Harmful Algal Blooms and Your Health

Harmful algal blooms are the rapid growth of algae or cyanobacteria in water that can harm people, animals, or the environment. Going in or near water with a harmful algal bloom can make you and your animals sick. Stay out if water looks discolored, has scum, or smells bad.

Algal Blooms Algae are always in natural bodies of water like oceans, lakes, and rivers, and a few types produce toxins. A harmful algal bloom (HAB) occurs when toxin-producing algae grow excessively in a body of water .
Algal Blooms

Algal blooms are rapid growths or gatherings of algae in aquatic systems like lakes, rivers, or oceans. Depending on the algae , such blooms can cause red, brown, or blue pigmentation in the water .
Harmful algal blooms (HABs) occur when algae — simple photosynthetic organisms that live in the sea and freshwater — grow out of control while producing toxic or harmful effects on people, fish, shellfish, marine mammals, and birds. There are many kinds of HABs, caused by a variety of algal groups with different toxins. The HABs in fresh and marine waters are usually very different, but ...

Algal bloom
A very large algae bloom in Lake Erie, North America, which can be seen from space. An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water or marine water systems. It may be a benign or harmful algal bloom . Algal bloom is often recognized by the discoloration in the water from the algae's pigments. [1] The term algae encompasses many types ...
Technical, scientific, policy, regulatory, statutory, guidance and research information about cyanobacterial harmful algal blooms and cyanotoxins in drinking water and water bodies.

How to Recognize a Harmful Algal Bloom
Why it's important Learning to recognize signs of a harmful algal bloom , and staying out of water if you see one, can help you avoid getting sick. Government agencies and other organizations are not able to monitor all bodies of water for harmful algal blooms . This means there will not always be an advisory posted near the water or online to warn you that a body of water has a harmful algal bloom .
Impacts of climate change like warmer water , saltier freshwater and sea level rise might lead to more intense harmful algal blooms occurring in more waterbodies.

Harmful Algal Blooms
This article discusses what harmful algal blooms (HABs) are and summarizes quick identification tips, water testing, and bloom control methods.



