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Aquatic Research and Water Quality Trends in the United States and Poland WILLIAM E. Co oP ER Michigan State University This chapter addresses trends in water quality in the United States and Poland and the ecological research associated with environmental assessments of the impacts of these trends. These impact analyses are generally based on risk assessments that involve transport, fate, exposure, and toxicology of various materials. The research activities discussed below are those that contribute directly to these processes. Mends in water quality parameters include both surface and groundwa- ter resources. The nutrient concentrations are limited to phosphorus and nitrogen. The toxic chemicals include the most commonly detected classes of chlorinated organic compounds. The U.S. data were obtained mostly from state and federal monitoring programs, and the discussion here uses the Laurentian Great Lakes as a prototype watershed. The Polish data were obtained primarily from the Board of Environmental Protection and Water Management in Poland. ECOLOGICAL RESEARCH Traditionally, environmental scientists have subdivided integrated eco- systems into a media-specific taxonomy. Research, teaching, and regulatory activities are organized into categories such as soil, groundwater, surface water (i.e., freshwater lakes and streams, manna-inshore, and bluewater), and atmosphere. - The basic concepts of ecology are thought to be generic to all media. The differences are associated with the physical constraints that limit the expression of ecological processes to a subset of the total array possible. These~physical constraints are usually media-specific. Impact assessments of environmental and ecological resources are currently required by many state and federal agencies. Many of these 297
298 ECOLOGIC USE regulations require the assessments to be anticipatory. The analyses are, therefore, based on predictive models, laboratory determinations of critical processes and rates, microcosm experiments with simplistic ecosystems, or field validations with small-scale test systems. These activities involve the use of scientific assumptions involving reality, precision, and scale. Substantial research activity has been directed toward understanding and measurement of the fate, effect, transport, and exposure pathway of toxic chemicals in the environment. Even so, there is a great deal more that we need to learn before impact assessment models will work generically under field conditions. If biological communities and transport pathways of chemicals were unique to each media, the existing organizational structure would be ideal. Unfortunately, there is considerable documentation that organisms with complex life histories occupy different media during their life span, and most chemicals cycle through ecosystems involving many media. For example, lake sediments are both sources and sinks for nutrients, and toxicants cycle in the planktonic community. Erosion is a major transport mechanism between terrestrial and aquatic communities. Most shallow groundwaters emerge as surface water through seeps, springs, and emergent water courses. Rain and snow scavenge materials from the atmosphere, resulting in wet deposition to both terrestrial and aquatic systems. Gravity does the same for larger particles as dry deposition. The pathways that couple media-specific subsystems do exist. The major issues involve the intensity of the transport processes relative to the processing capability of the media, given the concentrations of the materials and the retention times within the media receiving the input. This section will focus on those biological and chemical processes that affect the fate, transport, effect, and exposure of materials that are utilized in performing ecological risk assessments in freshwater environments. Predictions of ecological events can be based on stimulus/response be- haviors of interacting species populations. The flows of the requisite energy and material resources required to maintain viable populations involve a wide variety of biological processes. Multispecies interactions mediated through such processes as competition, predation, and succession deter- mine which constellation of organisms are predominant under a designated set of abiotic conditions. There is a dynamic structure to ecological sys- tems which is both opportunistic and adaptive. This hierarchical structure is both temporally and spatially distributed, and its behaviors are often nonlinear, with an array of process-specific time lags. The control systems are entirely feedback and are decentralized, as they are often associated with the processes themselves. These characteristics make it very unlikely that useful predictions of specific behavior resulting from the aggregation of multistage processes will
