STATE OF THE LAKES ECOSYSTEM CONFERENCE INTEGRATION PAPER DRAFT FOR DISCUSSION PURPOSES SEPTEMBER 1994 Canada USA ------- COOPERATING TO IMPLEMENT THE GREAT LAKES WATER QUALITY AGREEMENT MISE EN OEUVRE DE L'ACCORD SUR LA QUALITE DE L'EAU DES GRANDS LACS STATE OF THE LAKES ECOSYSTEM CONFERENCE INTEGRATION PAPER Prepared for SOLEC STEERING COMMITTEE Paul Horvatin, Co-Chair United States Environmental Protection Agency Harvey Shear, Co-Chair Environment Canada Grace Wever, Council of Great Lakes Industries Danny Epstein, Environment Canada Maureen Evans, Environment Canada Jennifer Wittig, Environment Canada Dieter Riedel, Health Canada Mary Hegan, Health Canada Neil Tremblay, Health Canada Tim Eder, National Wildlife Federation Fred Fleischer, Ontario Ministry of Environment & Energy. Kent Fuller, U.S. Environmental Protection Agency Philip Hoffman, U.S. Environmental Protection Agency Bob Beltran, U.S. Environmental Protection Agency Charlie Wooley, U.S. Fish & Wildlife Service by Joanna Kidd, LURA Group Toronto ENVIRONMENT CANADA 867 Lakeshore Road Burtington, Ontario L7R 4A6 For additional copies please contact: ENVIRONNEMENT CANADA 867, rue Lakeshore Burlington. Ontario • . L7R 4A6 ENVIRONMENTAL PROTECTION AGENCY Great Lakes National Program Office 77 West Jackson Blvd. Chicago, Illinois 60604 U.S.A. EPA 905-D-94-002 Integration Paper - October 1994 ------- TABLE OF CONTENTS Executive Summary 3 1.0 Introduction 5 2.0 Ecosystem Concepts and the Ecosystem Approach 9 3.0 The State of the Ecosystem 12 3-1 The State of Aquatic Communities 12 3.2 Human Health and the Effect of Environmental Contaminant Stresses ... 14 3.3 The State of Aquatic Habitat IS 3.4 Nutrient Stresses 16 3-5 Persistent Toxic Contaminant Stresses 17 3.6 Economic Stresses and Mitigating Activity 19 3.7 Overall Health of the Great Lakes Basin 20 4.0 Major Stresses and Their Interactions 24 4.1 Major Stresses on Aquatic Communities 24 4.2 Major Stresses on Aquatic Habitat 28 4.3 Major Environmental Contaminant Stresses on Humans 30 4.4 Key Interactions Among Stresses 32 5.0 Management Challenges for the Future 39 Appendix A: 400 Years of Change 42 STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- LIST OF TABLES AND FIGURES Table 1: Preliminary Indicators of Ecosytern Health 21 Table 2: Summary of Fish Species Lost or Severely Diminished in the Great Lakes 25 Table 3: Priority Contaminants of the Great Lakes , 27 Figure 1: The Laurentian Great Lakes Basin '....6 Figure 2: Dioxin Concentrations in Herring Gull Eggs 18 Figure 3: Primary Biophysical Stresses on the Great Lakes Ecosystem and their Linkages , , , 33 Figure 4: Contaminant Cycling in the Great Lakes Ecosystem 36 STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- EXECUT|VE SUMMARY The central purpose of the United States/Canada Great Lakes Water Quality Agreement is the restoration and maintenance of the chemical, physical and biological integrity of the Great Lakes Basin Ecosystem. In support of this purpose the governments are sponsoring a State of the Lakes Ecosystem Conference (SOLEC) to review and make • available information on the state of the system. A major purpose of the conference is to support better decision- making through improved availability of information on the condition of the living components of the system and the stresses which affect them. This paper 'undertakes to integrate the main themes of six working papers prepared as background for the conference. The Great Lakes Basin comprises one of North America's major industrial and agricultural regions. It is an area that is rich in natural resources, linked by a . strong transportation system, and host to a vibrant and growing tourism and travel sector. But the economic gains of the Basin have not been without environ- mental cost. The biophysical ecosystem in the Basin has been and continues to be subjected to a host of stresses — resource extraction, urbanization, defor- estation, industrial practices, nutrient loading, introductions of exotic species, alterations and destruction of natural areas, the contamination of air, water and soil and others. Further historic perspec- tive is provided in Appendix A, The condition of the living compo- nents of the system, including humans, is the ultimate indicator of its health, reflecting the total effect of stresses on the system. The effects upon the living system, often expressed as use impair- ments, are also the most meaningful indicators as far as the public is con- cerned, i.e. can we swim, fish and drink the water? Although effects on the living system are the ultimate indicators, mea- sures of the physical, chemical and bio- logical stresses that affect the system are equally important in describing the state of the Lakes arid providing vital informa- tion for programs that restore and protect the integrity of the ecosystem. Indicators are used to measure the state of living components in terms of both aquatic communities and human health, although human health is mea- sured primarily in terms of risks rather than direct health effects. Indicators of the state of aquatic habitats reflect both the condition of the living vegetative component of habitat, and physical and chemical components. Indicators are also used to measure three categories of stress: nutrients, persistent toxic contami- nants, and economic activity. For purposes of simplification, a small number of indicators for each of the background paper subject areas have been chosen and are shown in this paper. These simple indicators are intended to summarize the state of the ecosystem and progress made to date in addressing the many sources of these stresses. Conditions shown by the indicators are rated in four categories: poor, mixed/ deteriorating, mixed/improving and good/restored. The report draws on information from a variety of sources up STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- to the year 1993. Indicators within each of the six subject areas showed a mix of conditions and are summarized in tables beginning on page 21, The paper concludes with a brief section on challenges for environmental resource managers and decision-makers to consider in the future as they use ecosystem information. The integration paper is intended to focus and aid discussion among SOLEC participants. The SOLEC Steering Com- mittee welcomes suggestions from participants on how the paper can be improved for post-conference use. STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- 1.0 INTRODUCTION >y almost any standards, the . Laurentian Great Lakes Basin (see Figure 1) is rich in resources. The Great Lakes contain one-fifth of all the fresh surface water resources on Earth. The Basin is blessed with extensive forests and wilderness areas, rich agricultural land, hundreds of tributaries and thousands of smaller lakes, extensive mineral deposits, and abundant and diverse wildlife. There are 28 cities with populations of more than 50,000 in the region, and some 32.4 million people call it home. The Basin remains one of North America's major industrial and agricultural regions, is linked by a strong transportation system, and supports a vibrant and growing tourism and travel sector. Yet with all its riches, the Great Lakes Basin ecosystem is under tremendous stress from human activities. Past and current industrial practices, nutrient loading, resource extraction, urbaniza- tion, deforestation, introductions of exotic species, alterations and destruction of natural areas, contamination of air, water and soil — all these stresses, and more, have caused the ecosystem to tip out of balance. What is the state of the Great Lakes Basin ecosystem? This report tries to take a measure of that state. Restoration and maintenance of the chemical, physical and biological "... this first SOLEC is concen- trating on recent changes and rates of change. It is recog- nized that severe impacts have occurred in the past, but the need at this time is to address current conditions, stresses and rates of change." integrity of the Great Lakes Basin Ecosys- tem is the central purpose of the United States/Canada Great Lakes Water Quality Agreement (GLWQA). Restoration and maintenance can only be achieved with widespread support and action on the part of governments, industry, non- government organizations and the gen- eral public. To support this purpose the governments are sponsoring a State of the Lakes Ecosystem Conference (SOLEC). A major purpose of the conference is to support better deci- sion-making through improved availability of accurate, ecosystem- based information on the condition of the living components of the system and the I stresses which affect them. Specifically, the conference will: • provide information on the state of the Great Lakes ecosystem; • develop support for an integrated system which compiles and distributes environmental information to assist management plans and programs in the Great Lakes Basin; • provide information on existing Great Lakes management strategies; and • provide a forum for improved commu- nications and network-building within the Basin. STATE OF THE LAKES ECOSYSTEM CONFERENCE • I NT EG RAT I ON PAPER ------- The Great Lakes Basin Great Lnkes Profile O O in -< in 2 O O z z n o 70 O z TJ -o m 70 SI MifyKivci (.Snolockl) Mull riikj(u SI Clan Kiv« UkcSl I'Uu Dclfuil Klvci MINNI-SOTA N Aren of Avci aye Voluuiv kk&4uu2) Ucutk(iu) (kui3) Iiuii (yis) Superior 82100 147 12100 I'JI Michigan 57800 85 4020 99 Huron 59600 59 3540 22 Erie 25700 19 484 2 (> Ontario |g>J60 86 1640 6 -75 0 300km Source: Knviioilinvilliil Cunsciv.ihoii lirauch, I'liviioiinicnl C.ui. FIGURE I: THE LAURENTIAN GREAT LAKES BASIN ------- In the interest of focusing attention on decisions that affect the Lakes and gaining wider recognition of the need to consider impacts on the Lakes, this first SOLEC is concentrating on recent changes and rates of change. It is recog- nized that severe impacts have occurred in the past, but the need at this time is to address current conditions, stresses and rates of change. As European settlement began almost 400 years ago the Great Lakes were far different than they are today. Compared to their biological diversity at that time and the virtual absence of toxic sub- stances and human pathogens, the Lakes today are severely degraded. However, some recovery has been made. Most Great Lakes observers would agree that vast improvement has been made in water quality through the con- trol of nuisance conditions, nutrients, human pathogens, and biochemical oxygen demand. Also most observers would agree that much progress has been made in controlling toxic contaminants, although much remains to be done. On the other hand, although some progress is being made on protecting and restor- ing habitat, losses far exceed gains. In the case of biological diversity, because each loss of genetic diversity is permanent, all losses are additive. Thus while some progress can be made in reducing losses, overall losses of native species and ge- netic strains will continue faster than that expected in the absence of human activity. The long-term losses in biodiversity have been severe, as reported in the working paper on Aquatic Community Health. Similarly, losses in habitat have been severe, as reported in the paper on Aquatic Habitat and Wetlands. For both aquatic community health and habitat, while increasing efforts are being made and losses in biodiversity and habitat are slowing, the low point has probably not yet been reached. The hope for habitat is that preservation of habitat essential to high-priority ecosystems will accelerate, together with restoration successes. For biodiversity, its importance is at least becoming, widely recognized and steps are being taken to protect endangered species and the ecosystems necessary to support them. Unfortunately each genetic loss is permanent, at least in the time scale of the lives of humans and human civilizations. For human health, the low point was reached in the late 1800s before adequate treatment was provided for drinking water. In major cities large numbers of people died due to waterborne diseases. Now the risk of such illnesses from pathogens is slight. While the health of the Great Lakes basin ecosystem declined steeply, the health of the human population seems to have improved