What effect do algae blooms have on water quality?

Algal blooms have a significant negative impact on water quality, and they can indeed lead to allergic reactions in people. When algae proliferate excessively, they can produce toxins that become harmful to humans, especially through recreational water use, such as swimming or contact with contaminated water. These toxins can cause a range of health issues, from skin irritations to respiratory problems, depending on the type of algae and the level of exposure.

It's important to note that while some might assume algal blooms could provide benefits, such as additional nutrients for fish or the support of submerged plant growth, the overall consequences are often detrimental to aquatic ecosystems. Algal blooms can deplete oxygen levels in the water when they die off and decompose, leading to hypoxic conditions that harm fish and other aquatic life. Additionally, increased algal growth can block sunlight, impacting the photosynthesis of desirable submerged plants and reducing overall biodiversity.