Great Lake in North America Turns Lively Green Due to Toxic Algae Bloom

As summer nears its end, an ongoing algal bloom in Lake Erie continues to thrive, presenting a vibrant mix of green and blue hues. This bloom began forming in June, reinforcing its vivid presence, reports IFLscience.

On August 13, NASA's Landsat-9 satellite captured striking images of Lake Erie's bloom. The bloom enveloped about 830 square kilometers (320 square miles) within the western basin. By August 22, it had expanded to nearly 1,700 square kilometers (660 square miles), marking the likely largest extent for this season.

The striking color of this bloom stems from cyanobacteria, or blue-green algae. Warm temperatures and excess nutrients — primarily nitrogen and phosphorus from agricultural runoff — ignite this algal growth.

Additionally, weather conditions can escalate the bloom's intensity. For instance, in April 2024, Lake Erie experienced a historic rainfall, followed by a heatwave. This provided ideal conditions for the summer bloom.

Being the fourth largest of the Great Lakes, Lake Erie frequently Suffers from algal blooms, primarily fueled by nutrient runoff from the Maumee River.

Although visually captivating, these algal blooms pose threats to wildlife and humans alike. A principal player in the bloom is Microcystis cyanobacteria, notorious for producing the toxin microcystin. This toxin accumulates in surface scum and can even become airborne.

While severe health issues from exposure are rare, allergic reactions such as skin rashes, eye irritation, and respiratory symptoms can occur. This information comes from the Environmental Protection Agency.

Contaminated water can make both livestock and pets gravely ill. Furthermore, fish populations can experience mass die-offs in water bodies experiencing persistent blooms. This results from toxin accumulation and a lack of oxygen caused by the excessive microorganisms.

The NOAA’s Great Lakes Environmental Research Laboratory operates eight monitoring stations across western Lake Erie. They track the levels of these harmful toxins. Early data showed microcystin levels peaked in late July to early August. However, high concentrations were still present in early September.

Analyzing this data, combined with detailed satellite imagery, is crucial for understanding algal blooms and predicting their occurrence. This aspect of research may also explain why significant blooms are emerging in other Great Lakes, including Lake Superior. Climate change appears to be a major contributing factor.

Earlier, SSP reported that digging holes at the beach can be dangerous.