dramatically, as measured in longevity, or in the incidence of fatal or crippling infectious diseases such as poliomyelitis or typhoid fever. However, much of that improvement in human health is due to improvements in sanita- tion, to the development and use of vaccines, and to drinking water disinfec- tion. All of these measures have helped to keep the incidence of severe outbreaks of infectious diseases at a low level. On the other hand, there have been slow, but steady increases in the incidence of certain cancers and of some respiratory STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- illnesses, and we do not know whether or to what extent the many environmental contaminants contribute to these and other human diseases. In addition there are indications that certain kinds of chemical contaminants may interfere with the reproduction and development of animals and humans. These and other signs of possible subtle adverse effects of environmental contaminants on human health need to be investigated further. This paper has been prepared as a tool to assist managers and decision- makers attending the Conference. Draw- ing upon the most recent data available, it evaluates the state of the Great Lakes Basin ecosystem. It is hoped that the Paper will focus discussion and spark dialogue among participants about future strategic directions. This paper is based on. six "Working Papers" prepared as background for SOLEC which provide more complete information on the following topics: • health of aquatic communities; • human health and health risks; • aquatic habitat and wetlands; • nutrients; • toxic contaminants; and • economy-environment linkages. These Working Papers (provided under separate cover) were developed by binational teams with expertise in the relevant issue areas. They provide an account of current and historical condi- tions in the Great Lakes Basin using a variety of data sources compiled through 1992. They also identify data gaps, sug- gest priority areas for action, and raise important questions for debate. This Integration Paper provides infor- mation on ecosystem concepts and the Great Lakes ecosystem and describes briefly the changes that have taken place during the last 400 years. It draws from the information presented in the Working Papers to assess the state of the Great Lakes ecosystem today using a prelimi- nary list of ecosystem health indicators. The Paper identifies the major stresses acting on aquatic habitat and aquatic communities, and the major environmen- tal stresses on humans living in the Basin. Interactions among stresses are explored briefly, and the Paper ends with a number of management challenges for the future. As noted, the Integration Paper is designed to focus and aid discussion among SOLEC participants. The SOLEC Steering Committee welcomes sugges- tions from participants on how future versions of the Integration Paper can be improved. STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- 2.0 ECOSYSTEM CONCEPTS AND THE ECOSYSTEM APPROACH Under the binational Great Lakes Water Quality Agreement, an ecosystem is defined as "the interacting components of air, land, water and living organisms, including humans," A number of key ideas are embedded in this concept. These include: » Humans are part of the ecosystem, and not separate from it. * Ecosystems can operate and can be defined at many different scales — from global to local — forming a hierarchy of systems nested within sys- ( — terns. The Great Lakes Basin is an ecosystem within which are found * five smaller ecosys- tems — the Lake Superior, Lake Michigan, Lake Huron, Lake Erie and Lake Ontario sub-basins. Within these sub-basins are found rivers drain- ing watersheds, and within these watersheds are found streams drain- ing subwatersheds. • Ecosystems are not closed systems. Seeds, spores, animals, water, chemi- cals and nutrients travel between ecosystems or are carried by natural processes and humans. The Great Lakes Basin influences and is influ- enced by the regions outside of it. "Healthy ecosystems have integrity ... but ecosys- tems also have limits to the stress they can en- dure. Pushed beyond their ability to absorb or assimilate stress, ecosys- tems can become de- graded." » Ecosystems are dynamic systems in which change is normal and some- times unpredictable. Over long peri- ods of time, ponds and lakes age and dry up, terrestrial vegetation under- goes succession to reach climax states, and communities adapt to global changes in temperature. Eco- systems can be changed dramatically by natural episodes of fire, flood or glaciation. Healthy ecosystems have integrity — the resilience to absorb or assimilate external stresses. But ecosystems also have limits to the stress they can endure. Pushed beyond their ability to absorb or assimilate stress, ecosystems can become degraded. The multiple stresses on Lake Erie are an example. Habitat destruction, sedimenta- tion, over-fishing and i nutrient enrichment all contributed to a de- cline of the fishery and a -shift in. species composition. Excessive loading of nutri- ents during the first half of the 20th cen- tury lead to a proliferation of algae in the Lake. The breakdown of dead algae by bacteria used up much of the oxygen in the bottom waters of the Central Basin, leaving little for other aquatic life. Due to lack of oxygen, mayflies and their nymphs had vanished from large areas of STATE OF THE LAKES ECOSYSTEM CONFERENCE • INT EG RAT I ON PAPER ------- Lake Erie, depriving fish species such as perch, walleye, cisco and bass of a staple food. This compounded the already stressed stocks, severely depleted be- cause of the stresses just mentioned. In the case of the eutrophication of Lake Erie, concerted, basin-wide efforts to reduce phosphorus loadings brought the ecosystem back toward balance again, and aided the restoration of the fishery, already on its way back because of a fishing ban on walleye and whitefish in the early 1970s. In some cases, how- ever, ecosystem effects are irreversible. While ecological restoration can be achieved to some extent, the original aquatic community in Lake Erie with its total biodiversity and genetic diversity within each species can never be recre- ated. Ecosystem response time is also variable. While surface water can respond to a dramatic reduction in loadings of a particular organochlorine contaminant within a few years, it may take many decades for an equivalent reduction to take place in bottom sediments through natural biological and physical processes. Governments have traditionally ad- dressed human activities on a piecemeal basis, separating decision-making on environmental quality from decision- making on natural resource management or on social or economic issues. Even within the environmental field, agencies have traditionally managed air issues separately from those dealing with water, land or wildlife. An ecosystem approach to management is a holistic approach that recognizes the interconnectedness of and addresses the linkages occurring among air, water, land and living things. An ecosystem approach: • includes the whole system, and not just parts of it; • focuses on interrelationships among the components of the environment and between living and non-living things; • includes consideration of the natural environment, society and economy; • is based on natural geographic units such as watersheds; • incorporates the concepts of sustainability; and • respects species other than humans and generations other than the present. The application of the ecosystem approach under the GLWQA has been interpreted in many ways and debate will undoubtedly continue as to how inclusive the concept should be in terms of geo- graphic and socio-economic aspects. In terms of geographic extent, this paper focuses on the conditions in the Lakes themselves and rivermouth areas as influenced by activities throughout the Basin, and not on the conditions in upstream and terrestrial areas. In terms of socio-economic aspects, this report focuses on the state of the biophysical environment, not the state of the social or economic environments. The report considers human health only as it is related to environmental stresses, and does not consider economic health per se. However, some major economic stresses are considered to the extent that they impact the biophysical environment. The ecosystem approach and its applications continue to evolve as better STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- indicators of ecosystem integrity are developed and as management plans and programs are reoriented to produce environmental results measured in terms of ecosystem objectives and indicators. Remedial Action Plans for Areas of Con- cern and Lakewide Management Plans are leading examples. STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- 3.0 THE STATE OF THE ECOSYSTEM How healthy is the Great Lakes Basin Ecosystem? What constitutes good health? How can it be measured? The system is clearly different than before European settlement. To what extent has the biological, chemical and physical integrity been lost' What part of the genetic diversity of the system has been lost and how much remains? What modified state of integrity is it possible to attain? Many of these questions can not yet be answered. The biological state of the Lakes, with the partial exception of Lake Superior, has been unstable during recent decades. What new diverse, self-sustaining, inte- grated ar^d stable system can reasonably be expected? One way to determine the status of the Great Lakes ecosystem is to measure indicators of ecosystem health. Doctors use indicators such as blood pressure and weight to gauge human health; economists use indicators such as interest rates and housing starts to assess the health of economies. Ecosystem health indicators measure ecosystem quality or trends in quality that are useful to manag- ers and scientists. Many attempts to develop ecosystem health indicators have been made or are underway in the U.S., Canada and internationally, including those outlined in the Aquatic Community Health working paper. Because the current attempts to develop indicators of ecosystem health are not at stages where they can readily be used in simple terms, the SOLEC Steering Committee has developed its own preliminary list of indicators (see Table 1). The indicators selected include those for: the state of aquatic communi- ties, human health and health risks, aquatic habitat; and for three categories of stresses — nutrients, persistent toxic contaminants and economic activity. Economic activity is considered to be a stress because the economy of the basin is the basis for most of the activities that are the source of stresses affecting the ecosystem. Of course it is important to recognize that the economy also provides the means to control stresses and restore the system. The SOLEC Steering and Technical Committees rated the indicators based on information collected for the Working Papers. Rating was done in four broad categories: • poor, (meaning significant negative impact); • mixed/deteriorating (meaning that the impact is less severe, but that the trend is towards greater impact); • mixed/improving (meaning that the impact is less severe, but that the trend is towards less impact); and • good/restored (meaning that the impact or stress is removed, that the state of the ecosystem component is restored to a presently acceptable level). 