Great Lakes and Great Challenges:
|
|
Transcript
[Slide 1]
[Slide 2]
Yet, each of these groups typically operates in different spheres. Action is unlikely to be taken until an issue is recognized by all of them. A related problem is that we as individuals don't recognize the scale over which some of the issues are operating. We can only be in one place at a time, and the magnitude of an event can't be assessed without evaluation and communication across a region. Furthermore, small but measurable changes are difficult to recognize against an immensely variable background of environmental noise. Lastly, many issues act concurrently, so that it's difficult to ascertain the true cause of a problem or change. We may not be sure if we're observing an effect or a symptom of some other event. It's also human nature to ascribe changes we see to the most obvious co-occurring event. The causes of many of the events we observe may only be obvious in retrospect, when we can retroactively examine data along a long time course. Retrospective examination of crises often shows that gradual changes in indicators of these effects have occurred, but were not noticed until the changes became more pronounced and widely publicized. Generally, we have been fortunate in the Great Lakes to have an excellent long-term record of monitoring data generated by our agencies. They have tried to maintain core monitoring programs (despite interrupted financial support), which often permits us to reconstruct events leading up to the phenomena that now attract our attention. Is any single factor Athe culprit@? This problem is difficult to address because so many stresses are acting at once. A basic principle in ecology is the concept of limiting resources. Although many factors and resources are necessary for an organism, population, or community to persist, at any instant only the resource in shortest supply limits growth. An analogous situation can be said to pertain to ecosystem. Many stresses act in the Great Lakes to impair the condition of the ecosystem, but only one is 'most serious' at any given time. Mitigating that stress will improve the ecosystem, but only to the point at which some other stress becomes limiting. An analogy is to think of the ecosystem as a glass or vase, and the level of water inside represents the ecosystem health.
[Slide 4] A noteworthy example of the challenges of trying to interpret cause and effect can be seen by evaluating ecological phenomena against the background of changing total phosphorus levels in Lake Erie's central basin. Lake Erie is the location of some of the Great Lakes' greatest crises and success stories. Its pollution problems were recognized in the 1920s. Consequently, we have a better record of its condition through time than of any of the other Great Lakes. Phosphorus is the limiting nutrient for algae and rooted aquatic plant growth in Lake Erie as it is in most fresh waters. An excess of phosphorus can stimulate unwanted overabundance of algae and plants accompanied by low dissolved oxygen conditions known as accelerated eutrophication. In the 1960s Lake Erie was so turbid, green, and anoxic that the media declared that it was dead. At that time, total phosphorus concentrations in the central basin averaged over 20 µg/L and sometimes exceeded 30 µg/L. The goal of the clean-up efforts was to regulate phosphorus discharges to the lake through improved sewage treatment and land use practices, thereby reducing annual loadings to Lake Erie from over 25,000 metric tons/year of total phosphorus in the early 1970's to 11,000 metric tons/year. This reduction in phosphorus was believed to be sufficient to reduce algal growth in the lake and eventually result in a return to a healthy ecosystem.
[Slide 5] Zebra mussels invaded Lake Erie beginning in 1988, and their abundance grew dramatically. This was accompanied by increases in Lake Erie's water clarity in the early 1990's. Other biological changes accompanied these events, including the reappearance of burrowing mayflies (Hexagenia) in many places. Continuing decline of total phosphorus in the central basin was ascribed to the filtering activities of the zebra mussels.
[Slide 6] The last 3-4 years have seen an increase in the frequency, spatial extent, and/or duration of hypoxia in the bottom waters of central Lake Erie. It is tempting to ascribe this phenomenon entirely to rising concentrations of total phosphorus. But we must consider and evaluate other reasonable explanations too, because relationships can so easily be interpreted in different ways.
[Slide 7]
Total phosphorus is an important measure of trophic activity in lakes. But by itself it is only a partial indicator of overall lake health.
