The Great Lakes: Pollution's Impact And The Future

The Great Lakes, comprising Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, are a crucial source of freshwater, supporting the drinking water supply of over 40 million people in the US and Canada. However, these lakes are under significant threat from various pollutants, including toxic chemicals, plastic waste, agricultural runoff, and industrial discharge. The pollutants entering the lakes have severe ecological and health impacts, with toxins known to cause cancer and birth defects. The accumulation of pollutants in the lakes' closed system has led to concerns about water quality and the health of both the lakes' ecosystems and the people who depend on them.

Industrial waste and sewage

Industrial Waste

Industrial plastic waste is a growing concern for the Great Lakes. Industrial sites are major sources of plastic pollution, with pre-production plastic pellets, used to create various plastic products, being particularly problematic. These pellets can escape from transport vehicles or facilities and end up in the water. A 2020 study by Western University found high levels of plastic pellet pollution on beaches across the Great Lakes, with the issue being more severe in areas with a strong plastics industry presence, such as near Sarnia, Ontario, and Toronto.

In addition to plastic waste, other forms of industrial waste also contribute to the pollution of the Great Lakes. Industrial activities release toxic chemicals, emissions, and contaminants into the water, air, and sediment of the lakes and the surrounding environment. These toxins can have severe ecological and human health impacts.

Sewage

The aging infrastructure of many cities surrounding the Great Lakes contributes to sewage overflows, resulting in the release of billions of gallons of raw or poorly treated sewage into the lakes each year. This issue is particularly prominent in older cities with combined sewer systems, where a single pipe system transports both sewage and stormwater runoff. During heavy storms, the treatment plants can become overwhelmed, leading to untreated sewage being discharged directly into the lakes.

The consequences of sewage pollution in the Great Lakes are significant. Sewage can contaminate beaches with harmful bacteria, such as E. coli, leading to skin rashes, eye and ear infections, stomach problems, and diarrhoea in individuals who come into contact with the tainted water. It also results in beach closures, swim advisories, and economic losses for nearby communities.

Air pollution

One of the key air pollutants affecting the Great Lakes is ground-level ozone, which is created by emissions from vehicles, trucks, fossil fuel power plants, and other sources. The unique weather conditions along the Lake Michigan shoreline can lead to the formation of pockets of high levels of ground-level ozone. This pollutant is closely monitored by local and federal regulators, as it poses a significant risk to the environment and public health.

The impact of air pollution on the Great Lakes is not limited to a single source or pollutant. Various industrial activities and human-induced factors contribute to the overall degradation of air quality in the region. For example, smokestacks from industrial plants release toxic chemicals into the air, which then find their way into the lakes. Additionally, agricultural practices, such as the use of fertilizers and pesticides, contribute to air pollution that eventually affects the lakes.

Furthermore, climate change plays a role in the air pollution affecting the Great Lakes. As climate change impacts air quality, the subsequent changes in weather patterns and atmospheric conditions can influence the dispersion and concentration of pollutants over the lakes. This complex interplay between climate change and air pollution adds another layer of challenge in mitigating the effects on the Great Lakes ecosystem.

To address these issues, organizations like the Lake Michigan Air Directors Consortium (LADCO) and the International Joint Commission (IJC) have implemented measures to monitor and reduce air pollution. LADCO, for instance, utilizes high-resolution NASA satellite data and near real-time Earth observations to assess ozone pollution. The IJC, on the other hand, works to resolve disputes between Canada and the United States regarding the waters along their shared border.

Plastic pollution

The issue of plastic pollution in the Great Lakes is twofold. Firstly, plastic does not truly degrade or disappear; instead, it breaks down into smaller and smaller pieces known as microplastics. These microplastics have been found in all five Great Lakes, the fish that inhabit them, and even the drinking water, bottled water, and beer sourced from them. This poses a serious threat to both the environment and public health, as the building blocks of plastic are toxic, and plastic fragments can absorb other toxic chemicals and microbes.

Secondly, the production of plastic itself is harmful. Communities where plastic is manufactured suffer harm from the dangerous chemicals and emissions used and produced by plastic factories, which are highly toxic and carcinogenic.

The average concentration of plastic in the Great Lakes ranges from 43,000 particles/km2 to 6.7 million particles/km2, which is a higher concentration than the ocean's garbage patches. The problem is particularly acute in Lake Erie, which has been heavily polluted by the industrial presence along its shores.

While some efforts have been made to address the issue, such as the installation of Seabins (stationary cleaning machines) at marinas across the Great Lakes region, advocates and experts are calling for more stringent government regulations to tackle plastic pollution.

Agricultural runoff

The Great Lakes—Lake Huron, Ontario, Michigan, Erie, and Superior—are a vital source of fresh drinking water, as well as supporting ecosystems, wildlife, and recreational activities. However, agricultural runoff poses a significant threat to the health of these lakes.

The impact of agricultural runoff on the Great Lakes has been significant. For example, Lake Erie, with a high population density and extensive agricultural activity in its watershed, has been particularly affected by this form of pollution. The influx of nutrients from farmlands has resulted in eutrophication, causing severe algal fouling and fish die-offs.

The problem of agricultural runoff is not unique to the Great Lakes, but it is a widespread issue that affects water bodies globally. For instance, the Gulf of Mexico's dead zone is largely attributed to nutrient runoff from the Mississippi River Basin, which includes agricultural activities.

Addressing agricultural runoff is crucial for preserving the health and ecological balance of the Great Lakes. While some conservation practices have been implemented, such as the use of buffer strips and improved nutrient management, more comprehensive regulations and innovative solutions are needed to mitigate the impact of agricultural activities on these vital water resources.

The Alliance for the Great Lakes, for instance, advocates for mandatory regulations to reduce nutrient pollution entering the lakes, recognizing that downstream communities are often disproportionately affected by upstream pollution. By partnering with community groups, researchers, and government agencies, they aim to develop cost-effective and equitable solutions to prevent runoff pollution and protect the Great Lakes for future generations.

Climate change

The consequences of these rising temperatures are wide-ranging. One of the most visible impacts is the decline in ice cover on Lake Michigan, which has been decreasing over the last 40 years. This reduction in ice cover has contributed to rising water temperatures in the Great Lakes, with summer surface water temperatures increasing faster than air temperatures. Warmer water temperatures have several effects, including the expansion of invasive species such as zebra mussels and the encouragement of harmful algal blooms, which can pollute drinking water sources and harm fish populations.

The Great Lakes region is particularly vulnerable to the effects of climate change due to its energy-intensive economy. The region's per capita emissions of greenhouse gases are more than 20 percent higher than the national average. However, there is also a significant potential for emissions reduction and adaptation to mitigate the impacts of climate change.

The effects of climate change on the Great Lakes are expected to have social, economic, and environmental consequences. Communities around the Great Lakes may face significant costs for repairing coastal damage caused by climate change. Additionally, the region's economies, which rely heavily on fisheries, recreation, tourism, and commerce centred on the Great Lakes, are likely to be disrupted. The natural balance of the Great Lakes ecosystem is also at risk, with potential changes in the distribution and composition of plant and animal species.

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