Lake ecosystems are our sentinels of environmental change and their effective management is one of our key planetary challenges in the 21st century. The evolution of ecosystem science as a basis for management is reviewed using the nested set of the Laurentian Great Lakes, Lake Ontario, and the Bay of Quinte as a primary focus. Other great lakes of the world, many of which are in Canada, provide a secondary focus. Ecosystem science has a long history in the Laurentian Great Lakes with developments driven in large part by the Great Lakes Water Quality Agreement, Lake-Wide Management Plans, and Remedial Action Plans for Areas of Concern. By comparison most other large Canadian lakes have received little attention as is the case with many of the world's great lakes. The substantial arsenal of tools and knowledge accumulated in the Great Lakes can serve as a model for other lake systems. As the range of ecosystem management problems has continued to grow, the motivating theme has shifted from restoration through rehabilitation to adaptation. The main challenge is to coalesce the many stresses we previously have sought to manage singly: land use, population growth, habitat degradation, resource exploitation, invasive species, pollutant and contaminant loadings, and, finally, climate change. Essential features of effective ecosystem-based management are: a whole system view, active adaptive management, acceptance of science-based evidence, and shared goals with common objectives. The last two may prove the greatest hurdle as society becomes ever more divided and fractious given the global onslaught of environmental and societal challenges. The Great Lakes experience shows there is hope.
“One of the penalties of an ecological education is that one lives alone in a world of wounds. Much of the damage inflicted on land is quite invisible to laymen. An ecologist must either harden his shell and make believe that the consequences of science are none of his business, or he must be the doctor who sees the marks of death in a community that believes itself well and does not want to be told otherwise.”
Aldo Leopold (A Sand County Almanac, 1949).
A recent supplement of the journal Limnology and Oceanography (Vol. 54, Issue 6, Part 2, 2009) on climate change highlighted the central role of lakes as sentinels and integrators of the many environmental changes induced by human activities in watersheds, air-sheds, and landscapes. Great, or large, lakes (defined as those with a surface area, A0 ≥ 100.0 km2) represent a large portion of the earth's standing freshwaters (Downing et al., 2006). These large lakes (e.g. the African Rift Lakes, Lake Baikal, and the Laurentian Great Lakes) together with large rivers (e.g. Tigris-Euphrates, Nile, Ganges, Amazon, and Rhine) and productive coastal marine areas (e.g. North Sea, Sea of Japan) have been central to the development of human civilizations over the last 10,000 years.
Humans are making excessive demands on renewable resources within these water bodies. Rockstrom et al. (2009) identified nine key planetary boundaries, or thresholds (such as phosphorus, nitrogen, freshwater use and climate change), which are increasingly being tested by the high, global levels of all human activities. Eight of those boundaries have impacts on freshwaters. Freshwater is essential for human existence as it is a key element in many of the ecological goods and services we depend on for our livelihoods (Farber et al., 2006). Meanwhile, most human populations are presently preoccupied with a wide range of social and economic issues which are ultimately tied to the pursuit of growth in GDP (gross domestic product), ignoring the essential role of nature in sustaining human societies and economic development (Dasgupta, 2010). True sustainable development requires recognition of the need to balance ecological, social and economic demands within a framework of ecological boundaries, most likely without a growing GDP (Jackson, 2009). Balancing those demands will require effective ecosystem-based management, locally, regionally, and globally.
Ecosystem-based management (EBM) has been evolving rapidly in recent decades in many parts of the world. While the “ecosystem approach” (Christie et al., 1986) has been pursued for a long time in the St. Lawrence Great Lakes (SLGL), pursuant to the 1978 Great Lakes Water Quality Agreement (GLWQA) much of the conceptual development of EBM has occurred in marine ecosystems with particular attention to the harvest of fish, a major ecosystem stressor (Gavaris, 2009; Curtin and Prellezo, 2010). In this article, large lakes are taken as a primary focus of efforts to develop effective ecosystem-based management. An overview is provided for the Great Lake basin as whole, for Lake Ontario, and for the Bay of Quinte, in a spatially nested set. Both successes and remaining challenges are examined. Essential elements of EBM are outlined, future prospects discussed, and implications to other large lakes in Canada and the rest of the world are defined.
