Introduction:

The regulation of pollutants is often taken out of context of natural processes. We think of regulation as defined by built infrastructure under the framework of national, state and local governments. Yet, often it is the regulations taking place in our encompassing ecosystems that we must pay closer attention to. In the shadow of natural disasters, chemical spills, pollution and hundreds of other harmful events, it is important the question of which ecosystems services we can instate and/or revitalize to promote a healthy regulation capacity within our human and natural environments. It must be understood that the regulating of climate, water quality, and disease (Millennium Ecosystem Assessment, 2005) among other issues, is never simply an isolated solution; rather it is the outcome of complex interactions between humans and our supporting ecosystems. Regulatory functions should be understood in regards to the actions and impacts humans make everyday, and in turn, we should dictate our actions around the capacities of these natural systems to absorb our impact.

According to Herman & Daley, in Ecological Economics: Principles and Applications (2004), “Waste absorption capacity is an ecosystem service on which all life depends. But as a fund service, it occurs only at a fixed rate, while conversion of stock-flow resources into waste occurs at a rate that we control.” Therefore, as we take steps to improve the natural regulatory processes it must also be understood that there is a limit to the extent of waste these systems can handle. Recognizing these limits will allow regulation to be a longer-term, sustainable process, not something to be mismanaged. It is also necessary to see regulation under the larger health of an ecosystem. If we dismantle the structures that hold up the ecosystem we can be sure to see a drop in regulation capabilities. It is also important to understand that because ecosystems evolved to manage natural and biological wastes, they perform under these conditions (Daly, Herman & Farley, 2004). Therefore excreting highly toxic, man-made wastes into these regulatory bodies should be avoided at all costs.

II. Context of lake ecosystems within this broad service category

Lake ecosystems play a key role in delivering a broad range of ecosystem services that advance our human well-being. A lake ecosystem provides fish, fiber, water, water purification, climate regulation, flood regulation, coastal protection, recreational opportunities and tourism. Specifically, a lake ecosystem provides a wide array of regulating services that are essential to sustaining the ecosystem functions that provide benefits to humans. Of particular concern is the continued degradation of lake ecosystems and the ongoing decline in overall water quantity and quality. There is high certainty that such continual degradation of will result in further impoverishment of human health Some regulating services include:

  • Climate Regulation: Climate regulation includes the regulation of greenhouse gases, temperature, precipitation, and other climatic processes. Lakes also regulate the chemical composition of the atmosphere.
  • Hydrological regimes: This involves regulating groundwater recharge, discharge, and the storage of water for agriculture or industry.
  • Pollution control and detoxification: Lake ecosystems help to retain, recover, and remove extra nutrients and pollutants from the water.
  • Erosion protection: This is ensured through the retention of soils, and the prevention of structural change (like coastal erosion, bank slumping, etc)
  • Natural Hazards: Lakes help with flood control and storm protection

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Among its many regulating services, a lake ecosystem’s waste absorption capacity is vital to providing human and ecosystem health. A lake’s ecosystem structure is key to its waste absorption capacity.  Ecosystem structure includes the physical dimensions of the lake, the plants, animals, micro-organisms, and even abiotic resources.   For example, the larger the lake, the greater the water residence time, and the easier it is for the lake to absorb large amounts of floodwater, pollutants and heat without any immediately evident changes. A long water retention time also allows suspended materials to settle to the bottom, or sink, of the lake.

In order to assess the waste-absorption capacity of lakes, it’s essential to grasp an understanding of the key contaminants in a lake, its ecosystem structure and the ecological functions needed to process such wastes to ensure a healthy ecosystem. Some significant contaminants used in our assessment are mercury, PCBs, phosphorous, estrogen, and wastewater.

Part III: What are the past and present issues in Lake Champlain?

The Lake Champlain Basin provides us with many ecosystem services, such as the regulating function of health provisions. The Lake has specific chemical, biological and physical functions to dilute, dissipate and absorb both organic and inorganic contaminants in the Lake that could be harmful to human health. Each of these functions in the lake, however, does have a level where if reached, the contaminants in the lake cannot be absorbed anymore and human health, as well as the actual regulating service, becomes diminished or at risk. Currently in Lake Champlain, there are issues with five main contaminants: Phosphorus, Sewage, Mercury, PCBs and Estrogen.

