One of the focal events motivating the passage of the Clean Water Act in 1972 was the decline of water quality in Lake Erie, which was originally linked to insufficient treatment of wastewater in some of the biggest adjacent urban centers. The passing of the CWA and the adoption of the Great Lakes Water Quality Agreement in the early 1970s contributed to the quick improvement of water quality in the two ensuing decades, but the 1990s saw the return of water quality problems, indicated by the return of algal blooms to Western Lake Erie. Algal blooms typically occur when excess nutrients are produced by mixture of agricultural and urban practices, and they may threaten ecological stability and public health for millions dependent on the lake for drinking water, tourism, and fisheries. In this case study, we explore the relationship between human behavior and water quality impairments that lead to harmful algal blooms (HABs) in the Western Lake Erie Basin (WLEB), and in particular, the Maumee River Watershed. The case is designed to be taught in eight class meetings to an audience of upper-level undergraduate students, and has been tested in the classroom in consecutive semesters starting in the fall of 2015.
The following case is designed to help students achieve these learning outcomes: (1) describe the social ecological systems in the Maumee River Watershed and the Western Lake Erie Basin by identifying their constituent elements and their interactions, (2) identify the main variables driving farmers' behavior in the adoption of best management practices, (3) identify relevant stakeholders involved in the issue of HABs in Lake Erie, (4) examine the effectiveness of current policy responses, and (5) ascertain policy alternatives that could contribute to the reduction of the magnitude of harmful algal blooms.
CLASSROOM TESTED? YES
The Laurentian Great Lakes of North America, often colloquially referred to as “The Great Lakes,” are five interconnected lakes that collectively contain over 20% of the planet's surface fresh water. Lakes Superior, Huron, Erie, and Ontario are shared by Canada and the United States, while Lake Michigan is entirely located in the latter.
In the past two decades, symptoms of severe eutrophication have resurfaced in different parts of the Great Lakes. In Green Bay, Lake Michigan, for instance, Harmful Algal Blooms (HAB), sedimentation, and other factors have made summertime hypoxia (i.e., insufficient levels of dissolved oxygen in water that results in “dead zones”) a recurring feature [1, 2]. Saginaw Bay, in Lake Huron, also experiences similar problems [3, 4], which have significant socioeconomic and ecological costs, as they negatively affect drinking water quality, the health of fisheries, real estate markets, tourism, and more .
Lake Erie is the southernmost, shallowest (average depth less than 20 meters), warmest, and smallest by volume of the Great Lakes . Nowhere in the Great Lakes has the HAB problem been as acute as in the shallow Western Basin of Lake Erie (average depth less than 8 meters) and nowhere has the hypoxia problem been as bad as the Central Basin of Lake Erie. A historic occurrence, hypoxia was first detected in the 1930s, and by the 1940s researchers identified a massive area in the bottom of the lake that was starved of dissolved oxygen due to excessive nutrient (primarily phosphorus) loadings . In 1972, the passage of the Clean Water Act in the United States and the Great Lakes Water Quality Agreement (GLWQA) between the United States and Canada helped improve water quality, by aggressively targeting point source pollution, mostly from wastewater treatment plants .
However, in the 1990s, algal blooms returned with disastrous effects. In August of 2014, for instance, the City of Toledo had to issue a “do not drink” advisory for tap water for more than 400,000 residents as toxin concentrations from Lake Erie's cyanobacteria, colloquially referred to as “blue-green algae,” reached dangerously high levels in the city's drinking water (Figure 1). Many cyanobacteria can produce dangerous toxins that can attack the liver and nervous system and/or cause intestinal problems, skin rashes, and difficulty breathing . Lake Erie supplies potable water to approximately 11 million residents , and treating water contaminated by algal toxins can cost communities millions of dollars .
The negative effects of HABs are not confined to the quality of water for human domestic consumption. According to the Ohio Travel Association, HABs are likely to have a negative impact on tourism, particularly in coastal counties in the state that were responsible for almost US$13 billion annually in 2015, or a third of the state revenues generated by tourism . Additionally, HABs could also have negative effects on property values, particularly in properties located in shorelines, since they produce strong odors and give water a murky and polluted appearance. Past research has shown that water quality clearly affects property values around Lake Erie .
