Lake Superior is known for its pristine waters, but a combination of nutrient additions from increasing human activity (including farming and development), warming temperatures and stormy conditions have resulted in more frequent blooms of potentially harmful algae. Lake Superior is known for its pristine waters, but a combination of nutrient additions from increasing human activity (including farming and development), warming temperatures and stormy conditions have resulted in more frequent blooms of potentially harmful algae. Earth Sciences Environment Phys.org – latest science and technology news stories