Ecosystem-based management: Status and progress
Great lakes of the world
Downing et al (2006) estimated the earth has ≈2.28 million lakes with A0 ≥ 10 hectares and Minns et al. (2008) estimated 40% of those are in Canada (Table 1). While numerically large lakes account for <0.1% of the number of lakes, they represent 54.2% of the area of lakes on earth and 44.6% are found in Canada. As sentinels and integrators of human impacts, lakes worldwide are showing evidence of ecosystem stress (ILEC, 1997; Tilzer and Bossard, 1992), especially large lakes (Randall et al., 2009). Human impacts as expressed through the multiplicative effect of population, affluence (consumption of goods and services) and technology (including power generation) (Ehrlich, 1990) and pressing the limits of Earth's ecosystems, particularly through use and abuse of freshwater resources (Rockström and Karlberg, 2010). Those stresses include eutrophication, toxic chemical loads and waste, overexploitation, habitat destruction and alteration, loss of biodiversity, exotic species, and climate change. Large lakes are bearing a greater portion of the stresses due to the ability of their drainages to accommodate larger numbers of people through such benefits as drinking water, fisheries, and transportation.
Canadian large lakes
Canada holds a disproportionate share (39.5 and 29.1% by number and area, respectively) of the earth's large lakes and consequently has greater responsibility to show leadership in their sustainable management.
Yet most of Canada's large lakes are poorly known and relatively undeveloped as most are remote from the main human population centres (Minns, 2010). The large lakes provide much of Canada's freshwater fishery potential (Minns, 2009). Climate change, species invasions, and range expansions and contractions of native species will greatly affect these lake resources in the coming decades. The better known large lakes are the largest including the Laurentian Great Lakes bordering Ontario, Lake Winnipeg in Manitoba, the inter-montane lakes in British Columbia, and Great Slave and Great Bear Lakes in the Northwest Territories. While much remains unknown about many of our large lakes, the record of the Canada-United States partnership on managing the Laurentian Great Lakes is exemplary as will be shown in succeeding sections.
The Laurentian Great Lakes and the Great Lakes Water Quality Agreement
Governments of Canada and the United States have a long history of cooperation on management the Laurentian Great Lakes which are a major boundary feature between the two countries. In 1909 they signed the Boundary Waters Treaty to facilitate resolution of joint water quality and quantity issues. Early in the 20th century many urban areas faced similar human health problems arising from the profligate use of shared water resources as a result of human and industrial waste disposal. As a result, rudimentary sewage treatment facilities were developed and constructed. Then, after the Second World War the exponential growth of industry, population, and urban areas began to produce a host of environmental impacts in the Great Lakes and elsewhere in industrialized countries. Evidence of pollution problems grew throughout the 1960s and, in 1972, the two countries signed the Great Lakes Water Quality Agreement (GLWQA) in which they committed “to restore and maintain the chemical, physical and biological integrity of the Great Lakes Basin Ecosystem.” This agreement was renewed in 1978 and amended in 1987. The 1987 renewal included the identification of 43 Areas of Concerns (AOCs) which were seen to be some of the problem hotspots and initiated the Remedial Action Plan process to focus efforts on cleaning up and restoring those sites. Interestingly, no new AOCs have been added since though several have now been delisted. Currently both countries are again working to renegotiate of this historic agreement in 2010 with closer attention to emergent issue areas (habitat and biodiversity, climate change) and areas that received less attention in earlier versions of the agreement (governance, invasive species).
The GLWQA is the principal mechanism for ecosystem management in the Great Lakes with the bi-national International Joint Commission (IJC) providing coordination. Both countries have complementary agreements with either provinces or states and sometimes other levels of government to ensure coordination of efforts. In 1955 the Great Lakes Fishery Convention Act created the bi-national Great Lakes Fishery Commission (GLFC) with a mandate to coordinate fisheries research, control the invasive sea lamprey, and facilitate cooperative fishery management among government and aboriginal agencies. The state of fishery resources of the Great Lakes is seen as the best overall indicator of ecosystem health. The GLFC has strongly embraced the ecosystem approach and has been a valued collaborator with the IJC and other agencies in many GLWQA-linked activities.