The biggest issue is that gradual changes or trends are difficult to monitor or report on when:
Trying to understand and communicate the causes of (and solutions to) a problem like central basin hypoxia is difficult because there are different perceptions of what a 'cause' is. We tend to ask,"what is responsible for the present situation?@, with the implied hope that a single strategy can solve the problem. Furthermore, we each tend to have our own 'favoured cause' that reflects our individual expertise, perspective, and interpretation of the data. Oxygen depletion results from biological activity, which we summarize in terms of the food web. We have seen disruptions in the food web that we ascribe to having more phosphorus and fewer algae in the surface waters of Lake Erie than formerly or that would be predicted by our current understanding of how such a large lake behaves. But although these are the most immediate causes, they are likely results of other dynamics, such as changes in the dimensions of the hypolimnion and the distribution and cycling of the nutrients already in the lake.
[Slide 8] Cooperative Approaches to Addressing Great Lakes Problems: We have been most successful in finding patterns and understanding the trends they represent when cooperative efforts have provided comprehensive data and diverse points of view. Successful early efforts were conducted by groups at single institutions. Since then, some of the largest advances in our understanding have been binational efforts beginning in the early 1970s with Project HYPO on Lake Erie and the International Field Year of the Great Lakes (IFYGL) on Lake Ontario. Project HYPO was instrumental in providing the background data and understanding that guided us into phosphorus reduction targets. Achieving loadings of 11,000 metric tons per year was argued to be the key to restoring water quality and dealing with the intermittent but extensive anoxic 'dead' zones of western and central Lake Erie. Among many other things, the IFYGL project helped clarify the important role of meteorological conditions on lake dynamics. Economic constraints in the 1990s resulted in severely reduced funding for Great Lakes monitoring and research. This was somewhat but insufficiently compensated for by important advances in technology (new instrumentation and remote sensing technology) and communication (evolution of computer technology and the internet). Consequently, novel efforts were made to build interactions among researchers to understand emerging problems in the face of dwindling resources for research. Specially convened region-specific symposia at meetings of The International Association for Great Lakes Research, Ohio's Great Lakes Aquatic Ecosystem Research Consortium (GLAERC) and New York's York's Great Lakes Research Consortium (GLRC) are examples. The Lakewide Area Management Plan (LaMP) process also has provided a forum for researchers and managers to address lake-specific issues. In addition, The Remedial Action Plan (RAP) approach in the Great Lakes' Areas of Concern Concern addresses ecosystem-level problems at a local scale. Clearly, we have a good history of cooperation in the Great Lakes. But we still are not obtaining sufficient understanding of the lakes, possibly because these initiatives have had only limited success in simultaneously involving all 4 groups of Great Lakes players. So I'd like to talk about a novel, recent cooperative approach - the Lake Erie Millennium Network. The Lake Erie Millennium Network Approach: A grassroots approach to convening meetings to address Lake Erie problems developed in the 1990s. In 1998, Jeff Reutter, Director of the Ohio Sea Grant Program and GLAERC called together U.S. and Canadian scientists who became the ad hoc Lake Erie Phosphorus Group to evaluate whether declines in walleye stocks were indeed due to low levels of nutrients, and whether this justified permitting increased releases of phosphorus from sewage treatment plants (the consensus was, "no"). Meanwhile, Murray Charlton of Environment Canada's National Water Research Institute and Russ Kreis of US EPA's Large Lakes Research Station had been regularly holding small, informal gatherings for scientists to discuss their Lake Erie research efforts. Doug Haffner at the University of Windsor's Great Lakes Institute and Gary Sprules at University of Toronto had previously organized similar groups and headed a multi-university study of Lake Erie's status jointly, funded by the Canadian Great Lakes University Research Fund. These independent efforts ultimately merged late in 1998 to become what is now the Lake Erie Millennium Network. The Lake Erie Millennium Network (LEMN) has been an effective, lake-wide cooperative effort that has enabled scientists to learn about how the ecosystem functions, while responding to the most important management questions posed by agencies charged with implementing the goals of the Great Lakes Water Quality Agreement.