IMPACTS ON AQUATIC ECOSYSTEMS 299 result from simple numerical solutions. Most ecological predictions result from dynamical simulation models that contain a number of components; each component is represented by a set of state and response equations; and each equation involves a series of specific parameters. The values of these parameters are represented as distributive functions with coefficients of variation that usually exceed 30%. The variations in parameter values in- clude elements of genetic, physiological, and behavioral variability as well as sampling errors. There currently is no way to calculate confidence intervals around the final predictions from such complex ecological interactions. An illustration of the multifactor interactions that relate to the fate of toxic materials in the environment can be obtained from the anaerobic degradation of halogenated organic compounds. Bonwer et al. (1981) pre- sented results of microbial degradation of several halogenated compounds under anaerobic conditions. Cultures seeded with methanogenic bacteria showed significant reductions in the parent compounds within a 16-week period. Only the original compounds were analyzed, so there is no infor- mation on the extent of mineralization. Thus, the methanogenic pathway of carbon flow does result in the dehalogenation of several organic toxicants. Given that the mechanism does exist, the issue becomes the importance of this pathway of carbon flow in natural ecosystems. There are two major pathways for carbon flow in the anaerobic sediments of warm-water lakes. The methanogenesis pathway involves an array of microbes that utilize electron acceptors (i.e., HCO3) generated or regenerated internally within the zone of anaerobic metabolism. The sulfate reduction pathway involves a different array of bacteria whose metabolic rates are limited by electron acceptors (i.e., S04) generated or regenerated externally to the anaerobic sediment zone. LoYley and Klug (1986) presented a more detailed model of the two competing pathways. Both pathways utilize acetate, which arises from the leaching and hydrolysis of particulate organic matter followed by anaerobic fermentation. - The factors that. control the production of particulate organic matter involve nutrient availability, competition, and predation in the epilimnetic portions of a lake. The profundal sediments in oligotrophic and mesotrophic lakes have respiration indices (RI = i4Co2/~4CH4) of approximately 1.0 in the upper 4 cm. The eutrophic lakeswith higher organic inputs to the sediments and limited SO4 recharge from the water column have RI indices between 0.2 and 0.4. The dominance of either pathway is the result of a competitive interaction of two very different bacterial communities mediated by com- munity events in the adjacent water column Money et al., 1982; Lovley and Klug, 1982; Lovley and Klug, 1983~. Many of the diagnostic parameters of chemicals are measured under simple two-phase conditions. Volatilization rates are measured as trans- fers through an air,~water interface. Solubilities are measured as solute
300 ECOLOGICAL RISKS and solvent ratios in pure water. Bioaccumulation rates are related to octanolAvater partition coefficients that are measured with two phases in pure state. However, the behaviors of chemicals in natural systems cannot usually be predicted from these idealized parameters. Natural systems are "multiphasic" and the processes of adsorption, absorption, volatilization, hydrolysis, and photodegradation are not easily characterized by simple rate coefficients. A good example of the importance of chemical processes is the current dilemma with the Story/Ott/Cordova site in Muskegon, Michigan. The groundwater is a contained aquifer; the only outlet is surface flows through Bear Creek. The aquifer is contaminated with many thousands of kilograms of organic compounds, including benzene, dichloroethanes, toluene, and vinyl chloride. The parent company, Corn Products Corporation, has recommended an out-of-court settlement that involves monitoring, financial compensation for impairment of the resource, and air stripping through natural volatilization as the groundwater flows to the surface. However, environmental groups have demanded a multimillion dollar purge and incineration alternative. The analysis of trade-offs involves risks, benefits, and uncertainties which depend upon physical parameters that control the fate and transport of these volatile organic compounds. The behavior of contaminants in the environment is determined by two fundamental groupings of processes. Transport processes serge to move chemicals through the environment. This may simply involve flow within a medium such as the movement of the constituents in a wastewa- ter dischargedownstream with the flow of water. It can also involve the movement of chemical species between media, e.g., when the wastewater discharge contains a volatile compound which moves into the atmosphere as it travels downstream. Such intermedia transport processes result in a distribution of the contaminant, necessitating consideration of flow pro- cesses in two media. Consideration must also be given to transformation processesreactions that serge to alter the nature of environmental con- taminants. Transformation processes include such environmentally signifi- cant reactions as hydrolysis, protolysis and oxidation/reduction. The fates of organic and inorganic chemicals in the environment are highly influenced by biological, particularly microbial, processes (Alexander, 19814. These processes can involve mineralization, cometabolism, activa- tion, or incomplete biodegradation. Recently, there has been an increasing research effort to document the mechanisms, environmental constraints, and requisite microbial flora that produce these alternative scenarios. Pri- ority areas for research fall into several general categories. Synthetic organic compounds often do not have natural structural analogs. Evolution is not preadaptive, so there is no guarantee that an appropriate biochemical pathway is present in any given microbial community. The susceptibility of
