Science shows our Great Lakes are stressed by population growth and emerging issues. New challenges are overwhelming old solutions. Here we outline some of the challenges in the Great Lakes today.
Growth
Ontario’s future population growth is expected to be concentrated around the Great Lakes. At an annual growth rate of six per cent, ours is the fastest-growing population among Great Lakes jurisdictions. While growth can bring economic benefits, it can also put stress on the ecosystem. For example, insufficiently treated urban stormwater, and even treated sewage, put unwanted phosphorus and contaminants into the Great Lakes. Some Great Lakes watersheds are under stress from growing water demand. New roads, buildings and other development are costing us natural Great Lakes habitat.
Natural heritage
Loss of fish and wildlife habitats such as wetlands are affecting ecosystem health and cost us commercial and sport fishing opportunities and natural and cultural heritage.
The populations of some Great Lakes species have declined to the point where they are now at risk in Ontario and are protected under the Endangered Species Act, 2007 (ESA).
Invasive species
Invasive species are causing significant ecosystem disruption. Some populations of native fish species have declined dramatically. Invasive zebra and quagga mussels have reduced the amount of food available for fish, while causing increases in unwanted algae along shore lines. They have caused clogging problems at drinking water and industrial water intakes, and damaged the fragile heritage shipwrecks popular with recreational divers. Invasive plants have taken over some shoreline areas. The threat of an Asian carp invasion is a major concern. Asian carp could devastate ecosystems and fisheries. Work with our federal and U.S. partners is essential to address these threats.
Climate change
Impacts such as less ice cover, more evaporation and bigger storms, changing water levels, and high summer temperatures pose risks for Great Lakes communities and the ecosystem. For example, bigger storms lead to more water runoff, which sends pollution into the Great Lakes and also poses risks to public safety such as threatening needed infrastructure and increasing basement flooding problems.
Chemicals of emerging concern
There are increasing concerns about newer chemicals, such as flame retardants and pharmaceuticals, from urban, industrial and agricultural sources. Sewage treatment facilities were not designed to remove some chemicals, so keeping them out of sewers is the best approach.
Water level regulation
Artificial controls on Great Lakes water levels are a stress on the wetlands of Lake Ontario and the upper St. Lawrence River, which rely on periodic high and low waters.
Algae
More attached algae is growing in Great Lakes waters. Some shorelines are covered by slimy masses of these algae, a nuisance that degrades the quality of waterfronts. On Lake Erie, the fall of 2011 saw record levels of potentially toxic blue-green algae. Some bays in other parts of the Great Lakes, such as the Bay of Quinte, also experience problems with these blue-green algae blooms.
Beaches
Some of Ontario’s beautiful Great Lakes beaches are not only affected by aesthetic problems from excess algae, but also by excessive bacteria levels that make the waters less safe to swim. This is particularly a problem after heavy rains. When beaches are posted as unsafe to swim, it costs individuals their opportunity to enjoy the Great Lakes. These beach-use advisories also have costs to the economies, reputations and quality of life of shoreline communities.