Furthermore, HABs have other negative consequences as well. Scavia et al., for example, point to evidence showing that rapid changes in oxygen concentrations may trap fish in hypoxic waters leading to fish mortality or at least to behavioral responses that can affect reproductive rates, diets, etc. . The International Joint Commission (IJC) has also compiled evidence showing that HABs can affect recreational fishing, since they can lead to reduced catch rates .
The spike of HABs has been attributed to excessive phosphorus loading and agricultural activity in the Maumee River watershed, which is the largest source of phosphorus for Lake Erie [14, 16, 17, 18, 19]. Covering portions of Michigan, Indiana, and Ohio, this watershed drains 21,000 km2 of some of the most fertile agricultural land in the United States making it one of the largest drainage areas in the Great Lakes Region and the principal contributor of total phosphorus into Lake Erie, with a 2003–2013 average of 2617 metric tonnes per annum . While considerable efforts are ongoing to address excessive nutrient loading in the Maumee River watershed, the problem is not easily addressed for a variety of reasons, including: the technical difficulties to determine where exactly mitigating behaviors should take place and the inability of state and local governments to adequately control agricultural runoff via the current policy framework.
HABs in Lake Erie
As aforementioned, HABs have been common in Lake Erie since the first half of the twentieth century. Starting in the 1970s, federal programs targeting point source pollution (spearheaded by the Clean Water Act) led to steady reductions in HABs and improved water clarity. In addition to combating point source pollution, the implementation of no-till farming and agricultural Best Management Practices (BMPs) have helped contain agricultural runoff and soil erosion, which in turn has led to the stabilization of total phosphorus concentrations in the lake.
The fact that more severe HABs have occurred without an increase in total phosphorus concentrations led researchers to advance the hypothesis that the algal blooms are triggered by excess Dissolved Reactive Phosphorus (DRP) [14, 21, 22, 23]. Total phosphorus loading is composed of Particulate Phosphorus (PP) and DRP, with DRP being bioavailable in greater proportion—meaning that plants can use it more efficiently to grow. Although DRP concentrations decreased from the mid-1970s to the mid-1990s, they have subsequently gone up noticeably , likely leading to an increase in frequency and magnitude of HABs in Lake Erie.
The Maumee River watershed and HABs in Lake Erie
Research has shown that the Maumee River watershed is the largest contributor of phosphorous to the Great Lakes [14, 15, 17, 18, 19]. Figure 2 shows a map of the watershed and its different sub-watersheds.
Many point sources in the watershed (e.g., wastewater treatment plants, combined sewer overflow infrastructure, home sewage systems, and industrial waste) contribute nutrients to Lake Erie; however, nonpoint sources, particularly agricultural activity, are by far the biggest culprits for HABs. It is important to note that historically, large portions of the watershed consisted of wetlands, but drainage infrastructure developed consistently since the 1850s claimed land for agricultural production. This infrastructure created conditions for successful extensive agriculture, but simultaneously speeded up the transport of nutrients to Maumee River tributaries, and ultimately Lake Erie. Today, there are 18,000 farms in the watershed that produce mostly corn and soybeans , and that have collectively contributed to the excessive loading of nutrients in the past through excessive application of fertilizer and manure.
The loss of phosphorus is not spread evenly across this territory. According to estimates, 42% of acres are responsible for 78% of phosphorus and sediment loss, and 1% of acres account for over 40% of sediment loss . An important variable compounding this problematic situation is the low likelihood among a subset of the farmer population to adopt certain BMPs that could curve the amount of nutrients that end up in Lake Erie. According to some recently published research, about one third of farmers in the Maumee watershed are not likely to take needed action to curb water pollution without more aggressive encouragement .
The Great Lakes Water Quality Agreement (GLWQA)
The GLWQA is an important tool guiding discussions about reducing the negative impact of human activities on Great Lakes' water quality. The agreement was created by the IJC, a binational body formed by United States and Canadian representatives whose primary goal is to foster international cooperation to protect shared water resources. The first GLWQA was signed by Nixon and Trudeau in April 1972, and it was updated in 1978, 1983, 1987, and 2012. A main purpose of the agreement is to coordinate binational actions to restore and maintain water quality, including management of phosphorus and other nutrient loading. Actions and the goals for nutrient management are contained in Annex #4 of the 2012 agreement.