IMPACTS ON AQUATIC ECOSYSTEMS 301 synthetic compounds to mineralization in various media such as anaerobic groundwater, aerobic surface water, and saturated soil- is a critical area requiring further investigation. Often, portions of a metabolic sequence that would lead to mineral- ization are present. Limitations such as the lack of an adequate electron acceptor, insufficient concentrations of the parent compound to support a healthy microbial community, or ecological interactions like predation or competition from other organisms, can restrict the expression of some idealized process of mineralization. Since natural microbial communities evolved to exploit a vast array of natural organic compounds under many environmental conditions, there is an enormous number of combinations of "compound x microbial community x ecosystem" that are important to understand. The daughter products that arise from incomplete degra- dation present the ecologist with an impact assessment task of increasing complexity and uncertainty. Many toxic compounds exist in nature at trace levels of concentration. Even if the potential for microbial processing exists, the concentrations of organics are too low to supply sufficient energy to maintain adequate pop- ulations of the microbe (Boethling and Alexander, 1979~. "Piggybacking" energy resources with degradation processing appears to occur through cometabolism. In addition, bacteria produce polysaccharide substrates that bind dissolved organic matter and increase their concentrations in mi- crosites. We need to understand these natural reactions and investigate ways of enhancing these activities in both freshwater and marine aquatic ecosystems. Several types of natural organic substrates are quite resistant to micro- bial breakdown (Alexander, 1973~. Leaves with high levels of condensed tannins, the humic components of many soils, and wood materials contain- ing cellulose, lignins, and hemicelluloses all have been demonstrated to be recalcitrant. These substrates are also prime binding sites for trace organic toxicants. The accessibility of compounds for microbial degradation is often reduced when they are attached to the surfaces of large substrates. All of these factors are critical issues when one starts with ambient con- centrations of some toxicant and attempts to assess the ecological impact in some specified environment. Once the fate, distribution, and concentra- tion of the parent compound and daughter products are characterized, the remaining factor is the exposure rate for each biological species of concern. Exposure rates under field conditions are the most difficult measurements to obtain. This involves a blending of analytical chemistry, life history aspects of the organism, and the physiological processes of assimilation, deputation, and passive uptake. There are very few organisms of social and/or economic interests for which these rates are well documented.
302 ECOLOGICAL RISKS Over the past decade, an increased emphasis on study of the fate of chemicals in groundwater systems has developed. More than 40% of the U.S. population uses groundwater for drinking, often with no treatment other than disinfection in municipal systems. Rural sources of groundwater are often used for potable water without treatment. Therefore, the attention of both researchers and regulators has been focused on the problems of widespread use of substantial quantities of chlorinated organic solvents (more than 2.0 million tons/year in the United States) and the discovery of literally thousands of sites across the country where these materials, along with petroleum derivatives, have been detected as contaminants in freshwater aquifers. Contamination of groundwater is a serious problem because subsurface aquifers do not have the same natural degradation mechanisms that are present in surface water systems. A1- though groundwater systems are substantially less active both biologically and chemically than are surface water ecosystems, there are still a large number of processes that affect the transport and fate of trace contami- nants in subsurface aquifers. Questions of interest in understanding the environmental fate of trace organics include: · What are the mechanisms of removal or transformation? What are the intermediate and end products of the transforma- tions? · What are the transport kinetics of the chemical contaminants in relation to the general flow of the aquifer? What manipulations can be performed on contaminated areas most effectively to remove or reduce contaminant levels? Many of the same physical characteristics of the contaminant molecules that influence transport in surface waters are also important in groundwater movement. Water solubility and the adsorption potential of a chemical are among the most significant. Chemicals or chemical mixtures with low water solubilities and densities less than 1.0 generally exist as free-phase layers on top of the surficial aquifer. Depending upon the rate of infiltration and vapor pressure of the material, there may be significant losses to the atmosphere as well. The most common example of this behavior is the case of losses of gasoline or fuel oil from catastrophic spills or leaking underground storage tanks. In such cases, recovery systems can often be installed to withdraw the supernatant layer off of the aquifer and remove the bunk of the polluting material. Mace concentrations of organic contaminants often remain in the system at the limits of solubility and in the unsaturated overlying soils. The dynamics of the environmental transport and fate of these contaminants are therefore of great interest.