Phosphorus is highly present in the lake and most parts of the lake contain high levels of the chemical. The Missisquioi Bay, South Lake, and Northeast Arms exceed the established targets for Phosphorus levels for the 2008 State of the Lake Report. The Main Lake and Mallets Bay, however, are near the targets. When Phosphorus is in excess, it promotes too much plant and algae growth in the aquatic ecosystems. Aquatic organisms then become impacted from the reduced sunlight from blue-green algae blooms and lowered oxygen levels. These algae blooms are toxic and also harm human health. There have still been no recorded trends of any significance to the present and past phosphorus levels in Lake Champlain, which makes it hard to determine proper policies to address the high levels. The contributors to phosphorus contamination can be grouped into two categories: point sources and non-point sources. The point sources include industrial discharges, sewage treatment plants, and wastewater plants. Wastewater treatment plants average load of phosphorus has steadily decreased since 1990. Non-point source loads have significantly exceeded targets in four of the five major Lake regions. The factors that contribute to these higher non-point source loads include the conversion of agricultural and forested land to developed land, inadequate implementation of Best Management Practices on farms and in urban areas, stream erosion, and excessive use of fertilizers.

Sewage is another contaminant in Lake Champlain that can be absorbed by regulating services, but only to a point. Sewer overflows, storm drains and failing septic systems put these sewage related bacterium into waterways. Wildlife and pet wastes are also sources of contamination. Manure spread on farm fields before a rainstorm can runoff into the basin and add bacteria. All of these sources of contamination can lead to cyanobacteria and pathogens in the five regions of the Lake. When these regulating systems of the Lake reach their capacity other measures by institutions and organizations are put in place to prevent human health complications. State parks and municipal public beaches are monitored and warnings are posted when needed. An alert system was developed in early 2000 to warn the public of contamination. State, federal, and provincial funding exists for farmers to fence livestock away from streams and provide alternate sources of water. In all areas surrounding the Lake homeowners are required to have properly functioning septic systems. Recently, only a few traces of cyanobacteria toxins were found in treated drinking water facilities. In response to this issue, a process for testing and managing algae toxins in the water supply system was developed. According to the State of the Lake Report, the majority of the Lake is in either good or fair condition in terms of beach closures from pathogens, fish advisories, and blue-green algae blooms.

Mercury is the most widespread contaminant of concern in Lake Champlain. A 2006 assessment indicated that most of the mercury in the Lake (59%) enters from surrounding watersheds. Atmospheric deposition directly to the Lake’s surface accounts for 40% of this mercury contamination. The last 1% is from wastewater treatment effluent discharged directly into the Lake itself. There are five fish species in Lake Champlain with parts per million of mercury in the fish tissues. Walleye and Lake Trout have the biggest mercury concentrations of the fish species. Methyl mercury (an organic form of mercury) bioaccummulates in the food chain and is the main form of mercury contamination in the fish of Lake Champlain. In order to address this huge issue, hazardous waste and recycling programs in towns surrounding the Lake have been put into place to encourage proper disposal of such mercury sources.

PCBs are a well-known contaminant that has been popping up in aquatic ecosystems across the globe from industrial waste effluents. It is a persistent chemical that also bioacummulates in the environment and once it’s there, it’s everywhere. In the context of Lake Champlain, PCB related advisories are the result of high concentrations in the lake sediments near Wilcox Dock in Cumberland Bay. Subsequent monitoring has indicated a significant decline in PCB concentrations in both sediment (where it generally accumulates) and water, as well as a decline in fish species.

Estrogen is a generally unknown, but growing contaminant of great concern in aquatic ecosystems, like Lake Champlain. They have been called “The new generation of contaminants.” In a 2006 USGS study, many new generation contaminants, such as estrogen, were present in low levels in lakes. In Lake Champlain itself, over 70 different chemicals have been detected. Those with estrogen include plasticizers, fragrances, stimulants, and pharmaceuticals. More research needs to be done in order to fully understand the implications of these contaminants and their levels in the lake. The lake Champlain Basin Project’s Toxic Management Workgroup is currently developing a comprehensive toxic substance management strategy to address this growing problem.

IV. Analysis of specific services

1. Waste Absorption Capacity of Mercury

2. Waste Absorption Capacity of Estrogen

3. Waste Absorption Capacity of PCBs

3. Waste Absorption Capacity of Phosphorus

4. Waste Absorption Capacity of Sewage

References:

Daly, Herman and Farley, Joshua. (2004).  Ecological Economics: Principles and Applications. Washington DC: Island Press.

Ecosystems and Human Well-Being: Wetlands and Water Synthesis. (2005). In  Millenium Ecosystem Assessment. Retrieved from http://www.millenniumassessment.org/documents/document.358.aspx.pdf

ILEC. 2007. Integrated Lake Basin Management: An Introduction. International Lake Environment Committee Foundation: Kusatsu, Japan.

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