Harmful algal blooms (HABs) are occurrences characterized by rapid and excessive growth of algae in aquatic environments. These water bodies can be lakes and reservoirs that serve as drinking water sources for communities. Blooms can have detrimental effects due to the production of toxins or the sheer biomass they generate, impacting both aquatic ecosystems and human health. Primarily fueled by nutrient-rich waters, HABs are often dominated by cyanobacteria, also known as blue-green algae. Cyanobacteria thrive in freshwater environments like those found in Michigan's water bodies. These organisms can produce cyanotoxins, which pose significant risks to animals and humans. Exposure to cyanotoxins through ingestion, inhalation, or skin contact can lead to various health issues, ranging from gastrointestinal problems to neurological effects. Identifying HABs and whether they contain cyanotoxins can be challenging because they manifest in diverse forms and colors. Algal blooms can appear as patches or surface scums with colors ranging from blue-green, brown, yellow, white, purple, to red. They may also present as flecks, foam, or globs on the water's surface, sometimes giving the water a slick green sheen. Beyond toxin production, HABs can contribute to environmental degradation by depleting oxygen levels in water (hypoxia/anoxia) and altering pH levels (acidification). These changes can harm aquatic organisms such as fish and other wildlife, disrupting the delicate balance of freshwater ecosystems.
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