Over time the attention of the parties, Canada and the United States, has evolved. The lake waters themselves were the main focus but gradually the need to also consider the drainage basins was also recognized. Immediate human health concerns such as cholera outbreaks due to sewage and drinking waters being mixed drew initial attention alongside diversion and damming of waters. Later, concerns about the effects of nutrients, especially phosphorus, were added and concern about the risks of toxic chemicals and bioaccumulating contaminants followed closely. In recent decades the focus widened to consider the lakes and their basins as whole connected systems with the need to take an “ecosystem approach” to their management. More recently concerns about conservation of biodiversity and rare/endangered species, management of invasive species, and the overarching dangers posed by imminent climate change, have further expanded the scope. Expectations have also been evolving under the auspices of the GLWQA with shifts from restoration through rehabilitation toward adaptation as there was wider recognition that not all that has been inflicted on the Great Lakes can be undone, although the original condition remains a primary reference point.
Currently two topics are garnering much attention within the Great Lakes community (a) the bi-national negotiations to the update and renewal of the GLWQA and (b) the Great Lakes Restoration Initiative (GLRI) in the U.S. which arose from a commitment by the new federal administration. The GLWQA renewal includes all the elements found in past agreements as well as efforts to address the areas of governance, biodiversity and habitat, and climate change: each a large complex topic on its own. The negotiations began in January 2010 and were intended to conclude by December 2010 (an updated GLWQA was signed in Washington, D.C. on 7 September 2012). As new or renewed agreements necessarily involve governments making financial commitments, the U.S. GLRI has the potential to complicate the renewal process given that Canada might be expected to match U.S. commitments made in the absence of a new agreement. With the GLRI the U.S. administration made Great Lakes restoration a national priority and charged 15 agencies led by the Environmental Protection Agency, for the period 2010–2014, with shifting the emphasis of efforts from minimizing harm to proactive rehabilitation (see http://www.greatlakesrestoration.us for more details). The GLRI has fiver priority areas: (1) toxic substances and AOCs, (2) invasive species, (3) nearshore health and non-point source pollution, (4) habitat and wildlife protection and restoration and (5) accountability, outreach and partnerships. The timing of the U.S.’ GLRI has further complicated efforts to renew the Canada-Ontario Agreement wherein federal efforts are coordinated with provincial efforts given that much of the environmental jurisdiction sits with the lower level of government. The Ontario government has signalled its intentions with a commitment to a “Great Lakes Protection Act” with funds to tackle clean-up challenges in Areas of Concern, to reduce water pollution and to clean-up beaches.
Lake Ontario and Lakewide Management Planning
Under amendments to the GLWQA in 1987 Lakewide Management Planning (LaMP) groups were established for each Great Lake including adjacent connecting channels. LaMPs jointly engage federal, state, provincial, local and other agencies in efforts to: identify lake wide ecosystem issues, define ecosystem goals and objectives, coordinate environmental efforts, foster stewardship, and track progress. On Lake Ontario the LaMP is coordinated by the four lead agencies: Environment Canada (EC), U.S. Environmental Protection Agency (USEPA), New York State Department of Environmental Conservation (NYDEC), and Ontario Ministry of Environment (OME). As toxic chemicals, contaminants, and bioaccumulating chemicals had been longstanding key concerns on Lake Ontario, the Lake Ontario Toxic Management Plan (LOTMP) was a central pillar of the LaMP. Efforts to expand the scope of the LaMP to engage a full ecosystem-based agenda have had limited success.
The Lake Ontario LaMP takes in the issues identified in ten Areas of Concern (AOCs) including three of connecting rivers, four on the Canadian side of the lake and three on the U.S. side. Most of the lake AOCs are centred in embayments surrounded by urban and suburban area and have a wide range of beneficial use impairments (BUIs) including the impacts of eutrophication, chemical contamination, and habitat degradation. On the Canadian side of the lake two large, densely urbanized embayment areas, Toronto and Hamilton Harbours are AOCs which have longstanding problems and which have been the focus of some of the most extensive and lengthy public participation and consultation processes seen in the Great Lakes basin. Port Hope is the exception and is a small Canadian site where refining and processing of nuclear materials was conducted in the 1930s and 1940s (http://www.ec.gc.ca/raps-pas/).
