Home to about one fifth of the entire world's surface fresh water, the Great Lakes are a natural resource of global significance. In Northeast Ohio, our Great Lake Erie shapes our weather, and provides a constant source of drinking water, along with massive amounts of process and cooling water for industry and power generation. Lake Erie is also a vast recreational asset, a magnet for tourism and sport fishing. Undeniably, it is the dominant feature of our geography.

   However, our Great Lake Erie is also a very vulnerable, troubled lake. Although it contains the smallest water volume of all the Great Lakes, it is subject to the greatest pressures from human settlement. The Lake Erie Basin has more urban area, more heavy industry, higher population densities and more row crop agriculture than any other area surrounding the Great Lakes. Lake Erie also receives larger loads of pollutants than any other of the Great Lakes.

   As one would imagine, Lake Erie's ecosystem is in constant turmoil. In addition to dramatic water quality changes that have occurred over the past century, the composition of plant and animal species in the lake has fluctuated wildly. Whole species of fish, such as sturgeon and northern pike, have been virtually eliminated due to over-fishing, pollution and habitat destruction. Non-native species like the zebra mussel have fundamentally altered the base of the food chain by filtering most of the floating plant matter out of the water column. In short, although the lake is by no means "dead," it is highly unstable and fragile.

Some of the major issues facing Lake Erie today include:
   Conventional pollution: Thanks to hundreds of millions of dollars invested in treatment plants since the Clean Water Act was passed in 1972, we have made a lot of progress in controlling conventional pollution – municipal sewage, oil, grease, ammonia and other industrial discharges – which caused visible water quality problems in the lake. A major problem used to be high phosphorus levels from sewage, detergents and agricultural fertilizers. The phosphorus caused massive algal blooms, turning the lake water into a smelly, brown-green soup of decomposing algae, which consumed all the oxygen in the water to the point that fish could not survive. People said the lake was dead, but it was really too much alive – with a choking overgrowth of plant matter.

   Now, improved sewage treatment and a ban on phosphorus detergent in the Ohio Lake Erie Basin have reduced phosphorus loadings from their peak in 1968. As a result, algal blooms are rare and the lake is much clearer (also a result of the filter-feeding of zebra mussels). Oxygen levels have increased to the point where mayflies, which dwell on the lake bottom during most of their life cycle, have returned to the lake.

•  The “Erie” name comes from the Native     American nation called the Erielhonan that    used to inhabit most of the southern shores.    “Erielhonan” meant “the people of the     panther,” and many wore cougar pelts. •  There are at least 36 islands in Lake Erie;     however, the number is debatable because     some are now either connected to the     mainland or submerged, some are not fully in     Lake Erie, some are man-made and others     are tiny and unnamed. •  The lake was formed by glacial ice between 1     million and 12,600 years ago. •  It is the 12th largest lake in the world (by     surface area) at 241 miles long and 57 miles     wide. •  Of the five Great Lakes, it is the 4th largest in     surface area, the shallowest and the smallest     in volume. •  It is the warmest and most biologically     productive of the Great Lakes.

   However, in the past several years another problem has emerged. The central basin of Lake Erie (roughly the area between Sandusky and Erie) has developed a “dead zone” where oxygen is depleted at its lower depths during the summer. Scientists do not know why this is happening, and a big research effort is underway to determine the cause. It is possible that the ecological dynamics of the lake are not as well understood as once thought.

   Toxics: Persistent toxic substances are an invisible pollution threat to the Great Lakes. Even with the best pollution controls, toxic metals (such as lead, mercury and cadmium), pesticides and chlorinated substances like PCBs continue to enter the lake from a variety of sources. Some of these substances persist in the environment for many months or years and accumulate in the food chain, reaching harmful concentrations in predator species. That is why Lake Erie anglers are advised not to eat too much of certain fish.

   There is growing concern that extremely low concentrations of chlorinated organic compounds can mimic hormones which can interfere in subtle ways with human reproduction, development and the function of the immune and nervous systems. Since conventional, end-of-pipe pollution controls cannot prevent the release of these toxics into the environment, their use must be eliminated through changing industrial practices. That is why environmental groups and many scientists are calling for an end to the use of chlorine in plastics, solvents, paper production and other industrial processes. Pollution prevention programs are helping industry change over to clean production methods. Air pollution must also be curtailed, as a large proportion of certain toxic chemicals (especially mercury) come from coal-fired power plant emissions or are carried to the Great Lakes from power plant emissions hundreds of miles away.