3.1 The State of Aquatic Communities Compared to their chemical, physical and biological integrity 300 years ago, the STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- Great Lakes ecosystems are extremely unhealthy. The catastrophic loss of biological diversity and subsequent establishment of non-indigenous populations is the most striking indication of degradation of the Great Lakes. At least 18 historically important fish species have become depleted or have been extirpated from one or more of the lakes. Amplifying this loss of species diversity is the loss of genetic diversity of surviving species. Prior to 1950, Canadian j waters of Lake Superior supported about 200 distinctive stocks of lake trout, including some 20 river-spawning stocks. A large number of these stocks is now extirpated, including all of the river spawners. The loss of genetic diversity of lake trout from the other Lakes is even more alarming, with complete extirpation of lake trout from Lakes Michigan, Erie, and Ontario, and only one or two remnant stocks in Lake Huron. Accompanying this loss of diversity was a series of invasions and introduc- tions of exotic species. Since the 1880s, some 139 non-indigenous species have become established in the Great Lakes. Together, the non-indigenous species have had a dramatic and cumulative effect on the structure of the aquatic communities of the Great Lakes, and their persistence poses substantial problems for the restoration and maintenance of native species associations. "While aquatic communi- ties in all the lakes have been significantly dis- turbed and altered by a host of stresses... those in Lakes Michigan and Ontario are the most un- stable." The state of aquatic communities is the ultimate test of whether prevention, control and restoration programs are effective. Three indicators for measuring the health of aquatic communities were selected. The first indicator — the num- ber of native species lost — was rated as good/restored for Lake Superior, and mixed/improving for the other lakes. As compared to the other lakes, fewer aquatic species have been lost in Lake Superior due to the lower levels of devel- opment, industry and human population. Even in the more disturbed lakes, at- tempts to reintroduce depleted species of native predator fish such as walleye and lake trout have been partly successful. The second indica- tor, the Lake Trout Dichotomous Key, provides a measure of how balanced the aquatic ecosystem is. This key is based on scores of questions relating to lake trout and their habitat. Using this indicator, Lake Superior rated as good/restored, Lakes Huron and Erie as mixed/improving, and Lakes Michigan and Ontario as poor. While aquatic com- munities in all the lakes have been sig- nificantly disturbed and altered by a host of stresses (including over-fishing, exotic species, habitat destruction, nutrient enrichment and persistent toxic sub- stances), those in Lakes Michigan and Ontario are the most unstable. U.S. and Canadian government stocking programs to reintroduce lake trout and non-native STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- salmonid predators to the Great Lakes have resulted in the development of popular sports fisheries providing a wide range of species for anglers. The stability of fish communities and fisheries, however, are not predictable at this time. The third indicator for the state of aquatic communities is reproductive impairment. This indicator is rated as mixed/improving in all lakes. Exposure to a variety of environmental stresses including organochlorine compounds (some widespread, some local) has caused reproductive problems for Great Lakes wildlife, especially aquatic birds. In the 1950s and 1960s severe effects were observed and populations of some spe- cies declined, often due to thinning of egg shells. In recent years the problems are present in less obvious forms which cause birth defects or failure to repro- duce in a small percentage of the popu- lations. Population problems were some- times attributable to environmental contaminants, but in other cases popula- tions actually increased during times of high contaminant loadings, e.g. ring billed gulls. Reductions in loadings of organochlorines have allowed popula- tions of herring gulls, Caspian terns, black-crowned night herons and double- crested cormorants to become re-estab- lished in the Great Lakes. Indeed, cormo- rant populations have rebounded to levels never seen before. Continuing low rates of bill defects and other develop- mental abnormalities were seen through the 1980s in cormorant populations, suggesting that the birds were still being exposed to toxic amounts of PCBs and other organochlorine compounds from fish, particularly in "hotspots" such as Green Bay. Wisconsin. It is worth noting that the "background" frequency of defor- mities, as determined from Western Canada bird populations, does not differ significantly from the frequency of defor- mities in most areas of the Great Lakes, except for a few of these hotspots. While exposure of the aquatic com- munity to most known toxic contami- nants is declining, the effect of chronic exposure to low concentrations of persis- tent toxic substances remains uncertain. 3.2 Human Health and the Effect of Environmental Contaminant Stresses Environmental contaminants are only one category of factors that affect human health. Other factors include nutrition, adequate shelter, genetic makeup, exposure to bacterial or viral disease agents, lifestyle factors such as smoking, drinking and fitness, social well-being and others. Because human health reflects the effects of stresses of many kinds from many sources, direct measurement of the effect of any one stress or category of stress is extremely difficult and costly. As a result, most indicators of human health are expressed in terms of health risks attributable to various stresses. A number of factors make it difficult to establish a link between environmental contami- nants and human health; these are listed in chapter 4.3. Direct indicators of human health include the incidence of birth defects and cancer; longevity; children's body weight and development; and incidence of infec- tious diseases related to water sports and STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- drinking water. Indirect measures include beach closures and fish consumption advisories. Unfortunately, basin-wide data for these measures are not available at this time. A number of indicators to measure environmental contaminant stresses on humans in the Great Lakes are proposed. These include: water quality; air quality; atmospheric and total radioactivity. Even with measures of stress and exposure, information on differences among basin, national and global levels is limited. In "... levels of priority con- taminants ... in human tis- sues of Great Lakes resi- dents are similar to levels found in human popula- tions elsewhere...." order to better assess the impacts of environmental stresses on human health, better trend data over time must be collected on body burdens, exposures and potential health effects. Available information indicates that levels of priority contaminants such as PCBs, dioxins and furans in human tis- sues of Great Lakes residents are similar to levels found in human populations elsewhere, suggesting that exposures are also similar. The overall rating for environmental contaminant stresses from the Great Lakes on human health in the Basin is mixed/improving. Because little data exist to measure impacts of contaminant stresses on humans in the Great Lakes over time, we use the levels of contami- nants in me ambient environment and in fish and wildlife and in human milk as a surrogate. Based on this we can reason- ably say that the stress from toxic con- taminants on human health is likely to be mixed or in some cases improving. This rating reflects the general decline of concentrations of persistent toxic sub- stances in all media including fish throughout the Great Lakes, and the fact that the major route of human exposure to contaminants in Great Lakes waters is through fish consumption. 3.3 The State of Aquatic Habitat The first indicator selected for the state of aquatic habitat and wetlands is the loss of habitat (both in terms of quality and quantity) which was given a rating of poor. Loss of wetlands in the U.S., loss of coastal wetlands in Ontario, and loss of brook trout habitat in the Lower Lakes were aE considered evidence of poor conditions. Wetland losses, in particular, have been significant across the Basin. Studies show that in some areas up to 100% of coastal wetlands in Lakes Ontario, Erie, Michigan and St. Clair have been lost to development. Losses of total wetlands (including both coastal and inland wetlands) have been staggering, Sixty percent of the original wetlands in the Great Lakes Basin States have been lost since the 1780s; in Ontario, south of the Precambrian Shield, wetland losses have been estimated to be as high as 80%. While losses continue, current rates of loss are unknown, as are rates of impairment. In many cases, wetlands may STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- still appear to exist but may be functionally degraded through siltation. nearby development, the introduction of foreign plants and animals, and other stresses. Few data exist on the magnitude of losses for other critical habitats such as rocky shoals, sheltered bays, estuaries and tributaries. In contrast, the indicator for loss of brook trout stream habitat in the Upper "Sixty percent of the origi- nal wetlands in the Great Lakes Basin States have been lost since the 1780s; in Ontario, south of the Precambrian Shield, wet- land losses have been es- timated to be as high as 80%." Lakes was rated as good/restored. Fewer cold-water streams have been lost and degraded in the Upper Lakes basins because of the lower degree of urbaniza- tion and human disturbance. A second indicator — encroachment and development of wetlands — was also rated as poor. This reflects the continu- ing loss and degradation of wetlands basin-wide due to urban development, recreational uses, agriculture and other forms of encroachment. The third indicator selected consid- ered gains in habitat and wetlands through protection, enhancement and restoration efforts. There are various international, national and state/provin- cial policies and programs for habitat/ wetlands protection, some of which rate quite high in results. However, the net effect of protection, enhancement and restoration is considered to be poor since programs are not keeping up with habitat losses. An example of a program produc- ing good results is the North .American Wildlife Management Program which has resulted in the protection of more than 17,500 hectares of wetlands in the Basin. 3.4 Nutrient Stresses Four indicators to measure nutrient stresses were rated. Three were rated as good/restored. Two of these are total phosphorus loadings (GLWQA targets were achieved by 1991 in four of the five Lakes) and total phosphorus concentra- tions in open water (GLWQA objectives were achieved by 1991 in all Lakes). A third "good/restored" rating was given to an indicator measuring the levels of chlorophyll a in the Lower Lakes, which is a surrogate for the productivity of the system (the amount of algae growth). The low level of chlorophyll a found today is consistent with the GLWQA goal set in 1972 of "reduction in the present level of algal biomass to a level below that of a nuisance condition." The fourth indicator — levels of dissolved oxygen in Lake Erie's bottom waters — was considered mixed/improv- ing. Oxygen levels in Lake Erie's bottom waters are much better than they were twenty years ago. Notwithstanding this, and despite phosphorus loading reduc- tions, periods of anoxia (lack of oxygen) were still occurring from 1987 to 1991 in the late summer in some areas of the STATE OF THE LAKES ECOSYSTEM CONFERENCE • I NT E G RAT I ON PAPER ------- Central Basin. This continued anoxia may be attributable to the release of historical phosphorus from bottom sediments, or. it may be that intermittent anoxia is an inherent property of Lake Erie's Central Basin. 