[Slide 9]
[Slide 10]
The first part of the LEMN strategy was to identify the management problems facing the ecosystem as a whole.
[Slide 11]
Ultimately, the issues were classified as 48 items grouped under 7 subject themes for future evaluation. Each theme has become the focus of a planned or current research initiative by LEMN members. To take stock of what we did and didn't know about these subject themes, the first Lake Erie Millennium Conference was convened in 1999.
[Slide 13]
The next step was to clarify the research questions that needed attention by convening series of Research Needs Workshops. To date, workshops have been held to address 3 of the 7 themes.
[Slide 14] The purpose of each workshop is to identify data needs that test specific hypotheses and at the same time provide necessary values for modelling needs.
[Slide 15]
[Slide 16]
Determine how many measurements would be needed forfor"X" to be statistically significant (unlikely to have occurred by chance). Ideally, the critical data are measurements that are already part of routine agency-sponsored monitoring programs. The key is to make predictions before the data have been collected, and to plan the location and intensity of sampling necessary to provide the critical information. These data can also be used directly in modelling efforts to anticipate the outcome of various management scenarios.
[Slide 17]
[Slide 18]
The results of various workshops and research initiatives have been reported to the LEMN membership at large binational conferences that have been held every 2 years.
[Slide 20] The LEMN has been successful because it has had active participation from individuals in every aspect who have a genuine concern for and commitment to Lake Erie issues. Managers will devote resources if they are able to provide input and receive answers. Researchers participate if they
Most importantly, we can take a longer-term view of issues and questions within the framework of an ongoing structure than would be possible by addressing only one problem at a time. LEMN Workshop #1 - Disruption at the Base of the Food Web: The strategy of asking questions that help us understand processes rather than just solving immediate problems put LEMN workers in the right place at the right time to take advantage of an important research opportunity provided by US EPA. In fall 1999, the LEMN had convened a Research Needs workshop to propose hypotheses that could explain the summertime depletion of phytoplankton that appeared to be more severe than could be explained by the limitations imposed by open-water phosphorus concentrations. At that time, a concern of some was that there was too little phosphorus in the water and that this was imperilling the Lake Erie fisheries. The 20 workshop participants generated a suite of possible explanations that could be tested by making the appropriate measurements. Scientists from both US EPA and Environment Canada reported on phosphorus data collected by their monitoring program in the lake over this very same time frame at the 2001 Lake Erie Millennium Network. To everyone's surprise, the spring phosphorus concentrations in the lake had been rising, not falling as had been commonly believed. These data were so alarming that the US EPA held a meeting in December 2001 to ask Great Lakes experts what could be the possible causes of these changes. Consequently, the US EPA submitted a request for proposals to evaluate the problem of increasing phosphorus and the apparent increase in the size of the zone of central basin oxygen depletion in January 2002. The Millennium Network group was able use the recommendations of the 1999 workshop to submit a coordinated research plan. The proposal was submitted by March, and a binational collaborative effort of over 20 principal scientists was undertaken with the joint financial and in-kind support of EPA, Environment Canada, and a host of state, provincial and other agencies. The results of that research were reported at a special session of the 2003 annual meeting of the International Association for Great Lakes Research in Chicago. The LEMN has been successful because it has attracted a broad base of individuals committed to developing linkages, sharing resources, jointly developing ideas, and working collaboratively to implement them. Because it is an open and self-assembled group, its activities are not constrained to specific policies or points of view. Prospects for Continued Collaboration on the Great Lakes: The Great Lakes face challenges that are both the legacy of our past actions and the result of new stresses. Any strategy that will let us anticipate changes rather than react to them will require a better understanding of the underlying processes. This can be achieved with the ongoing commitment of people like those who make up the LEMN and those who participate in meetings like the IJC's biennial meetings. The LEMN is effective because it operates at a scale that captures the whole ecosystem but covers a small enough geographic area that all participants see the relevance to their local concerns. I suggest that a LEMN-type model adapted for the other Great Lakes would provide a framework that would bring together the critical mass of people and resources necessary to assess the unique needs of each lake. However, even if we had functional LEMN-type groups groups on each of the Great Lakes Lakes we would still need better data to work with, especially at the basin-wide scale. An overall network, such as the Ecological Observing and Forecasting Network proposed by the IJC's Council of Great Lakes Research Managers could provide the direction necessary to address issues that face the Great Lakes as a whole. We are forced to deal with a huge number of complicated problems. Some, such as contaminant releases and phosphorus loadings have been controlled but they haven't gone away. Furthermore, new problems are building on these every day. How can we go from reacting to anticipating? We can't be everywhere at once. Consequently, regular communication, such as public meetings of the IJC, SOLEC, the Great Lakes research consortia consortia and the Lake Erie Millennium Network are critical to our becoming aware of emerging issues.