IMPACTS ON AQUATIC ECOSYSTEMS TABLE 1 Trends in water quality, 1975-1981. Trends represent the number of streams showing significant differences at the 90% confidence level. Total Phosphorus Inorganic Nitrogen Increasing Trend 35 72 Decreasing Trend 29 24 No Change 245 152 SOURCE: USGS Stream Quality Accounting Network, 1984 lllENDS IN WATER QUALITY IN THE UNITED STATES Nutrients 303 Nutrient loadings to surface waters were a major focus of the 1972 Federal Water Pollution Control Act. Phosphorus and nitrogen were the two elements associated with cultural eutrophication. The geochemical cycling of phosphorus is highly influenced by physical parameters, while the nitrogen circle is strongly regulated by microbial activity. The U.S. Geological Survey (USGS) has maintained a network of stream monitoring stations since 1975 (USGS, 1984~. Able 1 presents the direction of trends that are statistically significant between 1975-1981. The pattern is obviously mixed, with the southern coastal areas indicating increasing concentrations and the majority of the interior section indicating a reduction in phosphorus concentration. In the Great Lakes Region, the trend reflects a systematic reduction in phosphorus concentration. The 1985 Report on Great Lakes Water Quality (Figure 1) presents total phosphorus concentrations in the surface waters of Lake Ontario. Between 1970 and 1983 there was almost a 50% reduction in concentration. The major changes in loadings resulted from a ban on the sale of high-phosphate detergents and the precipitation of phosphorus in the secondary treatment phase of municipal wastewater treatment plants (Figure 2~. Nitrogen, on the other hand, has demonstrated a trend of increasing concentrations in surface stream waters during the period from 1975-1983 Cable 1~. This trend is also apparent in the Great Lakes surface waters (Figure 3~. The sources of nitrogen are varied, and the transport processes more complex. On a regional basis, the most likely source of increasing inputs are human and animal wastes and mineral fertilizer from agricultural and domestic activities. The trend in nutrient concentrations in groundwaters is basically asso- ciated with nitrogen. Table 2 presents the nitrate-nitrogen concentrations of about 124,000 wells categorized by depth. The only significant increase in
304 ECOLOGICAL RISKS A CU 24 20 18 10 o 19 70 1971 1972 1973 197. 1975 1976 197 7 1970 1979 1980 1981 1982 1983 FIGURE 1 Area-weighted mean whole lake spring total phosphorus concentrations in the surface waters (1 m) of Intake Ontano, 197~1983. Data : from Environment Canada (12), 1985 Report on Great Intakes Ubter Qualibr, IJ.C. nitrogen concentration was observed in shallow aquifers less than 100 feet (30 m) in depth. The most likely sources of increasing inputs are animal production facilities, human septic fields, and mineral fertilizers. Hallbert (1987) reported that nitrate concentrations in groundwater for two well sys- tems increased from less than 10 to over 200 mgA during the period from 1934-1984. This correlates very well win the pattern of nitrogen fertilizer used in Iowa during the same period, which increased from small amounts to over 1.1 million tons per year. The regulation of nitrogen inputs into both surface and groundwaters is still a major problem that demands a high research priority. Toxic Chemicals Recent developments in analytical chemistry have expanded the array of toxicants that can be extracted for analysis from organisms, water, and sediments. Technical developments have also drastically lowered the level of detectability. For example, dioxin analyses can be conducted
IMPACTS ON AQUATIC ECOSYSTEMS Boon 35CO 3000 25~) 12000 '1500 110= c, 10500 Cal 10000 9500 ~ 9~0 0 5500 8000 c: 7500 ,~ 7~0 6500 6000 5500 o 5000 s 45= 8 4000 o4 3500 3000 O 2500 54 2C00 lSCO 1000 LAKE ERIE 1 GAS. toad an 1 I \<ted States - C~n~da Am. Anon / ~ ~ r - -,- ~ _ ~ _ , _, _ ~ _ ~ 19~72 19751976197719791979 198019811982 1983 305 `, echo- >a 45CO - . 1 4000 - 35co 3000 2s00 5CO - ~ A_ _ ~ 2000 - o s 1500 - - 8 £ w IS \~ LAKE ONTARIO \t \' _nited States ~ Cyanide Atari L~ 1 ~~ _ 0 - 197219751976 1977 ,978 19791g80 1961 n982 1983 FIGURE 2 Municipal phosphorus loadings to the lower Great I>kes, 1972-1983. Data from the 1985 Report on Great Intakes Water Quality, I.J.C. with quality control at levels of 1 x 10-12, with water samples utilizing high-volume filtration. As a result of these developments, there is an ever- increasing list of toxicants being detected in various environmental media. In 1983, the Great Lakes Water Quality Board reported finding over 1,000 anthropogenic chemical substances in surface waters. A general scan of organic compounds in the flesh of lake trout from Lake Michigan indicate some 160 identifiable organic compounds. There are, however, only a relatively few compounds that exist at concentrations high enough to cause concern for human health and the natural resource base. The compounds of most concern include PCBs, DDT, dioxins, and pesticides like dieldrin. Most of these compounds were identified as envi- ronmental contaminants back in the early 1970s. Measurements were also made of survivorship of young fish and eggs from both natural populations and hatchery stocks. Into facts are apparent: the body loads of PCBs and DDT are consistently decreasing in adult lake trout; and fry and egg sur- vival was not reduced by ambient concentrations of these two compounds. In general, the levels of toxicants in surface waters restrict the economic use of these living resources, but they do not threaten the survival of the natural aquatic populations. Most of the organohalogenated compounds of major concern have