   One indicator of improvements in the toxics issue has been the success of bald eagle reproduction along the shores of Lake Erie. However, we have yet to discover all the minute ways that these chemical “monkey wrenches” are affecting the health of humans and other animals.

   Urban runoff and sewer overflows: Water pollution comes not only from discharge pipes but also from many diffuse, "non-point" sources. Every time it rains, a witch's brew of pollutants washes off city streets into storm sewers and then into lakes and streams. In older urban areas, storm and sanitary sewers are combined in one drainage-pipe, so raw sewage can overflow into the environment along with the urban runoff (this is called a combined sewer overflow, or CSO). One immediate human health concern is the high bacteria levels contained in this runoff. For a couple of days after heavy rains many urban rivers and Lake Erie beaches become unsafe for swimming. Correcting urban runoff problems will require instituting everything from improved street sweeping to costly preventative construction projects. For example, the Northeast Ohio Regional Sewer District is spending hundreds of millions of dollars to construct deep tunnels to intercept and store much of the flow of CSOs.

  Agricultural runoff: In recent years, en-vironmental regulators have been paying more attention to the environmental impact of agriculture. As pollutant loadings from industry and sewage treatment plants have been reduced, the toxic runoff from farm fields has loomed larger as a source of pollution. When rain water runs off farm fields, it carries soil, fertilizer and pesticides with it. The resulting sediment clogs streams, destroys fish habitats and increases the need and therefore the costs associated with dredging. Fertilizer in the runoff overly enriches streams and the lake. In addition, pesticides from runoff can accumulate in the food chain. Of all the rivers feeding the Great Lakes, the Maumee flowing into Lake Erie at Toledo carries the largest amount of sediment and other agricultural pollutants. In response, Ohio EPA is working with local Soil & Water Conservation Districts and farm organizations to promote conservation tillage methods, buffer strips and other erosion prevention programs in the watersheds of Lake Erie tributaries.

   Exotic species: Incredible havoc in the Lake Erie ecosystem has been caused by exotic (non-native) species that have hitchhiked to the Great Lakes via the ballast water of ocean-going ships. One example of this is the notorious zebra mussel, a thumbnail-sized mollusk imported from Eastern Europe. In just a few years, dense colonies of zebra mussels spread throughout the Lake Erie basin, clogging water intakes and smothering native mollusks (many of which were already endangered species). The filter-feeding zebra mussels are also credited with making the lake remarkably clearer in recent years, but they have depleted the food supplies of Lake Erie fish. It is impossible to predict the effects that will be felt from other newly introduced species, such as the Eurasian ruffe, which may cause even more changes in the lake's delicate balance of life. In addition, exotic plants, such as the invasive purple loosestrife and phragmites (tall reed grass) are destroying native plant life in the lake's shoreline marshes while providing little food for wildlife.

   Lake levels and erosion: Different parties with different interests fight fierce battles to manipulate Lake Erie's water level Lakefront residents generally favor low water levels that will not erode their property. Shipping interests want high water levels so boats can carry more cargo through shallow channels. Marina operators want a stable level so they can build docks that do not become swamped or left high and dry. People interested in the ecology of the lake, however, believe that the lake and surrounding wetlands are dynamic systems that need naturally fluctuating water levels. A study several years ago by the International Joint Commission, the U.S./Canadian agency that monitors Great Lakes issues, found that building containments in an attempt to control water levels in the Great Lakes would cost billions of dollars, and would indeed harm the environment. The best solution is for humans to find ways to adapt to the rhythms of the lake, not to control the lake for our short-term convenience.

   Shoreline development: More than 80% of Lake Erie's shoreline in Ohio is developed, and much of the rest is under pressure to do so. Only fragments of the lake's once extensive marshes – vital habitat for fish and other wildlife – are still intact. Development increasingly encroaches on the rivers feeding the lake. While such development is often considered economic growth, such development also limits public access to the shore, destroys natural habitat and increases the likelihood of polluted runoff into the lake. In recent years, Ohio has developed a Coastal Management Program to encourage wise use of Lake Erie coastal area. The program addresses development in the lake's erosion area, the granting of leases to use submerged land under the lake, and other management issues. Other organizations are encouraging municipalities to require that new development be set back from riverbanks and wetlands.