With the 2012 update, came two mutually agreed upon “key commitments” of interest for this case. The first one is that, by 2016, binational objectives for phosphorus concentrations, loading targets, and loading allocations must be determined to address Western Basin HABs and Central Basin hypoxia. Heeding this commitment, representatives of both countries officially approved phosphorus loading targets in February of 2016. The target aimed at reducing HABs is set at a 40% reduction (based on the 2008 load) of the springtime (1 March to 31 July) phosphorus load, which would produce blooms comparable in size to the very small blooms observed in 2004/2012, or smaller, 9 years out of 10 (Figure 3).
The second key commitment of interest is that each party should develop binational phosphorus reduction strategies and Domestic Action Plans (DAPs) to achieve the targets by 2018 using adaptive management approaches. These plans are under development, and four binational working groups were created to help accurately track progress to reduce phosphorus loading to address HABs, hypoxia, and Cladophora, another problematic alga in Eastern Lake Erie.1
Western Basin of Lake Erie Collaborative Agreement
Initiatives that are likely to have an impact on improving water quality in the Great Lakes also exist at the state and provincial level. Perhaps the most important of these is the agreement signed by Michigan, Ohio, and the province of Ontario in June of 2015. This agreement stated a shared intention to reduce phosphorus loads to Lake Erie by 40% by 2025. This is the same as the goal referenced above and adopted by the United States and Canada in February 2016, with the difference that the goal in this collaborative agreement has a timeline for achieving it. While setting a clear timeline is obviously a good thing, one must notice that Indiana has not participated in the agreement. The consequences of this lack of participation are difficult to forecast. However, it is plausible (or even likely) that the absence of one of the three states that share the Maumee watershed from the agreement could end up undermining the efforts that are put forward by the other two to improve water quality.
In the past, the IJC has also recommended that the state governments “… list the waters of the western basin of Lake Erie as impaired because of nutrient pollution” . According to the IJC, doing so could help trigger the development of a phosphorus Total Maximum Daily Load Process (TMDL), which could provide additional help to improve water quality. Michigan indeed declared the western basin impaired in November 2016, but the Ohio government has only declared portions of beach and near shore waters impaired, mostly out of concerns that a declaration of impairment beyond these areas could have a negative impact on economic development .
Tri-State Western Lake Erie Basin Phosphorus Reduction Initiative
Another subnational initiative to tackle agricultural runoff is the tri-state Western Lake Erie Basin (WLEB) Phosphorous Reduction Initiative involving Ohio, Michigan, and Indiana. This initiative is a five-year program, which brings together the Natural Resource Conservation Service (NRCS) and other partners to provide technical and financial assistance to landowners in order to: improve water quality, protect soil health, control flooding and create wetlands, and protect fish and wildlife habitat. Ongoing efforts include the 4R Nutrient Stewardship program which espouses the application of the “right source of nutrients at the right rate and right time in the right place.” 4R provides education about BMPs as well as voluntary certification to nutrient service providers (4Rcertified.org). This program, among others, may help the states achieve the phosphorous reduction goals set by the GLWQA.
Ohio's Senate Bill One
Senate Bill One is an example of a state-level policy that could impact environmental health in the WLEB. The law was enacted as part of Ohio's strategy to control the amount of phosphorous running off from improper fertilizer application. Effective on July 3, 2015, this bill applies to the 11 watersheds in the WLEB and prohibits farmers from spreading manure or fertilizer under certain weather conditions. Specifically, farmers cannot spread fertilizer within 24 hours of a forecast of more than 50% chance of 0.5 inches of rain or within 12 hours of a forecast with greater than a 50% chance of rain exceeding 1 inch. The bill also prohibits manure or fertilizer from being applied to frozen, snow-covered or rain-soaked ground in the WLEB unless proper farming practices such as injection, tillage, or cover crops are also used.