[Slide 21] By thinking of the appropriate questions and predicting the values of some fundamental variables at specific times and places, we can use monitoring programs to evaluate those questions and predictions. The effectiveness of both science and monitoring efforts can be enhanced by planning the timing and placement of sample collection so that the most important questions and predictions can be evaluated. This is where recently proposed strategies such as a Great Lakes Observing System of automated buoys and remote sensors and a Great Lakes ecological forecasting system can help. Jeff Reutter of the Ohio Sea Grant Program has proposed development and deployment of a Large Lakes Observing System, a network of automated buoys that could provide simultaneous measurements at multiple locations in the lakes. Such a system can't replace the critical function of shipboard sampling for biota and many other measures of environmental condition, But it would help us detect and understand large-scale patterns as they develop and shed light on their causes and implications. Steve Brandt and the IJC's Council of Great Lakes Research Managers have proposed a plan to develop a Great Lakes Ecological Observing and Forecasting Network, which would be an example of the strong inference approach applied to understanding and solving both our current challenges and anticipating new problems that may arise from emerging issues. Notwithstanding the need for ongoing monitoring to track conditions and research to improve our understanding, we must devote more effort to addressing the most fundamental issues. The environmental pressures we're facing now are the same ones we've known about since the 1960's. They were listed in the Great Lakes Water Quality Agreement, and are still the priorities of the IJC's Council and Boards. We must:
These are major tasks, but progress must be put into context and into an appropriate time frame that acknowledges both the resources and time that will be necessary to restore the Great Lakes to their potential. We build and renovate the infrastructure of communities, transportation networks, industries, and mines in cycles ranging from tens to hundreds of years. Yet, managers, conservation and restoration groups, scientists, and others are asked to make plans and report on their environmental successes on a year-by-year basis, with 2-5 year time horizons at best. As David Lodge of the University of Notre Dame reported in his presentation at the IJC Invasive Species IJC Workshop, environmental strategies that make perfect economic sense over long time frames are argued to be untenable when evaluated over the scale of one political term or less. We need only look at the Lake Erie phosphorus data to recognize that when environmental phenomena are variable, even the greatest apparent short-term successes need to be monitored for a long enough time frame to let us rule out chance fluctuations or coincidences as the real sources of those 'improvements'. Government-sponsored entities like the IJC biennial meetings and SOLEC serve critical functions in providing a platform for binationally sharing information, but the quantity and quality of the information and its relevance to influencing resource management and policy is dependent upon the cooperation of Great Lakes institutions and individuals. The complexity of overlapping issues affecting the Great Lakes today demands a greater level of communication and cooperation than we've previously been able to achieve. We can't address these challenges working independently. However, self-assembled cooperative networks, such as the Lake Erie Millennium Network, can play a vital and increasingly important role in the Great Lakes by identifying needs, obtaining the necessary data, and providing timely and relevant information for resource managers and policymakers.
[Slide 22] |
|