306 360 340 3ao 300 \ ~ 240 V So V Marl 2ao ~0 160 140 120 ~0 ~0 60 40 20 1977 1978 1979 o ECOLOGICAL RISKS 1969 1g70 1971 1972 1973 1974 1~5 1976 1980 1981 1962 ~83 FIGURE 3 Area-weighted mean whole lake spring nitrate plus nitrite concentrations in the surface waters (1 m) of Intake Ontano, 1969-1983. Data from Environment Canada (12), 1985 Report on Great Intakes Water Quality, IJ.C. TABLE 2 Groundwater contamination (as percentages). Nitrate-Nitrogen Concentration Depth of Well Fraction of < 3mg.1 1 3mg.1 1 > lOmg.1 (feet) Wells Sampled -lOmg < 100 38 32 52 68 101 - 200 22 21 22 18 200 - 300 12 14 11 6 > 300 28 33 15 8 SOURCE: USGS, 1984
IMPACTS ON AQUATIC ECOSYSTEMS 307 partitioning coefficients between 104 and 106. Therefore, the compounds are tightly bound to particulates and do not occur in the aqueous phase. When collecting data to determine temporal trends ~ ambient concentra- tions, one should analyze sediments, not water, and deterimine sediment transport, not water Dow. This has not routinely been part of the U S. monitoring program, so available trend data do not exist before the early 1970s. There has been a considerable amount of effort spent on determining trends in concentrations of these organochlorine compounds in humans and natural fish and wildlife populations. Although there has been a rise in U.S. production of pesticides in the last 20 years, the concentrations of DDT dropped significantly, and the levels of dieldrin remained low in human diets during this same time interval (Conservation Foundation, 1984~. Figure 4 shows the trend for DDT and dieldrin for fish and bird populations. Again, there is a consistent reduction, except for dieldrin in waterfowl. The 1985 Report on Great Lakes Water Quality presented data for bloater chubs, lake trout, and herring gull eggs. The reductions in body concentrations are correlated with sharp reductions in U.S. production and use of these compounds. The majority of the inputs of PCBs into the surface waters of the Great Lakes are airborne materials emanating from municipal and industrial incinerators which are currently ret ycling through the ecosytem. In general, once a toxic compound is found in concentrations that raise immediate concerns for public health or the integrity of the eco- logical resource, actions have been taken that have reduced the ambient concentrations of the toxicant. Often, this means a ban or a very restricted use of the product. For those products that remain in use, the industrial expenditures on pollution control are considerable. A form of environmental pollution in the United States of particular social concern is groundwater contamination. With both state and federal ("Superfund") resources, all states have instituted major programs to char- acterize the quality of their groundwater resources. The USGS monitors the distribution of rural groundwater contamination in the United States. Each year the number of aquifers identified as contaminated has systemat- ically increased. However, this may not reflect an increase in the frequency of new pollution events; rather, this trend is the result of the increasing effort being spent on groundwater surveys. Most presently contaminated aquifers have contained pollutants for decades. Many of the organic contaminants found in surface waters are not major constituents in groundwater. The partitioning coefficients for these compounds are high, and the compounds are bound to the particulates in the soil matrix and are generally not found in the aqueous phase. This limits their mobility through soils and protects aquifers from surface
308 o 240 lo 11 can a) - IL 3 x A 200 160 120 80 40 o 1968 1970 1-972 . . o lo '~ 300 <Q 250 - > ' X LL C] he ECOLOG CAL RISKS ; Dieldrin . v . Fish . . _ 1 1 1974 1976 1978 YEAR 1- ' 200 150 100 50 o - Waterfowl A. Starlings ~ I I 1 DOT -. Fish ___ 1 _ ~ __ _ 1 1 1968 1970 1972 ~ _ 1980 1982 Waterfowl Starlings 1974 1976 1978 1980 1982 YEAR FIGURE 4 fiends in levels of dieldnn and DDT in wildlife, 19681979. Data from U.S. Fish and Wildlife Sentence. State of the Environment, 1981; a report from the Conservation Foundation. sources. The most common organic contaminants in groundwater are organic solvents. PCBs and dioxins move through the soil matrix only when they are comingled with organic solvents like TCE or DCE. Klepper et al. (1987) summarized the major sources of contaminants to groundwater (Table 3~. Underground gasoline storage tanks and poorly de- signed landfills are dominant sources of organic contaminants. Uncovered storage of salt for ice removal in the winter months is a major inorganic source. In some areas, the production and transport of petroleum products are also major sources. Landfills are obviously the source of the greatest array of chemical contaminants that enter groundwaters.