3.5 Persistent Toxic Contaminant Stresses To measure the effects of stress from persistent toxic contaminants, three indicators were selected: loadings of persistent toxic contaminants, levels of chemical contaminants in fish and levels in herring gulls. Each of these indicators is considered as mixed/improving. Levels "...although large per- 'centage reductions. have been achieved in compari- son to peak levels, for many contaminants, an additional level of magni- tude further reduction is needed to reach accept- able levels of risk." of persistent toxic contaminants have been reduced substantially since 1970 (see Figure 2 showing dioxin concentrations in herring gull eggs from 1971 to 1992). As to reductions in loadings of persistent toxic substances, detailed figures are not available basin- wide, but the ecosystem response over time can be seen in media such as open 'waters, sediments, fish and wildlife. Levels of organochlorine contami- nants in the tissues of top predator and forage fish initially declined significantly from the late 1970s to mid 1980s but have shown a slower rate of decline recently. Despite this overall trend, from 1986 to 1989, in some areas, particularly in Lake Ontario, levels of some of these contami- nants increased in some fish. On the other hand, from the late 1970s to the mid 1980s, concentrations of heavy metals showed little change. Levels of persistent toxic contaminants in some fish species in some areas continue to be high enough to restrict consumption by humans. One possible cause of these continu- ing high levels is that contaminant con- centrations in fish are influenced by changes in food which varies in availabil- ity and contaminant content. As a result, changes in contaminant levels in fish may be influenced by shifts in feeding behav- ior by fish or elsewhere in the food web. Overall, contaminant levels have shown good response to control pro- grams although the rate of response has slowed. Although overall contaminant levels have been substantially reduced from peak levels, for many contaminants, additional reductions (in the order of a level of magnitude) are needed to reach acceptable levels of risk. Also, as more is learned about long term exposure and endocrine effects, even lower levels may be required to reach acceptable risk. Chemical residues in herring gull eggs have been monitored by the Cana- dian Wildlife Service since 1974. All the chemicals routinely monitored since then (including PCBs, DDT/DDE, mirex, dield- rin and HCB) have shown a statistically STAT E OFTHE LAKES ECOSYSTEM CONFERENCE • INTE G.RAT ION PAPER ------- 2500- 2000- I500H «• 1000—I ft »«•# a 500- rinnnn r~i n 71 '72 73 74 75 76 '77 78 79 '80 '81 '82 '83 '84 '85 '86 '87 '88 '89 '90 '91 '92 YEAR Data Source: Weseloh. 1993 FIGURE 2: DIOXIN (2,3,7,8-TETRACHLORO-DI-BENZO-DlOXtN) CONCENTRATION {N HERRING GULL EGGS 1971-1992, EASTERN LAKE ONTARIO STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- significant decrease at more than 80% of the sites sampled. Chemicals monitored later in the program, such as oxy-chlor- dane, photo-mirex, and 2,3,7,8-TCDD, have also shown significant decreases, The greatest decrease observed occurred between 1974 and 1981; since then the rate of decrease has slowed and levelled off. In 1991-1992, increases in the level of certain contaminants have been noted in some locations. The reasons for this apparent increase are not known, and may be linked to changes in diet due to changes in the food web. 3.6 Economic Stresses and Mitigating Activity Economic activity produces both stresses on the ecosystem and the means to address or mitigate them. Ten economic indicators were se- lected. Two of these were rated as poor: infrastructure investment and loss of agricultural land and urban development. This rating reflects the continuing low levels of government investment in basic infrastructure (with the exception of some $10 billion U.S. in sewage treat- ment plant construction and sewer system upgrades during the past two decades), and the continuing trend to urban sprawl. Four economic indicators were rated as mixed/deteriorating — employment; research and development; personal income; and population growth and stability. For the years 1970 to 1990, employment growth in the Basin lagged behind that experienced overall by the U.S. and Canada. During this period, total U.S. employment grew at 53% while employment in the U.S. side of the Basin grew at only 25%. Similarly, total Cana- dian employment during this time period grew at 15%, while employment in the Canadian side of the Basin grew by only 6%. In recent years, personal income growth in the Basin has slowed substan- tially, reflecting the loss of manufacturing jobs and increase in service sector em- ployment. From 1970 to 1980, personal "Strategies for a sustain- able future must try to correct the past imbal- ance between the econ- omy and the environment, and apply ecosystem man- agement principles and sustainable development policies in the future/* income in the Basin grew by 140%; that for 1980 to 1990 grew at only 83%. The population of the Basin grew by less than 1% from 1970 to 1990, as compared to the combined population of the U.S. and Canada which grew by 22% over the same period. While urban sprawl clearly adds stress, population and economic growth add stfess and also provide the means to control both new and old stres- sors. Four indicators — pollution preven- tion, adoption of a stewardship approach, water conservation, and per capita en- ergy use — were rated as mixed/improv- ing, reflecting changing public attitudes STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- towards resource conservation and sus- tainable development. Increasing public concern about environmental issues and aggressive environmental regulation have focused attention on environment- economy linkages and on the concept of sustainable development. Strategies for a sustainable future must try to correct the past imbalance between the economy and the environment, and apply ecosystem management principles and sustainable development policies in the future. Rec- ognition of economic-environmental linkages in resource management and protection is increasing throughout the Great Lakes Basin. However, the leap between the concept of sustainable development and its application is a formidable one. 3.7 Overall Health of the Great Lakes Basin Ecosystem Overall, the health of the Great Lakes Basin Ecosystem is variable, depending on the measurement used. By some measures, the health is good/restored; this is certainly so for the aquatic community on Lake Superior. At the other end of the spectrum, a number of indicators show quite clearly that some aspects of ecosystem health are poor. These include habitat loss, encroachment and development of wetlands, and the imbalance of aquatic communities in Lakes Michigan and Ontario. In between the extremes, as we have seen, many indicators are mixed, with some trends improving and others deteriorating. STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- TABLE I-.PRELIMINARY INDICATORS OF ECOSYSTEM HEALTH INDICATORS STATUS OF INDICATORS Poor Mixed/ ; Mixed/ Good/ Deteriorating Improving Restored STATE OF AQUATIC COMMUNITIES Native Species Loss (# of native species) Lake Superior Lakes Huron, Michigan, Erie & Ontario 2, • Ecosystem Imbalance (Late Trout Dichotomous Key) Lake Superior Lakes Huron & Erie Lakes Michigan & Ontario 3. Reproductive Impairment Effects - all Lakes Body burdens - all Lakes HUMAN HEALTH AND ENVIRONMENTAL CONTAMINANT RISKS Overall state Air/water/soil/sediment contamination • contamination trends (Or SO4, dust) • hospital admission and death rates for respiratory illness rates (eg. asthma) * beach closings • infectious diseases related to recreational uses • atmospheric and total radioactivity 2. Fish consumption advisories * contaminant loadings 3. Human contaminant body burdens 4. Measurements of health status/health effects * birth defects and cancer * longevity * children's body weight/development Dashes indicate lads, of Strain-wide data STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- TABLE I: PRELIMINARY INDICATORS OF ECOSYSTEM HEALTH (continued) INDICATORS STATUS OF INDICATORS Poor Mixed/ ; Mixed/ Good/ , Deteriorating! Improving Restored STATE OF AQUATIC HABITAT AND WETLANDS 1 . Loss in habitat/wetlands quality & quantity United States - Michigan Survey ; • - other states • Ontario - CWS coastal wetlands i • - Brook Trout stream habitat (Upper Lakes) - Brook Trout stream habitat • (Lower Lakes) 2. 3. Encroachment/development Basin-wide Gains in habitat/wetlands quality & quantity Areas protected under the North American Wildfowl Management Plan ' Net effect • " " NUTRIENT STRESSES 1 . Total phosphorus loads • targets achieved in 4 of 5 Lakes (1991) 2. 3. 4. Total phosphorus intake concentrations • objectives achieved in all Lakes ( 1 99 1 ) Lake Erie dissolved oxygen (Central Basin hypolimnion) Chlorophyll 3 (as indicator of nuisance algal growth) in Lower Lakes / " • • . CONTAMINANT STRESSES 1. 2. 3. 4. Loadings Residue in fish Residue in birds (herring gulls) Body burdens — all Lakes I • • ' ! STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- TABLE I: PRELIMINARY INDICATORS OF ECOSYSTEM HEALTH (continued) INDICATORS STATUS OF INDICATORS Poor Mixed/ Mixed/ Good/ : Deteriorating Improving Restored ECONOMIC STRESSESAND MITIGATING ACTIVITY Employment (manufacturing & other sectors) 2. Infrastructure investment (public & private sectors) 3. 4. 5. 6. 7. 8, 9. 10. Research & development (measures of technological innovation) ' Land-use and reuse changes (loss of agricultural land & urban development) Population growth and stability (compared to other regions) Pollution prevention (expenditures and results - loadings/emissions/discharges) Personal income (statistics) Adoption of stewardship approach (public & private sectors) Water conservation (industry & per capita) Energy use (per capita) ' " " • • ' > • STATE OF THE LAKES ECOSYSTEM CONFERENCE • I NT EG RATION PAPER ------- 4.0 MAJOR STRESSES AND THEIR INTERACTIONS 4.1 Major Stresses on Aquatic Communities Great Lakes aquatic communities continue to be exposed to a multiplicity of physical, biological and chemical stresses. In terms of importance, the major stresses on aquatic communities are: • imbalances in aquatic communities and loss of biodiversity due to over-fishing and fish stocking, and pres- ence of exotic species; » degradation and loss of tributary and nearshore habitat; « impacts of persistent toxic contami- nants; and « eutrophication in localized areas. Imbalances in Aquatic Habitat and Loss of Biodiversity Although physical and chemical stresses have contributed to the decline in integrity of Great Lakes' ecosystems, stresses associated with biological factors have, in fact, caused much more severe degradation. In particular, over-fishing and introduction of exotic species have had tremendous impacts on aquatic communities, causing profound changes and imbalances. The loss of biodiversity and concomi- tant establishment of non-indigenous "The loss of biodiversity and concomitant estab- lishment of non-indig- enous populations in the Great Lakes has been little short of catastrophic/* populations in the Great Lakes has been little short of catastrophic. The history of the Great Lakes and the collapse of its commercial fisheries offer dramatic examples of the effects of over-fishing. Native top predators, once dominated by lake trout, have been replaced by hatch- ery-reared imports. Table 2 lists the many species of Great Lakes fish that have been extirpated or are se- verely depleted due to human activities, mostly over-fishing. What is not shown by the table is the funda- mental loss of genetic diversity among surviv- ing species. Accompanying (and sometimes accelerat- ing) this loss of diver- sity was a succession of invasions and deliberate releases of exotic aquatic species. Some 139 non-indigenous aquatic species have become established in the Great Lakes since the 1880s. Spe- cies that have established substantial populations include: sea lamprey; ale- wife; smelt; gizzard shad; white perch; carp; brown trout; chinook, coho and pink salmon; and rainbow trout. To this list can be added more recent imports such as the zebra and quagga mussel, ruffe, rudd, fourspine stickleback and others, and plant species such as purple loosestrife. Together, these species have had a dramatic and cumulative effect oh the structure of aquatic communities in the Great Lakes. The continuing pres- ence of these non-indigenous species STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- TABLE 2. SUMMARY OF FISH SPECIES LOST OR SEVERELY DIMINISHED BY LAKE INTHE GREAT LAKES. AN ASTERISK (*) INDICATES STOCKING PROGRAMS EXIST TO ATTEMPT RE- INTRODUCTION. STATUS CODES ARE I (DEPLETED), 2 (EXTIRPATED), AND 3 (EXTINCT). Common Lake sturgeon Longjaw cisco Lake herring Lake whitefuh Bloater Deepwater cisco Kiyi BJackfin Cisco Shortnose cisco Shortjaw Cisco Burbot Fourhorn Sculpin Emerald shiner Atlantic salmon Lake trout Sauger Blue pike Species Name Adpenser ffuvescens Cortgonus o/penoe C. arttdii C. c/upecformis C. hafi C. johannae Ckjyi C. n/gnp/nn;s C. reighardi C. zenitWcus Low Jots Myoxoccphalus quadricomis Notropis otheirinofdes Salmo sator Saivelinus namayaish Stizostedion canadcnse 5, vftreum gtaucum Lake Superior 1 " 1 1 2 1 Lake Huron 1 2 2 * 2* Lake Michigan 1 2 I ' 2 2' 2 \ . 