The Great Lakes are among the most important natural resources in the world. Learn more about their importance, history and ecology below.
The Third Coast
There’s a reason they’re often called “The Third Coast”—the striking beauty and sheer scope and size of the Great Lakes makes them seem more like inland seas than lakes. These massive bodies of water also nourish a rich biodiversity and provide a substantial amount of the fresh water essential for human survival.
- The Great Lakes are the largest group of freshwater lakes on Earth, making up 21 percent of the world’s fresh water and 95 percent of North America’s surface fresh water. The region includes 35,000 islands, minor lakes and rivers, and inland lakes within islands.
- Combined, the Great Lakes extend 94,250 square miles and could cover all 48 contiguous states to a depth of 9.5 feet of water. The largest of the lakes, Lake Superior, has a depth of over 1,300 feet.
- The Great Lakes region contains an astonishing array of plants and animals—46 species that are found nowhere else in the world and 279 globally rare plants, animals and natural communities. Millions of birds migrate and breed in the region.
- The region’s unique environment includes large, unfragmented boreal forests in the north that gradually give way to mixed and deciduous forests and tallgrass prairies in the south. The region also includes wetlands, marshes, swamps, bogs and fens that play a critical role in linking land with water.
An economic powerhouse
People living in the Great Lakes basin are inextricably connected to the natural abundance around them. They depend on the Great Lakes’ ecosystems for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism.
- About 37 million people live in the Great Lakes basin, and more than 26 million of these people rely on the lakes for drinking water.
- Approximately 110 million pounds of fish are caught commercially each year, and when combined with sport fishing, the fishing industry brings $4 billion a year to the region.
- The lakes and their waterways transport bulk cargo from the basin to the markets of the world; since 1959, over 2 billion metric tons of iron, coal, steel, oil, grains and other products have been shipped over the lakes.
- Tourists spend hundreds of millions of dollars each year in the basin; more than 60 million people annually visit the many parks that dot the lakes’ shores; and one-third of the land in the basin is used for agriculture.
History and climate
The names of the Great Lakes, derived from Native American languages and the descriptions of early explorers, are reminiscent of the region’s earliest human history. In later years, the Great Lakes were critical to the country’s industrial growth. The waterways also brought immigrants from all over the world to the region, forming the character that continues to define cities like Chicago, Gary, Detroit, Toledo, Cleveland, Rochester, Duluth, Toronto and many others.
The climate created by the Great Lakes is also a distinctive part of the region and the lives of local residents. The “lake effect” creates heavy snowfall and stronger storms, but the lakes also moderate seasonal temperatures—absorbing heat and cooling the area in summer and gradually radiating warmth in autumn. The temperate climate lends itself to seasonal foods typically associated with warmer regions, such as apples, cherries, peaches, grapes and berries.
A resource in need
While the Great Lakes have supported people for over 9,000 years, the last 150 years have brought dramatic change to the area. Hundreds of beach closings and declines in many fish populations are just a few indications of deeper, complex problems brought on by the human impact on the region.
The environmental challenges to the Great Lakes threaten their biodiversity, which in turn jeopardizes the health and economic vitality of the region. The major environmental challenges to the Great Lakes include:
- Habitat loss and fragmentation
- Invasive species
- Nonpoint source pollution
- Altered hydrology
- Climate change
Through efforts that include Sustain Our Great Lakes, the region is beginning to work together to find answers to these environmental challenges.
Sources: Great Lakes Regional Collaboration, Nature Conservancy, npr.org, great-lakes.net, Chicago Tribune