Frequently Asked Questions
What are Harmful Algal Blooms (HABS)?
What is an algal bloom? - An algal bloom occurs when the numbers of algal cells increase rapidly to reach concentrations usually high enough to be visible to the naked eye. Many types of algae form blooms. Not all algal blooms are toxic. Some, such as the blooms of diatoms in the early spring, are very important to the health of the ecosystem.
What is a HAB? - HAB stands for Harmful Algal Bloom. There are many species of single-celled organisms living in the oceans, including algae and dinoflagellates. When certain conditions are present, such as high nutrient or light levels, these organisms can reproduce rapidly. This dense population of algae is called a bloom. Some of these blooms are harmless, but when the blooming organisms contain toxins, other noxious chemicals, or pathogens it is known as a harmful algal bloom, or HAB. HABs can cause the death of nearby fish and foul up nearby coastlines, and produce harmful conditions to marine life as well as humans.
What are Cyanobacteria (blue-green algae)? - Blue-green algae is the common name for several different types of algae. They are actually bacteria (Cyanobacteria) which are able to photosynthesize, hence the green color. Cyanobacteria are bacteria that grow in water and are photosynthetic (use sunlight to create food and support life). Cyanobacteria live in terrestrial, fresh, brackish, or marine water. They usually are too small to be seen, but sometimes can form visible colonies. Cyanobacteria have been found among the oldest fossils on earth and are one of the largest groups of bacteria. Cyanobacteria have been linked to human and animal illnesses around the world, including North and South America, Africa, Australia, Europe, Scandinavia, and China. Cyanobacteria are the most common, but not the only, group of algae to from HABs.
What does a cyanobacterial bloom look like? - Some cyanobacterial blooms can look like foam, scum, or mats on the surface of fresh water lakes and ponds. The blooms can be blue, bright green, brown, or red and may look like paint floating on the water. Some blooms may not affect the appearance of the water. As algae in a cyanobacterial bloom die, the water may smell bad.
How do I know if water contains blue-green algae? - If you detect an earthy or musty smell, taste or see surface scums of green, yellow or blue-green the water may contain blue-green algae. Only examination of a water sample under the microscope will confirm the presence of blue-green algae.
How can I test for cyanobacterial toxins?
- Most of the toxins require specialized testing that can weeks to perform.
- Some kits are available to test for microcystins on site.
