Toxins produced by cyanobacteria, commonly known as blue-green algae, can have detrimental effects on both humans and animals. For humans, exposure to these toxins can result in symptoms such as diarrhea, nausea, vomiting, skin, eye, and throat irritation, allergic reactions, and breathing difficulties. In severe cases, the two most serious types of cyanotoxins—microcystin and anatoxin—can lead to liver failure, shock, respiratory arrest, and even death. High levels of exposure typically occur during activities such as swimming, diving, and water skiing.
Laura Robinson, a small animal veterinarian at Antonio Animal Hospital, highlights the increasing prevalence of cyanobacterial toxicosis in both dogs and humans, with a year-round risk in warm climates. She notes that there is no disproportionate risk observed among specific breeds, age groups, or genders. This raises concerns about the growing threat posed by cyanobacteria and their toxins.
Studies have shown that warming temperatures, attributed to climate change, play a significant role in the proliferation of cyanobacteria. For example, at Lake Tahoe, temperatures have risen by nearly 2°F since 1968, with peaks in 2015 reaching an average of 53°F. Lakes are particularly sensitive to climate change, as even minor temperature fluctuations can disrupt the ecosystem. This has led to earlier starts to cyanobacteria blooms, extending the period of hazard throughout the summer months.
The U.S. Environmental Protection Agency warns that harmful algal blooms are thriving due to climate change, with warmer temperatures and increased rainfall favoring cyanobacteria over beneficial eukaryotic algae. This shift in the ecosystem dynamics gives cyanobacteria a competitive edge, leading to their rapid growth and dominance in freshwater bodies. In controlled lab studies, cyanobacteria like Microcystis aeruginosa have been found to double their population in just 1 to 2 days under favorable conditions, outpacing the growth rate of eukaryotic algae.
In conclusion, the threat of cyanobacteria and their toxins is a growing concern, exacerbated by climate change-induced environmental changes. It is essential for both public health officials and environmental agencies to monitor and address the factors contributing to the proliferation of cyanobacteria in order to mitigate the risks posed to humans and animals alike. By understanding the impact of climate change on cyanobacteria growth, proactive measures can be taken to safeguard water bodies and prevent harmful algal blooms from endangering ecosystems and public health.
