Change

“Everything changes and nothing stands still.” - Heraclitus, ancient Greek philosopher

Cayuga Lake was born from change, and has changed continuously over its long history for many reasons. Humans have been one important cause of change in the lake and its surrounding landscape for thousands of years, and these changes have greatly accelerated in the last two centuries, since the arrival of Europeans. 

As a result of these changes, the kinds and communities of plants and animals that live in and around Cayuga Lake today are very different than they were just two centuries ago. These changes are not just of historical or scientific interest. They significantly affect the health, sustainability, and human utilization of the lake and the surrounding region.

Major Causes of Change

Almost all the life in Cayuga Lake entered it after the last retreat of the glaciers, around 17,000 years ago. Later, the arrival of European settlers in the late 18th and early 19th century resulted in dramatic changes to the lake’s biota.

Glaciers and Climate

Great ice sheets, thousands of feet thick, repeatedly covered what is now the Cayuga Lake Basin many times over the past 2-3 million years. These glaciers scoured the landscape, removing or displacing almost all the life that was here before. 

Since the glaciers last retreated around 17,000 years ago, temperatures have changed many times. Over most of the last 8,000-10,000 years, the region has warmed, remaining roughly stable.

If you wish to learn more about how the glaciers shaped the landscapes of the Finger Lakes region, we recommend the book Gorges History by Arthur Bloom. It can be purchased from our online store.

Native Americans

Humans entered what is now New York State sometime around 13,000 years ago. They affected the local environment by hunting large mammals, including caribou, deer, and the now-extinct mastodon. As the climate began to warm around 8,000–4,000 years ago, humans shifted to a more varied diet, including fishing. Around 3,000 years ago, the onset of farming led to more forest clearing, which may have caused increased sediment runoff. Farming expanded about 900 years ago, leading to the establishment of more permanent towns. This change led to a further increase in tree removal and runoff.

Euro-Americans

European colonists wrought many profound changes on North American environments, including the Cayuga Lake Basin. One of the largest was deforestation. Between 1600 and 1900, forested areas in eastern North America decreased by around 80%. The environmental impact of this deforestation was enormous. The landscape became hotter in summer and colder in winter. The soil could hold less water, runoff increased, and flooding became more common. 

Since 1900, forested land area has increased steadily. Today, New York State is about 63% forested, and Tompkins County about 50%.

Introduced Species

European contact with the Americas began a flood of species of exotic plants, animals, and other organisms, which is still accelerating today. Introduced animals in Cayuga Lake include many species of fishes and zebra mussels (explored elsewhere in this exhibit). Hydrilla, a fast-spreading aquatic weed, produces choking green mats across wide expanses.

Sewage Treatment

Ithaca installed its first sewage pipes in 1896, pumping raw sewage directly to the inlet near the mouth of Cascadilla Creek. In 1908, the City installed its first wastewater treatment facilities, expanding them several times over the 20th century. In 1973, New York State banned phosphates in household laundry detergent, reducing the amount of phosphorus entering the lake. During the early 21st century, Ithaca’s wastewater treatment plants were significantly upgraded and currently release very few nutrients into the lake.

Runoff

Most nutrients enter the lake from streams that drain the surrounding fields, forests, and farms. Agricultural land usually has more runoff than forests, although modern farming practices have greatly reduced runoff rates.

Lake Source Cooling

In 2000, Cornell University opened its Lake Source Cooling (LSC) facility on the southeast side of the lake. The facility provides chilled water to the campus for building climate control. LSC takes water from the deep in the lake and returns it near the lake surface. In late summer, deep water is higher in nutrients than surface water, so LSC redistributes nutrients in the lake.