Bay of Quinte and Areas of Concern/ Remedial Action Plans
While a number of problem areas around the Great Lakes were acknowledged in the 1972 GLWQA, the revised 1987 agreement formally recognized 42 AOCs, including the Bay of Quinte, and directed agencies to develop Remedial Action Plans (RAPs). Each AOC was characterized according to 14 beneficial use impairments (BUIs; Table 2). BUIs were the precursor of what are called ecosystem goods and services today, evidence of the early development of EBM thinking in the SLGL The Annex of the 1987 GLWQA outlined three RAP stages: (1) assessment, (2) action plan and (3) implementation with AOCs being delisted once all three stages were considered completed and all BUIs eliminated. Detailed definitions of BUIs and delisting criteria were not laid out at the beginning and the development of such criteria remains an on-going area of research amid efforts to accelerate delisting. While many AOCs have received only cursory attention over the succeeding decades, considerable attention has been directed toward the Bay of Quinte AOC. Indeed, the sustained activity in the Bay of Quinte has provided a detailed model for ecosystem-based management (Koops et al., 2009). The public's engagement in the Quinte RAP process developed more slowly than in Toronto and Hamilton likely because of the momentum Project Quinte's science program already had when the AOC designation occurred and because of the smaller, more rural population base in the Quinte basin and along its shores.
As the momentum for major efforts to restore the Great Lakes had been growing since the late 1960s, a group of scientists led by Dr. Murray G. Johnson, then with the Ontario Water Resources Commission and later with Fisheries and Oceans Canada, had established a long-term ecosystem monitoring program on the Bay of Quinte in the summer of 1972. They recognized the need to look at the whole ecosystem, and monitored many key components algae, macrophytes, zooplankton, benthos, and fish). The first substantial reductions in phosphorus loading to the bay began in the winter of 1977–1978, and by the early 1980s the research group (Project Quinte) interpreted the whole ecosystem response to eutrophication control (see the comprehensive set of papers in Minns et al., 1986). Hence the research group was quickly able to take up the challenge of developing a RAP in the mid-1980s. In the Bay of Quinte eleven of fourteen beneficial uses were considered impaired (Table 2). Many of the BUI were linked to eutrophication and chemical contaminants. While the research had been primarily focused on eutrophication and its consequences, the RAP technical advisory committee (TAC) expanded its scope and expertise. The RAP TAC used modelling extensively to scope problems associated with various BUIs while the RAP steering committee developed programs and activities to engage the public in the assessment and decision-making efforts required (Stride et al 1992). The RAP Stage 1 report, Time To Decide, was produced in 1990 and the Stage 2 report, Time To Act, in 1993. Stage 3 implementation has been actively under way ever since. Besides the science and regulatory activities the RAP Implementation Council has an active public engagement and communication program (see http://www.BQRAP.CA website for more information).
As Stage 3 has progressed, the Project Quinte group has continued to provide annual monitoring reports on many aspects of the bay ecosystem while provincial regulatory agencies, conservation authorities and municipalities have tackled the challenges of implementing the many actions required to restore the ecosystem. For example, a phosphorus management model was developed to help identify a point-source loading target and to assist the regulatory agencies with decision-making on use of sewage treatment plant capacity and future improvements in P-removal technology (Minns et al., 2004; Minns and Moore, 2004). The continuing invasions of exotic species like Dreissenid Mussels in the 1990s have had impacts on all parts of the Great Lakes including the Bay of Quinte, complicating the interpretation of cause and effect when changes were observed. After Dreissenid Mussels invaded and improved water clarity, macrophyte communities rapidly expanded changing the food-web structure and altering the supply of suitable habitat for various fish species. Habitat supply analyses provided the basis for mapping priority fish habitats (Minns et al 2006) and assessing the role of changing habitat in the post-Dreissenid decline of Walleye (Sander vitreum), a species which had expanded after 1978 when P control began and when a harsh winter decimated many of its competitors such as White Perch (Morone americana) and Alewife (Alosa pseudoharengus) (Chu et al., 2004). Successive species invasions have disrupted the bay's food-web, and a dynamic energy flow model has been developed to allow examination of the complex biotic interactions against the backdrop of changing nutrient and habitat conditions (Koops et al., 2006). Efforts are underway to again summarize and interpret ecosystem trends in a dedicated series of publications, beginning with issue 14(1) of Aquatic Ecosystem Health and Management in 2011.
