Here is a map of the Great Lakes watershed. Fracking operations surround the entire area, with heavy fracking in Pennsylvania and Ohio and the Dakotas, newly growing industries in Illinois and Michigan, and attempts to muscle in to New York and Ontario despite fierce local resistance. Sand used in fracking is being mined in the Driftless Region of Wisconsin, Minnesota, and Iowa. Tar Sands extraction is way off the map in Alberta, but every Great Lakes state has at least one existing pipeline crossing through it, and expansions are proposed for all of them. Sulfide Mining activity is greatest on the North Shores of Lake Superior and Lake Huron, where there are about 20 existing metal mines. But it is also trying to move into the South Shore of Lake Superior, with proposed copper-nickel, gold, and platinum mines in Minnesota, Wisconsin, and Michigan.
So let’s ground ourselves in the land where tonight’s stories take place. I mean that quite literally – “to ground” – I want to describe the complex geological history that made these mineral and fossil formations possible, as well as the dramatic twists and turns of the evolution of life that brought forth the biodiversity we see today.
I will begin at 3.5 billion years ago. The entire planet was covered in a vast ocean. Cyanobacteria, the first lifeforms that were able to capture energy from the sun, began appearing. The oxygen they produced as a byproduct of photosynthesis was toxic to previously existing single-celled life, so the introduction of photosynthesis, which is the basis of every ecosystem today, was actually the cause of the first major extinction event. That’s ironic, eh? This shows us how dramatic transformations can come from even the tiniest changes, and how adaptable and tenacious life can be!
The rocks that formed the continents began to coalesce and rise to the surface only 3 billion years ago, and between 3 billion and 1 billion years back the growing continents wreaked havoc on the planet, skating around over the thinner yet denser ocean floor, repeatedly colliding and causing many deformations including mountains, trenches, and faults. When one landmass subsided under another, chains of volcanoes formed from explosively melting rock and spit out all sorts of metals and other heavy elements from the earths mantle up onto the surface. Imagine that at one time the land that we are standing on was violently erupting volcanoes washed by clouds of acid rain! It was during this period that sulfide deposits were formed. Chemical composition of the oceans and atmosphere fluctuated dramatically for about 4 billion years. The earth was a hostile place, especially the barren continents.
500 million years ago, conditions were finally ripe for life to flourish, and the Cambrian explosion of biodiversity began.
An especially important evolution began 350 million years ago during a time that we call the Carboniferous era. Carboniferous means there was much more carbon in the atmosphere, which meant the climate was much hotter, so there were little to no polar ice caps, and therefore much of what is now dry land was under shallow seas and brackish swamps. We wouldn’t like this world, but it was great for plants! Dense algae populations, as well as ferns the size of trees, sucked up carbon, changing the climate in the process. They also absorbed many of those heavy metals and other toxins like sulfur, and when they died and sank in the waters they sequestered all the carbon and toxins, because bacteria that can decompose things underwater had not evolved yet. So basically all these plants just stacked up, and over millions of years they eventually transformed into oil, coal, and the byproduct methane which makes up most of natural gas. Generations of plants cleaned up the land and water and helped to stabilize the climate, paving the way for more biodiversity to follow.
In fact, it was only during the Carboniferous era that life began moving onto land, like this Ichthyostega, the common ancestor of all amphibians.
250 million years ago an unknown cataclysmic event wiped out 95% of life on earth. But life is tenacious, and during the next period, known as the Mesozoic, all sorts of crazy critters evolved – like dinosaurs!
Also, flowers and the bees that pollinate them appeared during this era.
Fast forward to 5 million years back… The age of giant mammals like this glyptodont. The growth of enormous forests all over the planet had reduced the atmospheric carbon to 100ppm, a fraction of the 3800ppm at the beginning of the Mesozoic. This triggered the ice age that we are still living in today. As the climate cooled, massive glaciers were grinding across Northern landscapes.
Glaciers were one of the major forces which made the Great Lakes and surrounding lands into what we have today. They left behind a huge reserve of clean water – 95% of surface water in North America is in the Great Lakes watershed! This abundance of water, the source of all life, has brought great biodiversity to this region in spite of its cold northern location.
When humans showed up on the scene in much more recent times, they adapted their lifestyles to the diverse locales they settled in. Cultural diversity was the result of figuring out the best ways to live in each unique place, and this only added to the regions biodiversity.
Taking a cue from keystone species like these beavers who make dams to slow river flow and build new fertile soil, many indigenous people stewarded the land in clever and effective ways, cultivating food forests and maintaining prairies through regular burning, so that herds of elk and bison and other valuable animals could grow to huge numbers.
When Europeans arrived in the so-called “New World,” they were astounded by the abundance of life not only on land but also in the lakes and streams and in the air. They regularly recorded sightings of flocks of birds so big they blotted out the sky.