2 2 2* Lake Lake Erie Ontario I 1 2 2 1 2 ! ! 2 ; 2 i i ; 1 3 I 2* 2* 2* 2 3 ; 3 poses substantial problems for the reha- bilitation and maintenance of native species associations. Habitat Degradation and Loss It is difficult to overestimate the importance of adequate and diverse aquatic habitat for healthy aquatic communities — it is simply the most basic building block of ecosystem health. Without adequate habitat in which to spawn, breed, nest, stopover, forage and hide, many species of fish and wildlife cannot survive. In Lakes Ontario and Michigan, and to a lesser extent in Huron and Superior, stocking of predators obscures the effects of degraded habitat: the lack of spawning areas, for example, becomes less obvious. In highly polluted areas of the Great Lakes, fish communities may have already compensated for these effects by restructuring and eliminating tributary- dependent stocks. Lack of basin-wide STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- data on the amount and quality of aquatic habitat is a major barrier to measuring habitat health, quantifying habitat status, and rehabilitating aquatic communities. Ensuring the health of aquatic habitats and wetlands is a priority concern for ecosystem health in the Basin, and will require a greater share of resources than it has been receiving to date. Persistent Toxic Substances Persistent toxic contaminants have had an impact on fish and wildlife species in the Basin. Observed effects include alteration of biochemical function, patho- logical abnormalities, tumors, and devel- opment and reproductive abnormalities. Recent studies have suggested that estro- genic effects of some organochlorines are implicated in developmental abnormali- ties in wildlife species. A possible conse-. quence of the above effects is a decrease in fitness of populations. In fish, how- ever, it is difficult to link cause (i.e. exposure to one or more toxic contami- nants) to effects. There are some labora- tory studies and evidence by association that tumors in Great Lakes bullheads and suckers (both bottom feeders) may be caused by contaminated sediments. In general, however, the effects of exposure to low levels of contaminants are less clear for fish populations than for wildlife in the Basin. For a list of priority con- taminants see Table 3. Various studies have identified con- taminant-associated effects on 11 species of wildlife in the Great Lakes. Affected species include fish-eating mammals (mink and otter), reptiles (snapping turtle), and fish-eating birds (double- crested cormorant, black-crowned night heron, bald eagle, herring and ring-billed gull, and Caspian, common and Forster's terns). All of these but the ring-billed gull and otter showed historical evidence of reproductive impairment due to contami- nants. Populations of fish-eating birds declined dramatically throughout the 1960s and 1970s as a result. With the reduction in loadings of persistent toxic contaminants such as PCBs, most of these bird populations recovered. The repro- ductive success of breeding eagles eating Great Lakes fish remains lower than that of those nesting inland. However, recov- ery of the bald eagle to pre-1950 levels is likely limited by the absence of appropri- ate habitat, and may be limited by food supply. Substantial parts of the Lake Erie shoreline, and substantial portions of the shorelines of Lakes Ontario, Michigan and Huron are not suitable habitat for the bald eagle because of agriculture, urban sprawl and human disturbance. As indi- • cated in chapter 3-0, continuing low rates of bill defects and other developmental abnormalities were seen through the 1980s in cormorant populations, suggest- ing that the birds were still being ex- posed to excessive amounts of PCBs and other organochlorines from fish, particu- larly in "hotspots" such as Green Bay, Wisconsin. Eutroph/cot/on Although eutrophication is no longer a problem in the Great Lakes on a lake- wide basis, it continues to occur in local areas and has a moderate impact on aquatic communities. This is particularly of concern in coastal marshes and inland wetlands. Nutrient enrichment causes STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- TABLE 3: PRIORITY CONTAMINANTS OF THE GREAT LAKES CHEMICAL REFERENCE Aldrin Benzo(a)pynene Chlordane Copper DDT and metabolites Dieldrin Fyran Heptachlor Heptachlor epoxide Hexachlorobenzene Alkylated Lead a Hexachlorocychlohexane 8 Hexachlorocyclohexane Mercury Mirex Octachlorostyrene Polychlorinated biphenyls 2,3.7,8-TCDD (dioxin) Toxaphene References: 1,5.7 1,3,5,7,8 1,2,3,6,7 1,2,3 1,2,3,5,6,7 i,2,3,6,7 1,3,5,7 1,2,3 1,3 1,2,3,5,6,7 1,3,4,5,7 1,3.8 1,3,8 1,2,3,4,5,6,7 1,3.5,7 1,3,6,7 1,2,3,5,6.7 1,2,3,5,6,7 1,2,3,5,6,7 I = GLWQAAnnex I, list I (173 total pollutants in lift) 2 = GLWQI guidance list of 33 pollutants 3 = LAMPS critical pollutants lists (Laic Michigan 15 total, Lake Ontario 9 total) 4 = Pollution Prevention (IndustrialToxics Project, 17 total) 5 - Eleven Critical Pollutants (1985 1JC Report) 6 = Lake Superior Binational Initiative (9 total) 7 = Canada-Ontario Agreement Tier 1 list of 13 virtual elimination contaminants 8 = Canada-Ontario Agreement Tier 11 list of 26 (including ! STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- excess growth of algae which depletes the water column of oxygen needed to sustain other forms of aquatic life. 4.2 Major Stresses on Aquatic Habitat Wetlands, tributaries, connecting channels, open lakes and nearshore areas of the Great Lakes each play a vital role in ecosystem function. The ultimate health of the Great Lakes ecosystem is strongly dependent on the health, availability and capacity of these components. A number of differ- ent classification sys- tems exist for aquatic habitat. For the pur- poses of this paper, habitats can be divided into the following types: • open-lake; i • inshore (including coastal wetlands, rocky shoals, shel- tered bays and estuaries); • shoreline (including sand dunes, beaches, gravel shores and lakeplains); • tributaries (those rivers and streams that drain into the Great Lakes); • connecting channels; and • inland habitats (including fens, bogs,. marshes, wet meadows, ponds and lakes). Aquatic habitats function in many important ways. They play a vital role in nutrient cycling, uptake and transfer. "Physical alteration of aquatic habitat has been the greatest cause of habi- tat loss in the inland, shoreline and inshore zones of the Great Lakes." They are among the most productive of systems in terms of the growth of photo- synthetic organisms (the assimilation of energy by plants). Aquatic habitats help to maintain water quality and regulate water flows and levels. They play impor- tant, sometimes very specific roles in the life cycles of mammalian, aquatic and avian species, providing habitat for spawning, nesting, rearing, foraging and sheltering. Aquatic habitats provide a significant proportion of the total biodiversity of the Great Lakes Basin Ecosystem. Amongst all types of aquatic habitats, the inshore j zone (and its wetlands) ranks highest in terms of performing these functions. Basin-wide data on the quality and quan- tity of aquatic habitats are scarce and frag- mented, and the best information that exists is for wetlands. A U.S. National Wetlands Inventory is now being developed which will map wetlands survey information, now only broken down by state or province, on the basis of drainage basins. Environment Canada, in cooperation with other agencies and groups, is gathering habitat-related infor- mation through a number of programs. Notwithstanding these initiatives, quanti- fying habitat status remains largely de- scriptive and anecdotal, and there are no accepted basin-wide classification sys- tems that integrate all aquatic habitat types and allow habitat health to be easily measured. The major stresses acting on aquatic STATE OFTHE LAKES ECOSYSTEM CONFERENCE • I NT EG RATION PAPER ------- habitat in the Great Lakes can be divided into five categories. In terms of impor- tance (i.e. magnitude of effect) these are: * physical alteration (filling, channelization, dredging, bulkheading, etc.) * hydrological changes (alterations in water levels and flows, loss of connec- tivity) * physical process changes (tempera- ture changes, sedimentation) • biological changes (addition of exotic species) * chemical changes (addition of nutri- ents, persistent toxic substances) Physical alteration of aquatic habitat has been the greatest cause of habitat loss in the inland, shoreline and inshore zones of the Great Lakes, Such alterations as lakefilling in urban areas, dredging, building dock walls in harbors, and the channelization of rivers eliminate the highly productive shallow water habitat that is particularly crucial to forage fish species and wading birds. Filling and draining of wetlands for agricultural or urban use eliminates not only the habitat, but the invertebrate, fish and amphibian populations living in that habitat. The development of shorelines and riverbanks for private docks, cottages and housing, and the buildihg of bridges usually can degrades nearshore habitat. Hydrological changes can have serious effects on inland wetlands, tribu- taries, inshore and shoreline habitats. Alterations in levels and natural fluctua- tions of the Great Lakes can have severe impacts on coastal marshes by flooding out or drying up vegetation. Unnatural stream flows can be caused by poor stormwater management which causes flushing of vegetation, sedimentation and erosion. Overconsumption of groundwa- ter leads jto reductions in base flows in streams, so that insufficient water is present for fish spawning. Wetlands which are hydrologically disconnected from their sources of water (e.g. coastal wetlands cut off from a lake) will degrade and dry up. Physical process changes that can affect aquatic habitat include temperature changes due to the removal of bankside vegetation, and increased sedimentation. Temperature increases in a headwater stream will eliminate habitat for cool- water species such as brook trout. Sedi- mentation covers fish spawning beds, ] rendering them unusable, and suspended sediment limits plant growth. Sediment- laden river beds also provide ideal habi- tat for sea lamprey (ammocoetes) in their life cycle prior to becoming parasitic. Biological changes have had a pro- found effect on aquatic habitat in the Great Lakes. The introduction of sea lamprey, carp, purple loosestrife, zebra. and quagga mussels, the ruffe and other foreign species has had a significant impact on aquatic habitats, but the scope of the impact is not yet well-understood. Both zebra and quagga mussels, for example, eat organic detritus. In Lake Erie, this has resulted in the extinction of native Unionidae clams, and may be contributing to declines in stocks of smelt, yellow and white perch. Chemical changes are moderate threats to aquatic habitat. The major chemical changes are excessive nutrients STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- and the presence of toxic substances. Eutrophication continues to be a local- ized problem in tributaries and inshore habitats in many of the Areas of Concern. Increased controls have reduced inputs of toxic compounds from industries and municipalities, but loadings continue from urban and agricultural run-off and releases from contaminated sediments already in the system. 