Harmful Algal Blooms 101
This blog is part of a feature on Harmful Algal Blooms. To learn more about this topic, visit our Harmful Algal Blooms page, read our blog on Phosphorus, HABs 101 Blog, and read HABS FAQ.
What are Harmful Algal Blooms?
To get us started, let’s focus on the basics. Harmful Algal Blooms (HABs) occur when cyanobacteria capable of producing toxins grow to extremely high numbers and are concentrated at the surface of a lake. Some species of cyanobacteria are capable of producing powerful cyanotoxins, which can be harmful to people and pets. It’s important to note that not all cyanobacteria release cyanotoxins, and not all blooms are harmful.
What are cyanobacteria?
Cyanobacteria are tiny photosynthetic microorganisms that produce oxygen in waterbodies. Cyanobacteria are a form of phytoplankton, which encompass microscopic plants and other photosynthesizing organisms that live in salt and fresh water environments. Phytoplankton produce over 50% of the oxygen on Earth, and are critical for aquatic ecosystems as they are primary producers. When conditions are just right, cyanobacteria can grow exponentially, a phenomenon known as a bloom. In larger lakes (or the ocean), these blooms can cover hundreds of square miles and be seen via satellite imagery – such as the PACE (Plankton, Aerosol, Cloud, ocean Ecosystem) satellite, deployed and managed by NASA.
What causes HABs to occur?
Harmful Algal Blooms in the Adirondacks typically develop under sunny, warm weather conditions with low wind activity. Warm temperatures and sunlight increase growth rates, and calm conditions allow the cyanobacteria to rise and congregate at the surface without being mixed into the water column by wind and wave energy. When these factors combine with sufficient nutrient levels, they create the perfect environment for blooms to occur. The nutrients most often attributed to HABs are phosphorus and nitrogen, which are naturally occurring in the environment, but are also byproducts of wastewater treatment facilities, septic systems, or agricultural, residential, or industrial runoff.
What does a HAB look like?
The images below illustrate examples of Harmful Algal Blooms in the Adirondack Park. These blooms share common characteristics, such as resembling spilled paint, streaks, or clumps on the surface of the water. If you encounter something in the water that looks similar, follow the Know it. Avoid it. Report it. protocol detailed below.
Know it.
It’s important to know that most algae, cyanobacteria, and phytoplankton in general are not harmful and important members of the aquatic food web. HABs are most likely to occur in the Adirondacks May-September, but can occur in April, October, and other months given the right conditions. Certain lakes and ponds might be more prone to HABs if they are shallower, have more nutrient input, or are overall more productive waterbodies. Knowing what HABs look like, and when they can most likely occur, can help protect you and your pets.
Avoid it.
People, pets, and livestock such not interact with floating mats of vegetation, or water with green, blue-green, or yellow coloration. This includes not using the water as drinking water or preparing the water for cooking, in case the bloom does have elevated levels of toxins, which can pose threats to human health and can be deadly for pets or livestock.
Report it.
If you see something similar to the photos above, please submit a report to the NYS DEC’s Suspicious Algal Bloom Report Form. It is recommended to take several images, including one that is close-up, and one that shows the landscape and location.
The Paul Smith’s College Adirondack Watershed Institute is working to better study Harmful Algal Blooms in the Adirondack Park. To learn more, visit Harmful Algal Blooms.