No one has swum across Lake Superior at its max width of 160 miles. However, multiple marathon swimmers have swum the 20 miles between Orienta, Wis. to Two Harbors, Minn. It took Victoria Keith 17 hours to finish in 1988.
While there have been past “sightings,” most have turned out to be pranks or misidentifications. The reality is that the largest of the Great Lakes (Lake Superior and Michigan) are extremely deep lakes that are too cold for sharks.
Lake Michigan is considered the lake that holds the most deaths among the five Great Lakes in North America. Despite its reputation for powerful undercurrents claiming a minimum of a few lives each year, the warm, welcoming water is a favorite swimming spot for locals and visitors.
Lake Superior in a nutshell:The world's largest lake by surface area. The largest of the Great Lakes. Contains more water than all four other Great Lakes combined. Water flows from Lake Superior out to Lake Huron.
Lake Victoria, Tanzania and Uganda. Lake Victoria is referred to as the world's most dangerous lake. Don't let the calm water fool you; more than 5,000 people die in the waters every year.
Lake Karachay is a small lake in western Russia's southern Ural highlands. It is regarded as the most polluted lake or even site on the planet. The lake, which is only one square mile in size, was used by the Soviet Union as a nuclear waste dump for 12 years between 1934 and 1957.
Alligators are rarely found in the Great Lakes. Although some alligators thrive in freshwater, it's just too cold in the north for them to survive. They don't typically live farther north than North Carolina. It's unclear how the alligator arrived to Lake Michigan.
But Heithaus said it would not be possible for a bull shark to reach the Great Lakes on their own because most don't travel very far upstream. If one did reach the lakes, it would not be able to survive due to the cold water temperature.
Lake Superior is the largest freshwater lake in the world by surface area and the third-largest by volume, holding 10% of the world's surface fresh water.