measurements carried out in different parts of the lake, especially in Kuşcenneti, have shown that the water is highly polluted with respect to different quality parameters. The parameters with alarming levels of boron and chloride. Our studies showed that the boron concentrations in sediment, soil and water also exceed the standards stipulated by the regulations. Another threat for the lake is soil erosion that has been accelerated in recent years due to improper land use. There exist intensive industrial activities in the catchment of the lake and the wastewater produced at different steps of manufacturing are given to the receiving water bodies without any treatment, in most of the cases. The number of industries located in the area is around 40 and 24 of them cause severe quality deterioration in the nearby water bodies. The largest industry in terms of its production is Etibank Borax and Boric Acid Factory with a total wastewater discharge of 6300 m³/day from different units. The amount of wastewater given to Sığırcı stream is approximately 1700 m³/day (Celtemen, 1998). There are some towns and villages located along the tributaries. All of them have sewage system without any treatment. The domestic wastewater of these settlement areas are being discharged to the nearby water bodies directly. The evaluation based on the 90 % probability values show that the water quality is very poor in Sığırcı stream which is flowing through Kuşcenneti. Boron parameter has values exceeding class IV standards in the regulation (Water Pollution Control Regulation). Boron is already in high amounts in the water. Since there are farmlands around the stream basin, intensive use of fertilizers also affects the water quality adversely (Table 6). For there is no measurement about the pesticides, it is difficult to estimate the levels of pollution and toxicity in the water. However, it is known that many different types of pesticides are being used in the area. As it can be seen from the table that the pollutant load of the lake is extremely high due to the man-made activities in its catcment area. If the above table is examined, it can be concluded that the main contributor in terms of pollution is Sığırcı stream. Especially, the parameters of B and COD need more concern to figure out the present situation of the lake and its natural life. The pollution is originated primarily from domestic and agricultural activities in Kocaçay. The similar types of pollution sources are valid for Mürvetler stream and Karadere, but in the case of Sığırcı stream, of primary concern for natural life, the pollution is mainly due to industrial activities along with domestic one. CONCLUSIONS High level of boron, chloride, organic and inorganic pollutants being transported by Sığırcı stream which affects the whole National Park, particularly when water level is high and covers the park area, has been severely effective leading to phytotoxic characteristics over the soils of the region and the bottom mud properties. The research team concludes that the foregoing chemical negativeness is associated with the water regulation being anthropogenically affected and causes a synergistic impact through the agency of flooded vegetation. Vegetation, particularly under flood was observed to be highly affected. Due to altitude, where the water influence does not become effective, vegetation could gradually survive. Although the complete demise of the vegetation, particularly in the immediate vicinity of the Sığırcı stream, may not be ascribed to a single factor, hazardous impacts of boron, chloride and other chemicals steming from excess water being the basic negativeness, manifested themselves simultaneously. The possibility of the nutrients deriving from widespread poultry practices being transported to the lake is high. This is an important factor affecting the rapid change of water quality. It has been understood that an important water reservoir is vanishing, due to the rapid change in water quality of the lake which once used by the people of the region as a source of potable water in the 1960's. RECOMMENDATION In order to prevent water pollution in the lake, and particularly within the park boundaries, the required measurements should be taken to rehabilitate the quality of Sığırcı stream carrying boron, chloride and other wastes of industrial origin, and Dutlu stream transporting mostly solid and liquid wastes of poultry activities and household wastes. The main factor limiting vegetative life in the National Park is that a water management plan which is able to create a condition which reflects the ecosystem of 1990's, the healthy life of which was dependent upon natural water rhythm and seasonal movements, hasn't been yet established. Therefore, as emphasized in the previous management plan project (1997), a programme taking into consideration all the aspects of the volume-area-altitude relations should be implemented, in order to ensure that the lake level will be maintained to the extend that it will conserve ecological values (Erkakan, 1997). Taking the results of the study and field observations into account, it can be stated that unless the deteriorating effects of the changing water regime and the hampering impacts of the phytotoxic soil-water-mud combination caused by increasing chemical pollution, the main ones being boron and salt, are removed, a healthy vegetation will not sustain its life. The fact that a nursery of 16 000 willow (Salix alba) trees was established in the months following 1998 can be considered a superficial approach to the problem. Such activities should be on a scientific basis and be done within a specific time period. REFERENCES American Public Health Association (1992). Standard methods for the examination of water and wastewater. APHA, AWWA-WPCF, Washington DC. Anonymous (1998). Lake Kuş. Republic of Turkey Ministry of Environment, General Directorate of Environmental Protection, Ankara. Celtemen S.P. (1998). Development of a water quality management plan for Lake Manyas. Ph D. Thesis. Ankara. Erdem O. (1995). Bird paradises of Turkey. Ministry of Environment, General Directorate of Environmental Protection, Ankara. Erkakan F. (1997). Manyas Lake watery areas administration plan project. Republic of Turkey, Ministry of Environment, General Directorate of Environmental Protection, Ankara. Rump H.H., Krist H. (1992). Laboratory manual for the examination of water, wastewater and soil. VCH, D. 6940 Weinheim, Federal Republic of Germany. |