IMPACTS ON AQUATIC ECOSYSTEMS TABLE 3 Rural groundwater contamination. Major contaminants associated with known groundwater contamination incidents, excluding urban-heavy manufacturing incidents. 309 Contaminant LF DMP GUSI AGR CUSI AGT OIL PET SALT Benzene Xylenes Toluenes Ethylbenzenes Cadmium Chromium Copper Lead Nickel Zinc Cyanide Arsenic Phenols Dichloroethanes Trichloroethanes Trichloroethylene Tetrachloroethylene Naphthalenes Chloroform Hexachlorobenzene PCBs Phthalates Paint Residues Nitrate Pesticides Salt/Brine . . ~ . LF = Landfill; DMP = Dump; GUSI - Gasoline Underground Storage; AGR = Agriculture; CUSI = Chemical Underground Storage; AGT = Above Ground Tanks; OIL = Oil Transport; PET = Oil Field Operations; SALT = Salt Storage. Data from Klepper et al., 1987. TRENDS IN WATER QUALITY IN POLAND In Chapter 19 (this volume), Gromiec presents the current river classi- fication for Poland (see Figure 6~. A majority of the major rivers in Poland are currently experiencing serious degradation of water quality. Untreated municipal waste streams, salt-water discharges from coal mines, direct in- dustrial discharges, and nonpoint inputs from agriculture are all identified as major sources (see Chapter 19, Figure 1~. As approximately one-half of the areas of the major rivers are classified as either Class III (industrial use
310 ECOLOGICAL RISKS TABLE 4 Distribution of 230 natural lakes in Poland studied in 1974-1983, in categories of lake susceptibility to degradation. Category Number of lakes Percent (%) 1st 24 10 2nd 103 45 3rd 66 29 out of 3rd category 37 16 TOTAL 230 100 SOURCE: Cydzik et al., 1982; Cydzik and Soszka, 1988. only) or nonclassified (pretreatment required before any direct use), pollu- tion of the riverine resources is currently a major environmental problem in Poland. In Chapter 17 (this volume), Hillbricht-ILkowska presents several clas- sification systems that are presently being used to assess trends in water quality for fresh water lakes in Poland. Hillbricht-ILkowska also provides data for trend analyses for several of the larger lakes in Poland. Able 4 presents the results of class~ing 230 natural lakes in terms of their susceptibility to anthropogenic degradation. The parameters that determine the ranking include lake morphometry, persistence of stratifi- cation, residency time of water, presence of point-source pollution, and the intensity of land use in the riparian watershed. Category 1 represents lakes that are expected to be most resistant to eutrophication, and "out of Category 3" represents lakes that are seriously threatened. About 45% of Polish lakes are moderately susceptible to eutrophication, and an additional 45% are rather highly susceptible. Many of these lakes are in the Masurian Lake District and support an important tourist industry. Another classification system was utilized to examine 221 Polish lakes in terms of existing conditions of water quality Cable 5~. This system relies on spring and summer measurements of 18 parameters like nutrient and dissolved oxygen concentrations, transparency (SD), chlorophyll, and other values (see Chapter 17, Able 4~. Approximately one-quarter (26%) of the volume of the examined lakes are currently mesotrophic, and these include most of the largest and deepest lakes in Poland (these data refer to lakes examined in the years 1973-1979~. Fifty-six percent of the lakes by number, and 41% of the surface waters by volume, are currently experiencing a serious level of water quality degradation. This results in frequent fish kills, permanent
