Lake Erie is known for being the most polluted of the Great Lakes.

Lake Erie has faced significant pollution challenges over the years, primarily due to industrial runoff, agricultural chemicals like fertilizers, and urban wastewater. These pollutants have contributed to algae blooms, which deplete oxygen levels in the water, creating "dead zones" where aquatic life struggles to survive. While efforts have been made to clean up the lake, such as the Great Lakes Water Quality Agreement between the U.S. and Canada, Lake Erie remains particularly vulnerable due to its shallow depth and high levels of human activity along its shoreline.