Sometimes human activities like fishing and farming that generate nutrient-rich surface runoff can make the presence of organic seston increase dramatically.
Especially in the more shallow parts of Lake Okeechobee, the algae grows very well because it requires sunlight to carry out the process of photosynthesis to make food for itself.
Because parts of Lake Okeechobee are so shallow, there is a high degree of light penetration through the water, which allows more of the algae to receive the sunlight it needs.
Some symptoms in people include nausea and vomiting, but the worst side effect could be liver failure.
Since Lake Okeechobee waters are released to the ocean through canals to the east and west, coastal areas in Florida are affected too.
The algae bloom has caused businesses near the ocean to close and hurt tourism revenues in recent years.