   Strong citizen activism is needed in order to protect Lake Erie from damaging encroachment. The challenges to a public lakefront are constant. In the past year, for example, lakeshore property owners have been seeking state legislation to prevent public access to the beach along the shore.

   Water diversions: As unsustainable development in the parched Southwest creates water shortages there, we will likely be confronted again with grandiose schemes to divert water from the Great Lakes. Aside from the enormous cost of pipes or canals, such diversions could damage the Great Lakes ecosystem and take away our competitive advantage of abundant water. Currently, all of the eight Great Lakes’ governors must grant approval for new or increased diversions of water out of the Great Lakes Basin. This issue bears close watching as the political pressure for diversions mounts in the future.

   Nuclear power plants: A major accident at one of the three nuclear power plants on the shores of Lake Erie could contaminate the drinking water of millions of people for many years. The reactors are also having difficulty disposing of radioactive waste and are beginning to store spent fuel on site in "temporary" casks. If there is a worst-case scenario for the lake, it could very well involve these nuclear plants. The threat has been magnified recently by the increased risk of terrorism.

   Climate change: A longer-term threat to Lake Erie is global warming from greenhouse gases, such as carbon dioxide. If the Earth's temperature increases 1.5 to 4.5 degrees centigrade by the year 2030, here are some possible impacts according to one study: Greater evaporation and transpiration rates will reduce water supply in the Great Lakes Basin by 23 to 51%, with Lake Erie losing about 10%. Less water will mean greater competition for it between agricultural, industrial and urban consumers. Water quality will decline, as there will be less water volume to dilute pollutants. Pressure will increase for water to be diverted from the Great Lakes and Canada's James Bay to the arid Southwest, abetted by free trade agreements like NAFTA. The mean lake level of Lake Erie will fall about 4 to 5 feet. This will leave marinas high and dry which will increase dredging and the cost of shipping. Contaminated sediments along the shore will be exposed. Coastal wetlands will be at risk, especially if they are enclosed by dikes and cannot migrate lake-ward as water levels change. Shoreline erosion will be reduced, but that will bring the danger of increased development along the newly exposed land (developments that will be in danger if lake levels rise again). In addition, Lake Erie will turn over (exchange cold bottom water and warm top water) less frequently, if at all. This could cause the bottom of the lake to become so devoid of oxygen and nutrients that no fish are able to live there at all. The ecological implications are catastrophic.

David Beach is the founder and executive director of EcoCity Cleveland, a nonprofit organization that believes that Cleveland should think of itself as a green city on a blue lake. For more information, see www.ecocitycleveland.org, or explore the regional network for sustainability in Northeast Ohio at www.greencitybluelake.org.

Lake Erie is both a global treasure and the local reservoir of our environmental sins. It needs to be protected. Thankfully, the lake has many advocates. Here are some of the groups and planning processes focusing on the lake. • Council of Great Lakes Governors: www.cglg.org • Environment Canada: www.on.ec.gc.ca/greatlakes • Great Lakes Commission: www.glc.org • Great Lakes Information Network: www.great-lakes.net • Great Lakes National Program Office, U.S.    Environmental Protection Agency: www.epa.gov/glnpo • Great Lakes United: A bi-national citizens'    organization working to protect the Great Lakes/St.    Lawrence River ecosystem. www.glu.org • International Joint Commission: The U.S./Canadian    agency that monitors boundary issues between the    two nations, with a special focus on Great Lakes    water quality and lake levels. www.ijc.org • Lake Erie Lakewide Management Plan: Part of a    broad-baseU.S./Canadian program to set objectives    for the lake. www.epa.gov/glnpo/lakeerie • National Wildlife Federation Great Lakes Natural    Resource Center: www.nwf.org/greatlakes • Ohio Office of Coastal Management, Ohio Department    of Natural Resources: www.ohiodnr.com/coastal • Ohio Lake Erie Commission: Coordinates the state's    Lake Erie programs and administers the Lake Erie    Protection Fund, which supports research and    programs to protect and restore the lake.    www.epa.state.oh.us/oleo • Ohio Sea Grant: Promotes research and public    education about Lake Erie resources.     www.sg.ohio-state.edu

Photos by Bob Perkoski, www.Perkoski.com.