IMPACTS ON AQUATIC ECOSYSTEMS TABLE S Distribution of 221 Polish lakes, 1974-1983; classified by state of water quality. Number of Lakes Lake Volume number percent volume percent Class (Jo) (10 m ) (%) 1. lst and intermediate 20 9 2126701 26 between 1st and 2nd 2. 2nd end intermediate 77 35 2606 131 33 between 2nd and 3rd 3. 3rd 70 32 1 808469 24 4. Out of classification 54 24 1 308 469 17 311 TOTAL 221 100 - 7 898 907 100 SOURCE: Cydzik et al., 1982; Cydzik and Soszka, 1988 TABLE 6 Percentage distribution of the number of 50 Polish lakes according to the yearly load of total P (L,p, g m~2 lake area yet), share (%) of the point sources in Lop, and relation to the permissible and dangerous load based on Vollenweider's critena. % of point Lop % of sources In % of % of (g m~2 yr~l) lakes Lop lakes Lap is: lakes < 0.1 20 0-10 53 ~ permissible 26 0.2~.9 54 20-50 17 2 permissible 20 ~ dangerous 2 1.0 26 2 60 30 2 dangerous 54 _ SOURCE: Hillbncht-lLlcowska, 1984. anaerobic conditions in the hypolimnion, and dense blooms of green and blue-green algae in surface waters. Although 45% of the lakes are considered highly susceptible to eu- trophication (Bible 4), 56% of the lakes have already experienced serious degradation Amble 5~. A primary cause of this increased rate;of lake eutrophication is presented in Table 6. The loading of total phosphorus (L~p) is considered to be the most important stimulus of lake degradation. Fifty-four percent of the lakes are currently experiencing dangerous levels of inputs and 60% of the Lop is from point sources in 30%0 of the lakes. Those are potentially treatable sources that should be given immediate attention. Itend data exist for three lakes in Poland (Table 7~. Lake Hancza is the
312 ECOLOGICAL RISKS TABLE 7 Trends in transparency (SI:)) in three Polish lakes* Lake Hancza Lake Mikolajskie Lake Mamry Date SD (m) Date SD (m) Date SD (m) 925 7.5 1950 2.~-3 5 1950 4.6 1931 65 1957 3.0 19S6 4.3-6.5 1935 8.2 1958 2.7 1957 5.1 1955 8.3 1967 1.5-2.2 1958 3.3 1956 7.9 1971 1.~2.0 1968 5.5 1957 8.0 1972 1.0-2.0 1972 55 1958 5.5 1976 1.3-1.7 1976 5.1-5.8 1977 go- 1977 1.1 1977 5.5 1984 8.5 1984 1.5 1978 3.8 1986 1.3 1986 4.3 1987 1.2 ~ . . . *Data selected from Hillbricht-Ilkowska, 1988; Zdanowski et al., 1984; Hillbricht-Ilkowska, in press. deepest lake in Poland (108.5 m) and has a surface area of 311.4 ha. The annual total phosphorus loading is 0.066 g m~2y~i (Hillbricht-ILkowska, in press), which is below the permissible level. The lake has maintained a mesotrophic state for the last 60 years. Consistent high transparency measurement and high summer hypolimnetic oxygen concentrations of 8.0- 10.0 ppm support this nondegredation trend. Lake Mikolajskie, on the other hand, is 28 m deep, with a surface area of 460 ha. This lake currently receives an annual phosphorus loading of 0.77 g m~2y~i, which is four times the permissible load based on Vollenweider's criteria. The predicted load for 1990 increases to 1.63 g m~2y~i due to estimated increases in tourism and agricultural uses of fertilizers (Giercuszkiewicz-Bajtlik et al., 1983~. The transparency data (Bible 7) indicate an eutrophic state existed in 1950 and has degraded even further in the last four decades. Chorophyll concentrations have also increased from 14.2 fig l-: In 1973 to 51.8 ,ug l-i in 1986 (Hillbricht- ILkowska, 1988~. Lake MamIy is one of the largest lakes in Poland, with an area of 2504 ha and a maximum depth of 43.8 m. The total phosphorus loading is 0.06 g m~2yr~~, which is well below the estimated permissible load (Giercuszkiewicz-Bajtlik et al., 1983~. The transparency data show a consistent trend of mesotrophy over the 36-year period Cable 7~; however, according to Gliwicz and Kowalczewsl~i (1981), there is a visible increase of oxygen deficit in the hypolimnion. The trend data support the notion that external phosphorus loading
