Where does the water from the Great Lakes come from, and how does these lakes wildlife compare to Lake Prespa?

Origin of Water in the Great Lakes

The water in the Great Lakes originates primarily from the melting of ice sheets at the end of the Last Glacial Period, approximately 14,000 years ago. As the ice sheets retreated, they exposed the basins they had carved into the land, which then filled with meltwater. Additionally, the Great Lakes are replenished by precipitation, runoff from the surrounding land, and inflow from numerous rivers and streams5.

Comparison of Wildlife: Great Lakes vs. Lake Prespa

Biodiversity and Species Count

• Great Lakes: The Great Lakes are home to a vast array of wildlife, including more than 3,500 plant and animal species. This ecosystem supports approximately 250 different species of fish, various mammals such as black bears, elk, and gray wolves, and numerous bird species like the bald eagle and great blue heron125.
• Lake Prespa: In contrast, Lake Prespa, located in the Balkans, hosts a more limited but still diverse array of wildlife. The lake is home to around 11 native fish species, with nine of these being endemic. It also supports 274 bird species, 22 reptile species, 11 amphibian species, and 60 mammal species3.

Ecosystem Impact and Non-Native Species

• Great Lakes: The Great Lakes face significant challenges from non-native species, such as zebra mussels, quagga mussels, sea lampreys, and Asian carps, which have invaded the ecosystem and compete with native species for resources, leading to potential extinctions and loss of biodiversity2.
• Lake Prespa: While Lake Prespa also has its own set of ecological challenges, the focus is more on preserving the unique and endemic species that inhabit the lake. The lake's designation as an Important Bird Area (IBA) by Greece, Albania, and North Macedonia highlights efforts to protect its avian and other wildlife3.

Ecological Role

• Great Lakes: The Great Lakes play a critical role in the regional economy, providing drinking water for over 40 million people, supporting a $6 trillion regional economy, and generating significant revenue from recreation and fishing. They also serve as a major habitat for a wide range of aquatic and terrestrial species1.
• Lake Prespa: Lake Prespa is important for its unique biodiversity and as a habitat for various bird species. It is recognized for its ecological significance and is protected through designations such as Important Bird Areas, but its economic and recreational impact is not as vast as that of the Great Lakes3.

In summary, while both the Great Lakes and Lake Prespa are significant ecosystems, the Great Lakes are much larger, support a far greater number of species, and play a more substantial role in the regional economy and environment. Lake Prespa, however, is notable for its unique and endemic species, highlighting the importance of preserving biodiversity in smaller, yet ecologically valuable, ecosystems.