4.3 Major Environmental Contaminant Stresses on Humans Hundreds of chemicals have been identified as being present in the Great Lakes ecosystem. Of these, the IJC has identified 11 as critical pollutants, based on: 1) presence in the Great Lakes environ- ment; 2) degree of toxicity; 3) persistence; and 4) ability to bio- concentrate and bioaccumulate. These 11 substances are listed in Table 3 together with several others identi- fied for priority consideration. While these are L~~:~~ recommended for priority consideration, there are numerous other substances which must also be considered due to their known or suspected impact on the ecosystem and human health. There are a number of pathways by which humans in the Great Lakes Basin can be exposed to persistent toxic con- taminants. The major route of human exposure to PCBs, dioxins, furans, orga- "While there is a large vol- ume of scientific evidence to show that these agents are harmful, it is not cer- tain how much harm they are causing to the inhab- itants of the Great Lakes Basin." nochlorine pesticides and certain heavy metals is food consumption, particularly consumption of contaminated fish. Food is believed to contribute from 40% to nearly 100% of total human intakes for many of these substances. Studies of fish eaters in the Great Lakes Basin have shown a correlation between sport- caught fish consumption and body bur- den of PCBs and DDE in blood and serum. Other routes of exposure include drinking water, breathing contaminated air, and dermal exposure. For contami- nants other than toxics, such as microbes, the major routes of exposure for humans are through poorly treated drinking water and recreational activities such as swimming. An example of microbial problems is the proto- 1 zoan Cryptosporidium which has recently caused intestinal prob- lems, including some deaths, due to its presence in drinking water. Human populations in the Great Lakes basin, like those living j elsewhere, are exposed '. I to many toxic pollut- ants present in the environment. Those of particular concern in relation to the GLWQA include dioxins and furans, organochlorine pesticides and their byproducts such as hexachlorobenzene, combustion byproducts such as polycyclic aromatic hydrocarbons (PAHs), and certain metals and their compounds such as cadmium, lead, and mercury. Other contaminants include radioactive elements such as STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- radon and air contaminants such as ozone. While there is a large volume of scientific evidence to show that these agents are harmful, it is not certain how much harm they are causing to the inhab- itants of the Great Lakes Basin. There are several reasons for this uncertainty. *One reason is the surprising scarcity of suit- able health statistics (indicators) to show the spatial and temporal trends of the state of health of various Great Lakes populations relative to that of people living elsewhere. -Suitable data are lack- ing, for example, on the "normal" growth and physical and mental development of children, on the general state of health and longevity of people living in various regions, on the number of people seek- ing treatment for infectious diseases caused by contaminated recreational or drinking water, and on the number of people admitted to hospitals for ill effects caused by exposure to chemical environ- mental contaminants. Reliable statistics on the occurrence of birth defects or cancers are lacking for some regions of the Basin. It is also difficult to ascertain exposure (i.e. to what kinds of contami- nants and to what, levels people are exposed). A large number of contami- nants occur at low concentrations, some of which may gradually accumulate in the body; others arc excreted without leaving a trace, although they may have done some damage. A number of factors make it difficult to establish a link between environmental contaminants and human health effects. These include: • the continuous nature of exposure over many years to low levels of contaminants; « exposure to mixtures rather than individual compounds; • the large number (and in some cases poor definition) of health effect endpoints to be examined, and the difficulty of measuring some effects; • experimental design problems (in- cluding the inability, in some cases, to obtain adequate sample sizes and measurements that are suitably sensi- tive and specific to detect changes); « dose-response questions; • accurate exposure assessment; and » confounding variables that may hinder research studies. In the past, health researchers and policymakers have tended to focus on dramatic episodes accompanied by obvi- ous health effects such as massive spills of chemicals, or smog episodes, arid on the most serious kinds of health effects such as cancer. Recent scientific evi- dence, however, based mostly on obser- vations in animals, raises concerns that exposure to low levels of certain con- taminants may cause subtle reproductive, developmental and physiological effects that may go easily unnoticed, but which in the long term may lead to serious cumulative damage. This includes such effects as immunotoxicity, neurotoxicity, so-called hormone mimicry, subtle pre- and postnatal developmental effects, and decreased fertility. In trying to assess the effects of contaminants on human health, the U.S. and Canadian governments have moved to use a so-called "weight of STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- evidence" approach which relies on information from many sources, includ- ing data on animals as well as humans. This allows educated guesses to be made which can then be tested through appro- priate medical and scientific studies. 4.4 Key Interactions Among Stresses As outlined in Chapter 2, an ecosystem can be defined as the interacting components of air, water, land and living organisms, including humans. While the notion of the ecosystem approach . : has been embedded in the GLWQA since 1978, policymakers have only relatively recently begun to grapple with actually using the ecosystem approach in planning. One of the challenges of the ecosystem approach is that it requires a focus on interactions and linkages, as distinct ' from more traditional environmental approaches in which thinking tended to be compartmentalized. Because an ecosystem such as the Great Lakes ecosystem is so complex, understanding the interactions between actions and effects is not easy. Like a pond into which a stone is tossed, seem- ingly innocent actions can have rippie effects that are cumulative, indirect, and far-reaching. Figure 3 is a simplified diagram that attempts to illustrate some of the linkages among major ecosystem "One of the challenges of the ecosystem approach is that it requires a focus on interactions and linkages, as distinct from more tra- ditional environmental approaches in which think- ing tended to be compart- mentalized." stresses and the environment. The dia- gram illustrates only the biophysical (natural) environment, and accordingly does not include important social and economic aspects of the ecosystem. It shows the major linkages among three components of the environment (human communities, aquatic habitat and aquatic communities) and three key stresses (nutrients, toxic contaminants and exotic species). The figure shows the major activities that cause stress on the Great Lakes ecosystem. These include-, nutrient and contaminant loading, : introduction of exotic species, over-fishing and stocking, and physical and hydrologi- cal impairment,of aquatic habitat. Physi- cal impairment of habitat includes lakefilling, dredging, channelization, defor- estation, sedimentation and other stresses. ! | Hydrological impair- ment includes loss of hydrological connectivity and alterations in water levels and flows. As can be seen from Figure 3, not only do these human activities put stress on aquatic communities and aquatic habitat, they also cause stress on human communities. Discharging toxic contami- nants into the environment, for example, potentially exposes humans to these contaminants through air, drinking water, eating fish and other food grown within the Basin, and swimming and other water sports. This illustrates a fundamental STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- TOXIC CONTAMINANTS QUAUtY/ QUANTITY OF HABITAT AQUATIC COMMUNITIES FIGURE 3: PRIMARY BIOPHYSICAL STRESSES ON THE GREAT LAKES ECOSYSTEM AND THEIR LINKAGES STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- tenet of the ecosystem approach, one that sets it apart from conventional environ- mental planning — humans are part of the ecosystem, not separate from it. Loss of Aquatic Habitat Figure 3 also shows how an environmental problem such as loss or degradation of aquatic habitat can have many causes. Habitat loss and impairment can be caused by a host of stresses — physical alterations, hydrological changes, the introduction of exotic species, the presence of toxic contaminants, high levels of nutrients and changes in community structure. These stresses can operate individually or in concert. In practice, aquatic habitat in the Great Lakes will usually be exposed to more than one of these stresses. This illustrates a fundamental aspect of ecosystem health — because ecosystems are so complex, effects are rarely caused by only one stress. Figure 3 also illustrates how one "problem" can have many different con- sequences. As an example, aquatic habi- tat loss and impairment will have a direct impact on the health of aquatic communi- ties. Loss of spawning or foraging areas for pike, for example, will directly affect the ability of that species to survive lo- cally, and will in turn affect forage fish populations and other parts of the food web. Habitat loss and impairment can have negative impacts on human commu- nities because of accompanying loss of aesthetic and natural values, and reduced opportunities for sport and commercial fishing. Wetland loss and impairment, in particular, contributes to higher loadings of nutrients and contaminants in the Great Lakes ecosystem because of de- creased contaminant retention and biodegradation. And these higher levels of contaminants in the system will in- crease the potential exposures to hu- mans. This example illustrates the com- plex interrelationships that lie at the heart of the ecosystem approach: at first glance, paving over a wetland seems far- removed from increased human expo- sures to contaminants, but the connec- tions are indeed there. The next section provides some more examples of the many complex interactions and linkages that characterize the Great Lakes ecosys- tem and that challenge managers. . Contaminant Cycling One of the important linkages that is not directly illustrated by Figure 3 is how contaminants can move through the Great Lakes Basin ecosystem (and into the Basin from outside). The ecosystem approach tells us that "everything is connected to everything else." A PCB molecule discharged into Lake Ontario, for example, may not stay in solution in the water. Once in Lake Ontario, the molecule, can volatilize, in which case it may be carried by air currents to fall out in another lake or on land. Alternately, once in the water, the molecule may bind to a particle and settle to the bottom. Here it can stay and eventually be broken down by bacterial processes, or it can be ingested by bottom-dwelling organisms, in which case it can move up the food chain when these organisms are eaten. Even if the PCB molecule stays in the water column, it can enter plankton which are then consumed by pelagic or benthic organisms which are in turn STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- consumed by forage fish. The forage fish may in turn be eaten by a herring gull, or by a large fish which may in turn be eaten by a Great Lakes angler. Another biological transfer that has greatly increased in the last few years is transfer of materials including contami- nants from the water column to bottom sediments by zebra mussels. The mussels produce prodigious quantities of pseudo-feces, undigested material which they filter from the water and release to bottom sediments. This has the potential for a major shift in not only energy trans- fers, but movement of contaminants as well. This may at least partially account for changes in contaminant trends being observed in fish. Figure 4 provides a simplified sche- matic of contaminant cycling showing various pathways. It also illustrates why restoration strategies must be based on a knowledge of the ecosystem. Fundamental questions remain about how contaminants move around the Great Lakes ecosystem. What are the total loadings of contaminants of concern? What is the net effect on the Lakes of atmospheric deposition and volatilization of contaminants? How can we effectively deal with long-range transport of con- taminants from other countries and continents? What is the relative contribu- tion of historical sources (such as re- leases