The Laurentian Great Lakes –GLWQA
While much has been achieved through the two countries collaborating under the GLWQA, many issues and problems have been ignored or neglected. For example, eutrophication reductions were achieved through reductions in the use of high phosphate cleaning compounds, the upgrading of sewage treatment facilities, and the imposition of end-of-pipe concentration limits for phosphorus. Unfortunately, these measures are beginning to be undermined by population growth and the need for the construction of new sewage treatment facilities. Absolute nutrient load limits are required to ensure the benefits are maintained into the future. Further, only phosphorus has been tackled and rising nitrogen levels largely ignored. For example, levels of selected toxic and bioaccumulating chemicals have declined considerably since the early 1970s, but the number of chemicals reported to be hazardous to ecosystems and humans has continued to rise. New chemicals are being added to lists all the time. Retrospective surveys with archived biological and sediment samples are revealing high levels and upward trends in chemicals for which analytical methods have only been developed recently. The ability to regulate chemicals is outpaced by the use of new, replacement chemicals; these substitutes are often more hazardous than the chemicals they replace. Invasive species and climate change were not considered in earlier versions of the GLWQA. Invasive species have brought substantial food-web changes to the Great Lakes and the evidence of climate change effects is now rapidly accumulating across the basin. The revision of the agreement now being negotiated will recognize these issues but substantive measures such as closing the basin to ocean-going ships and filling in the Chicago Ship Canal to prevent further exotic species invasions, and large cuts to greenhouse gas emissions to contain global warming still appear to be far off.
Governance and public involvement has a complex history. In the 1970s and 1980s the IJC played a major role in coordinating assessment efforts, communicating results, and engaging the public in decision-making. After the 1987 GLWQA and as NGOs and public interest groups became much more active and vocal, the role of the IJC was reduced and much of the activity shifted to the Binational Committee (BNC) where the two lead agencies EPA (US) and Environment (Canada) made decisions without the perpetual glare of public scrutiny. The BNC has concentrated much of its public efforts on the biennial State of the Lakes Ecosystem Conferences (SOLECs). The SOLEC conferences provide an arena for the NGOs to understand major trends, but contribute little to the implementation of EBM. These conferences focus largely on repeated use of old data and summarization of trends in ad hoc indicators. The current approach does not guarantee real progress toward fulfilling the promise of the ecosystem approach but does maintain its visibility.
Issues such as regional development, management of invasive species, conservation of biodiversity, and curbing climate change have yet to be successfully incorporated in the scope of EBM in the Great Lakes basin. As the 2010–2011 discussions to renegotiate the GLWQA proceed hopefully efforts to increase accountability and transparency will lead to a rejuvenation of the IJC as the venue for broad-based examination of all efforts to restore and maintain ecosystem health in the Great Lakes.
Lake Ontario – LaMPs
On each Great Lake, the LaMP has tended to focus on different aspects of EBM. In Lake Ontario, the preoccupation with toxic and contaminating chemicals has meant that other aspects of EBM have been neglected or only treated cosmetically. In the 1990s, after the renewal of the 1987 renewal of the GLWQA, concerted but unsuccessful efforts were made by many parties to broaden the focus of the Lake Ontario LaMP. The lead agency representation preferred to keep the focus as it was. Certainly concerns about potential chemical and related threats to human health continue to garner a disproportionate share of public attention despite the tremendous improvements that have been seen with declining concentration levels in various biota, especially birds and fish, and the expansion of signal species like cormorants and bald eagles. However, the knottier challenges involved in shifting from concentration-based to absolute load management for nutrients and recognizing the constraints on land use by humans needed to protect habitats necessary to sustain diverse biotic communities remain.
