Commercialism, human settlement, and even climate change are all coming into play for the past 200 years, gradually causing the Great Lakes' decline. Lakes Erie, Huron, Michigan, Ontario, and Superior accounts for 20 percent of earth's freshwater but dreaded natural and human activities are threatening it.

Journalist Dan Egan published a book The Death and Life of Great Lakes to provide a glimpse of how extensive the damage is being done. There are details of how global trade and urbanization fast-tracked the already significant impact of climate change as well.

Scientists believe that the Great Lakes were formed as an aftermath of failed continental drift when the glaciers retreated. These phenomena caused the Great Lakes to be isolated from the ocean, thus becoming freshwater. But not until canals and seaways were made to allow ships around the globe to navigate.

Egan blamed this human intervention as the reason behind an estimated 200 non-native species that are thriving in the Great Lakes. These alewives, sea lampreys and mussels are invading and efforts to contain them are failing. To make the problems worse, these aliens are ruining the natural food webs. On the natural side of problems, Egan said that climate change is causing an extreme loss of water level.

If there is a glimmer of hope for the Great Lakes, it could be another human intervention - this time to correct the mistakes. While ignorance of how nature works led to disaster, what humans learned over the century could save the Great Lakes. Trout and whitefish are reclaiming their home, thanks to environmental projects. There is also a gene drive being done to stop the Asian carp to multiply, Global News reported.

Lastly, Egan argued that the hardest battle is yet to come. While canals and seaways are giving the US its fortune, they are also leaving a hole for alien species to invade. Egan concluded that when it comes to global trade's impact, only the future generations can genuinely save the Great Lakes.