from sediments) to levels found in water and fish? What is the effect of zebra mussels on contaminant cycling? Why are contaminant levels in biota no longer declining even though loadings of persis- tent toxic contaminants have been steadily reduced since the 1970s? Clearly, the ecosystem responses to actions such as decreased loadings of contaminants are not simple. As an ex- ample, "turning off the tap" of PCBs from industrial discharges has not fully solved the problems of PCBs in fish: policymakers need to consider all sources, including bottom sediments and air, and need to consider the interactions among these sources. They must also recognize the response times involved once the "taps are turned off. Zebra Mussel; Great Lakes Filter In 1986,,the zebra mussel arrived unannounced, discharged from the ballast water of a European ship. Its introduction into the Great Lakes set in "... the zebra mussel may go far beyond that of a nuisance. Some Great Lakes researchers believe that the zebra mussel has the potential to funda- mentally alter aquatic community structures." motion a series of cascading events. With few natural predators, the imported bivalve proliferated rapidly. Concern in the early years coalesced around threats to infrastructure, especially clogging of water intake pipes, and the bottom fouling of ships and boats. However, recent studies indicate that impacts of the zebra mussel may go far beyond that of a nuisance. Some Great Lakes researchers believe that the zebra mussel has the potential to fundamentally alter aquatic STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- -I > H n O t/i -< CO -I m 3 n o z 2 n z H m D GROUNDWATER O Z f/GURE 4. CONTAMINANT CYCLING IN THE GREAT LAKES ECOSYSTEM -o m 70 ------- community structures. The half-inch long zebra mussel has a voracious appetite. It feeds on plankton and detritus that it filters from large volumes of water. In so doing, it transfers energy from the pelagic (open water) system to the benthic (bottom-dwelling) system, Zooplankton that otherwise would be available for forage fish, instead fuel a population explosion of zebra mussels. Increased water clarity has been observed across the basin as zooplankton and detritus are removed by mussels from the water column. In relatively shallow areas, this improved clarity has resulted in increased penetration of light and increased growth of submerged aquatic vegetation. This has likely in- creased spawning, nursery and forage areas for some fish species, while prob- ably reducing them for others, Predaa'on on fry can also increase due to increased clarity. As noted in Chapter 4.1, in Lake Erie, the impacts of zebra mussels on detritus and zooplankton have resulted in the severe impacts on native Unionidae clams, and may be contributing to de- clines in stocks of smelt, yellow and white perch. Impacts of the Changing Nutrient. Reg/me The reduction in phosphorus loading achieved over the last 25 years has reduced the total quantity of algae in Great Lakes waters enough to meet the objectives set out in the GLWQA. This reduction of phosphorus to historical levels appears also to be having an impact on the abundance of plankton in the Great Lakes. Declines in levels of zooplankton have been noted in Lakes Ontario and Michigan. Zooplankton sustain forage fish such as alewife and smelt, which in turn sustain top predator fish. Levels of top predator fish in the Great Lakes have been sustained at unnaturally high levels through the en- hanced productivity of the system (high levels of phosphorus which supported very large populations of forage fish) and through stocking of indigenous and exotic species such as chinook salmon and rainbow trout. While this has contrib- uted to the growth of an extensive sport fishing industry, it is not sustainable in a system in which nutrient levels are de- clining. From an ecological (and ecosys- tem management) point of view, expecta- tions for fish yield (both commercial and sport) need to be adjusted to levels that are sustainable over the long term. This has implications for targets for stocking programs throughout the Basin, eco- nomic implications (from reduced yield) and poses potential conflicts with angler groups. A related issue is the question of what types of top predators should be stocked. Species such as chinook salmon, while they are desirable sport fish, are not established as naturally-breeding populations (except in some tributaries in Lakes Ontario and Superior); lake trout, one of the "natural" top predators in the Great Lakes, are not so popular with anglers. A second set of scientific questions arises from the question of the impact of changing nutrient regime on community structure. If lowered phosphorus loadings are affecting community structure, are they also having an effect on contami- nant cycling? At this point; the answer is not known. STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- Restoring Aquatic Systems A recent report. Great Lakes Environmental Assessment (LTI, 1993), outlines starkly the current conditions of the Great Lakes fishery: "Fish populations in the past were comprised only of native species which evolved together into a rich and diverse population that was self-regulating, productive, and comprised of many species representative of oligotrophic conditions. Fish communities in the Great Lakes today are of smaller mean size, composed principally of pelagic (open- water) species, and large benthic and predatory species that dominated early fish communities are severely dimin- ished. Communities are now dominated by fecund (i.e. capable of rapid popula- tion growth), non-indigenous (i.e. exotic) species such as alewife and rainbow smelt. Numerous native species are now extinct or have been extirpated. Top predators are also exotics (Pacific salmon) or stocked hatchery-reared, genetically inferior lake trout and the sea lamprey...Current fish communities are unstable, are difficult to manage, require large amounts of public moneys to main- tain some semblance of integrity, and are constantly changing in response to the various stresses that are imposed upon them." There are many lessons to be learned from the past. One of these is that there is no quick fix to the ecological problems facing the fishery. Past management decisions — stocking of non-indigenous predators, alterations and destruction of habitat — were made without consider- ation of the impacts on the total aquatic system. Ecological systems are complex webs of interconnections, and. seemingly innocent actions — building a dam here. introducing a sport fish there — have had profound and irreversible effects. Actions to restore the Great Lakes fisher- ies must proceed based on a firm under- standing of the impacts of actions on aquatic birds, mammals, amphibians and reptiles, aquatic organisms at all trophic levels, and people. STATE OFTHE LAKES ECOSYSTEM CONFERENCE • I NT EG RAT I ON PAPER ------- 5.0 MANAGEMENT CHALLENGES FOR THE FUTURE As shown in Chapter 3, the health of the Great Lakes ecosystem is variable. In Lakes Huron and Superior which are less urbanized and industrialized, water quality, aquatic communities and habitats are relatively healthy; in the other lakes, human activities have caused widespread environmental degradation. Even in the other Lakes, though, progress has been made in halting or undoing the damage caused by past unsustainable practices: water is cleaner, fish and wildlife communities are healthier than they were twenty years ago, some progress has been made to protect and enhance aquatic habitat, and some indigenous top predators are undergoing a resurgence. Society is moving — many may argue, too slowly — to embrace the principles of sustainability, waste reduction, pollution prevention, and resource efficiency. Despite the progress that has been made in the last twenty years, much remains to be done. Persistent contaminants continue to cycle through the ecosystem affecting fish and wildlife, and the effects of long term exposure to small concentrations of contaminants continue to be discovered. Aquatic habitat loss has been slowed, but it continues to take place on a massive scale. Exotic species "The complexity of the ecosystem and the intri- cacy of interrelationships pose tremendous chal- lenges for managers in the 1990s. How well these, and other challenges are met will define the condi- tion of the Great Lakes for future generations." continue to destabilize aquatic communities, degrade habitat, and alter cycling of nutrients and contaminants. Individuals, municipalities, industries and farms still discharge pollutants into air, soil and water, The complexity of the ecosystem and the intricacy of interrelationships pose tremendous challenges for managers in the 1990s. How well these, and other challenges are met will define the condi- tion of the Great Lakes for future genera- tions. Some of these challenges include: The challenge of adequate informa- tion: This report (and the Working Papers on which it is based) cite numerous examples of areas in which basic research and data collection needs to be done. Needs include basic economic data on the Great Lakes Basin, data on quality and quantity of aquatic habitat, information on contaminant cycling, a better understanding of food web dynam- ics, and spatial and temporal data on the health of humans and aquatic biota. Effective steps forward require good information on which to base decision- making, information on stresses, interac- tions and effects. It is vital to fill these priority data gaps. The challenge of information man- agement and communication: Informa- tion on environmental conditions is STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- possessed by hundreds of boards, agen- cies, commissions, and interest groups in the Basin. But all too often this informa- tion is locked in filing cabinets, or sitting on shelves. Moving forward to restore ecosystem health will require taking advantages of the tremendous strides made in computer networks, integrated information, cable, and other telecommu- nication opportunities to improve com- munication on environmental issues. The challenge of how decisions are made: Traditional decision-making is linear. A decision is made by an indi- vidual or agency, it is passed along for review or approval by a long "chain of command." This is time-consuming, compartmentalized, and antithetical to the ecosystem approach. The ecosystem approach requires "round table," interdis- ciplinary, inter-jurisdictional and inter- sectoral approaches to decision-making, approaches which aim for consensus among stakeholders. The challenge of institutional ar- rangements: The goal of restoring and maintaining the integrity of the Great Lakes Basin ecosystem poses many challenges to institutional structures. It requires recognition of ecosystem im- pacts from all decisions: recognition of effects beyond the narrow purposes of specific laws, regulations or organiza- tional missions. It also requires a consen- sual "buy in" to goals, objectives and strategies from federal, state, provincial, regional and municipal governments, and from the private and non-governmental sectors. Because of the complexity of the Great Lakes Basin ecosystem, and the complex nature of the problems it faces, partnerships and coordination of actions are key to implementing an ecosystem approach to management. The challenge of sustainability: Restoration and protection of the Great Lakes ecosystem requires a commitment to achieving sustainability. As a society, we still deplete non-renewable resources, still spend our environmental "capital." A truly healthy Great Lakes ecosystem will be one in which the consideration of the environment and the economy will be integrated with the needs of humans in a balanced and sustainable manner. The challenge of dealing with biodiversity: Recognition of the need to protect genetic resources and the habi- tats needed to sustain various species, genetic variety within populations, and biological communities poses new chal- lenges that fit well within the ecosystem approach. Two of these challenges are whether programs can be adapted to supply the information needed to address the issue, and whether effective strategies to protect biodiversity can be developed. The