Bay of Quinte – AOC/RAP
The Bay of Quinte AOC is rapidly approaching its time for delisting. This poses a challenge as the cumulative science investment from 1972 to the present and the understanding gained strongly indicate there should be a continuing focus on the Quinte ecosystem, especially as few other AOCs has received such broad investigation over a long period. Regulatory agencies and government funders favour moving on as Quinte becomes an “Area of Recovery.” Past experience indicates that delisting leads to a loss of funding support. The chief difficulty is that EBM is not a short-term activity with a fixed end-point but rather it is a permanent responsibility with no foreseeable end-point, especially as new stressors are continually emerging. The purpose of EBM is to ensure the continuance of a healthy ecosystem providing a broad range of sustainable ecological goods and services. Rather the Bay of Quinte should become an “Area of Sustainability” recognizing the need for eternal vigilance as human development continues and tries to attain a sustainable future (the phrase “Area of Recovery” has been suggested but, implicitly, it is still tied to a fixed end-point). Randall et al. (2011) uses concepts based on the Canadian approach to EBM in its ocean areas proposing a shift on the Great Lakes, on Lake Ontario, and on the Bay of Quinte from the negative stance generated by the AOC designation to a positive one based on continuing EBM centred on sustaining essential habitats with high levels of natural productivity and biodiversity.
Overall, the events of the last half century in the Great Lakes, Lake Ontario, and the Bay of Quinte show much progress can be achieved but also reveal the accelerating accumulation of ecosystem management issues. Old issues do not go away but are either only temporarily held in check or are subsumed by new larger issues. The widening array of issues also has cross-connections and interactions that make single-issue management approaches less likely to be effective as well as being risky. This coalescence of issues makes finding remedies much harder.
Ecosystem-based management: Essential elements
To be effective, EBM should include: (a) a whole system view including both humans and the natural environment; (b) a shared set of goals and objectives including ecological sustainability and a recognition of the non-monetary value of many ecosystem goods and services; (c) a continuing program of active adaptive management and (d) an acceptance that science-based evidence will strongly influence decision-making. A “whole system view” will, of necessity, involve complex nested hierarchies of spatial (lake watershed basin, tributary drainage basin, upland sub-watershed, etc.) and temporal (daily, seasonal, annual, decadal, and longer) scales and, also, of governance (federal, state or province, conservation authority, municipality or township, etc.) and societal structures (industries, non-governmental organizations, communities of interest, etc.).
To date, most ecosystem management efforts globally have been piece-meal, fragmentary and short-term and have largely failed to acknowledge that management of human activities is a prerequisite. In the Great Lakes, there have been longer-term efforts and, perhaps, better recognition of the need to management human activities. Implementation of the ecosystem approach in the Great Lakes has been informal rather than centrally coordinated although the various inter-agency boards like the IJC, BNC, GLFC, LaMPs, RAP committees, etc., have likely provided the collaborative mechanisms for iterative comparison of experiences and learning. Most humans have short-range spatial and temporal perspectives. Successful ecosystem management requires long-range perspectives. Past actions have continuing consequences and new actions will have long-term impacts. The whole system view must be founded on the need to balance economic and societal demand with ecologically sustainable supply, recognizing that economic activity is completely dependent on the other two components and that the ecosystems are fundamental (e.g. the ecosystem pyramid; Minns, 1999). The spatial and temporal aspects of the whole ecosystem require broader perspectives than most take today; most attention is local and short-term when the global and longer-term scales need more attention.
In today's world, societies are increasingly fragmented and polarized, making consensus decisions harder to achieve. Nonetheless, given the finiteness and current over-exploitation of lake resources, unanimous and sustained agreements must be sought before nature imposes its own solutions to the imbalances. Decision-making is often unbalanced biased due to uneven weighting of monetary and non-monetary factors. Further, given the undue influence of money much attention has been devoted in recent years to monetizing ecosystem goods and services in an attempt to gain influence in the economic realms. Jackson (2009) has argued that it is preferable to argue for better consideration of non-monetary valuations with regard to human and ecological needs. Ultimately money cannot be substituted for natural ecosystem processes essential for life on earth; the popular goods and services metaphor may blind us to the complexities of both ecosystem and human responses to changing conditions (Norgaard, 2010). Another major problem in decision-making is that achievability of ecological sustainable outcomes and human-preferred outcomes often do not match (Reeves and Duncan, 2009). This problem is compounded by the immense societal inertia engendered by global environmental problems (Scheffer and Westley, 2007).
