What was the pollution in the Great Lakes in the 1970s?
With minimal government oversight, waste from surrounding city sewers made its way into the lake, along with fertilizer and pesticides from agricultural runoff. The pollutants contained high levels of phosphorus and nitrogen, two chemicals that contribute to the eutrophication, or premature aging, of the Lake.
Once Lake Erie was declared dead in 1969, the Cuyahoga River caught fire, bringing even more negative national publicity to Lake Erie's surrounding area, specifically to Cleveland and its overly polluted rivers.
1972 Great Lakes Water Quality AgreementOn April 15, 1972, Prime Minister Pierre Trudeau and President Richard Nixon signed the Canada-US Great Lakes Water Quality Agreement ( GLWQA ) in recognition of the urgent need to improve environmental conditions in the Great Lakes.
Significant progress has been made in reducing toxic chemicals in the Great Lakes, but some chemicals, such as PCBs, still pose a threat to human health and the environment. polycyclic aromatic hydrocarbons (PAHs), are higher in the waters of lakes Erie and Ontario than in other lakes.
Threats to the Great Lakes' ecosystems, include invasive species, climate change, pollution, and habitat destruction. Climate change affects water temperatures, weather patterns, and lake levels.
Threats & ConservationThe source of toxic pollutants includes decades of industrial waste, raw sewage overflows, runoff from cities, and mining operations. Excess nutrients that throw the ecosystem out of balance enter the lakes from agricultural runoff and untreated sewage.
An estimated 6,000 vessels were lost on the Great Lakes with approximately 1,500 of these ships located in Michigan waters. These are unique resources. The history of Michigan can be traced by the material records of its shipwrecks. They are a wood and steel chronicle of the history of naval architecture on the lakes.
During the 1960s, Lake Erie was declared a “dead lake” due to eutrophication and pollution. The children's book, The Lorax, written by Dr. Seuss, actually included the following line referring to fish: “They will walk on their fins and get woefully weary in search of some water that isn't so smeary.