challenge of agreeing on end- points for restoration: Since some of the genetic diversity and physical features of the system have been irrevocably lost, and some exotic species appear to be permanently established; how can physi- cal, chemical and biological integrity be defined? What measurable conditions should programs seek to attain? The challenge of dealing with a focus on places: Applying an ecosystem approach to restoring and maintaining the Great Lakes Basin ecosystem requires a recognition of the extent to which natural systems vary from place to place, and how local systems relate to those around them. Traditional environmental regulations and programs have used STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- blanket objectives and standards, used on a national, provincial or state-wide basis. One of the challenges for governments and other stakeholders is to understand and address restoration with respect to local ecosystems (both structure and function) and their linkages elsewhere. The challenge of connecting deci- sions with ecosystem results: A major part of the challenge is to understand ecosystem problems and the stresses that cause them. Another important aspect of the challenge is establishment of well defined ecosystem objectives and indica- tors to measure success in restoring and maintaining ecosystem integrity. Such indicators can provide a focus for bring- ing together seemingly disparate pro- grams and serve as a basis for integrating programs that were originally created to deal with separate aspects of environ- mental quality, resource management or other purposes. The challenge of subtle effects of toxic substances on people and wild- life: The subtle effects of long term exposure to small quantities of toxic substances poses a challenge to managers as well as to researchers. If some sub- stances have effects at such low concen- trations that the ecosystem has virtually no ability to absorb them, or the global environment already contains concentra- tions at levels that may be causing ad- verse effects, how can use or generation of them be avoided or prevented? STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- APPENDIX A 400 YEARS OF CHANGE Physical Characteristics To understand the Laurentian Great Lakes Basin ecosystem, one needs to understand the scale and unique characteristics of what the French missionary, Father Gabriel Sagard, dubbed the "Sweetwater Seas". The Great Lakes — the world's largest freshwater system — cover an area of 244,160 square 'kilometers [km] (94,278 square miles [m]). More than 80,000 smaller lakes and some 750,000 km (466,041 m) of tributaries lie within the Great Lakes Basin. It drains an area of 765,990 square km (295,772 square m), an area bigger than the State of Texas. Ontario and eight U.S. states lie completely or partially within the Basin (see Figure 1). Because of their large surface area, the Great Lakes are vulnerable to atmo- spheric deposition of contaminants. In other words, they are a "sink" for air- borne pollutants, some of which are transported from great distances outside the Basin. Also, and importantly, the Lakes are a source for some persistent toxic contaminants such as PCBs that volatilize from their surfaces (primarily .during the summer months) into the air and cycle through the system. Not only are the Great Lakes large in terms of surface area, they are also, (with the exception of Lake Erie) very deep (see Figure 1). These large, deep lakes contain a huge volume of water, less than 1% of which leaves the system annually through the bottleneck of the St. Lawrence River. Because the flushing time for the Lakes is so long — for ex- ample, some 191 years for Lake Superior — relatively small percentages of pollut- ants entering the Lakes are exported through their outflows. Contaminants can also accumulate In bottom sediments and in the food web. History In the year 1615, Samuel de Champlain first sighted the Great Lakes. What he and subsequent explorers discovered in the Basin was a complex, balanced and extremely diverse ecosystem. It was a land in which many of the landforms had been carved out or left behind in the wake of the retreating Wisconsin Glaciers. The retreating glaciers left behind a legacy of lakeplains, moraines, eskers, kettle lakes, inland wetlands, and extensive rivermouth estuaries. A wide variety of vegetation had adapted to the diverse landforms and moderate climate. In the cool, dry north, vast coniferous forests clung to the thin, acidic soils of the Boreal zone; in the wetter and warmer south, Carolinian hardwood forests grew on rich soils. Diverse wildlife communities had adapted to the vegetation and topography. Population numbers remained low until European settlement started in earnest in the mid to late 1700s, The history of European settlement is directly linked to the area's principal geographic feature — the Great Lakes and their tributaries. In the absence of road net- works, settlement of the Basin by Euro- peans and transportation of goods was dependent on transportation by water STATE OF THE LAKES ECOSYSTEM CONFERENCE • INTEGRATIONPAPER ------- through lakes, rivers and linking canals. Major "gateway" cities in the region such as Montreal, Toronto, Buffalo, Cleveland, Detroit, Chicago, Milwaukee and Duluth all began as ports. Canal building was started early to improve links within and without the Basin; the Erie Canal link was made in 1826. Commercial fishing in the Lakes started in the early 1800s. The major settlement period of the Great Lakes coincided with, the rapid develop- ment of industrial and transportation technologies: with abundant water re- sources, cheap hydroelectric power, productive agricultural land, access to raw materials and an available labor force, the region developed an unparal- leled advantage in domestic and overseas markets. The presence of the Great Lakes encouraged the development of water- intensive industries and waterborne shipment of raw material and finished goods; later intensification saw the emergence of a complex of primary and secondary manufacturing. Along with the economic growth came rapid changes in the natural envi- ronment. By the beginning of the 20* century, settlers had cleared huge tracts of forests in the Basin for agricultural purposes or for timber, forcing many species of wildlife to retreat. Dams built on rivers to provide power for milling grain and lumber were interfering with fish spawning, and the removal of trees and shrubs from streambanks was caus- ing erosion and sedimentation. This also led to changes in the temperature regime of these rivers, contributing to the demise of cold-water species. In coastal cities, bulkheads and piers were built, nearshore areas and coastal marshes filled, and harbors and river mouths dredged. This habitat destruction, coupled with over- fishing, was causing a decrease.in fish populations. Additional stress on aquatic communities came later from exotic species such as alewife and sea lamprey that spread to Lake Erie and the Upper Lakes through canals. To support rapidly increasing populations, cities spread outwards, and houses were built on agricultural lands, forested areas, river valleys, and wetlands. Residents were dumping garbage and sewage into Lakes and rivers or onto land, and industries were discharging their wastes directly into the air or water. By the beginning of the 20th century, there were many indications that water quality was deteriorating and the Great Lakes Basin ecosystem was out of bal- ance. Public health concern over the incidence of water-borne diseases such as typhoid was such that in 1912 the Cana- dian and U.S. governments referred the issue of pollution of the Great Lakes to the International Joint Commission (IJC) for study. As a result of the Commission's work, governments began building water treatment and sewage treatment plants in urban centers. This usually included chlorinating the drinking water and sewage effluent. In the 82 years since that first referral, many Great Lakes environ- mental problems have come to light — problems including eutrophication, high coliform bacteria levels in recreational waters, impacts of persistent toxic con- taminants on wildlife and fish, imbal- ances in aquatic communities, loss of habitat and many others. Governments , have tackled these issues as they arose. Stocking programs were introduced STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- in an attempt to re-establish native top predator fish such as walleye and lake trout. The walleye fishery in Lake Erie has rebounded because of strict harvest controls and a total fishing ban in the early 1970s and also because of phospho- rus controls. Walleye populations are undergoing a resurgence in Lake Ontario and have stabilized in Lakes Huron and Superior. However, attempts to re-estab- lish naturally-reproducing populations of lake trout have not been successful ex- cept in parts of Lakes Huron and Supe- rior. Effective binational programs were set up .to control populations of invading lamprey. As new threats emerged from such exotic species as zebra mussels, quagga mussels, and purple loosestrife, governments in the Great Lakes Basin began to develop strategies to control them. The eutrophication of Lake Erie grabbed headlines and attention in the late 1960s and early 1970s and prompted the U.S. and Canadian governments to sign the Great Lakes Water Quality Agree- ment of 1972. Under this agreement, which focused on the eutrophication problem, the governments developed programs to reduce the loadings of phos- phorus to the Lakes. As a result of joint actions, phosphorus loadings to all the Lakes have declined since 1976. Concen- trations of phosphorus in open water have also declined, which has resulted in a noticeable reduction in the growth rate of algae, both offshore and in nearshore areas. Today, although eutrophication is still a localized problem in some Areas of Concern, it is no longer a problem in the open waters of the Great Lakes. In. 1978 the GLWQA was renegotiated by the Parties and its scope was broad- ened to include such issues as control of persistent toxic substances, non-point source pollution, and other matters. In 1987 the Agreement was expanded to include contaminated sediments, air- borne contaminants, management plans and ecosystem indicators. The Parties (and their provincial and state partners) have used a mix of strate- gies to tackle the problems of persistent toxic substances. Basin-wide monitoring and surveillance programs were devel- oped to monitor contaminant levels in air, water,, sediment, fish and wildlife. Regulatory programs continue to reduce discharges of pollutants. Demonstration programs are showing the feasibility of cleaning up contaminated sediments and of restoring and protecting habitat. Pollu- tion prevention is increasingly being used to reduce use and discharge of contaminants. Increasingly, ecosystem-oriented multimedia approaches are being devel- oped. Under the GLWQA the Parties agreed to prepare ecosystem-based Remedial Action Plans in 43 Areas of Concern in the Great Lakes to address impaired uses. Under that agreement, the Parties are also developing Lakewide Management Plans to address lake-wide contaminant problems, and are expand- ing these to include other issues such as habitat. Strategies to deal with environmental problems have changed in the last two decades. In terms of pollution control, governments are moving from a reliance on "react and cure" approaches to those that anticipate and prevent problems from occurring. As part of this shift, the STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- Parties agreed in 1990 to develop Pollu- tion Prevention strategies for the Great Lakes to assist municipalities, industries and individuals reduce their loadings of persistent toxic substances. With respect to ecosystem impacts from physical and biological stresses, governments have been slower to respond. Habitat contin- ues to be lost and exotic plant and animal species are having profound effects on the ecosystem, while most funds are spent on the control and clean up of persistent toxic substances, STATE OFTHE LAKES ECOSYSTEM CONFERENCE • INTEGRATION PAPER ------- NOTES ------- NOTES ------- NOTES ------- NOTES ------- |