To be truly successful, long-term sustainability in lake ecosystems will require continuous adaptation and eternal vigilance. Active adaptive management (AM) provides the means for this. AM consists of structured, iterative “learning by doing” (Walters and Holling, 1990). Given a defined group mission, AM consists of five main steps: Modelling, Management plan, Monitoring plan, Implementation, and Assessment, which are preceded by a commitment to start and followed by a commitment to learn from previous cycles and to begin the next. The outcome leads to a refined mission statement or a shift of focus to related issues and the AM cycle is repeated. Unfortunately the AM term has been widely misused, and while there is considerable scientific support for AM, sustained applications have been limited as many institutions are risk-averse with regulatory agencies being unwilling to engage in large-scale “experimental management” to measure the effectiveness of preferred actions (Johnson, 1999).
The RAP process in the Bay of Quinte has closely matched the AM cycle without explicitly committing itself to AM and has many of the characteristics of EBM (Table 3). Science-based evidence has played a central role since the early 1970s as a result of the personal commitment of Project Quinte members. A key difference is that while AM should be iterative, the RAP process was intended to be linear with an end-point. Hopefully the current renewal of the GLWQA can address that fundamental weakness.
As cumulative pressures on lake ecosystems continue to build on a global scale, the efforts and successes in the Great Lakes Basin have shown what can be achieved as the principles of ecosystem-based management have been implemented. Eutrophication has largely been reversed though permanent absolute measures, such as area-based load limits, and such measures are still needed to sustain that success. Efforts to achieve virtual elimination and/or zero discharge of toxic and contaminating chemicals have also been very successful although, again, there are still many newer substances which have yet to be fully assessed and controlled. The numbers of newly-manufactured, potentially hazardous substances still outstrips the numbers of established substances being withdrawn from use. Issues such as habitat and biodiversity, and climate change have yet to be fully incorporated into the EBM framework.
At the AOC level, the Bay of Quinte RAP and Project Quinte have together provided a clear demonstration of how to implement many aspects of EBM on a local scale. Despite the disruptions of the continuing invasions of exotic species, eutrophication has been controlled and the driessenid-mediated recovery of the macrophyte communities has led a recovery of the bay's biodiversity albeit coupled with the re-emergence of toxic algal blooms.
While applauding the successes in the Great Lakes and the Bay of Quinte, we must continue to remember the many large lakes elsewhere in Canada and the world where the people and resources available to effectively manage these ecosystems are much more limited. We are engaged in a global battle to find a balance point where the sustainability of natural ecosystems can be ensured while reasonable demands of the human population are met far into the future.
Much of the scientific development of the “ecosystem approach” in the Great Lakes and ecosystem-based management elsewhere has placed considerable emphasis on measuring and understanding ecosystem structures and functions. Too little attention has been given to acknowledging that EBM is always primarily about managing the demands and expectations of humans (Reeves and Duncan, 2009) within the inherent limits set by nature (Mos,s 2008). Given the essential central role of adaptive management perhaps the phrase EBM should be giving way to the idea of “Ecosystem-Based Adaptation” (EBA; Vignola et al., 2009) where locally, regionally, and globally the demands and expectations are modified to live within the sustainable capacities of the ecosystem which provide the ecological goods and services upon which humans are vitally dependent. Moss (2008) neatly summarizes the conundrum facing successful EBM in his recent paper on the Water Framework Directive in Europe:
“It seems that the advance of the 18th century enlightenment that there are absolute phenomena independent of human view has been sidelined. What seems to take precedence over natural phenomena, in the issues of environmental management, is human policy for human convenience.”
Scientific evidence and understanding have contributed much to the substantial progress made toward restoration objectives in the Laurentian Great Lakes during the last century. These efforts have been guided since the 1970s by the all-inclusive ecosystem approach concept which provided a unifying and integrating focus.
Despite recent economic setbacks which have weakened hard-won commitments to the environment in general, much hard work and decision-making remains before we can meet the central challenge of this era: finding a sustainable balance among the irrevocably interconnected ecological, social and economic expectations and limitations in the Great Lakes and beyond.
Many thanks to Mohi Munawar for the invitation to participate in the GLOW VI conference at Lake Tahoe, August 2010, and to prepare this article. My thanks also to Dr. Henry Regier, and an anonymous reviewer for their helpful comments and suggestions on the penultimate version of this article.