Voluntary Conservation Programs
There are a number of programs that can help farmers better managed their soil and, by extension, reduce the amount of nutrients that end up in Lake Erie. Most of these programs are managed by the U.S. Department of Agriculture. One of the most popular ones is the Conservation Reserve Enhancement Program (CREP), which provides financial incentives for farmers to remove land adjacent to waterways from production and plant riparian buffers, improving natural filtration and decreasing nutrient application. Another example is the Environmental Quality Incentives Program (EQIP), which provides cost-share opportunities for the adoption of varied conservation practices that include improved manure storage, stream bank fencing and livestock crossings, riparian buffers, conservation tillage, and floodplain or stream bank restoration, among others. Finally, the Agricultural Conservation Easement Program (ACEP) offers financial and technical assistance to American Indian tribes, state and local governments, and nongovernmental organizations with the purpose of conserving wetlands and agriculture. The conservation easements limit nonagricultural uses of the land and restore, protect, and enhance wetlands .
Challenges to meet
There are many actors involved in ameliorating HABs, and in order for their efforts to be fruitful, they must engage in meaningful coordination. However, this is difficult to accomplish in the WLEB, since stakeholders are spread out across states and counties that may tackle water quality protection through myriad mechanisms that are not necessarily consistent with each other. This fragmentation is a defining feature of U.S. federalism, and makes it difficult to effectively address HABs through uniform policy efforts.
This problem is compounded by the fact that many sources of water pollution from agriculture can be difficult to identify. This problem has led some to argue that more efforts must be spent to at least identify areas where BMPs are needed the most . To curve practices that have a negative impact on the environment, it is crucial that policy-makers understand land-use decision-making behavior and act in a concerted effort to address the motivations that underlie those behavioral patterns.
It is important to note, however, that even if governmental agencies coordinated their behaviors better and refined their regulatory approaches, their success in curving the HAB problem would ultimately be greatly affected by the level of support from the farming community. While many farmers heavily invest in improving water quality, the fact remains that not all farmers are “created equal” and may not participate in conservation methods regardless of potential legal consequences.
In the particular case of application of fertilizers at the “right time,” Zhang et al. show that farmers are more likely to adopt time-appropriate practices when they perceive (our emphasis) these practices to be efficacious in reducing phosphorus runoff . The authors conclude that this result points to the importance that improved education may have on the adoption of BMPs. Thus, while improved policy could provide a variety of incentives for the farming community to curve nutrients loading, expanding education efforts might be critical to secure their collaboration in solving the “wicked” problem of HABs in Western Lake Erie.
CASE STUDY QUESTIONS
The following questions are to be used in class to prompt a critical assessment of some of the variables that might contribute to HABs in Lake Erie.
What's the current overall state of water quality in western Lake Erie? (see material for “Class 1” in the teaching notes to answer this question)
How have agricultural practices affected water quality in Lake Erie? (see material for “Class 2” in the teaching notes to answer this question)
What individual variables make farmers more likely to adopt farming best management practices? (see material for “Class 3” in the teaching notes to answer this question)
What types of social ties affect the adoption of best management practices? (see material for “Class 3” in the teaching notes to answer this question)
Who are the main stakeholders in the topic of HABs in Lake Erie, and how do their agendas differ? (see material for “Class 4” in the teaching notes to answer this question)
What are the best types of policy instruments to tackle the problem of HABs? (see material for “Class 5” in the teaching notes to answer this question)
What are the strengths and limitations of current policy instruments used by federal and state governments to tackle HABs in Lake Erie? (see material for “Class 5” in the teaching notes to answer this question)
Berardo coordinated the project and used the case study in his Environmental and Natural Resources Policy class at The Ohio State University. Formica curated data used in lectures. Singh codesigned the case study with Berardo. Reutter provided material included in the lectures. All authors cowrote the article.
The authors would like to thank the participants of the Workshop on Teaching Social-Environmental Synthesis with Case Studies organized by the National Socio-Environmental Synthesis Center in Annapolis in July of 2015 for valuable input on how to organize the case. Cindy Wei in particular provided very helpful comments to strengthen the case. Three anonymous reviewers provided outstanding comments to improve this article. All errors remain ours.
This work was supported by the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation DBI-1052875.
The authors have declared that no competing interests exist.