IMPACTS ON AQUATIC ECOSYSTEMS 313 from anthropogenic sources is the primary stimulus of lake eutrophication in Poland. Unfortunately, there are no data on heavy metals and synthetic organics to evaluate the toxic chemical loadings to these lakes. Thus, there is real need to expand the lake monitoring program to include toxic chemicals in addition to the cultural eutrophication. REFERENCES Alexander, M. 1973. Nonbiodegradable and other recalcitrant molecules. Biotechnology and Bioengineering (XV):611~47. Alexander, M. 1981. Biodegradation of chemicals of environmental concern. Science 211~9~:132-138. Boethling, R.S., and M. Alexander. 1979. Microbial degradation of organic compounds at trace levels. Environ. Sci. Technol. 13:989-991. Bouwer, EJ, B.E. Rittman, and P.L~ McCarty. 1981. Anaerobic degradation of halogenated 1- and 2-carbon organic compounds. Environ. Sci. Technol. 15:59~599. Conservation Foundation. 1984. State of the Environment. Washington, D.C. Cydzik, D., D. Kudelska, and H. Soszka. 1986. The system of evaluation of lake quality and its application by the field agencies of the environmental protection. Pp. 11-20 in Monitoring of the Lake Ecosystems, A. Hillbricht-Ilkowska, ed. Ossolineum, Wroclaw. Cydzik, D., and H. Soszka. 1988. Atlas of water quality of lakes studied in 1980-1984. Wydawnictwo geologivine, Warsaw (in Polish). Environment Canada, Water Quality Branch, Burlington, Ontario. Giercuszkiewicz-Bajtlik, M., R. Lessow, and C. Mientki. 1983. The means for the lake protection and recultivation. Pp. 55-74 in The Protection of Lakes, B. Cie onska- Siko~ka, ed. Epoka (in Polish). Gliwicz, Z.M., and A. Koalezewski. 1981. Epilimnetic and hypolimnetic symptoms of eutrophication in Great Masurian Lakes, Poland. Freshwater Biology 11:425-433. Great Lakes Water Quality Board. 1985. Report on Great Lakes Water Quality. Report to International Joint Commission (IJ.C.~. Hallbert, G.R. 1987. Nitrates in Iowa groundwater. Pp. 23~9 in Rural Groundwater Contamination, D'Itri and WolEson, eds. Chelsea, Michigan: L~wis Publishers, Inc. Hillbricht-Ilkowska, A. 1984. The indices and parameters useful in the evaluation of water quality and the ecological state of temperate, low-land lakes connected with their eutrophication. Pp. 55~9 in the Proceedings of the International Conference, "Consenration and Management of World Lake Environment." Otsu Shiga, Japan, August 24-30, 1984. Hillbricht-Ilkowska, A., ed. 1988. The lakes of Masurian Landscape Protected Area Eutrophication, protection, management. Ossolineum, Warszawa, (in Polish, with English summa~y). (in press). Hillbricht-Ilkowska, ~ (in press). Some properties of the functioning of low-land lakes presenring their mesotrophic character. Internationale Revue der Gesamten Hydrobi- ologie. Klepper, G., G. Carpenter, and D. Gruben. 1987. Groundwater contamination from landfills, underground storage tanks, and septic systems. Pp. 147-160 in Rural Groundwater Contamination, D'Itri and WolEson, eds. Chelsea, Michigan: Lewis Publishers, Inc. Kudelska, K.D., D. Cydzki, and H. Soszka. 1981. A proposal of lake water quality classification. W'ad. Ekol. 27:149-173 (in Polish with English summary). Lovley, D.R., and M.J. Klug. 1982. Intermediary metabolism of organic matter in sediments of a eutrophic lake. Appl. Environ. Microbiology (March 19823:552-560. Lovley, D.R., and MJ. Klug. 1983. Methanogenesis from methanol and methylamines and acetogenesis from hydrogen and carbon dioxide in the sediments of a eutrophic lake. Appl. Environ. Microbiol. (April 1983~:1310-1315.
314 ECOLOGICAL RISKS Lovley, D.R., and MJ. Klug. 1986. Model for the distribution of sulfate reduction and methanogenesis in freshwater sediments. Geochimica et. Cosmochimica Acta (Vol. 50~:11-18. Lovley, D.R., D.F. Dwyer, and M.J. Klug. 1982. Kinetic analysis of competition between sulfate reducers and methanogens for hydrogen in sediments. Appl. Environ. Microbial. (June 1982~:1373-1379. Vollenweider, R.A. 1976. Advance in defining critical level for phosphorous in lake eutrophication. Mem. Inst. Ital. Idrobiol. 33:53-83. United States Geological Survey. 1984. Hydrologic events: Selected water~uality issues and groundwater resources. Water Supply Paper 2275. Zdanowski, B., A. Ko~ycka, and J. Zachwieja. 1984. Thermal and oxygen conditions and the chemical composition of the water in the Great Masurian Lakes. Ekol. Poll 32:651-678.
